ATOMIC ENERGY WjS& L'ENERGIE ATOMIQUE OF CANADA …PROGRESS REPORT October 1 to December 31, 1977...

AECL-6094

ATOMIC ENERGY WjS& L'ENERGIE ATOMIQUEOF CANADA LIMITED f j f i j f DU CANADA LIMITÉE

PROGRESS REPORTBIOLOGY AND HEALTH PHYSICS DIVISION

October 1 to December 31, 1977

PR-B-116

Chalk River Nuclear Laboratories

Chalk River, Ontario

PREVIOUS REPORTS IN THIS SERIES

AECL-6O82 July 1 to September 30, 1977 P R - B - U 5

AECL-5855 April 1 to June 30, 1977 PR-B-IH»

AECL-5806 January ) to March 31, 1977 PR-B-113

AECL-5703 October 1 to December 31, 1976 PR-B-112

ATOMIC ENERGY OF CANADA LIMITEDChalk River Nuclear Laboratories

PROGRESS REPORT


Biology and Health Physics Division

PR-B-116

Chalk River, Ontario

AECL-6091»

NOTE TO OUR READERS

This report summarizes the work for the

past year; however, în future the reports

will summarize only the work of the

previous quarter.

PROGRESS REPORT


Biology and Health Physics Division

Director - A.M. Mar ko

Secretary - C.L. Nagy

Machinist - M.I. Gibson

CONTENTS

1. Summary - A.M. Marko 1 - 6

2. Health Physics Branch - G. Cowper 7 - 3 5

3. Environmental Research Branch - I.L. Ophel 37 - 86

k. Population Research Branch - H.B. Newcombe 8 7 - 9 6

5. Biology Branch - D.K. Myers 97 - 121

B I O L O G Y A N D H E A L T H P H Y S I C S D I V I S I O N S U M M A R Y

A . M . M A R K O

H e a l t h P h y s i c s

C a l c u l a t i o n s o f n e u t r o n l e a k a g e s p e c t r a u s i n g M o n t e C a r l ot e c h n i q u e i n v o l v e c o n s i d e r a b l e c o m p u t e r t i m e w h e n t h e a n a l y s e sa r e e x t e n d e d t o i n c l u d e t h e r m a l n e u t r o n e n e r g i e s . A s a n a l t e r n -a t i v e w h i c h c a n p r o v i d e i n f o r m a t i o n m o r e q u i c k l y a d i s c r e t eo r d i n a t e s c o d e h a s b e e n u s e d t o o b t a i n n u m e r i c a l s o l u t i o n s o f t h eB o l t z m a n n t r a n s p o r t e q u a t i o n . T h e l e a k a g e s p e c t r u m ( i n c l u d i n gt h e r m a l n e u t r o n s ) h a s b e e n c a l c u l a t e d f o r t h e c a s e o f a w a t e rs p h e r e h a v i n g s o u r c e s o f 1 4 - M e V a n d f i s s i o n n e u t r o n s a t i t s c e n t r e .G o o d a g r e e m e n t h a s b e e n f o u n d b e t w e e n t h i s c a l c u l a t i o n a n d p r e v i o u sM o n t e C a r l o c a l c u l a t i o n s f o r a l l e n e r g i e s a b o v e 1 e V .

T h e r e s p o n s e f u n c t i o n o f s m a l l o r g a n i c s c i n t i l l a t o rc y l i n d e r s t o m o n o e n e r g e t i c n e u t r o n s o f v a r i o u s e n e r g i e s u p t o6 M e V is b e i n g c a l c u l a t e d . S u c h s e i n t i 1 1 a t o r s a r e u s e d f o r t h em e a s u r e m e n t o f n e u t r o n l e a k a g e s p e c t r a in t h e e n e r g y r a n g e a b o v et h a t w h i c h c a n b e h a n d l e d b y h y d r o g e n - f i l l e d p r o p o r t i o n a l c o u n t e r s .P r e d i c t e d s p e c t r a a r e b e i n g c o m p a r e d w i t h s p e c t r a m e a s u r e d w i t hc y l i n d e r s o f N E - 1 0 2 p l a s t i c s c i n t i l l a t o r . G o o d a g r e e m e n t is f o u n db e t w e e n c a l c u l a t i o n a n d m e a s u r e m e n t f o r r e c o i l p r o t o n s a b o v e3 0 0 k e V in e n e r g y . A t l o w e r e n e r g i e s t h e c a l c u l a t i o n s a r e l i m i t e db y l a c k o f a c c u r a t e k n o w l e d g e o f t h e r e l a t i o n s h i p b e t w e e n r e c o i lp r o t o n e n e r g y a n d s c i n t i l l a t o r p u l s e h e i g h t .

T h e p o s s i b i l i t i e s o f u s i n g e l e c t r o c h e m i c a l e t c h i n g a sa m e a n s o f d i s p l a y i n g c h a r g e d p a r t i c l e d a m a g e t r a c k s in p l a s t i cf i l m s e x p o s e d t o f a s t n e u t r o n s a r e b e i n g e x a m i n e d . T h i s t e c h n i q u ec o u l d b e u s e d a s a n a l t e r n a t i v e f o r n e u t r o n d o s i m e t r y t o s p a r kc o u n t i n g o f f i s s i o n f r a g m e n t d a m a g e t r a c k s p r o d u c e d b y n e u t r o ni n t e r a c t i o n w i t h a f i s s i l e f o i l h e l d a g a i n s t a p l a s t i c f i l m .In a d d i t i o n , t h i s t e c h n i q u e , w h i c h p e r m i t s r e s o l u t i o n o f c l o s e l ys p a c e d d a m a g e t r a c k s in a t a r g e t f o i l , h a s a n o t h e r p o s s i b l ea p p l i c a t i o n in t h e d e t e c t i o n o f t h e s m a l l - s c a l e f l u c t u a t i o n s o f2'3 5 U c o n c e n t r a t i o n s in T h Û 2 f u e l m a t e r i a l

C o m m i s s i o n i n g o f t h e F I N S a c c e l e r a t o r is c o n t i n u i n g .It h a s o p e r a t e d w i t h d e u t e r o n b e a m s u p t o 1 3 m A . T h e r a d i a t i o ns a f e t y m o n i t o r i n g s y s t e m is i n s t a l l e d a n d o p e r a t i o n w i t h at r i t i u m t a r g e t w i l l b e t e s t e d s o o n .

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T e s t s a r e c o n t i n u i n g on the p e r f o r m a n c e o f s e n s i t i z e dT L D ' s * for p e r s o n a l d o s i m e t r y and e n v i r o n m e n t a l m o n i t o r i n g . L o s sof s e n s i t i v i t y a f t e r r e p e a t e d use is s i g n i f i c a n t l y less w i t h thes e n s i t i z e d T L D ' s and the s p r e a d in s e n s i t i v i t y is a l s o r e d u c e d .E a r l i e r t e s t s i n d i c a t e d that s e n s i t i z e d T L D ' s a r e l i n e a r o v e r aw i d e r r a n g e o f d o s e s and t h e i r e n e r g y d e p e n d e n c e is b e t t e r thanthat of T L D ' s u s e d in t h e s t a n d a r d f a s h i o n .

D o s e s to v a r i o u s o r g a n s in a s t a n d a r d m a n p h a n t o m and ther a d i a t i o n e x p o s u r e in a i r h a v e b e e n m a d e in a l o c a t i o n w h e r e theb a c k g r o u n d is p r i m a r i l y f r o m '''Ar d i s c h a r g e d f r o m the r e s e a r c hr e a c t o r s . T h e p h a n t o m is n o w l o c a t e d in a n o r m a l b a c k g r o u n da r e a to o b t a i n c o m p a r a b l e d a t a f r o m n a t u r a l g a m m a r a d i a t i o n .All d o s e s and e x p o s u r e s a r e b e i n g m e a s u r e d w i t h s e n s i t i z e d T L D ' s .

T e s t s h a v e b e e n c a r r i e d out of a k x k a r r a y of s i l i c o nd i o d e r a d i a t i o n d e t e c t o r s held in a m u l t i - c o l 1 i m a t o r a s s e m b l yfor the v e r i f i c a t i o n o f s p e n t fuel in the s t o r a g e b a y s o f theP i c k e r i n g G e n e r a t i n g S t a t i o n for s a f e g u a r d s c o n t r o l . T h e o r i g i n a lc o l l i m a t o r d e s i g n has b e e n i m p r o v e d by t a k i n g a d v a n t a g e o f thee x t r a s p a c e n o w a v a i l a b l e in fuel e x a m i n a t i o n . T h e i n i t i a lr e q u i r e m e n t w a s to m o n i t o r fuel a l r e a d y s t o r e d in c l o s e l y s p a c e ds t a c k s w h i c h l i m i t e d the l e n g t h o f the c o l l i m a t o r s but t h i sl i m i t a t i o n no l o n g e r a p p l i e s .

F i e l d t r i a l s of i o d i n e m o n i t o r s for b o t h 1 3 1 I a n d 1 2 5 Ia r e b e i n g c a r r i e d out at t h e p r o d u c t i o n f a c i l i t i e s for " M oand 1 Z 5 I r e s p e c t i v e l y .

T h e c a u s e of d e t e r i o r a t i o n in t h e p e r f o r m a n c e o ft r i t i u r n - i n - w a t e r d e t e c t o r s w h i c h use m u l t i p l e thin s h e e t s ofp l a s t i c s c i n t i l l a t o r has b e e n i d e n t i f i e d as d a m a g e c a u s e d by ac o m m e r c i a l b a c t e r i o c i d e used for p e r i o d i c c l e a n i n g of t h e s c i n t -i l l a t o r . S o n i c a t i o n of t h e d e t e c t o r cell d u r i n g c l e a n i n g c a u s e ss o m e c r a z i n g o f the s c i n t i l l a t o r s u r f a c e but t h i s in i t s e l f d o e snot a f f e c t the d e t e c t i o n e f f i c i e n c y .

S i x p r o t o t y p e m o d e l s of the r a d o n - i n - a i r m o n i t o r h a v ebeen p r o d u c e d and t e s t s h a v e been c a r r i e d out in a s t a n d a r dr a d o n a t m o s p h f t r e . T h e p e r f o r m a n c e of the l a b o r a t o r y m o d e l hasbeen c o n f i r m e d . A v e r a g e c o n c e n t r a t i o n s of less t h a n 0.5 p C i / l i t r e

( 1 . 8 5 x 1 0 ~ 2 B q ) a r e d e t e c t a b l e . T h e o u t p u t f r o m t h e T L D c h i pe x p o s e d to c o l l e c t e d d a u g h t e r p r o d u c t s f r o m t h i s c o n c e n t r a t i o nis a p p r o x i m a t e l y e q u a l to that c a u s e d by a g a m m a e x p o s u r e o f10 mR and a b o u t f i f t y t i m e s l a r g e r t h a n the o u t p u t f r o m anu n e x p o s e d T L D .

• lThermo I um i n e s c e n c e D o s i m e t e r s

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E n v i r o n m e n t a l R e s e a r c h

A s p a r t of o u r r e s e a r c h on a q u a t i c f o o d - c h a i n s , s t u d i e sa r e b e i n g m a d e o f t h i e f f e c t s o f w a t e r t e m p e r a t u r e on t h ec a r b o h y d r a t e a n d p r o t e i n c o n t e n t o f s i x s p e c i e s o f a l g a e g r o w nat 2 0 , 2 5 a n d 3 0 ° C . T h e p r o t e i n c o n c e n t r a t i o n o f o n e s p e c i e s{Chlorella) at 2 0 ° C w a s t h r e e t i m e s g r e a t e r t h a n t h e o t h e r a l g a e .O n l y s l i g h t c h a n g e s in t h e p r o t e i n - c a r b o h y d r a t e c o m p o s i t i o n o ft h e a l g a e c e l l s o c c u r r e d d u r i n g t h e g r o w t h c y c l e .

D i s s o l v e d o r g a n i c m a t t e r c o n c e n t r a t i o n s o f up tok m g / l i t r e h a v e b e e n m e a s u r e d in g r o u n d w a t e r of t h e P e r c h L a k eb a s i n . T h e s e o r g a n i c c o m p o u n d s m a y p l a y an i m p o r t a n t r o l e inc h e m i c a l c h a n g e s w h i c h o c c u r in t h e g r o u n d w a t e r , w h i c h in t u r na f f e c t t h e u n d e r g r o u n d t r a n s p o r t o f t r a c e e l e m e n t s ( i n c l u d i n gr a d i o n u c l i d e s ) . T h e s e c o n s i d e r a t i o n s h a v e p r o m p t e d us toi n i t i a t e a p r o g r a m f o r m o r e d e t a i l e d a n a l y s i s o f t h e o r g a n i cc o n s t i t u e n t s o f g r o u n d w a t e r .

W a t e r t e m p e r a t u r e p r o f i l e s o f P e r c h , M a s k i n o n g e a n dU p p e r B a s s L a k e s w e r e m e a s u r e d d a i l y f r o m s p r i n g b r e a k - u p tof r e e z e - u p in l a t e N o v e m b e r . In a d d i t i o n , b o t h s p a t i a l a n dt e m p o r a l t e m p e r a t u r e d i s t r i b u t i o n in P e r c h a n d M a s k i n o n g e L a k e sw e r e s t u d i e d i n t e n s e l y d u r i n g s e v e r a l p e r i o d s o f w i n d y w e a t h e r .T h e s e s t u d i e s h a v e g i v e n c o n s i d e r a b l e i n f o r m a t i o n a b o u t t h em i x i n g o f h e a t a n d c h e m i c a l c o n s t i t u e n t s in t h e s e t y p e s o f l a k e s .

A d d i t i o n a l p i e z o m e t e r s a n d d r i l l e d w e l l s f o r g r o u n dw a t e r v e l o c i t y m e a s u r e m e n t s h a v e b e e n i n s t a l l e d n e a r W a s t eM a n a g e m e n t A r e a ' F ' , w h e r e w a s t e s f r o m t h e P o r t H o p e a n d O t t a w ac l e a n - u p s a r e b e i n g e m p l a c e d . D r i l l i n g r e s u l t s i n d i c a t e ac o m p l i c a t e d g e o l o g y , w i t h c l a y l a y e r s s e p a r a t i n g s a n d a q u i f e r s .D y e s o l u t i o n w a s i n j e c t e d i n t o t w o w e l l s in A r e a 'F' a n d g r o u n dw a t e r is b e i n g s a m p l e d f r o m v a r i o u s l o c a t i o n s in t h e d r a i n a g ea r e a a n d a n a l y z e d f 1 u o r o m e t r i c a l 1 y to e s t i m a t e t r a v e l t i m e tothe n e a r e s t s u r f a c e w a t e r .

S e d i m e n t c o r e s w e r e t a k e n f r o m soil c o n t a m i n a t e d byf i s s i o n p r o d u c t s o r i g i n a t i n g f r o m t h e 1 9 5 ^ a n d 1 9 5 5 e x p e r i m e n t a ld i s p o s a l s in W a s t e M a n a g e m e n t A r e a ' A 1 . C o n s i d e r a b l e d i f f i c u l t yw a s e x p e r i e n c e d in o b t a i n i n g u n d i s t u r b e d c o r e s d u e to t h e n a t u r eo f t h e c a b l e - t o o l d r i l l i n g . S e d i m e n t f r o m t h e c o r e s a n d a s s o c -i a t e d g r o u n d w a t e r w a s a n a l y z e d for t h e d i s t r i b u t i o n c o e f f i c i e n to f 9 0 S r a n d 1 3 7 C s , c a t i o n e x c h a n g e c a p a c i t y , s e d i m e n t a r y o r g a n i cm a t t e r a n d m i n e r a l c o m p o s i t i o n .

- il -

S o i l s a m p l e r s w e r e d r i v e n h o r i z o n t a l l y u n d e r t h eB u i l d i n g 20*» rod b a y s in t h e h o p e t h a t t h e s a m p l e s m i g h t p i n p o i n ta s u s p e c t e d l e a k . U n f o r t u n a t e l y , t h e s a m p l e r s had to be d r a w nt h r o u g h a c l a y l a y e r w h i c h p a c k e d i n t o t h e s a m p l i n g s l o t s a n db l o c k e d t h e m . F r e q u e n t l y o n l y v e r y s m a l l s o i l s a m p l e s w e r eo b t a i n e d . S t r o n t i u m - 9 0 , 1 2 5 S b a n d 1 3 7 C s w e r e d e t e c t e d in t h es a m p l e s but o n l y in l o w c o n c e n t r a t i o n s .

P o p u l a t i o n R e s e a r c h

E x p e r i m e n t a l w o r k o n a m a j o r s t u d y o f r a d i a t i o n -i n d u c e d t u m o u r s o f s k i n in l a b o r a t o r y r a t s h a s n o w b e e n l a r g e l yc o m p l e t e d , a n d t h e d a t a a r e b e i n g a n a l y z e d . O n e f i n d i n g f r o mt h i s w o r k is t h a t a t u m o u r is m o r e l i k e l y to b e c o m e m a l i g n a n tif it a ) a p p e a r s e a r l y a f t e r i r r a d i a t i o n , b) g r o w s r a p i d l ya f t e r it is f i r s t s e e n , a n d c ) is p r o d u c e d by a h i g h d o s e o fr a d i a t i o n . T h e s e a s s o c i a t i o n s h o l d w h e t h e r t h e t u m o u r h a s t h ea p p e a r a n c e o f a w a r t , a c y s t , o r a d e l a y e d u l c é r a t i o n . It isi n f e r r e d t h a t t h e c a p a c i t y f o r m a l i g n a n c y is e i t h e r p r e s e n t o ra b s e n t f r o m a v e r y e a r l y s t a g e , a n d t h a t it is n o t , a s isc o m m o n l y a s s u m e d , t h e r e s u l t o f a d e l a y e d c h a n g e o c c u r r i n g l a t ein t h e d e v e l o p m e n t o f a t u m o u r .

B i o 1 o g y

W o r k in t h e B i o l o g y B r a n c h h a s c o n t i n u e d t o f o c u s u p o nt h e e f f e c t s o f r a d i a t i o n o n a v a r i e t y o f l i v i n g o r g a n i s m s , r a n g i n gf r o m b a c t e r i a l v i r u s e s t o h u m a n s . T h e p r i n c i p a l s e n s i t i v e t a r g e tf o r l o n g - t e r m b i o l o g i c a l e f f e c t s o f r a d i a t i o n o n all l i v i n go r g a n i s m s is D N A , t h e g e n e t i c m a t e r i a l . T h e c h e m i c a l n a t u r eo f t h e d a m a g e c a u s e d in D N A by r a d i a t i o n a n d t h e r e s p o n s e o fc e l l s to t h i s d a m a g e is b e i n g s t u d i e d by a v a r i e t y o f b i o c h e m i c a la n d g e n e t i c t e c h n i q u e s .

H e r e d i t a r y f a c t o r s a f f e c t i n g t h e r a d i a t i o n s e n s i t i v i t yo f h u m a n s a r e b e i n g e x p l o r e d in t h e t i s s u e c u l t u r e p r o g r a m .S t u d i e s o n t h e m o l e c u l a r b a s i s o f i n c r e a s e d r a d i o s e n s i t i v i t y int h e h e r e d i t a r y d i s e a s e , a t a x i a t e l a n g i e c t a s i a , a r e b e i n g c o n t i n u e d .A s l i g h t b u t r e p r o d u c i b l e i n c r e a s e in r a d i a t i o n s e n s i t i v i t y h a sa l s o b e e n o b s e r v e d w i t h c e l l s f r o m t h r e e m e m b e r s o f a f a m i l y w i t hf a m i l i a l a c u t e m y e l o g e n o u s l e u k e m i a .

An a s s a y o f g e n e t i c d a m a g e b a s e d o n g e n e c o n v e r s i o n (af o r m o f m u t a t i o n ) in y e a s t h a s b e e n r e f i n e d to t h e p o i n t w h e r et h e e f f e c t o f r a d i a t i o n d o s e s a s l o w a s 1 rad (0.01 G y ) c a n bed e t e c t e d . T h e n u m b e r o f g e n e t i c e v e n t s i n d u c e d by r a d i a t i o n w a sf o u n d t o b e d i r e c t l y p r o p o r t i o n a l t o t o t a l r a d i a t i o n d o s e .

mm C —

E x p e r i m e n t s w i t h M i c r o c o c c u s r a d i o d u r a n s h a v e d i s t i n g u i s h e db e t w e e n t h e e f f e c t s o f v a r i o u s r a d i a t I o n - i n d u c e d f r e e r a d i c a l so n c e l l s u r v i v a l . H y d r o x y r a d i c a l a p p e a r s t o b e t h e p r i m a r yl e t h a l s p e c i e s p r o d u c e d b y i o n i z i n g r a d i a t i o n . S u p e r o x i d e a n i o nis m u c h l e s s e f f e c t i v e t h a n h y d r o x y r a d i c a l , w h i l e o t h e r f r e er a d i c a l s a p p e a r t o h a v e l i t t l e e f f e c t on c e l l s u r v i v a l .

H y d r o x y r a d i c a l s a r e a l s o r e s p o n s i b l e f o r t h e r e l e a s eo f s p e c i f i c p r o t e i n s f r o m t h e m e m b r a n e - l i k e m i d - w a l l l a y e r o fM i c r o c o c c u s r a d i o d u r a n s . In t h i s c a s e , it h a s b e e n s h o w n t h a t t h er e l e a s e o f c e l l w a l l c o m p o n e n t s r e s u l t s f r o m p r o p a g a t i o n o fr a d i c a l s t h r o u g h t h e c e l l w a l l f r o m m a n y i n i t i a l s i t e s o f a t t a c kby h y d r o x y r a d i c a l s . O x y g e n c a n i n t e r a c t w i t h t h e s e s e c o n d a r yr a d i c a l s a n d t h u s p r o t e c t t h e c e l l a g a i n s t r e l e a s e o f c e l l w a l lc o m p o n e n t s f o l l o w i n g e x p o s u r e to r a d i a t i o n .

A n e w t e c h n i q u e h a s b e e n d e v e l o p e d t h a t p e r m i t s f r a c -t i o n a t i o n o f c e l l u l a r D N A o n t h e b a s i s o f p o l y p y r i m i d i n e c o n t e n t .T h i s t e c h n i q u e h a s b e e n u s e d t o s t u d y t h e r e p a i r o f d i f f e r e n tp o r t i o n s o f t h e D N A f o l l o w i n g e x p o s u r e o f h u m a n c e l l s t o u l t r a -v i o l e t l i g h t . T h e s a m e t e c h n i q u e m a d e it p o s s i b l e t o s t u d yt h e o r g a n i z a t i o n o f p o l y p y r i m i d i n e s e q u e n c e s in t h e D N A f r o md i f f e r e n t l i v i n g o r g a n i s m s . It a p p e a r s t h a t t h e s e s e q u e n c e s a r er e g u l a r l y s p a c e d at i n t e r v a l s a l o n g t h e l e n g t h o f t h e D N A f r o me i g h t d i f f e r e n t s p e c i e s .

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1.1 PUBLICATIONS

Marko, A.M. Myers, D.K., Ophel, I.L., Cowper, G. andNewcombe, H.B. - Research in Radiation Biology, inthe Environment and in Radiation Protection at CRNL.Atomic Energy of Canada Limited, Report No. AECL-591'.

1.2 VERBAL PRESENTATIONS

1.2.1 Local Talks

Marko, A.M. - "Radiation Biology", Presentation toTreasury Board, AECL, CRNL, 5 January 1977.

Marko, A.M., Myers, D.K. and Barry, P.J. "Everything youalways wanted to know about biology". Presentation toScience Teacher's Seminar, AECL, CRNL, 25-26 FebruaryJ977.

Marko, A.M. - "Effects of Radiation on Humans",Summer Student Lecture, 17 June 1977-

Marko, A.M. - "Metabolism of Radionuclides". Presentedat the 19th Annual Health Physics Course, CRNL,26-30 September 1977-

Marko, A.M. - "Radiation and Man", Presentation to theParliamentary Press Gallery, CRNL, 6 October 1977.

1.2.2 Invited Speakers

Prof. R. Haynes, York University, Downsview, Ontario -"Mathematical Analysis of UV Induced Mutagenisis inYeast", 11 April 1977-

Dr. J. Muller, Ontario Ministry of Labor, Toronto, Ontario"Uranium Mining", 22 September 1977.

HEALTH PHYSICS BRANCH

by

G. Cowper

2.1 Staff2.2 Introduction2.3 Fast Neutron Dosimetry

2.3.1 Calculation of Recoil Proton Spectra inHydrogenous Scintillators

2.3.2 Unfolding Recoil Proton Spectra from HydrogenousScintillators

2.3.3 Spectra and Dosimetry of Therapeutic Beams ofFast Neutrons in a Water Phantom

2.3.4 Spectra of Neutrons Transmitted and Multiply-Scattered by Concrete Walls

2.3.5 Neutron Spectra Calculations Using a DiscreteOrdinates Code

2.3.6 Spectra from 2 3 8U Spherical Assemblies Containinga Source of 14-MeV Neutrons

2.3.7 Accuracy of Criticality Accident Neutron DosesUsing Calculated Spectra from Simple Assemblies

2.3.8 Nuclear Data Requirements for Radiotherapy withNeutrons

2.3.9 A Neutron Spectrometry System2.3.10 Measurements of Various Neutron Spectra2.3.11 Electro-chemical Etching of Damage Tracks in

Plastics2.3.12 Participation in Fourteenth ORNL Intercomparison2.3.13 FINS Accelerator Facility2.3.14 Improvements to Apparatus for Detection of Pu

Waste Containers2.4 Thermoluminescence Dosimetry

2.4.1 Automatic TLD Readers2.4.2 Dosimetry2.4.3 Measurement of 3-Dose from 63Ni in Smoke

Detectors2.5 Fuel Bundle Verifiers for Nuclear Material Safeguards2.6 Environmental Monitoring

2.6.1 Measurement of Absorbed Dose in a Phantom fromEnvironmental yrays

2.6.2 Environmental yMonitoring with a Lithium-DriftedSilicon Detector

2.7 Radiation Instrument Development2.7.1 Area Monitoring System for the Neutron Generator

and y-Irradiation Facility2.7.2 Liquid Crystal Numerical Displays for Portable

Health Instruments2.7.3 Low Background y-Survey Meter AEP-53022.7.4 High Range y-Survey Meter AEP-53092.7.5 Wide Range 8Y~Survey Meter AEP-52882.7.6 Portable Contamination Monitor AEP-5297

- 8 -

2.8 Tritium and Noble Gas Monitoring2.8.1 AEP-53012.8.2 AEP-52702.8.3 AEP-52932.8.4 AEP-52992.8.5 AEP-52522.8.6 AEP-52752.8.7 AEP-5216

2.9 Detection of Radio-Iodine in Air2.9.1 1 3 1I2.9.2 1 2 5I

2.10 Microscopic Flying-Spot Scanner2.11 Radon Monitoring2.12 Routine Dose Monitoring

2.12.1 Body Radiation Doses2.12.2 Hand Radiation Doses

2.13 Publications and Lectures2.13.1 Publications2.13.2 External Lectures2.13.3 Internal Lectures2.13.4 Reports

- 9 -2.1 STAFF

Branch Head G. Cowper

Secretary A.M. Steer

W.G. Cross Assistants P.J. Bunge

H. Ing D.J. RobertsonB.C. Greiner

A.R. Jones Assistants A.H. OhnoW.F. Richter

R.V. Osborne Assistants A.S. CoveartR.M. Holford N.W. Tepley

J.G. Plato

Personnel Monitoring R.M. Rondeau (Miss)J.M. Vincent (Mrs.)

Draftsmen B.A. MacDonald (1)J.M. Sneddon (1)

(1) On loan from the drawing office

- 10 -

2.2 INTRODUCTION

This report, for the final quarter of 1977, reviewsall of the work carried out in the calendar year 1977 andreported in part in the three preceding quarterly reports.

2.3 FAST NEUTRON DOSIMETRY - W.G. Cross and H. Ing

2.3.1 Calculation of Recoil Proton Spectra in HydrogenousScintillators - W.G. Cross and H. Ing

Derivation of neutron spectra from measured pulse-height distributions produced by organic scintillatorsrequires that the distributions be known for monoenergeticneutrons of all energies of interest. Such "responsematrices" have been determined accurately only forscintillators of one sizel . Since it is often necessaryor advantageous to use smaller scintillators we are makingcalculations of their pulse-height distributions.

These calculations use an analytical approach toaccount for double scattering from hydrogen and carbon andfor losses of recoil protons through the scintillatorboundaries. These apply only to scintillators small enoughthat the chance of more than two scatterings is negligible.Previous analytical estimates of these effects have notproperly taken account of the non-linearity of the lightoutput from protons and alpha particles. The correctionfactors we obtain for double scattering from hydrogen andfor boundary effects have quite different shapes to thosepublished. A computer program has been written that usesthese factors to calculate the response matrix for any smallcylindrical scintillator for neutrons up to 6 MeV. We arealso using Monte Carlo calculations as a check on theimportance of more than two scatterings.

These predicted proton spectra are being compared withmeasured spectra from small NE 102 scintillators, for incidentmonoenergetic neutrons mainly between 2.4 and 3 MeV. AlthoughNE-213 liquid scintillators will be used for spectrometry(because of their neutron-gamma separation capabilities) itis easier to get NE-102 plastic in the wide variety of shapesand sizes desired for tests. As a rigorous test of boundarylosses, comparison was made for a scintillator of thicknessonly 1.5 times the maximum range of recoil protons. Whilethe agreement of the spectral shapes to within 10% demonstratesthat the calculations are substantially correct for protonsabove 300 keV, the remaining disagreement is larger thanexpected. The general shape of double scattering correctionshas also been verified but a precise quantitative comparison

(1) V.V. Verbinski, W.R. Burrus, T.A. Love, W. Zobel andN.W. Hill, Nuc. Inst. Meth. 65, 8(1968)

- 11 -

has not yet been made. Calculations are hampered by lackof accurate knowledge of the relationship between protonenergy and pulse height at energies below 1 MeV.

2.3.2 Unfolding Recoil Proton Spectra from HydrogenousScintillators - W.G. Cross and H. Ing

A computer program for unfolding recoil proton spectrahas been written. This divides the pulse-height spectruminto up to 50 equal energy bins, differentiates it and usesa spectral stripping technique and the response matricesdescribed in the previous section to correct for doublescattering and boundary losses. It iz applicable only torelatively small scintillators and to neutrons up to about6 MeV. In contrast to matrix unfolding methods, this canbe run on a desk-top computer. The program is now beingtested.

2.3.3 Spectra and Doslatetry of Therapeutic Beams of Fast Neutronsin a Water Phantom - W.G. Cross and H. Ing

Calculation of spectra and dose distributions in awater phantom, irradiated by a beam of neutrons producedby 16-MeV deuterons on Be, has been described (PR-B-112).For field sizes less than 10 x 10 cm, calculated dosevariations along the beam axis..agreed reasonably well withthose measured at Hammersmith ' but for larger fields(20 x 20 cm) there were significant discrepancies. Thesehave now been removed by doing Monte Carlo calculations withthe neutron source at its actual distance from the phantom,rather than for a parallel incident beam. Although a low-energy (below 2 MeV) component in the incident spectrum isstill required to give the best fit to experimentalattenuation, its intensity is considerably smaller than before.Good agreement with measured dose distributions outside thebeam is also obtained.

The small calculated changes in the spectrum on thebeam axis with depth (PR-B-112) are estimated to change theO.E.R. by no more than 2% - too small to be detected bybiological measurements. However, we estimate that thesespectral changes could be observed by precise measurementswith threshold detectors. The low-energy "tail" assumed forthe incident spectrum would increase the ratio of surfacekerma to that at 10 cm depth by 6% and the ratio of skindose to dose at 2 mm depth by 4%.

2.3.4 Spectra of Neutrons Transmitted and Multiply-Scatteredby Concrete Walls - W.G. Cross and H. Ing

Calculations of transmission and scattering of neutronsby concrete (PR-B-112) have been continued in an attempt tounderstand the sometimes high (> 80%) measured values for

(1) D.K. Bewley, private communication

- 12 -

the fraction of dose equivalent arising from "intermediateenergy" (I-E) neutrons (in the energy range from thermalto 0.1 MeV). For various incident spectra (unmoderated andmoderated fission neutrons, monoenergetic neutrons of 2.8and 14 MeV), the following conclusions apply to neutronstransmitted by concrete :

- the relative I-E fraction increases at depths upto 10 to 20 cm and then decreases at greater depths;

- any I-E component in the incident spectrum has anegligible effect at depths greater than 60 cm;

- beyond 100 cm, because of the "window" in the oxygencross section at about 2.3 MeV the spectrum oftransmitted neutrons up to 180 cm shows no furtherincrease in the proportion of intermediate energyneutrons.

Transmission through concrete therefore cannot produce ahigh proportion of I-E neutrons.

When fission neutrons are scattered repeatedly, thedose equivalent (D.E.) fraction from I-E neutrons increasesby about a factor of 2 at each scattering, the value after3 scatterings being 24%. Transmission of these neutronsthrough 30 cm of concrete decreases this fraction to 12%.Multiple reflections can thus give a high I-E fraction butonly if reflected neutrons alone contribute to the D.E. Inpractice such a situation may arise in a shielding maze. Onthe other hand, multiple reflections from the walls inside ashielded room do not give a large I-E fraction since mostof the fluence comes from the original source. The type ofscattering that occurs in most practical shielded areas isunlikely to give a very high proportion of D.E.from I-Eneutrons. It would seem that the very high measured valueswhich have been reported arise from uncertainties in theenergy responses of the instruments used.

2.3.5 Neutron Spectra Calculations Using a Discrete OrdinatesCode - in Ing and P.Y. Wong (Mathematics and ComputationBranch)

Calculations of neutron spectra, using a modifiedversion of the 05R Monte Carlo code, have been made forseveral years (PR-B-112). Although the Monte Carlo techniqueis extremely powerful in its ability to handle a vast varietyof problems, its execution requires considerable computationtime - especially when thermal neutrons are also of interest.

In calculations involving only one-dimensional geometry,the numerical solution of the Boltzmann transport equationcan provide accurate spectral information more quickly. Tohave this additional computational capability, we havecalculated leakage spectra from a 10 cm radius H-0 sphere

- 13 -

containing, 1.4- MeV and fission neutrons at its centre usingthe ANISN ' discrete ordinates code. The cross-sectionfile for these computations was obtained,from the ENDF/T- IVcross-section library using the SUPERTOG code. Leakagespectra were calculated in 100 groups including a thermalneutron group which was omitted in previous Monte Carlocalculations (PR-B-96) because of long computation times.Above 1 eV, the spectra produced by ANISN agreed with thoseby 05R to within the statistical uncertainty of the latter.

2.3.6 Spectra from 2 3 8U Spherical Assemblies Containing a Sourceof 14-MeV Neutrons - H. Ing and W.G. Cross

Previous calculations (PR-B-112) of leakage neutronsfrom Z 3 8u spheres containing a point source of 14-MeV neutronsat the centre indicated that maximum fluence was obtained fora sphere of 12 cm radius. In practice, the uranium spheremust have a central cavity to contain the tritium targetassembly. Leakage spectra have therefore been calculatedfor spheres of several diameters with a wall thickness of12 cm of depleted uranium. Such assemblies may be used bothin radiobioïogy and in dosimetry experiments.

As expected from geometric considerations, the leakagespectra changes with the size of the central cavity. Althoughthe unattenuated 14-MeV fluences are identical (because allthe spheres have the same wall thickness), the broad distri-bution at lower energies (about 90% of total fluence) producedby fission and inelastic scattering decreases in averageenergy with increasing cavity size. For cavities with radiiof 5, 10 and 30 cm the average energies are approximately0.5, 0.4 and 0.35 MeV respectively. The total leakagefluence also decreases with increasing cavity size. For theradii listed above, the flux multiplications are respectively2.7, 2.5 and 2.3 whereas a factor of 2.8 was obtained(PR-B-112) for the point source.

Average cross sections for various reactions useful inneutron dosimetry and average kerma per unit fluence werealso computed for these leakage spectra. Because of theunattenuated 14-MeV neutrons, the spectral variations in thelower energy region reduces the average kerma by only 7%.

2.3.7 Accuracy of Criticality Accident Neutron Doses UsingCalculated Spectra from Simple Assemblies - H. Ing and W.G. Cross

The accuracy of neutron dose determinations using thecalculated spectra of geometrically simple systems contained

(1) Ward W. Engle, Jr. "A Users Manual for ANISN" USAECResearch and Development Report K-1693 (1967).

(2) R.Q. Wright, N.M. Greene, J.L. Lucius and C.W. Craven, Jr."SUPERTOG: A Program to Generate Fine Group Constantsand P Scattering Matrices from ENDF/B" Oak RidgeNational Laboratory Report ORNL-TM-2679 (1969).

- H -

in the IAEA Compendium of Criticality Accident Spectra(PR-B-112) has been studied for assumed exposures frommany existing assemblies having "known" neutron spectra.The assemblies include unshielded and shielded metallic andaqueous systems ranging from small burst reactors tosophisticated fast reactors.

For a dose of 1 rad (10 mGy), readings of dosimetersusing the following reactions: ' ° 3Rh{n,n' ) 1 ° 3inRh,115In(n,n')115mIn, 3 2S(n,p) 3 2 P and 237Np(n,f) werecalculated using the "known" spectra of the assemblies. Thesereadings were then used in conjunction with appropriate spectrafrom the Compendium to derive an estimate of the dose. Thedeviation of the estimated dose from the "true" dose wasdetermined.

For most assemblies studied, a dosimeter containingIn and S detectors is capable of providing dose estimateswithin the + 25% accuracy recommended by an IAEA panel .The exceptions are complex assemblies containing severalmaterials and those in which the high energy part of thespectrum is strongly attenuated. In these cases, theaddition of either a Np or Rh detector to the dosimeteryields estimates to the required accuracy.

2.3.8 Nuclear Data Requirements for Radiotherapy with Neutrons -W.G. Cross

Clinical trials of neutron therapy are now being madeand planned at neutron energies up to 70 MeV or more atseveral radiotherapy centres. Various nuclear data areneeded for the design of new accelerators and for understandinginteractions of high energy neutrons with tissue and withdetectors. A survey has been made of these data requirementsand of the extent to which they are satisfied by existing data.

Among data for neutron source reactions (deuterons andprotons on Li, Be and D targets) the greatest need is forfurther measurements of neutron spectra, particularly forproton-induced reactions. The latter have the advantage, ascompared with deuteron reactions, that a given mean neutronenergy can be obtained from a smaller cyclotron. However,spectra from Li-p and Be-p reactions contain a strongcomponent below 5 MeV that is disadvantageous for therapy.It is important to learn how the intensity of this componentvaries with proton energy and target thickness. Present dataon total neutron yields from these reactions appear to beadequate.

The major need among neutron interaction data is forspectra of charged particles emitted in the interactions of8 to 70-MeV neutrons with O and C. These data are required

(1) "Nuclear Accident Dosimetry Systems" (IAEA, Vienna,1970) p.181

- 15 -

for converting fluence to tissue dose, for calculatingrelative biological damage and for interpreting detectorand spectrometer readings. Energy and angular distributionsof neutrons scattered inelastically from 0, C and Fe arerequired for transport calculations, but calculated crosssections, supplemented by a few measurements, may be adequate.Cross sections of threshold reactions, up to 50 MeV, arerequired for spectral measurements.

2.3.9 A Neutron Spectrometry System - H. Ing and W.G. Cross

A neutron spectrometry system has been assembled formeasuring neutrons over the energy range 35 keV to 20 MeV.It consists of a NE-213 scintillation detector for coveringthe energy range 1.5 MeV to 20 MeV and a set of 4 sphericalproportional counters (PR-B-112) for the range 35 keV to4.5 MeV. In its present form, both detector assemblies areoperated independently.

In the scintillation detector, neutron and gamma pulsesare separated by their different pulse shapes, only theneutron signals being analyzed. The pulse-shape discriminatoris constructed from standard Ortec modules using "constant-fraction pick-off" and "zero cross-over" timing techniques.The resulting.pulse-height spectrum is v •olded using the.2.FERDOR code and the response matrix . Ingersoll et al.

The 4 spherical proportional counters are operatedsimultaneously. They are mounted on a light aluminum framewhich rotates back and forth at 3 rpm to ensure that theyare all given the same radiation exposure. The counters usea specially built electronics unit (PR-B-114) which providesdifferent high voltages to the various counters, amplifiesthe signals from them and routes these signals to respectivequadrants of the analyzer memory. This pulse-height informationis unfolded using a modified version of the SPEC-4 codel .The spectrum as measured by the NE-213 scintillator is usedas input to this code to provide data in the energy rangeabove that measured by the proportional counters.

Both detector assemblies have been checked by measuring14-MeV and 2.8-MeV neutrons and the results indicate that theyare functioning properly.

(1) W.R. Burrus and V.V. Verbinski, Nucl, Inst. Meth. 67(1969) p.181

(2) D.T. Ingersoll, B.W. Wehring and R.H. Johnson, ORNL/RSIC -40 (1976) p.47

(3) P. W. Benjamin, C D . Kemshall and A. Brickstock, AWREReport 09/68

- 16 -

2.3.10 Measurements of Various Neutron Spectra - H. Ing and W.G. Cross

Using the scintillation detector and proportional countersystem described above, the spectra for alarge (1.2 x 10 7

neutrons.s~ ) and a small (10^ neutrons.s ) Pu-Be sourcewere measured. Results indicate that although the spectralfeatures are identical for both sources, a greater fractionof neutrons from the large source is in the lower energyregion. Since this source is used for calibrating neutronmonitoring instruments at CRNL, its dose equivalent per unitfluence was calculated from the»measured spectrum. This gave3.7 x 10 mrem per neutron«cm which i§5in excellentagreement with our old value of..1.8 x 10 calculated froma published spectrum measured1 with nuclear emulsions.

A preliminary measurement was also made of a Pu-Lisource used in the non-destructive assay of Pu. The resultsindicate that the maximum fluence is at about 0.5 MeV andthat less than 10% of the neutrons have energies greaterthan 1 MeV.

The spectrometers were also used to measure the spectrumof 14-MeV neutrons transmitted through 2 3 8 U . In thisexperiment depleted uranium fuel pellets were stacked aroundthe tritium target of a neutron generator to simulate a 5 cmradius sphere containing the source at the centre. Themeasured spectrum was in reasonable agreement with thatcalculated by the 05R code.

2.3.11 Electro-chemical Etching of Damage Tracks in Plastics -W.G. Cross and H. Ing

Recent improvements * ' in techniques of electro-chemicaletching suggest that visual detection of tracks of heavyion recoils, produced in polycarbonate sheets by fast neutrons,could become a practical method of neutron dosimetry. Aprogram to study the possibilities of electro-chemical etchinghas been started. Etching in KOH solutions is done in cellscontaining only a few mL of etchant. Tracks, etched todiameters of about 100 ]im for 14-MeV neutrons and 75 pmfor 2.8-MeV neutrons, are counted by eye in a x 20 microficheviewer.

Track densities per rad are about half as great for2.8-MeV neutrons as for 14-MeV neutrons. Background inunirradiated foils is equivalent to about 15 mrad(0.15 mGy) of2.8-MeV neutrons. While recoil-track measurements cannotyield neutron doses as accurately as fission-track measurements,

(1) L. Stewart, Phys. Rev. 9£ (1955) P.740

(2) G.M. Hassib, J.W.N. Tuyn and J. Dutraunois, NinthInt. Conf. on Solid State Track Detectors, NeuherbergOctober 1976

- 17 -

the former have the advantage that no fissionable materialis required in the personal dosimeter badge, and the accuracyis sufficient for some applications.

A requirement has arisen within AECL to determine thespatial distribution of 2 3 5U in ThO» fuel. Fission tracks,produced in plastic placed against the fuel and irradiatedwith thermal neutrons, have been counted under-the microscopeand in an automatic track counter (Quantimet) . We haveexplored the possibilities of using electro-chemical etchingto enlarge the tracks so that they can be counted more easily.For the spatial resolution and statistical accuracy required,track diameters of about 25 ]im appear to be most suitable.This diameter was easily obtained and tracks can be countedin a microfiche viewer. They are also more suitable forautomatic counting than are microscopic tracks.

2.3.12 Participation in Fourteenth ORNL Intercomparison - H. Ingand W.G. Cross

CRNL participated in the Fourteenth Intercomparisonof Nuclear Accident Dosimetry Systems held at Oak RidgeNational Laboratory, July 15 - 22, 1977. Thirty-fourparticipants from 16 organizations took part in this inter-comparison. Our interest in this intercomparison was theintroduction of two new shields (concrete + steel and concrete)for the Health Physics Research Reactor (HPRR) which provideda softer spectrum than previously used at ORNL for testingour dosimetry system.

Three irradiations were made with the reactor in thepulsed mode and in the following configurations (1) shieldedwith concrete + steel, (2) unshielded, (3) shielded withconcrete. For each of these bursts, a CRNL dosimeter badgewas placed on a phantom facing the reactor.

In the first burst, the neutron surface dose wasmeasured with Rh, In and S activation threshold detectorsand Np and Th damage-track detectors. In the second andthird bursts, only the S, Np and Th detectors were used.(These badges were irradiated by ORNL personnel and sentto CRNL for analysis a week later.) In all the bursts, thethermal neutron fluences were measured by Au and Cd-Au foilswhile gamma doses were measured by TLD-700 chips inside small6Li shields (to reduce their neutron response).

As requested by ORNL, the interpretation of neutrondosimeter readings were made (a) with the aid of the"Compendium of Neutron Spectra for Criticality Accident

(1) P. Campbell, private communication

BurstNo.

1

2

3

IrradiationCondition

HPRR + Concreteand steel shield

HPRR unshielded

HPRR + Concreteshield

- 18 -

Dosimetry1 and (b) using calculated spectra for thethree irradiation configurations provided by ORNL. Theneutron kermas and gamma doses reported by CRNL are shownbelow.

CRNL Results for the 14th ORNL Intercomparison

Neutron Kerma (rad)* GammaUsing Compendium ORNL Spectra Dose (rads)*

115 129 69

973 992 215

129 149 83

* 100 rads = 1 Gy

2.3.13 FINS Accelerator Facility - W.G. Cross and H. Ing incollaboration with J.D. Hepburn, Accelerator Physics Branch

(2)The FINS accelerator which will provide an intensesource of 14-MeV neutrons, has been moved from Building 610and installed in Building 513 by the Accelerator PhysicsBranch. The accelerator has been tested for deuteron beamsup to 13 mA. The radiation safety system has been designedand installed. It is expected that a tritium target willbe put in the machine within a month.

2.3.14 Improvements to Apparatus for Detection of Pu WasteContainers - H. Ing and W.G. Cross

For detecting Pu in waste containers, CRNL has purchaseda Bulk Fuel and Scrap Assay Unit from National NuclearCorporation. This unit consists essentially of a 200-litreparaffin-filled drum containing a 45-litre irradiation cavitywith a Pu-Li neutron source embedded in the paraffin. WastePu undergoes fission in the predominantly thermal neutronfield inside the cavity and the neutrons and gamma rays fromfission are detected by two plastic scintillators.

An increase in the sensitivity of this unit would beuseful. Rough calculations by the manufacturer haveindicated that significant increases in sensitivity couldbe obtained by replacing the paraffin moderator with D_O.

(1) H. Ing and S. Makra, Compendium of Neutron Spectra forCriticality Accident Dosimetry (IAEA, in press)

(2) J.D. Hepburn, J.H. Ormrod and B.G. Chidley, IEEETrans. Nucl. Sci. NS-22,3,1809 (June 1975)

To estimate the achievable improvements, measurementsin mock-up assemblies containing H-O and D~O have beer*performed. A similar drum was filled with H_0 and the thermalflux in the cavity was mapped for various distances of thesource from the cavity and various positions of the cavityinside the drum. Good agreement was obtained between themeasured flux in the present unit and in the mock-up assemblyfor the same configuration of source and internal cavity.

The H-0 moderator was then replaced by D-0. Becauseof the longer thermalization length for neutrons in D_0,paraffin reflectors were placed around the outside of thedrum and paraffin moderators of various thicknesses wereplaced around the neutron source itself. Fluxes werere-measured for these configurations.

Similar measurements were made with the size of theirradiation cavity reduced to 10 litres (still large enoughto accommodate the cans containing the waste).

These experiments led to the following conclusions:

- Replacement of paraffin by D_O and the judicioususe of paraffin reflectors and moderators willincrease the thermal flux inside the 45-litrecavity by a factor of 2 to 3.

- The use of the smaller cavity increases the thermalflux inside the cavity by a factor of 3 for an HJOmedium and 5 for D2

0/ a s compared to the present unit.Since the smaller cavity also allows the detectors tobe moved closer to the sample, an overall increase ofsix times in counting rate per unit mass of Pu islikely achievable for D_O.

- "Background" from fast neutron fission of 238U inthe waste can be several times lower when a D_O ratherthan a paraffin moderator is used. The thermal fluxdoes not decrease so rapidly as the source is movedaway from the cavity because of lower capture indeuterium than hydrogen. Moving the source back willalso decrease gamma background from the source.

2.4 THERMOLUMINESCENCE DOSIMETRY - A.R. Jones

2.4.1 Automatic TLD Readers

The prototype automatic TLD reader has been modifiedso that, as far as its electronics is concerned it conformsto the latest drawings of the model AEP-5256A. The firstunit delivered to Ontario Hydro has been modified to changeit from Model AEP-5256 to AEP-5256A so that all Ontario Hydrounits are the same for maintenance and spares. The manualfor the reader is being printed.

- 20 -

2.4.2 Dosimetry

The sensitivity of the CRNL and AECL CommercialProducts (CP) stock of plaque-mounted TLD's is beingmeasured. The purpose is to obtain a calibration factorfor each dosimeter plaque linked with its identity. Thesefactors can then be used in a computer program to reducethe errors due to variation in the dosimeter sensitivities.

A number of intercomparison measurements have beenmade with other organizations (Ontario Hydro, Health andWelfare Canada, Hydro-Quebec, WNRE, NRC) and at aninternational intercomparison at Oak Ridge NationalLaboratory of TLD's for environmental and personneldosimetry. However, not all the results from these inter-comparisons have yet been received.

Three hundred and fifty TLD plaques have been madefor environmental monitoring. Sensitized TLD-100 chipswere used which were annealed in an oven built to irradiatethe TLD's with UV during the anneal. Each TLD plaque iscalibrated and its calibration factor stored on magnetictape to permit individual correction for readings with anelectronic calculator. This system has been placed inservice for environmental monitoring at CRNL and CP.

Similar sensitized TLD plaques have been tested toassess their suitability for personnel monitoring. Thesame tests were applied also to TLD plaques similar to thosein present use to provide a basis for comparison.

The tests show that sensitized TLD's are linear overa wider range of doses than unsensitized ones. The energydependence of the sensitized TLD's measured in holdersmounted on a phantom is appreciably different from that ofunsensitized ones. This is believed to be due to a smallersensitizing factor observed for higher LET radiations(e.g. low energy y- or x-rays). For this reason the sensitizedTLD's should have a smaller sensitizing factor for neutronsand this should be tested as it could have a practicaladvantage.

The behaviour of the sensitized TLD's when read 100times and subjected to prolonged anneals (80 C for 20 days)to simulate 100 annealing cycles and the passage of 8 yearsat 20 C has been studied. The effect of this treatment ontheir sensitivity is shown in the table below:

Percent Loss in Sensitivity after 100 Readingsand 20 days at 80 C

Standard TLD's Sensitized TLD's

Thick TLD 7 + 6 0 + 5

Thin TLD 1 2 + 8 5 + 5

- 21 -

The effect of this treatment on the variation insensitivity between TLD's was also measured. Each dosimeterreading after 100 reading cycles was divided by the readingafter 50 reading cycles so as to obtain a measure of thechange in the reading during the final 50 reading cycles.Thus, calibration factors measured after 50 cycles areused for the readings obtained after 100 cycles. Thefollowing table shows the spread in the readings obtainedafter individual calibration. Although the spreads in thereadings of both kinds of TLD's are acceptable the sensitizedTLD's show less spread in the calibrated readings.

Percent Standard Deviation of Calibrated Dosimeters

Standard TLD's Sensitized TLD's

Thick TLD 5.6 3.7

Thin TLD 4.7 3.0

Tests have been made on high-temperature cements tobond the TLD's to the kapton tape used to mount the TLD'sbut no cement has yet been found which will bond to thesmooth surface cf the tape.

2.4.3 Measurement of 6-Dose from 6 3Ni in Smoke Detectors

Thin (0.13 mm) LiF-Teflon TLD's are being used toestimate the skin dose-rate to workers assembling smoke-detectors at AECL Commercial Products. The 63Ni source inthe smoke detector is in the form of nickel plating on aprinted circuit-board.

2.5 FUEL BUNDLE VERIFIERS FOR NUCLEAR MATERIAL SAFEGUARDS - A.R. Jones

Tests made with an eleven-detector collimated arrayat Douglas Point Generating Station demonstrated thedifficulty of verifying fuel bundles when mounted touchingone another in storage trays in the arrangement used atDouglas Point. In the storage trays proposed for the600 MW stations the bundles are spaced apart. To verifybundles arrayed in this way a prototype set of 3 detectorswas built and tested on NPD fuel bundles (with axes 117 mmapart) in the NRX fuel bay. Because the bundles are in a2-dimensional array (in a tray which can be removed forinspection) it was possible to view the bundles at rightangles to their axes. This permits their examination atany point along their length and the collimator cone doesnot intersect with neighbouring fuel bundles (in contrastto end-on detectors which must be used with the Pickeringfuel basket). Satisfactory results were obtained with theprototype and these results and essential collimator dimensionswere given to Power Projects to permit the engineering designof a verifier.

- 22 -

Subsequently, in the fuel bundle, spacing was reducedto 105 mm for the Point Lepreau and Gentilly II GeneratingStations and a new set of prototype collimators are beingmade and will be tested in the NRX fuel bay.

The most urgent need for a fuel bundle verifier is atthe Pickering Generating Station. Originally (AECL-5376,PR-B-108), there was a requirement for a verifier whichcould be placed in the 100 mm space between stacks ofbaskets. Now this space limitation has been removed andlonger collimators with narrow collimation cones can be used.A supplementary collimator with narrow collimation coneshas been built for a test at Pickering. Also three dummybundles made from hollow aluminum tubes have been made.These are designed to simulate dummies which a divertermight make and, being hollow, they provide minimalattenuation of the Y-âdiation from neighbouring fuelbundles. This radiation, if detected, reduces thediscrimination obtained between irradiated and dummy fuel.

Tests have begun on the rectifiers used as detectorsin the bundle verifier to determine both their sensitivityto y~radiation and their forward voltage drop as a functionof Y~radiation damage. If these two quantities are wellcorrelated it may be feasible to test the verifier with arelatively simple electrical .test instead of using largey-radiation sources. It would be a simpler matter toprotect from tampering a small electrical test unit than alarge radiation source. The test will also determine thedose needed to render the verifier ineffective.

2.6 ENVIRONMENTAL MONITORING - A.R. Jones

2.6.1 Measurement of Absorbed Dose in a Phantom from EnvironmentalY-rays

Measurements have been made of absorbed doses in arealistic phantom and of the external exposure due, principally,to Âr. The measurement was made over a 49-day period whenthe exposure was 33 mR. The dose was measured using sensitizedTLD's at the testes site and at various points in the bonemarrow and in other parts of the phantom. From this the organdose could be calculated as a function of the external exposurewhich was also measured using sensitized TLD's. The resultsagree with theoretical calculations and are consistent withprevious measurements made earlier on a rotating phantom ina beam of photons.

Following this, the phantom has been set up in a lowbackground area, free of 1*1Ar, to repeat the measurementwith Y-rays of terrestrial origin only. To obtain sufficientexposure (> 10 mR), a long period (̂ 4 months) is needed. Apossible source of error is the internal activity of the

- 23 -

phantom. Measurements made on the phantom in a whole bodycounter by the Medical Research Branch indicate that thedose due to internal y-activity would be less than 0.5 mrad*in 4 months.

2.6.2 Environmental y-Monitoring with a Lithium-Drifted SiliconDetector

The capability of a lithium-drifted silicon detector todetect and measure small changes in background radiation dueto man-made radiation sources is being tested. The pulseheight distribution in twenty equal-energy intervals from0.1 to 2 MeV is being measured when (a) a background monitorindicates a dose rate of about 10 prad/h* and (b) when thebackground is greater than 40 prad/h*. The high backgrounddose rate occurs when the detector is being exposed to *• !Argamma radiation from the NRX and NRU reactor air effluents.

A simple twenty-channel pulse-height analyzer wouldsuffice for routine measurements but use of a large analyzerenables the stability of the system to be monitored moreeasily.

2.7 RADIATION INSTRUMENT DEVELOPMENT - A.R. Jones

2.7.1 Area Monitoring System for the Neutron Generator andy-Irradiation Facility

Three channels of the Multi-Channel Area MonitorAEP-5282 have been installed in the rooms containingthe neutron generator, the TLD calibration source and theX-ray set. The read-outs are installed at the controls ofeach of the facilities to inform the operators when itis safe to enter after the radiation source has been switchedoff (or returned to its shielding). Audible and visiblealarms are turned on in each room to warn anyone workingin them when a radiation hazard exists.

2.7.2 Liquid Crystal Numerical Displays for Portable HealthInstruments

Liquid crystal displays (LCD's) are suited forapplication in portable health instruments because theymay be read under a wide range of lighting conditions andrequire little power. Unfortunately, the analog-to-digitalconverters in many LCD digital panel meters from commercialsuppliers consume considerable amounts of power. To overcomethis difficulty, an LCD has been designed and tested withthe particular requirements of portable radiation instrumentsin mind. It uses low power components, is not dependent uponsupplies from a particular manufacturer and may be adapted tothe space limitations of particular applications.

* 1 prad = 10"8 Gy

2.7.3 Low Background y-Survey Meter AEP-5302

An engineering prototype has been built and is beingtested. This version has a light-emitting diode (LED)display and a second using an LCD is being designed. Becauseof the lower power needs,the weight of the latter versionwill be less and the display will be continuously powered.

2.7.4 High Range y-Survey Meter AEP-5309

A survey meter is being developed to measure y-doserates in the range 0 - 2,000 rad/h (0 - 20 Gy/h). To coverthis range a counter tube has been selected and a counting-loss correction circuit/ which had been developed previously,is used.

This development was needed because of unavailabilityof components used in existing high-range survey meters,AEP-2163 and AEP-5225.

2.7.5 Wide Range By-Survey Meter AEP-5288

The design was completed.

A LCD version is being developed. The circuits havebeen designed and tested and are now ready for mechanicaldrawing effort.

2.7.6 Portable Contamination Monitor AEP-5297

The design was completed.

A LCD version is being developed. The circuits havebeen designed and tested and are now ready for mechanicaldrawing effort.

2.8 TRITIUM AND NOBLE GAS MONITORING - R.V. Osborne

The program of developing monitoring methods fortritium has continued through the year with:

- demonstrating a new method using liquid scintillatorfor tritium in air and in water effluents (AEP-5301),

- advancing from laboratory to field prototype stageanother ionization chamber-based system for tritiumin air,

- completing the engineering, commissioning anddocumenting of an air-effluent monitor (AEP-5293)and in-line monitors for an experimental reactorloop facility (AEP-5299),

- 25 -

- investigating a long-term loss in sensitivity of thescintillator detector in the water effluent monitor(AEP-5252),

- preparing the service manual for an area monitor(AEP-5275), and

- guiding a contractor in revising the design of theauto-urinalyzer (AEP-5216).

The design of the air effluent monitor (AEP-5293) hasalso been adapted for monitoring other radioactive gases.Monitors to this design have been installed on the effluentsfrom two facilities.

2.8.1 AEP-5301

A method using liquid scintillator has been investigatedfor measuring tritium in both air and water. The mainspecifications and design constraints have been identified.The potential advantages are a high sensitivity for tritiumdetection and an insensitivity to contaminants, bothradioactive and inactive, in sampled media. The mainconstraint on the method is the requirement to use liquidscintillator at an economic low rate.

In the method being investigated, water vapour iscollected directly from a sample air flow by a flow ofliquid scintillator. Water is sampled by bubbling inactiveair through it at a fixed temperature and subsequentlycollecting the evaporated water from the air stream inliquid scintillator as above. The controlled evaporationand metering of the vapour-air mixture provides the lowflow of water that is needed to mix with the scintillator andalso separates tritiated water vapour (HTO) from the othercontaminants in a sampled water stream. The important partsof the design are the evaporator (for sampling water streams)and the vapour - liquid scintillator contactor. Thesensitivity of the method for tritium detection isproportional to the products of the efficiency of transferof HTO to the scintillator and the ratio of air flow toliquid scintillator flow. The efficiency of transfer decreaseswith increase in the ratio of flows; hence the sensitivity(i.e. counting rate per unit concentration of HTO in air) isinsensitive to the flow-rate ratio - an important practicalconsideration since tight control of flows in an on-lineinstrument would be expensive.

The initial design of the water evaporator providesair with a dew point within 0.1 C of the 10 C set value;i.e. the concentration of HTO varies by less than 1% fromthe average. The value of the product of efficiency and flowratio defined above with a liquid scintillator flow of only0.1 cmVmin that has been attained with the initial design of

- 26 -

contactor is 2 x 101*. The predicted detectable concentrationswith this value and a 400 mm3 detector cell are ^ 3 nCi/m3

(fv 100 Bq«m""J)for HTO in air and 'v. 0.1 pCi/L (̂ 4 kBq/kg) forHTO in water.

2.8.2 AEP-5270

The laboratory prototype of the monitor (described inPR-B-112) has been completed using digital and analogcircuits designed to be used in both this monitor andAEP-5293 (q.v.). Satisfactory operation of the heatlessdrying system and cancellation of the signals from gaseousradionuclides and from gamma radiation have been demonstrated.The field prototype is now being built.

2.8.3 AEP-5293

Monitors have been installed on three effluents duringthe year. The original application was as a tritium monitorfor the 3He control rig on the X6 loop of NRX. The designhas been adapted subsequently for noble gas monitoring onthe 99Mo production facility and on the ventilation ductfrom the X2 experimental loop of NRX. Engineering drawingsand the service manual for the monitor have been completed.

2.8.4 AEP-5299

Two in-line ionization chambers (̂ 2 cm3 volume) havebeen designed, built and installed in the 3He control rigof the X6 loop so that operators may have an indication ofthe build-up of tritium in the rig gases (see PR-B-112).The calibrations have been checked periodically through theyear by collecting and analyzing samples of the monitoredgas. The analysis distinguished between tritiated watervapour and tritiated hydrogen (HT); so far the latter haspredominated and the monitor responses have been as predicted.The main uncertainty in the calibration - the extent ofsorption of HTO on the ionization chamber walls - has not yetbeen assessed. The manual for the monitor has been completed.

2.8.5 AEP-5252

This monitor, using plastic scintillator to detecttritium in water, has been in use at nuclear power stationsfor many years. A steady decrease in the detection efficiencyhas been observed for detectors cleaned regularly over theyear. The cause has been identified as the bacteriocideused in cleaning the scintillator assemblies. Sonication ofthe assemblies during the cleaning causes some crazing ofthe scintillator but does not appear to affect the detectionefficiency.

2.8.6 AEP-5275

Most of the service manual for the monitor has beencompleted; a fault diagnosis section remains to be done.

- 27 -

2.8.7 AEP-5216

The design of the electronic control of the auto-urinalyzer, put into operation in 1967, is being updatedin industry under contract. Although the contract is notcontrolled by this Branch technical advice has been providedto the contractor throughout the year.

2.9 DETECTION OF RADIO-IODINE IN AIR - R.M. Holford

2.9.1 1 3 1I

The prototype Iodine-in-Air Monitor AEP-5217 wasoperated in the NRX reactor building for the first part ofthe year monitoring the air in the main exhaust duct to thestack. In this mode of operation there is a direct relation-ship between the count-rate displayed by the instrument andthe amount of 1 3 1i activity released to the stack. This waschecked by recovery of the filter medium (charcoal-loadedfilter paper) for recounting in the laboratory and bycomparison with the daily releases reported by R. & I.S. Branch.Agreement over a 24-hour period was reasonably good, butinstrument readings in the first hour after a change offilter medium are due mainly to short-lived radio-iodines andare therefore not a reliable indication of the amount of 1 3 1Ipresent. It is difficult to compensate for the presence ofthe other radio-iodines by background subtraction becauseof the number of different isotopes which can be present.One of them, the 46 s isomer of 3 6 I , produces gamma radiationat 380 keV which cannot be readily distinguished from the365 keV radiation produced by 1 3 1I in an instrument based ona scintillation detector.

In August the iodine monitor was moved to Building 225to monitor the 99Mo process. It was initially connecteddirectly to the exhaust from the dissolution cell and wassuccessfully used to indicate the times and relativemagnitudes of releases of 1 3 1 I . It has now been moved toa sampling point beyond the filters (2 charcoal and 1 HEPA)in the exhaust system so that its readings should provide aquantitative estimate of the amount of 1 3 1i released to theenvironment. While 1 3 6i is not likely to be a problem inthis location, there may be difficulties due to the variablechemical forms of the iodine produced in the 9 9Mo extractionprocess.

The analog rate-of-rise meter which was built as anoptional extra for the iodine monitor has not performedsatisfactorily. One reason for this is that it is restrictedto the same smoothing time-constant as the count-rate displayon the main instrument, and experience has now shown thata rate-of-rise indicator requires a longer smoothing time-constant to give meaningful results. A second defect is itslong memory for transients, such as those generated bychanges of linear range. A simple digital rate-of-rise

- 28 -

meter, based on a single up-down sealer, avoids theseproblems but is inefficient because of the long waitingperiod between readings. The availability of large-scaleintegrated circuits with a complete 6-decade up-down sealeron a single chip has however made it practical to design amore efficient digital rate-of-rise meter in which the intervalbetween readings is only a fifth of the averaging time. Aprototype has been constructed and is currently being evaluatedas an accessory to the iodine monitor.

2.9.2 1 2 5I

Some work was carried out during the year on evaluatingand improving current sampling and counting practices in thelight of the recommendations given in "Air Sampling forIodine-125", Atomic Energy of Canada Limited, report AECL-4598.

Since all exhaust air from the reactors is eventuallydischarged to the main stack, it should be possible tomonitor for releases from the I 2 5i production facility byexamining the daily "May-pack" samples of this effluent,taken primarily to monitor release of 1 3 1 I . The problemswith this approach are interference by 1 3 1i x-radiationwith the 12î measurement, and the high, and possiblyvariable, degree of self-absorption of the soft 1 2 5Iradiation by the "May-pack" components. The first problemcan be solved in principle by allowing the 1 3 1i sufficienttime to decay, although this can be inconvenient in practice.The second problem is partially corrected by the method ofcalculation which is used, as explained in AECL-4598. Thiscorrection is only approximate, however, so that, although itapparently works reasonably well most of the time, itcannot be relied upon in all situations. More consistentresults can be obtained by dismantling the "May-pack" andplacing the charcoal, which contains most of the 1 2 5 I , in aplastic container, but trials have shown that the standardmethod of calculation underestimates the self-absorptionunder these conditions, so that a correction factor isrequired.

Estimates of 1 2 5i releases can be obtained more rapidlyby taking samples at a point nearer to the production facility,before the exhaust air is mixed with that containing fissionproduct iodines. Since there is less dilution of theeffluent a lower sampling air flow can be used, and thisallows the use of smaller charcoal-filled capsules made ofplastic and aluminum wire cloth and dimensioned to fit insidea 'one-inch' well counter. This technique allows almostcomplete correction for self-absorption. Trials indicatedthat the capsules might be failing to absorb part of theiodine in the air passing through them, but investigationrevealed that this was an artifact due to the presence, infresh samples, of 1 2 5Xe, the precursor of 1 2 5 I . This isotopeemits photons at 55 keV which can simulate the detection of

- 29 -

the coincident x-ray photons normally characteristic of1 2 5 I . Since the half-life of 125Xe is less than a day, ashort period of storage eliminates it. The levels of allthe radio-xenons in a charcoal sample can be reduced by atleast tenfold without losing the X^5I by purging withclean air, or merely by storing the samples for a few days(in a fume hood) in an unsealed condition.

2.10 MICROSCOPIC FLYING-SPOT SCANNER - R.M. Holford

This instrument is being modified for use in countingetch pits in Kodak LR115 cellulose nitrate foils, used fordetection of heavy ionizing particles. To improve the lineresolution and mechanical stability of the instrument it isbeing rearranged to allow horizontal mounting of the cathoderay tube and use of a full-sized raster on the tube face.The reliability and linearity of the deflection circuits havebeen improved and the high voltage supply has been extensivelyredesigned to reduce arcing.

2.11 RADON MONITORING - G. Cowper

An instrument has been designed to measure long-termaverage concentrations of radon-in-air. It is intended foruse in homes and public buildings where, as a result ofusing radium-contaminated building materials or becauseconstruction has occurred on ground containing radioactiveminerals, abnormal radon levels exist.

Since radon concentrations in buildings containingemanating sources may vary over wide limits depending uponboth meteorological conditions as well as the actions ofthe occupants, measurements must be made over sufficientlylong periods of a week or more to obtain realistic estimatesof chronic hazards.

The instrument which has been developed is capable ofmeasuring average concentrations of less than 0.5 pCi/L (̂ 0.02 Bq/L)over a one-week period. An air sample of about eight litresis defined by a cylindrical volume which has a porous foamwall through which radon may diffuse but which traps radondaughter products existing in the air. Daughter productsborn within the volume and carrying a positive charge arecollected electrostatically on a thin (0.00075 mm) Al foilbehind which is located a TLD chip (CaF-Dy; TLD-200)3 mm x 3 mm x 0.38 mm. The exposed TLD chips are processedin a commercial reader (Harshaw Model 3000). The instrumentcontains a second TLD chip not exposed to radon daughters toallow corrections for background gamma radiation exposure tobe made. The base of the instrument contains a 1200 V batterypack to provide the electrostatic field.

The instrument has been tested in a 1.8 m3 enclosurethrough which air passes continuously after bubbling througha 50 yg radium solution to provide a radon concentration ofabout 250 pCi/L.(9 Bq/L).

Reproducibility of TLD chips and various post-irradiationannealing procedures have been tested by exposing them in agood geometry in an evacuated enclosure to alpha radiationfrom an 21flAm source. Several types of TLD material wereexamined and CaF (Dy) was selected for its high sensitivity.Exposure to radon at a level of 0.5 pCi/L (0.02 Bq/L) for oneweek will give a TLD output approximately equal to that froma gamma radiation exposure of 10 mR and some fifty times largerthan the output from an unexposed TLD.

The electrostatic collection of daughter products isdependent upon relative humidity and tests indicate that amonitor calibrated at 50% RH will give readings within+ 15% of the true value over the range 20 - 80% RH.

2.12

Three annealing procedures have been tested: 30 C forone hour, 100 C for ten minutes, and storage at roomtemperature for 16 hours. Room temperature storage givesthe most reproducible results owing to deficiencies in thetemperature stability of the annealing ovens. Six instrumentshave been built for first field trials and are being tested.

ROUTINE DOSE MONITORING - R.M. Rondeau and J.M. Vincent

2.12.1 Body Radiation Doses

In the fourteen week period ending 15 December 1977and the calendar year to this date there are the followingdistributions of radiation exposures.

Penetrating Radiation Dose - CRNL

Dose Range

rems

no radiation0 - 0.490.50 - 0.991.00 - 1.491.50 - 1.992.00 - 2.492.50 - 2.993.00 - 3.493.50 - 3.994.00 - 4.49

Average doseper monitoredperson

Average doseper exposedperson

Fourteen Weeks

No. ofmonitoredpersons

87217910628

TotalDose

Man-rem

0166.2272.4632.40

113 mrem

11'' mrem

Calendar


6518801589895561611138

413

425

Year

TotalDose

Kan-rem

0305.73114.47120.77164.80125.2542.7035.8149.1033.70

mrem

mrem

- 31 -

Penetrating Radiation Dose - CP

Dose Rangerems

no radiation0 - 0.490.50 - 0.991.00 - 1.491.50 - 1.992.00 - 2.49



Fourteen Weeks


18214131

TotalDose

Man-rem

016.557.981.12

104 mrem

112 mrem

Calendar Year


16186211562

TotalDose

Man-rem

024.0114.9917.4610.134.67

290 mrem

310 mrem

Penetrating Radiation Dose - PP

Dose Rangerems

no radiation0 - 0.490.50 - 0.991.00 - 1.491.50 - 1.99



Fourteen Weeks


17615

TotalDose

Man-rem

00.27

2 mrem

18 mrem

Calendar Year


13839932

TotalDose

Man-rem

04.496.393.733.87

97 mrem

349 mrem

- 32 -

Surface Radiation Doses - CRNL

Dose Rangerente

no radiation00.50 -1.00 -1.50 -2.00 -2.50 -3.00 -3.50 -4.00 -4.50 -5.00 -5.50 -6.00 -

Average

0.490.991.491.992.492.993.493.994.494.995.495.996.49

doseper monitoredperson


Fourteen Weeks


87211913447103

TotalDose

Man-rem

137 mrem

142 mrem

0154.0894.0957.2416.946.47

Calendar


651852148897765432017105522

Year

TotalDose

Man-rem

0300.82105.50110.21134.39144.58115.8963.6863.0142.8024.1426.2211.1812.06

483 mrem

497 mrem

Surface Radiation Doses - CP

Dose Rangerems

no radiation0 - 0.490.50 - 0.991.00 - 1.491.50 - 1.992.00 - 2.492.50 - 2.993.00 - 3.493.50 - 3.99



Fourteen Weeks


18203204

1

TotalDose

Man-rem

018.2714.335.10

2.22

162 mrem

175 mrem

Calendar Year


16175241565131

TotalDose

Man-rem

024.2117.0917.8510.6310.672.69

10.113.60

394 mrem

421 mrem

- 33 -

Surface Radiation Dose - PP

Dose Rangerems

no radia t ion0 - 0.490.50 - 0.991.00 - 1.491.50 - 1.99



Fourteen Weeks

No. ofmonitored

persons

17615

TotalDose

Man-rem

00.27

2 mrem

18 mrem

Calendar Year

No. ofmonitored

persons

13838

852

TotalDose

Man-rem

04.445.496.213.87

104 mrem

377 mrem

The two-weekly administrative control limits for wholebody doses were exceeded once at CRNL and twice at CP duringthe fourteen week period.

2.12.2 Hand Radiation Doses

In the fourteen week period ending 2 December 1977 andin the calendar year to this date there was the followingdistribution of extremity doses as measured by finger tipTLD's.

Dose Rangerems

less than 0.991.-0 - 1.992.00 - 3.994.00 - 5.996.00 - 7.99

CRNL

CalendarYear

14113631

FourteenWeeks

334210

CP

CalendarYear

481310

30

FourteenWeeks

94100

PP

CalendarYear

O O

O O

O\

FourteenWeeks

10000

2.13 PUBLICATIONS AND LECTURES

2.13.1 Publications

(1) W.G. Cross and H. Ing, "Spectre and Dosimetry of NeutronsInteracting with Concrete Shielding." Proc. IVthInternational Radiation Protection Association Congress,Paris, April 1977, p.377

- 3k -

(2) H. Ing and W.G. Cross, "Calculated Spectra for theDosimetry of D O-moderated Neutrons." Health Physics32_, (1977), p.351

(3) A.R. Jones, "Spent Fuel Monitor for Nuclear Safeguards."IEEE Transactions on Nuclear Science NS-24, #1, p.602,(1977) AECL-5588

(4) A.R. Jones, "A Versatile &y Survey Meter with NumericalDisplay." IEEE Transactions on Nuclear Science. NS-24p.635, (1977), AECL-5587

(5) D.K. Myers, J.D. Childs and A.R. Jones, "Sensitizationof Bacteriophage T4 to 6nCo Y-Radiation and Low Energyx-Radiation by Bromouracil. " Radiation Research 6_9_,pp.152 - 165, (1977), AECL"564i

(6) A.R. Jones, "The Application of an AutomatedThermoluminescence Dosimetry System to EnvironmentalY-Dosimetry." Health Physics Society Annual MeetingAECL-5385

(7) A.R. Jones, "A Five Channel Area Monitor for GammaRays." Proc. of the IVth International Congress,IRPA, p.801, (1977)

(8) R.V. Osborne, "Hazards and Protection from TritiumProduced from Pressurized 3He in an ExperimentalReactor Loop." Proc. IVth International RadiationProtection Association Congress (1977), p.671

(9) R.V. Osborne, "A Transportable Monitor for TritiatedWater Vapour." Proc. IVth International RadiationProtection Association Congress (1977), P.805

2.13.2 External Lectures

I H. Ing and W.G. Cross, "Accuracy of Criticality AccidentNeutron Doses Using Calculated Spectra from SimpleAssemblies," presented at 22nd Annual Meeting of HealthPhysics Society, Atlanta, Georgia, July 3 - 8 , 1977

II H. Ing, W.G. Cross and B.J. Tymons, "Current Work inNeutron Dosimetry at CRNL," presented at Sixth Workshopon Personnel Neutron Dosimetry, ORNL, Tennessee,July 11 - 12, 1977

III H. Ing, "A Compendium of Neutron Spectra forDetermination of Neutron Doses in CriticalityAccidents," presented at Fourteenth DosimetryIntercomparison Study, ORNL, Tennessee, July13 - 22, 1977

- 35 -

IV H. Ing and W.G. Cross, "Calculated Leakage Spectra from2 3 eU Spheres Containing Sources of 14-MeV or FissionNeutrons for Radiobiological Applications," ThirdSymposium on Neutron Dosimetry in Biology and Medicine,Munich, May 1977

V A.R. Jones, "A Five Channel Area Monitor for y-presented at IVth International Congress, IRPA, Paris,April 1977

VI A.R. Jones, "The Application of an AutomatedThermoluminescence Dosimetry System to Environmentaly-Dosimetry," presented at 22nd Annual Meeting of theHealth Physics Society, Atlanta, July 1977

VII A.R. Jones, "Radiation Protection Instrumentation forPersonnel Dosimetry, Area and Environmental Monitoring,"presented at IAEA Regional Seminar on the Preparation ofRadiological Safety and Environmental Protection forNuclear Programmes in Latin America, Caracas, November 1977

VIII R.V. Osborne, "Monitor for Tritiated Water at LowConcentrations in Air and Water Effluents," presentedat IVth International Radiation Protection AssociationCongress, 1977

2.13.3 Internal Lectures(given at CRNL Health Physics Course26 - 30 September 1977)

G. Cowper - Non-ionizing RadiationA.R. Jones - Measurement of RadiationR.V. Osborne - Radioactivity, Radiation Physics and Units

2.13.4 Reports

(1) W.G. Cross (compilée) Canadian Progress Report to theInternational Nuclear Data Committee INDC (Canada)18/G, April 1977

(2) W.G. Cross, "Nuclear Data Requirements for Radiotherapywith Neutrons," INDC (Canada) 17/G, May 1977

(3) R.M. Holford, "An Examination of the CRNL Stack DilutionStudy." Atomic Energy of Canada Limited UnpublishedReport, CRNL-1593.

- 37 -

ENVIRONMENTAL RESEARCH BRANCH

by

I.L. Ophel

3.1 Staff3.2 Studies on Effects of Heated Water on Aquatic Organisms3.3 Beneficial Uses of Waste Heat

3.3.1 Polyculture of Fresh Water Organisms3.4 Effects of Temperature on Algae3.5 Biochemistry, Biogeochemistry and Microbial Ecology

3.5.1 Biogeochemistry of. the Waste Management Area3.5.1.1 Geochemistry, General3.5.1.2 Organics in Ground Water3.5.1.3 Bacterial Populations in Ground Water

3.5.2 Operation of the Total Carbon System3.5.3 Control Mechanisms in the Cellular Metabolism

of Ustilago maydie3.6 Aquatic Radioecology and Fresh Water Biology

3.6.1 Role of Organic Matter in Perch Lake3.7 St. Lawrence River Studies3.8 Perch Lake Project

3.8.1 Energy Budget and Lake Evaporation3.8.2 Water Budget and Lake Chemistry

3.8.2.1 Perch Lake Models3.8.2.2 Snow Course

3.8.3 Data Storage3.8.4 Snowmelt Studies3.8.5 Simulation Modelling of Perch Lake Streams and

Ground Water Flow Rates3.8.6 Transfer and Deposition of Atmospheric Sulphur3.8.7 Symposium/Workshop

3.9 Atmospheric Diffusion Study3.10 Stack Argon Measurements3.11 Snowmelt and Evapotranspiration in a Forested Catchment

For Figures 1, 2 and 3 see end of section

- 38 -

3.12 Neutron Activation Analysis3.13 Waste Management Areas

3.13.1 Soil and Ground Water Sampling3.13.2 Investigation of Rod Bay Leakage3.13.3 Arsenic in Environmental Samples3.13.4 Stabilization of Ferro-Niobium (Columbium) Wastes

3.14 Cooperation With Outside Organizations3.14.1 Cooperation With Universities

3.14.1.1 University of Waterloo, General3.14.1.2 University of Waterloo Contract3.14.1.3 Queen's University Contract

3.14.2 Rain Sampling Program in Cooperation With CanadaCentre for Inland Waters

3.15 Contaminant Hydrogeochemistry3.16 Isotope Evaporation Studies3.17 Infiltration Studies on the East Side of Perch Lake Basin

3.17.1 Natural Infiltration3.17.2 Artificial Flooding Experiments

3.18 T/D and Oxygen-18/Oxygen-16 Ratios in the Bruce HeavyWater Plant

3.19 Mixing of Melt Waters With Sea Water in an Arctic Fjord3.20 Isotopic Composition of Precipitation Across Canada3.21 D/H Analysis of Small Water Samples3.22 Environmental Impact Assessment3.23 Gamma Exposure Rates at the CRNL Boundary3.24 Off-Site Monitoring3.25 Liquid Effluent Monitoring3.26 Liquid Disposal Area3.27 Gamma Exposure Rates in the Exclusion Area3.28 Monitoring of Land Gamma Background Radiation3.29 Examination of Samples of Contaminated Soil3.30 Tritium Survey3.31 Survey Summary3.32 Publications3.33 Verbal Presentations

3.33.1 Presented Papers3.33.2 Lectures or Seminars3.33.3 Local Talks

3.34 Invited Speakers

- 39 -

3.1 STAFF

3.1.1 Branch Head - I.L. Ophel

Environmental Chemistry and Meteorology

P.J. Barry Assistants: P.C. JayR.E. LégèreE. RobertsonD.P. Wildsmith

L.K. Hendrie1

Natural Isotope Studies

R.M. Brown Assistant: CD. Fraser

Biochemistry and Microbial Radioecology

D.R. Champ Assistant: J.L. Young

Radiochemistry and Terrestrial Radioecology

W.E. Grummitt2 Assistants: G. LahaieL.A. MaskH.M. McLaughlinW.J. Pierson

Contaminant Hydrogeochemistry

R.E. Jackson3 Assistant: K.J. Inch3

Biology and Aquatic Radioecology

J.W. McMahon Assistants: A.E. DochertyS-R. Gentner

I.L. Ophel Assistant: J.M. Judd

attached staff from Dept. of Geography, University ofToronto, Toronto, Ontario. Terminated 14 October 1977.

2Retired 30 December 1977.3Attached staff from Inland Waters Directorate, Environ-ment Canada, Ottawa, Ontario.

- ko -

3.1.1 STAFF (cont'd)

Hydrology and Trace Element Analysis

W.F. Merritt Assistant: B.A. Risto

Secretarial

D.J. TerMarsch

3.1.2 Other Attached Staff

University of Waterloo, Waterloo, OntarioJ.F. Pickens* - Arrived 6 June 1977H. Vandor* - Arrived 4 July. Terminated

7 October 1977.

L.M. Johnston - Inland Waters Directorate, Environ-ment Canada, arrived 12 September.Working with W.F. Merritt on traceelements in ground water. Terminated25 November 1977.

L. Tremblay - Ecole Polytechnique, Montréal, Québec.Working with I.L. Ophel on Master'sThesis.

G.B. Allison - Commonwealth Scientific and IndustrialResearch Organization (CSIRO), Australia,arrived 9 November. Working with R.M.Brown on hydrology projects. Terminated21 December 1977.

Queen's University, Kingston, OntarioK.E. Lyon* - Arrived 6 July 1977. Terminated

16 September 1977.

S.G. Roper* - Arrived 6 July 1977. Terminated9 September 1977.

*Research contract between AECL and the University

- i t l -

3.2 STUDIES ON EFFECTS OF HEATED WATER ON AQUATIC ORGANISMS- J.W. McMahon and A.E. Docherty

Field studies at the Maskinonge Lake experimen-tal heating facility on the effects of temperature onfresh water plankton concentrated on three main topics :(1) effects of depth of intake and discharge of heatedwater on phytoplankton, (2) combined effects oftemperature and nutrient enrichment on algae growth,and (3) combined effects of temperature and arsenic(a possible contaminant of radioactive waste) on theplankton community.

Our initial study examined the effects on thephytoplankton of heated water discharged from threedifferent configurations: surface intake-surface dis-charge; deep intake-deep discharge; deep intake-surface discharge. The last arrangement had a mini-mal effect on the ecosystem in terms of biological,chemical and physical changes in the lake compartmentstudied.

A second study examined the interaction oftemperature and nutrient enrichment on algal produc-tivity. In situ experiments, using heated water (5 to1C°C above ambient) were carried out in polyethylenecylinders inoculated with different concentrations ofnitrate and phosphate. Initial results show a signifi-cant increase in carbon production rates in algae sub-jected to a combination of nitrogen and phosphorus atelevated temperatures as compared to non-heated con-trol columns.

Another series of experiments examined the com-bined effects of temperature and arsenic on the growthof phyto- and zoo-plankton in Maskinonge Lake. Analysesto date indicate a detectable effect of arsenate onalgal productivity in heated water only when the arsenateion was present in a concentration of >300 yg/L. Analysesof these results are in progress.

- k2 -

3.3 BENEFICIAL USES OF WASTE HEAT - J.W. MeMahon, A.E.Docherty and S-R. Gentner

3.3.1 Polyculture of Fresh Water Organisms

A new project was initiated to study nutrientrequirements at different temperatures for the massculture of naturally occurring algae in MaskinongeLake water. Controlled experiments are being carriedout in large fibreglass tanks containing heated water.In one study nutrient-enriched water (nitrogen, phos-phorus and iron), at a temperature of 27°C, yieldedsignificant increases in algal production (1450 mg C/$n3-h) compared with 450 mg C/fa3.h) in unheated, nutrient-enriched water). Dominant algal organisms wereChroocoocus3 Microcystis, Synedra, Chlamydomonas andAnkistvode8mu8.

A large experimental culture tank (5 m diam. x1.5 m depth) has been erected near the heating faci-lity. Preliminary studies are concentrated on thethermorégulation of heated water supplied to the tankfrom the heat exchanger system. Problems have beenencountered with respect to dissolved oxygen concen-tration and sedimentation in the polyethylene culturecylinders placed in the tank. An air compressor iscurrently being installed to help minimize these pro-blems .

A small-scale plastic tubing apparatus has beenconstructed for the continuous growth of unicellularalgae. This is designed to permit the culturing ofdense suspensions of algae by providing maximum expo-sure of the algae to sunlight.

Considerable effort has been devoted to improve-ment of a recently developed technique for determiningbiomass by measuring adenosine triphosphate in livingorganic material. The pH of the "tris" buffer andstabilization time of the sample in the liquid scintil-lation counter are two critical factors in this pro-cedure .

- ii 3 -

3.4 EFFECTS OF TEMPERATURE ON ALGAE - J.W. McMahon andS-R. Gentner

Selected algal species were cultured in thelaboratory at 25, 30 and 35°C. Primary productionrates (as measured by l̂ C fixation) were optimal at25°C for Ankistrodesmus braunii, Chlorella vulgarissScenedesmus acuti form-is and S. bijugatus. Coelastrummiorosporum and Chamydomonas angulosa showed higherproductivity at 30°C. Correlation between carbonproduction rates and organic carbon content of algalcells was not consistent. Problems noted above inthe technique for measuring organic carbon mightexplain these discrepancies.

Studies are also being made of the effect oftemperature on the carbohydrate-protein compositionof six algal species grown at 20, 25 and 30°C. Theprotein-biomass ratio of Chlorella vulgar-is at 20°Cwas three times greater than the other algae. Aslight shift in protein-carbohydrate composition ofalgal cells occurred during the growth cycle. Asnumbers of cells increased in a fixed culture, pro-tein content increased slightly while the carbohydratecontent decreased rapidly.

Three genera: Ankistrodesmus, Coelastrum andChlorella show slight decreases in protein contentwhen grown at temperatures above 20°C.

3.5 BIOCHEMISTRY, BIOGEOCHEMISTRY AND MICROBÏAL ECOLOGY

3.5.1 Biogeochemistry of the Waste Management Area

3.5.1.1 Geochemistry^ General - D.R. Champ

During the past year the collaborative programwith R.E. Jackson (Environment Canada) and J. Gulens(General Chemistry Branch) has continued. The re-sults of analyses of ground water from the Perch Lakebasin have supported a number of predictions made bythe model that we have formulated for oxidation-reductionprocesses in ground water flow systems (see Section3.5.2, PR-B-112, AECL-5703). The data for the Perch

3.5.1.1 Geochemistry^_ General^ (cont'd)

Lake basin agrees with our closed system model; asground water moves downstream Eg decreases while pHincreases, dissolved O2 and NO3 concentrations de-crease, dissolved inorganic carbon increases andsulfate decreases. A slight increase in sulfide isobserved. The disappearance of sulfate and the ap-pearance of sulfide are presumably due to the presenceof sulfate-reducing bacteria which were found inground water samples taken from deeper piezometers.An increase in sulfide concentration corresponding tothe decrease in sulfate is not observed, presumablybecause of the precipitation of ferrous sulfide (theconcentration of iron decreases by an equivalentamount).

Samples taken from two sampling locations lastwinter suggested that only minor variations occur inthe ground water chemistry with the termination ofinfiltration of fresh water into the aquifer. Oneexception was an almost twofold increase in the dis-solved O2 concentration in the recharge area over theperiod. Seasonal changes in the ground water chemistrywill be more intensively studied during the comingwinter.

3.5.1.2 Organi£S_in GroundJWater - D.R. Champ andJ.L. Young

Dissolved organic carbons of 0.8 to 4 mg/L havebeen observed in the Perch Lake ground water flowsystem. This organic material may play an importantrole as reducing agents in the redox processes of thesystem, as metabolites for bacteria, as well as in thesolubilization and transport of many trace elements.These considerations have prompted us to examine tech-niques for more detailed analyses of the organic con-stituents. Fractionation of the organics by ultra-filtration through Amicon membranes with exclusionlimits of 500 to 100,000 (molecular weight) has beentried. Two possible difficulties with the procedureare evident. Leaching of organics from the membranesand cell components and adsorption of organics ontocell surfaces may occur. These membranes have beenused by others in a similar manner with surface waters,

- i.5 -

3.5.1.2 9_rg_an_i£s_in Ground_Water (cont ' d)

and to obviate the first problem they have washed themembranes with distilled water until there was no de-tectable absorbance at 200 nm. This endpoint is un-suitable for our requirements, since up to 0.4 mg/L oforganic carbon were still present in the ultrafiltrate— a very significant background in our studies. As aresult extra precautions are taken in the preparationof cells and filters and in determining backgroundvalues for each filtration operation. This fractiona-tion study is continuing. Preliminary results haveshown that: (1) a reproducible fraçtionation can beachieved, (2) the bulk of the organics have an apparentmolecular weight less than 10,000 and (3) recovery ofapproximately 65 to 80% of the original organic C isachieved. Losses are presumably due to adsorption.

3.5.1.3 Bacteria^ Pop_ulation£ in_Ground Water - D.R.Champ

Recent analytical efforts have shown the pre-sence of bacteria in the ground water of the PerchLake basin. This study served as a test for oursampling techniques, staining methods and microscopicprocedures. Some quantification of the aerobic andanaerobic components of the bacterial flora at variouspoints in the flow system was achieved. Wide variationsin the population density were evident. Colony andcell morphology indicated that quite a number of speciesare present. Further characterization of key speciesand metabolic capabilities is planned for the next fieldseason (summer 1978).

3.5.2 Operation of the Total Carbon System - D.R. Champ andJ.L. Young

The total carbon analyzer has seen increasinguse during the past year. The following analyses havebeen done :

(1) Organic and inorganic analyses for our owngeochemistry program.

3.5.2 Operation of the Total Carbon System (cont'd)

(2) Inorganic carbon analyses on ground waterobtained by K.E. Lyon and R.G. Roper(Queen's University). They are employinga coring and squeezing technique in orderto examine the chemistry of the ground wa-ters on a finer scale.

(3) Organic carbon analyses of water samplesfrom L.K. Hendrie's (Univeristy of Toronto)evapotranspiration site. The results haveshown that large amounts of organic materialare leached from tree surfaces by the flowof rain water down them. Organic carbonconcentrations of as high as 60 mg/L havebeen observed in stemflow water. Thequantity of organics leached appears tobe species dependent.

(4) Organic carbon analyses on water from thefeed water treatment system of the G.S.Mobile Pilot Plant. This cooperative ef-fort may continue in the future with alarge proportion of the preparative andanalytical work being handled by staff fromthe Chemical Engineering Branch.

3.5.3 Control Mechanisms in the Cellular Metabolism ofUstilago may dis - D.R. Champ and J.L. Young

Two glycoproteins from the smut fungus Ustilagomay dis have been isolated and partially purified.The isolation procedure involves crushing the cellsat high pressure, autoautolysis, salt fractionationwith ammonium sulfate, anion exchange chromatographyon DEAE cellulose, affinity chromatography on concana-valin A sepharose and heat treatment. Both glycopro-teins can solubilize large DNA molecules, with amolecular weight of 25.2 x 106, in dilute acid.

Characterization of the two glycoprotein frac-tions has shown that: (1) both require free sulfhydrylgroups for activity, (2) both are stable to boilingand active in the presence of high salt concentrations(0.5 M) and anionic detergents, (3) metal cofactors

3.5.3 Control Mechanisms in the Cellular Metabolism ofUstilacjo maudis (cont'd)

are not required for activity, (4) both form com-plexes with DNA which can be dissociated with alkalisuch that intact DNA molecules are recovered, (5) thefast sedimenting DNA-glycoprotein complexes may re-sult from the formation of DNA-glycoprotein-DNA com-plexes, (6) DNA breakdown does not occur followingcomplex formation, (7) they have molecular weightsof approximately 46,000 and 70,000 on the basis oftheir sedimentation coefficient in glycerol gradients,(8) no loss of activity occurs during disc gel electro-phoresis on polyacrylamide, (9) recoverable activityplus all carbohydrate staining material run togetheron the gels, (10) contaminating protein species arepresent in both fractions, as shown by other proteinbands on the gel which do not contain activity and(11) forty percent of the protein in the ASP I frac-tion and seventy percent of the protein in the ASP IIfraction are associated with the activity-containingglycoprotein band respectively.

3.6 AQUATIC RADIOECOLOGY AND FRESH WATER BIOLOGY - I.L.Ophel and J.M. Judd

3.6.1 Role of Organic Matter in Perch Lake

Work has continued on sediment samples fromPerch Lake. Ash from 1 cm sequential sections of an80 cm sediment core is being analyzed for individualinorganic elements. Previously, cation-exchangecapacities, using 60co as a tracer, were determinedfor each 1 cm section of the core as well as thetotal inorganic and organic content.

Cation-exchange capacities of soil and sedimentsamples from the Perch Lake area were determined forR.E. Jackson of Environment Canada.

3.7 ST. LAWRENCE RIVER STUDIES - I.L. Ophel

Studies related to the effects of cooling waterdischarged from the Gentilly Nuclear Generating Sta-tion on biota of the St. Lawrence River are beingcarried out by a group from the Université du Québecà Trois-Rivières under contract to AECL. The samegroup under the direction of Professor G. Vaillancourtis conducting related studies for Environment Canadaand for Hydro-Québec. Coordination of the studies isperformed by a committee chaired by Dr. G. Paterson(Environment Canada).

Earlier studies for AECL were concerned withdistribution and productivity of aquatic plants andof the associated epiphytic organisms and benthicfauna. Present research is a laboratory study of theeffects of elevated water temperatures on the compo-nents of a typical aquatic food chain. Observationsare being made on thermal tolerance, effects on growthand on behavioural responses of the organisms tosimulated effluent conditions.

3.8 PERCH LAKE PROJECT

3.8.1 Energy Budget and Lake Evaporation - P.J. Barry, E.Robertson and R.E. Légère

Temperature profiles of Perch, Maskinonge andUpper Bass Lakes were measured daily from springbreak-up to freeze-up which occurred in the thirdweek of November. This is the most complete andlongest period of continuous record so far obtained.In addition, both spatial and temporal temperaturedistribution in Perch and Maskinonge Lakes werestudied intensely during several periods of windyweather. These studies have given considerable in-formation about the mixing of heat and chemical con-stituents in the lakes.

3.8.1 Energy Budget and Lake Evaporation (cont'd)

Net radiation, incoming and reflected solarradiation have been measured continuously at bothPerch and Maskinonge Lakes. Wind speeds at the 10 mlevel have been recorded at all three lakes.

Six evaporation pans, three at each of Perchand Maskinonge Lakes were operated in cooperationwith the Atmospheric Environment Service of Environ-ment Canada. Previous experience has demonstratedthat pans sited over lakes give more realistic esti-mates of lake evaporation than pans situated on shore.The problem, however, is that pans on rafts spillwater during windy weather particularly on largerlakes. This year, one pan on Maskinonge Lake wasfitted with a thin, transparent plastic grid whichhas effectively reduced spillage. Although the pre-sence of the extra material may disturb the radiationbalance of the pan, comparisons of net evaporationfrom the gridded and regular pans showed that thedifferences were no greater than those for two regu-lar pans operated side by side. Since the periodssuitable for comparison were rather short due tospillage from the regular pan, further experiments areplanned for next summer.

3.8.2 Water Budget and Lake Chemistry - P.C. Jay

Tritium analyses of water from Perch Lake Outlet,Perch Creek Weir and No. 1 and No. 2 Inlets were con-tinued throughout the year. Composite water samplestaken from the same locations in early summer wereanalyzed for the major ions.

Dissolved oxygen profiles in the lake were re-sumed on a weekly basis when weather conditions per-mitted.

Water samples collected from seepage meterswere analyzed for tritium and major ions in coopera-tion with D.R. Lee of the University of Waterloo.

- 50 -

3.8.2 Water Budget and Lake Chemistry (cont'd)

Analyses of rain and snow samples from runofftraps were done in cooperation with L.K. Hendrie ofthe University of Toronto. Approximately 200 samplesof incident precipitation collected from rain waterflowing down the stems of trees were analyzed perevent for major cations and pH. Local incident preci-pitation has a pH of between 3.8 and 4.2 but afterflowing down the steins of some trees, particularlybirch and small-tooth aspen, the pH is significantlychanged. Stemflow from birch has a reduced pH of 3.0and that from small-tooth aspen has an increased pHof 6.8 to 7.2 The concentration of calcium andmagnesium ions increased significantly in stemflowwater particularly that from the small-tooth aspen,e.g. calcium concentration is between 30 and 40 mg/Lcompared to that in incident rain of less than 1tng/L.

3.8.2.1 Perch Lake_Models_ - P.C. Jay and P.J. Barry

Two scale models of the disposal area north ofPerch Lake were completed. One model shows surfacetopography, underground sampling points and piezometernests from Disposal Area "A" to Perch Lake Outlet.A second model shows the stratigraphy of the same areaand the location of underground radionuclide plumes.

3.8.2.2 Snow_Course - P.C. Jay, D.P. Wildsmith andF.J. Barry

Two snow courses were cut through the forest.The weight and depth of snow are measured every twoweeks at various sampling points to estimate springrunoff from the various drainage areas into Perch Lake.

3.8.3 Data Storage - D.P. Wildsmith

Card punching of soil temperature data for1976 is now complete and card processing of 1977 datahas begun.

- 51 -

3.8.3 Data Storage (cont'd)

Wind speed and direction data from Perch Lakefor 1977 is on punched cards.

The Perch Lake Inlet and Outlet stream flowdata for the period January 1977 to August 1977 hasbeen received from Water Survey of Canada of Environ-ment Canada.

3.8.4 Snowme1t_Studies - P.J. Barry, R.E. Légère and E.Robertson

In late October, A, Wankiewicz of the InlandWaters Directorate of Environment Canada installed72 sensors to measure soil temperatures. These areon the east side of Perch Lake and within the experi-mental area already being used for similar or relatedstudies by collaborators from the Universities ofToronto and Waterloo. The array of sensors is de-signed to determine the effects of terrain, slope,proximity to trees and exposure on soil frost penetra-tion. These studies are aimed at improving estimatesof snowmelt infiltration and runoff in spring for usein a flood prediction model for the Ottawa River.Soil temperatures are read twice-weekly by CRNL staffthroughout the winter though it is expected that morefrequent readings will be taken during the snowmeltperiod.

L.K. Hendrie and A. Price of the University ofToronto have installed two snowmelt plots in the samearea. Both plots are 5 m square, one is open at thebottom while the other is completely lined with poly-ethylene. Underground collecting systems have beenbuilt to meter the rates of water runoff from theplots; that for the plot lined with polyethylene isdesigned for continuous recording of water flow,while the other will be metered manually. Snow depthsand water equivalents in snow cores are measured twice-weekly at the times soil temperatures are measured.

- 52 -

3.8.4 Snowmelt Studies (cont'd)

Three devices for the non-destructive measuringof water equivalent in the snow pack are being builtfor installation in the region of the snowmelt plots.These consist of a 41 mCi* o^Co source placed on theground and a metal frame for exactly locating a radia-tion detector relative to the source at a height of1.5 m above the ground. During the snowmelt period,the intensity of the source should make it possible toestimate the water equivalent during an hour's observa-tion period.

3.8.5 Simulation Modelling of Perch Lake Streams and GroundWater Flow Rates - P.P. Wildsmith and P.J. Barry

Simulations of water flows for streams enteringPerch Lake from 1969 to 1976 have been run by S-Y.Shiau of the Inland Waters Directorate of EnvironmentCanada. These consistently overestimate the flowsfrom sub-basin 5 and underestimate those from sub-basin 4. A program to investigate the causes of thesediscrepancies has been submitted to CRNL by Environ-ment Canada.

One possible cause is that ground water is flow-ing from basin 5 into basin 4. It is also known thatthe 1958 topographic map of the area is seriously inerror while the most recent map (1973) does not includebasins 3 and 4. An extension of the 1973 map to in-clude these areas has been ordered.

3.8.6 Transfer and Deposition of Atmospheric Sulphur - P.J.Barry

A study of atmospheric sulphur transport and de-position has been proposed by the Atmospheric Environ-ment Service (AES) of Environment Canada, with a moni-toring station to be installed at the extreme northend of the Perch Lake basin. A cooperative agreementbetween CRNL and AES for the installation and operationof the station was approved late in the fall. Unfor-tunately, unusually early heavy snowfalls and very coldweather intervened before the site could be prepared.However, a partial program of snow sampling and analysiswill be implemented early in the new year.

9*41 mCi = 1.52 x 1(T Bq

- 53 -

3.8.7 Symp os ium/Work shop - P.J. Barry

A two-day meeting was held at CRNL in Januaryfor scientists collaborating in research studies inthe Perch Lake basin. It was attended by 41 partici-pants from AECL, Environment Canada, Queen's Universityand the Universities of Toronto and Waterloo. Shortprogress reports on current research were given andfuture programs were discussed.

3.9 ATMOSPHERIC DIFFUSION STUDY - P.J. Barry and D.P.Wildsmith

This study was terminated as of 1 January 1977.The data gathered during the eight years will continueto be analyzed and interpreted.

3.10 STACK ARGON MEASUREMENTS - D.P. Wildsmith and P.J.Barry

In cooperation with reactor personnel, monitor-ing of the stack argon releases were continued. Theresults of the monitoring during 1977 are given inTable I. The time of sampling given is eastern stan-dard time.

TABLE I. 41Ar Releases from Main Reactor Stack 1977

SamplingDate

11 Jan.

14 Jan.

18 Jan.

26 Jan.

28 Jan.

1 Feb.

10 May

19 May

17 June

27 Oct.

3 Nov.

Time

10:26-10:30

10:20-10:24

09:45-09:49

11:37-11:41

09:14-09:18

13:19-13:23

11:38-11:42

09:43-09:47

10:01-10:05

09:00-09:04

09:03-09:07

Ci-d-1

6123456

5184

4469

4539

3835

4234

5126

4935

5242

953

NRUmegawatts

9093

C02 (L-s*1)

2.5nil

not operating

8085

2.52.5

not operating

not operating

fluctuating conditions

10096110

2.52.52.5

NRXmegawatts

not operating

not operating

2828282827272727

not operating

-e-

1 Ci = 37 GBq

- 55 -

3.11 SNOWMELT AND EVAPOTRANSPIRATION IN A FORESTED CATCH-MENT - L.K. Hendrie

The data bank for the snowmelt section of thisexperiment has been examined, spurious values removedand hourly averages computed. Data collected for theevapotranspirational phase, as outlined in the pre-vious progress report, has continued throughout thequarter. The continuous monitoring of the meteorolo-gical parameters influencing evapotranspiration fromthe forest has been complemented by detailed dailyanalyses of the proportioning of precipitation, andregular examination of soil moisture, ground watercharacteristics and stomatal resistances measured witha diffusion porometer.

In conjunction with Dr. A. Price, University ofToronto, further investigation of the energy exchangesinvolved during snowmelt in the forested Perch Lakebasin will be undertaken in 1978. Towards this end anadditional site including a fully lined 25 m2 runoffplot has been prepared.

Stemflow from a variety of species, throughfall,surface runoff and precipitation in the open have beensampled for a number of major precipitation events,and in conjunction with P.C. Jay and other Branch membersare being analyzed for major cations and anions. Inter-esting changes in pH and considerable enhancement ofconcentrations of calcium and magnesium (in particular)have been detected.

To further investigate the mechanisms involvedsamples have been collected and analyzed followingtwo rainfall simulations; the first with distilledwater (pH ~ 6), and the second with acidified distilledwater (pH s 3).

- 56 -

3.12 NEUTRON ACTIVATION ANALYSIS - W.F. Merritt

Six samples of a long core taken from a peatbog in England were analyzed for a number of elementsand the results sent to the Department of EarthSciences of the University of Waterloo. Samples ofleachate from a variety of soil types were analyzedfor several trace elements, particularly Cs, Co, Srand Ba, in collaboration with R.W. Gillham of theUniversity of Waterloo.

A sample of ground water from the Perch Lakebasin was partitioned through membranes which sepa-rate organic constituents according to molecularweight. The various fractions were analyzed fortrace elements to see if any were preferentially as-sociated with a particular organic fraction. Resultswere inconclusive.

3.13 WASTE MANAGEMENT AREAS

3.13.1 Soil and Ground Water Sampling - W.F. Merritt andB.A. Risto

Soil and water sampling was carried out aroundthe reactor and chemical pits in the liquid wastemanagement areas and a series of wells for watertable measurement and ground water sampling were in-stalled. When sufficient data has been collected areport on the existing distribution of radionuclideswill be prepared.

A series of piezometers and wells for groundwater velocity measurements were installed in theswamp to the west of Waste Management Area "F", wherethe wastes from the Port Hope and Ottawa clean-upsare being emplaced. A report from the geological con-sultants indicated that any leachates from the wasteswould travel rapidly in this direction. The drillingresults indicated a complicated geology, with claylayers separating sand aquifers and widely varyingground water velocities in different aquifers. Rhoda-mine B solution was injected into two wells in Area"F" proper and water from various sites in the proposed

- 57 -

3.13.1 Soil and Ground Water Sampling (cont'd)

drainage area is being sampled and analyzed fluoro-metrically to estimate the travel time to the nearestsurface water. A weir to measure the flow from thedrainage basin was installed in the creek upstream ofthe culvert under the plant road. No dye has beendetected to date. The assistance of a hydrologisthas been requested from the Research Division of InlandWaters Directorate of Environment Canada to aid in in-terpreting the results and assist in planning morework in the area.

Undisturbed core samples from the front of thecesium plume of the 1954 test disposal were obtainedfor pore water chemistry investigation and for thedetermination of distribution coefficients (Kd) for90Sr and 137cs. Wells, piezometers and water samplerswere installed in various parts of the waste managementareas as required.

A series of soil sanmles of the plume from the1954 test disposal was supplied for plutonium analyses tothe group under A. Friedman at Argonne National Labor-atory. Previous samples taken in 1976 indicated thatsome plutonium had probably migrated at least 20 mfrom the disposal pit.

Plans are under way to recover a nepheline-syenite glass block containing fission product wastefrom the first test disposal site. The blocks havebeen located and a detailed sampling program will becarried out before a single block is exhumed nextspring. Handling equipment is being designed.

3.13.2 Investigation of Rod Bay Leakage - W.F. Merritt andB.A. Risto

Soil samplers were driven horizontally underthe Building 204 rod bays in the hope that the samplesmight pinpoint a suspected leak. Unfortunately, thesamplers had to be driven through a clay layer whichpacked into the sampling slots and blocked them.Consequently, only very small samples were recoveredif at all. Cesium-137, 9°Sr and 1Z3Sb were detectedin the samples in small amounts.

- 58 -

3.13.3 Arsenic in Environmental Samples - I.L. Ophel andJ.M. Judd

Attempts to utilize flameless graphite furnacetechniques for the determination of arsenic in en-vironmental samples were unsuccessful. The I.L. 445flameless atomizer, with pyrolytic graphite furnace,was tried using several different atomization programsbut reproducible results were unobtainable. Thesystem was eventually abandoned. The method finallychosen was one in which arsine gas, generated byNaBH4 added to the dissolved sample, is passed througha heated quartz tube located in the optical path ofthe atomic absorption spectrophotometer. Using thismethod reproducible results were readily obtained.Response to various concentrations of arsenic islinear from 0 to 100 ng As/mL. Repeated analysis of100 ng As/mL standards gave a standard deviation of± 2.5 ng As/mL and the lowest detectable amount is1 ng As/mL.

Background water samples from Toussaint Lakeand Chalk Lake showed less than 1 ng As/mL as didseveral other surface water samples from locationsnear Waste Management Area "F".

Leaching experiments were carried out on con-taminated soils from Ottawa and Port Hope. Prelimi-nary experiments indicate that less than 1% of thearsenic contained in Port Hope and Ottawa wastesstored at Waste Management Area "F" is lost whenleached for 48 hours with a dilute acid (0.1 N) solu-tion. Leaching by rain water will also be investigated.

Arsenic measurements of water samples were donefor J.W. McMahon and assistance was given to L.M.Johnston of the Inland Waters Directorate of Environ-ment Canada in building a similar arsenic analyticalsystem for their Ottawa laboratory.

* 59

3.13.4 Stabilization of Ferro-Niobium (Columbium) Wastes -L. Tremblay and I.L. Ophel

Ferro-niobium (columbium) waste material fromsites in Ottawa has been delivered for disposal atCRNL. These wastes contain low concentrations ofthorium and radium and high levels of other metals.A research program is being conducted to determinemethods for permanent stabilization of these wastes.

Growth rate experiments on various concentrationsof the wastes using radish (Raphanus sativus), turnip(Brassiaa napus), rye (Seoale oereale), timothy(Phleum pratense) , Red clover (Tri.folium pratense)and Bird's foot trefoil (Lotus aovnioulatus) showthat growth rate in the 100%* waste concentration isseverely retarded.

However, the results of nutrient tests usingradish suggest that plant growth on the wastes willimprove with proper fertilization; though there isstill a statistically significant difference betweenthe growth rate in fertilized 100%* concentration ofwastes and the control soil.

A comprehensive literature survey is completedand a report is in preparation.

3.14 COOPERATION WITH OUTSIDE ORGANIZATIONS

3.14.1 Cooperation With Universities

3.14.1.1 Uniyersity of Waterloo^ General - W.F.Merrïtt and" B.5. Ris to

A successful hydrogeological field school washeld 3-9 May 1977 in cooperation with the Departmentof Earth Sciences, University of Waterloo. Thisyear academic credit was given to participants. TheCRNL drilling crew demonstrated various ground waterand soil sampling techniques in routine use for under-

*1007o waste refers to the waste material as received at CRNL

- 60 -

3.14.1.1 Uniyersity_of_ Waterloo _̂ General (cont'd)

ground monitoring of radioactive wastes. Demonstra-tions of the point dilution technique for ground wa-ter velocity measurements were given using both radio-active and specific-ion electrode techniques. Streamgauging using fluorescent dyes was added to thecurriculum this year.

Fundamental studies in ground water dispersionare continuing at "0" nest in cooperation with J.F.Pickens of the University of Waterloo. In the latestexperiment ground water labelled with 131i was pumpedinto an upstream well to create a marked cylinder ofwater around the well. A downstream well was subse-quently pumped to the breakthrough curve obtained.Movement of the tracer was monitored using the inter-vening multi-level samplers. The results are beinganalyzed. A closer network of multi-level samplershas been installed so that dispersion may be studiedunder natural rather than enhanced flow conditions.

In collaboration with J.A. Cherry, Universityof Waterloo, the ground water velocity in the leachateplume from the Camp Borden (Armed Forces Base) sani-tary landfill site was measured by point dilution us-ing 131i a s a tracer. The results agreed with moreconventional methods but are obtained much morequickly. The study was licensed by the Atomic EnergyControl Board and only 30 yCi (1 MBq) of 131i w asused for the study. This quantity could be furtherreduced using a more sensitive detector in the appar-atus.

3.14.1.2 Uniyersity_of Waterloo_Contrac£ - P.J.Barry

Three projects are proceeding under this con-tract. These are:

(1) A study of isotopic mixing in the soilwater of the unsaturated zone.

(2) A study of dispersion in a shallow sandyaquifer in an area between Disposal Area"A" and Perch Lake.

3.14.1.2 University_of Waterloo_Contract (cont'd)

(3) A study of the transport of conservativesolutes into Perch Lake from the groundwater and of the effects of phreatophyticpumping, seasonal recession of base-flow,precipitation events and changes in lakestage on ground water discharge into thelake.

Several field experiments were carried out dur-ing the summer and fall on each of these projects.Results from these experiments are still being analyzed.

3.14.1.3 Queen/£ UniversityjContract^ - W.F. Merritt

The group from Queen's University under R.J.Patterson spent the summer taking samples of localsands and soils, "squeezing" them to extract thepore water and carrying out field measurements of ERand pH. Both water and soil samples were preservedfor further analysis at the university. Water willbe analyzed for elemental content by atomic absorp-tion spectre-photometry. The surfaces of the soilparticles will be examined by X-ray diffraction andoptical microscopy, and surface layering by scanningelectron microscope.

A survey of the Pleistocene geology of theCRNL outer area carried out during the summer hasconsiderably expanded our knowledge of the processesinvolved in its geological history.

3.14.2 Rain Sampling Program in Cooperation With CanadaCentre for Inland Waters - P.C. Jay

A rain sampling program which was started inthe spring has been completed. A special rainsampler and collector were installed at Perch Lakemain site in cooperation with W.M.J. Strachan ofthe Canada Centre for Inland Waters of EnvironmentCanada. An earlier sampling program in the GreatLakes region had revealed the presence of polychlori-nated biphenyls (PCBs) and pesticides in rain. Theprogram was therefore extended to more remote areasto obtain background levels of these compounds.

- 62 -

3.15 CONTAMINANT HYDROGEOCHEMISTRY - R.E. Jackson and K.J.Inch (See also Section 3.5.1)

The measurement of hydrogeochemical parametersin the lower Perch Lake basin involves three generalsteps — field measurement, sample preservation andanalysis. In the field, following the measurement ofground water temperature, dissolved oxygen and specificelectrical conductance, electrode measurements of pH,Eu and sulphide are taken using air-tight flow cells.The ground water is collected in a 600 mL Milliporelucite sampler and filtered in a nitrogen environment.Alkalinity, dissolved organic and inorganic carbon aredetermined immediately and the filtrate (acidified andnonacidified) is preserved at 4°C for the remainingion analyses. This year the samples will be analyzedfor their trace elements (by L.M. Johnston, Environ-ment Canada, Ottawa).

The 1975 water quality data were analyzed usingthe WATEQ computer program to assess geochemicalchanges in the ground water and the dissolved contami-nants in the lower Perch Lake basin. An examinationof the data shows that the ground water of the sandyaquifer system of the lower Perch Lake basin is con-taminated with acid precipitation, road salt and ra-dioactive wastes. The attenuation of each is a func-tion of ion exchange, oxidation-reduction and solu-bility processes. A general conceptual model of thesediagenetic processes has been developed and is nowbeing tested for :

(1) oxidation of organic matter

(2) hydrolysis of silicate minerals

(3) precipitation of carbonates and silica.

Sediment cores were taken from soil contaminatedby the 90sr and 137cs plumes originating from the 1954and 1955 experimental disposals in Perch Lake basin.Considerable difficulty was experienced in obtainingundisturbed cores due to the nature of the cable-tooldrilling. It is intended to redesign the soil samplerin the hope of obtaining better samples.

- 63 -

3.15 CONTAMINANT HYDROGEOCHEMISTRY (cont'd)

Sediment from the cores and associated groundwater (obtained by centrifugation of 60 mm of core)were analyzed for the distribution coefficient of90sr and 137cs, cation exchange capacity, sedimen-tary organic matter and mineral composition.

Mineralogical examinations of the sand fractionfrom the stratigraphie units under the basin werealso made. The extent of in situ weathering of thesediments is of considerable importance. The absenceof kaolinite and presence of hornblende in these samplessuggest little geochemical weathering.

Methods for sampling, preservation and analysisof contaminated waters have been developed and arepresently being tested.

A new sampling program has been started toexamine changes occurring in the ground water flowsystem throughout the year. Piezometers are beingsampled on a monthly basis and will be more frequentlysampled during spring recharge. These ground watersamples will be analyzed for both major and trace ions.

3.16 ISOTOPE EVAPORATION STUDIES - R.M. Brown, CD. Fraserand G.M. Allison

Evaporation pans of 1 m diameter with startingvolumes of 20 and 40 L were operated on the Perch Lakeraft, on the shore of the lake and in the forest inthe east basin during the 1977 field season. It washoped to obtain 6 , the heavy isotope concentrationattained as V -»• 0, and m, the relative rate of iso-tope enrichment, from long evaporation runs in pansprotected from rainfall by a canopy. These parametersare then used to deduce ôg, the heavy isotope concen-tration of water evaporating from a nearby lake, whichis usually required in isotope water balance studies.

In practice, humidity changes disrupted mostruns, preventing the obtaining of meaningful measuredvalues of 6 and m. However, one period of stablemeteorological conditions did yield significant values

3.16 ISOTOPE EVAPORATION STUDIES (cont'd)

of m which could be compared with values calculatedfrom the theoretical approximation:

where h = mean daily relative humidity

E = isotopic enrichment factor

Ae = kinetic component of e.

This comparison indicated that it was better to usethe free air relative humidity in this equation thanhumidity normalized to the temperature of the wateras is usually done.

Using m calculated from Equation (2) and theisotope concentration-volume relationship:

Ô - S /s - m (2)6o "

<SS and hence fig were obtained on a day-to-day basisand the seasonal trend as indicated by the differentpans observed.

In order to avoid the difficulty of estimatingSs in Equation (2), we have exposed pairs of pans, oneof which was modestly spiked (<5D of +?.00°/ ). Thedifferences in isotope concentrations between two suchpans may be used to deduce m without requiring a pre-liminary estimate of 6S. This gave significant valuesof m for relatively short evaporation periods andlooks quite promising. Again, measured values of mcorresponded more closely with m calculated from freeair relative humidity than with m calculated from nor-malized humidity.

- 65 -

3.17 INFILTRATION STUDIES ON THE EAST SIDE OF PERCH LAKEBASIN

3.17.1 Natural Infiltration - R.M. Brown and CD. Fraser

Suction lysimeters at the non-vegetated in-filtration site were activated in March at the be-ginning of the snowmelt period. The evolution ofthe concentrations of tritium and deuterium in thenatural infiltration waters was followed until Julywhen the site was used for the following slug-infiltration experiments.

3.17.2 Artificial Flooding Experiments - R.M. Brown, H.Vandor, R.W. Gillham* and G.B. Allison

Two infiltration experiments involving artifi-cial flooding of a 7 x 7 m plot with 40 L/mZ waterwere performed in July and August 1977. Water of thefirst experiment was labelled with a tritium contentof 50,000 Tritium Units (TU) while the second floodwater, applied two weeks later, was Ottawa Riverwater containing 150 TU. Passage of the water im-pulses through the system was monitored by neutronmoisture gauge scanning and tensiometer readings(University of Waterloo personnel) and micro-wavedielectric scanning (Geological Survey of Canadaand Agriculture Canada personnel).

Water samples for isotope and chemical analysiswere obtained from suction lysimeters at variousdepths in the unsaturated zone. This sampling wasnot very satisfactory in that it produced small amountsof water which were sensitive to cross contaminationby previous samples left in the lines or cups. Theactual sampling time was indefinite since the rate offilling of the lysimeter cups was unknown and depen-dent on the soil moisture content.

*Dept. of Earth Sciences, University of Waterloo

- 66 -

3.17.2 Artificial Flooding Experiments (cont'd)

Soil cores of 5 cm diameter were taken periodi-cally after each flooding by driving thin-wall alumi-num tubing into the ground with a jack hammer. Waterwas recovered from 20 cm sections of each tube by asqueezing-displacement technique or by azeotropicdistillation with toluene.

In each experiment, the water table respondedwithin a few hours of the flooding. In the firstexperiment, the tritium front moved down to a depthof 60 cm within eight hours, where it remained untildisplaced a further 60 cm by incoming water of thesecond flooding two weeks later. The site was coveredwith plastic sheeting between floodings.

Further analyses of tritium, deuterium andoxygen-18 and interpretation of the results are underway.

3.18 T/D AND OXYGEN-18/OXYGEN-16 RATIOS IN THE BRUCE HEAVYWATER PLANT - R.M. Brown

The relative distributions of hydrogen andoxygen isotopes in the Bruce Heavy Water Plant duringnormal operation in June 1977 are shown in Table II.Oxygen isotope analyses were done by the Departmentof Earth Sciences, University of Waterloo. Precision(1 a) of these was 2 x 10-7 for the first four samples,3 x 10~5 for the last two where dilutions were neces-sary.

Environmental tritium is enriched in the plantmuch less efficiently than deuterium. In going from0.015 to 9.9 mole % D2O in the H2S-H2O process, tri-tium is depleted relative to deuterium by a factorof 23. In the final distillation step, tritium isenriched relative to deuterium by a factor of 1.25.(Factors two-fold higher than these were given inSection 3.15, PR-B-115, AECL-6082, in anticipationof 20% rather than 10% D20 in the product of the GSprocess.)

TABLE II. Relative Distribution of Hydrogen and OxygenIsotopes in the Bruce Heavy Water Plant. June 1977

00

Water Sample

Feed Water (LakeHuron)

1st GS StageProduct

2nd GS StageProduct

3rd GS StageProduct

DistributionUnit Product

FlF2

Tritiumf̂ f\Y\ f* O n f* IT £k t* 1 fiYlWVJllWs-J.ll.i. CIL. .LUil

(Bq/L)

16.3 ± 1.3

48.2 ± 1.2

158 ± 4

468 ± 6

5868 ± 60

5832 ± 60

D/(H + D)

0.0001484

0.00054

0.0038

0.0988

0.995

0.996

Atom Ratios

T/D

91.6 x 10"14

74.4 x 10"14

34.8 x 10"14

3.93 x 10"14

4.97 x 10"14

4.94 x 10"14

18o/16o

1.9907 x 10'3

1.9886 x 10"3

1.9814 x 10"3

1.9655 x 10"3

4.043 x 10"3

3.580 x 10"3

o

§ ^rt oo

1f-t

o

11 Ci - 37 GBq

- 68 -

3.18 T/D AND OXYGEN-18/OXYGEN-16 RATIOS IN THE BRUCE HEAVYWATER PLANT (cont'd)

Oxygen-18 shows slight but consistent depletionrelative to oxygen-16 through the HgS-HÔ process andsignificant enrichment in the distillation stage.

3.19 MIXING OF MELT WATERS WITH SEA WATER IN AN ARCTICFJORD - R.M. Brown

Variations of deuterium and tritium concentra-tions through eight depth profiles in the d'lbervilleFjord, Ellesmere Island (8035 N, 7900 W) give informa-tion on the mixing of snowmelt runoff waters with seawater in the fjord. The Frozen Sea Research Group ofEnvironment Canada is correlating the isotope datawith salinity, temperature, density and hydrographiemeasurements made at the time of sampling.

3.20 ISOTOPIC COMPOSITION OF PRECIPITATION ACROSS CANADAR.M. Brown and CD. Fraser

Analysis of the tritium and deuterium contentof monthly composite samples of precipitation fromnine sites across Canada continues. Data will bepresented when results for the whole year are avail-able.

3.21 D/H ANALYSIS OF SMALL WATER SAMPLES - R.M. Brown

The CRNL-designed inlet system of our massspectrometer normally operates on a flow system re-quiring a water sample of at least 20 mL. W.M.Thurston (General Chemistry Branch) has developed atechnique of evaporating a sample into the inletsystem from a few milligrams contained in a glasscapillary tube. Reproducibility from tube to tubewas limited to ± 1 ppm due to sensitivity to differ-ences of inflow rates from various tubes. Attemptsto obtain uniform evaporation rates from differenttubes were successful. However, it has been found

3.21 D/H ANALYSIS OF SMALL WATER SAMPLES (cont'd)

that the sensitivity to inflow rate variations canbe greatly reduced by critical adjustment of thedamping on the Mass 3 pre-amplifier. A precision of± 0.1 ppm can now be obtained on a 25 yL sample.

3.22 ENVIRONMENTAL IMPACT ASSESSMENT - I.L. Ophel

The present task of the Environmental Protec-tion Working Party (EPWP) is to assist other workinggroups responsible for environmental impact assess-ment of proposed and existing AECL facilities. TheEPWP will provide generic procedures and the database to enable the calculation of radiation doses toman resulting from exposure to radioactive wastesdischarged during the operation of these facilities.

3.23 GAMMA EXPOSURE RATES AT THE CRNL BOUNDARY - W.E.Grummitt, G. Lahaie and L.A. Mask

TLDs placed at the perimeter of the CRNL exclu-sion area are used to measure mean exposure rates andthe annual integrated exposures. Results in TableIII give the sum of contributions from CRNL and naturalgamma radiation. Values are lower during the wintermonths because of shielding of the terrestrial compo-nent of the snow cover.

- 70 -

3.23 GAMMA EXPOSURE RATES AT THE CRNL BOUNDARY (cont'd)

TABLE III. TLD Gamma Exposure Rates in Public Area*(yR/h)

Location(See Figure 3)

12

345

678

13Harrington Bay**

Deep River

Third Quarter1977

9.56.1

3.54.810.0

3.95.38.38.76.03.5

1976Average

10.4

5.4

4.35.94.85.4

5.47.98.56.66.2

1975Average

13.8

8.45.38.46.9

6.38.711.3

10.6

9.39.8

*Sum of natural background and airborne contamina-tion from CRNL. The contribution from cosmic ra-diation has been deducted. In 1977 a change inthe method of estimating the cosmic contributionresulted in lower totals at all stations (-1.9 pR/h)

**Harrington Bay, P.Q., 11 km east from plant stack.

3.24 OFF-SITE MONITORING - W.E. Grummitt, G. Lahaie, H.M.McLaughlin and L.A. Mask

Precipitation samples collected at Deep Riverwere analyzed radiochemically for 90gr and spectro-metrically for 137cs and other gamma emitters.Monthly composite samples of water from the OttawaRiver, collected at Rolphton, Deep River, Pembrokeand CRNL, were also analyzed for gamma emitting nu-clides, tritium and 90sr. The results are shown inFigure 1. The main source of activity in these sam-ples continues to be weapons' fallout.

- 71 -

3.25 LIQUID EFFLUENT MONITORING - W.E. Grummitt, G. Lahaie,H.M. McLaughlin and W.J. Pierson

At CRNL, three liquid effluent streams dischargeradioactivity to the river from the inner area. Theyare the Process and Sanitary Sewers plus the 04 StormSewer combined with 04A seepage. Each of these issampled regularly and is analyzed for individual nu-;elides. The mean daily releases from the Process Sewerare given in Table IV for the third quarter of 1977.Most of the radionuclides are measured by gamma rayspectrometry.

TABLE IV. Mean Daily Release from the Process SewerThird Quarter 1977

Radionuclides

90sr

137cs

144Ce

106R U

l40Ba131X

239Np

95Zr

54Mn

46sc

59Fe

65Zn

60Co

Daily ImCi/d

7261191017092941609109142

leleaseMBq/d

2609504400

3606270

3420

3460

5970

35036034053075

- 72 -

3.25 LIQUID EFFLUENT MONITORING (cont'd)

Perch Creek (see map, Figure 3), draining PerchLake and Disposal Areas, also flows into the riverand is sampled regularly. The total amount of radio-activity discharged from CRNL per day is calculatedfrom the measured flow rates and radionuclide concen-trations in individual streams (see Figure 2).

At no time did the average concentrations ofradioactivity in the combined effluent flows exceed1% of the ICRP*40-hour occupational MPCtfor drinkingwater.

3.26 LIQUID DISPOSAL AREA - W.E. Grummitt, G. Lahaie andL.A. Mask

Weekly samples and flow readings were taken atweirs on the surface streams carrying contaminatedseepage water from the Liquid Disposal Area into Perchand Maskinonge Lakes (see map, Figure 3). Sampleswere combined and analyzed monthly for 90sr, 35s and3H as well as quarterly for gamma emitting radionu-clides. Strontium-90, 60Co and 3H are still the maincontaminants in the Perch Lake basin.

3.27 GAMMA EXPOSURE RATES IN THE EXCLUSION AREA - W.E.Grummitt and G. Lahaie

Shielded (indoor) and unshielded (outdoor)gamma ray exposure rates in the CRNL exclusion areaare given in Table V. The reduction in exposure rateobserved in Bldg. 513 is due to shielding from 35 cmof concrete in the floors above the detector.

*ICRP - International Commission for Radiation ProtectiontMPC - Maximum Permissible Concentration

- 73 -

3.27 GAMMA EXPOSURE RATES IN THE EXCLUSION AREA (cont'd)

TABLE V. TLD Gamma Exposure Rates in Exclusion Area*1977 R"7fi)

Location(See Figure 3)

9

11

9 office**

FirstQuarter

39

14

24

SecondQuarter

26

8.3

12

ThirdQuarter

18

9.2

30

1976Average

27

13

16

*Sum of natural background and airborne contamina-tion from CRNL. The contribution from cosmic ra-diation has been deducted. In 1977 a change inthe method of estimating the cosmic contributionresulted in lower totals at all stations (-1.9 pR/h)

**First floor office in Bldg. 513. Shielding factorfor 4lAr gamma ray is -12. Background in the roomdue to brick and concrete construction materials is13 yR/h.

3.28 MONITORING OF LAND GAMMA BACKGROUND RADIATION - W.E.Grummitt, G. Lahaie and L.A. Mask

Land gamma surveys were carried out in therestricted area of CRNL and on Highway 17 up to 30 kmfrom the village of Chalk River, using a sensitiverecording instrument mounted on a vehicle. The re-sults in the restricted area are affected by the pre-sence of known radiation sources in storage or intransit. Surveys of the plant road, and the PortHope waste area bypass road during 1977, showed nochanges in exposure rates over the period of measure-ment (TABLE VI).

3.28 MONITORING OF LAND GAMMA BACKGROUND RADIATION (cont'd)

TABLE VI. Land Gamma Surveys at CRNL*(yR/h)

Public AreaChalk River to PetawawaPetawawa to PembrokeChalk River to Deep River

Restricted Area1 Active Area2 Inner Area3 Outer Area

Main Stack RoadMattawa Road eastMattawa Road westPlant Road, main gateto C2

Plant Road, C2 toHwy. 17

C2 Fire TrailSandpit RoadPort Hope waste areabypass road

Average Gamma Radiation

1976

8.79.57.9

37.012.0

12.07.16.717.0

7.8

5.56.87.1

1977

6.58.17.5

59.012.0

12.06.97.215.0

7.7

6.16.97.0

*The contribution from cosmic radiation has been de-ducted .

3.29 EXAMINATION OF SAMPLES OF CONTAMINATED SOIL - W.E.Grummitt and G. Lahaie

At the request of the Atomic Energy ControlBoard, 28 soil samples were analyzed for 226Ra,222Rn daughters, 232Th, 228xh and 227AC. The sampleswere collected in Ontario at Port Hope, Elliott Lakeand Ottawa (Albion Road, Rideau Road and Masterloysites), and at Uranium City, Saskachewan. Radiumconcentrations were in the range 0.5 to 2060 pCi/g*with most samples being in the low range.

*0.02 to 76 Bq/g

- 75 -

3.29 EXAMINATION OF SAMPLES OF CONTAMINATED SOIL (cont'd)

Assay of a composite representative sample ofmaterial deposited during 1976/77 in Area "F" at CRNL(Port Hope Disposal Area) gave an average value of40 pCi*22o£a/g Local soils contain approximately0.3 pCit226Ra/g.

3.30 TRITIUM SURVEY - W.E. Grummitt and G. Lahaie

Average concentrations of tritium in streamswithin the exclusion area are given in Table VII to-gether with the amount released during the thirdquarter of 1977.

TABLE VII. Tritium in Streams in the Exclusion AreaThird Quarter 1977

Process SewerSanitary Sewer04 Storm Sewer(plus 04A)

Perch CreekDuke Stream*

ConcentrationviCi/L

0.0250.009

0.043

0.0754.9

kBq/L

0.92

0.34

1.6

2.8180.0

Quarterly ReleaseCi

320

0.6

16.0

5.564.0

GBq

1.2 x 10*

23

590

2002400

*Duke Stream discharges into Maskinonge Lake; allother streams flow directly to the Ottawa River.

3.31 SURVEY SUMMARY - W.E. Grummitt and G. Lahaie

No significant contamination of the environmentresulting from operations at CRNL has been detectedin these surveys.

*40 pel = 175 BqtO.3 pCi = 0.01 Bq

- 76 -

3.32 PUBLICATIONS

BARRY, P.J. (Ed.)- Hydrological and geochemical studiesin the Perch Lake basin: A report of progress. Proc.of a Symposium/Workshop held at Chalk River NuclearLaboratories, 12-13 January 1977. AECL-5836*

BARRY, P.J. and E. ROBERTSON. Water and energy budgetsof lakes in the Chalk River area, pp. 140-143 in 2ndConf. on Bydrometeorology. American MeteorologicalSociety, Boston, Mass., U.S.A.

BROWN, R.M. Tritium distribution in trees in the PerchLake basin, pp. 49-52 in Hydrologiaal and GeoehemiealStudies in the Perch Lake Basin: A Report of Progress.PART OF AECL-5836*

VANDOR, H., P. FRITZ, R.W. GILLHAM and R.M. BROWN. En-vironmental isotope studies of the infiltration pro-cess, pp. 53-61 in Hydrological and Geoahemical Studiesin the Perah Lake Basin; A Report of Progress. PARTOF AECL-5836*

CHAMP, D.R., J. GULENS and R.E. JACKSON. Redox processesin natural and contaminated ground waters (Abstract),p. 11 in Abstracts with Programs, Vol. 2. GeologicalAssociation of Canada, Vancouver, B.C.

GULENS, J., D.R. CHAMP and R.E. JACKSON. Redox processesin ground water, pp. 67-77 in Hydrological and Geochem-ical Studies in the Perch Lake Basin: A Report of Pro-gress. PART OF AECL-5836*

FRITZ, P., E.J. REARDON, J. BARKER, R.M. BROWN, J.A.CHERRY, R.W.D. KILLEY and D.C. McNAUGHTON. The carbon-isotope ground water system in northern Ontario, pp.89-92 in Hydrologiaal and Geoahemical Studies in thePerah Lake Basin: A Report of Progress. PART OFAECL-5836*

GRUMMITT, W.E. and G. LAHAIE. Environmental monitoringat Chalk River Nuclear Laboratories. Part I. Gammaray spectrometric analysis of the NRX and process ef-fluents. AECL-5698.*

*Atomic Energy of Canada Limited Report

- 77 -

3.32 PUBLICATIONS (cont'd)

MERRITT, W.F. High-level waste glass: Field leachtest. Nuclear Technology 32: 88-91. AECL-5573*

PICKENS, J.F., W.F. MERRITT and J.A. CHERRY. Studiesof dispersion in a sandy aquifer (Abstract). EOS,Transactions, American Geophysical Union 58(6):391-392.

EASTWOOD, T.A., I.H. CROCKER and W.F. MERRITT. A re-port on a meeting to consider searching for naturalnuclear reactors in Canada. AECL unpublished inter-nal report.

TOMLINSON, M., S.A. MAYMAN, H.Y. TAMMEMAGI, W.F.MERRITT, J.A. MORRISON, H.S. IRVINE, G.A. VIVIAN,J. GALE, B. SANFORD and P.J. DYNE. Management ofradioactive wastes from nuclear fuels and powerplants in Canada. IAEA Int. Conf. on Nuclear Powerand Its Fuel Cycle, Salzburg, Austria, 2-13 May1977. AECL-5706*

MERRITT, W.F. Fixation of radioactive waste in glass,pp. 81-85 in Nualear Power: The Canadian Issues.AECL-5800*

PICKENS, J.F., J.A. CHERRY, R.W. GILLHAM and W.F.MERRITT. Field determination of the physical contami-nant transport parameters in subsurface flow systems,pp. 63-66 in Hydrological and Geochemical Studies inthe Peroh Lake Basin: A Report of Progress. PART OFAECL-5836*

OPHEL, I.L. and J.M. JUDD. Sediment-radionuclide in-teractions in Perch Lake, pp. 109-118 in Hydrologicaland Geoohemical Studies in the Perch Lake Basin: AReport of Progress. PART OF AECL-5836*

MARKO, A.M., D.K. MYERS, I.L. OPHEL, G. COWPER and H.B.NEWCOMBE. Research in radiation biology at ChalkRiver Nuclear Laboratories and the biological effectsof radiation. AECL-5911*


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3.32 PUBLICATIONS (cont'd)

JAY, P.C. and D.P. WILDSMITH. Major element budgets ofthe Perch Lake basin system — A pilot study, pp.99-106 in Eydrologiaal and Geoehemiaal Studies inthe Perch Lake Basin: A Report of Progress. PARTOF AECL-5836*

HENDRIE, L.K. Snowmelt and evapotranspiration in aforested catchment, pp. 33-38 in Hydrologioal andGeoahemioal Studies in the Perch Lake Basin: A Reportof Progress. PART OF AECL-5836*

INCH, K.J. Phreatophytic evapotranspiration in thePerch Lake area, pp. 21-31 in Hydrological and Geo-chemiaal Studies in the Perch Lake Basin: A Reportof Progress. PART OF AECL-5836*

GENTNER, S-R. Uptake and transport of iron and phosphateby Vallisneria spiralis. J. Aquatic Botany 3(3):267-272.

ROBERTSON, E. Energy budget studies: Vertical mixingin lakes, pp. 3-20 in Eydrological and GeochemiaalStudies in the Perch Lake Basin: A Report of Progress.PART OF AECL-5836*

ROBERTSON, E., D.P. WILDSMITH and P.C. JAY. Energy,water and tritium budgets for Perch Lake: 1975.AECL-5717.*

DEN HARTOG, G. and E. ROBERTSON. Lake evaporation fromclass A pan and energy budget data, pp. 189-193 in2nd Conf. on Hydrometeorology. American MeteorologicalSociety, Boston, Mass., U.S.A.


- 79 -


3.33.1 Presented Papers

BARRY, P.J. and E. ROBERTSON*. Water and energy budgetsof lakes in the Chalk River area. 2nd Conf. on Hydro-meteorology, 25-27 October 1977, Toronto. INVITED

BROWN, R.M.* and P.J. BARRY. A review of HTO evapora-tion studies at Chalk River Nuclear Laboratories. IAEA Ad-visory Group Mtg. on the Application of Nuclear Tech-niques to the Study of Lake Dynamics, 29 August-2September 1977, Vienna. INVITED

ALLISON, G.B.*, R.M. BROWN and P. FRITZ. Behaviour ofstable isotopes in evaporation pan experiments. IAEA Ad-visory Group Mtg. on the Application of Nuclear Tech-niques to the Study of Lake Dynamics, 29 August-2September 1977, Vienna INVITED

CHAMP, D.R.*. J. GULENS and R.E. JACKSON. Redox processesin natural and contaminated ground waters. Geologicaland Mineralogical Associations of Canada, Society ofEconomic Geologists and Canadian Geophysical Union,25-27 April 1977, Vancouver.

CHAMP, D.R. , P. UNRAU*, C E . GRANT and J.L. YOUNG. Nucleicacid binding glycoproteins which solubilize deoxyribo-nucleic acid in dilute acid: Species distribution andpossible role in DNA condensation. NATO Advanced StudyInstitute DNA Synthesis: Present and Future, 20-29June 1977, Santa Flavia, Sicily. INVITED

GRUMMITT, W.E.* and G. LAHAIE. Reliable monitoring ofradioactive effluents. IAEA Int. Symp. on Monitoringof Radioactive Airborne and Liquid Releases from Nu-clear Facilities, 5-9 September 1977, Portoroz, Yugoslavia.

McMAHON, J.W.*, A.E. DOCHERTY and S-R. GENTNER. Environ-mental effects and possible beneficial uses of low-gradeheat on fresh water phytoplankton. IAEA 3rd CoordinationMtg. on the Physical and Biological Effects on the En-vironment of Cooling Systems and Thermal Discharges fromNuclear Power Stations, 5-9 December 1977, Kalpakkam,India. INVITED

*Paper presented by

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3.33.1 Presented Papers (cont'd)

PICKENS, J.F.*, W.F. MERRITT and J.A. CHERRY. Studiesof dispersion in a sandy aquifer. 1977 Mtg. of AmericanGeophysical Union, 30 May-3 June 1977, Washington, D.C.

TOMLINSON, M.*, S.A. MAYMAN, H.Y. TAMMEMAGI, W.F. MERRITT,J.A. MORRISON, H.S. IRVINE, G.A. VIVIAN, J. GALE, B.SANFORD and P.J. DYNE. Management of radioactive wastesfrom nuclear fuels and power plants in Canada. IAEA Int.Conf, on Nuclear Power and Its Fuel Cycle, 2-13 May 1977,Salzburg, Austria.

MERRITT, W.F. Possible natural matrix materials for en-vironmental radioactivity standards at Chalk River Nu-clear Laboratories. Mtg. of Low-Level Techniques Groupof the Int. Committee for Radionuclide Metrology, 9-10November 1977, Woods Hole, Mass., U.S.A. INVITED

PICKENS, J.F.*, J.A. CHERRY, R.W. GILLHAM and W.F. MERRITT.Field studies of dispersion in a shallow sandy aquifer.Invitational Well Testing Symp., 19-21 October 1977,Berkeley, California.

OPHEL, I.L. Aquatic food chain transport of radionuclides.ORNL Workshop on Evaluation of Models Used for the En-vironmental Assessment of Radionuclide Releases, 6-9September 1977, Gatlinburg, Tenn., U.S.A. INVITED

OPHEL, I.L. Radiation doses and their effects in con-taminated aquatic ecosystems. IAEA Advisory Group Mtg.on Methodology of Radiation Effects Experiments onAquatic Organisms and Ecosystems for the Evaluation ofEffects of Releases of Radionuclides into Aquatic En-vironments, 21-25 November 1977, Vienna. INVITED

DEN HARTOG, G.* and E. ROBERTSON. Lake evaporation fromclass A pan and energy budget data. 2nd Conf. on Hydro-meteorology, 25-27 October 1977, Toronto. INVITED

*Paper presented by

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3.33.2 Lectures or Seminars**

(A) Perch Lake Study Symposium/Workshop, 12-13 January1977, CRNL

BARRY, P.J. Major element budgets of the Perch Lakebasin system — A pilot study.

BROWN, R.M. Tritium distribution in trees in the PerchLake basin.

FRITZ, P.*, E.J. REARDON, J. BARKER, R.M. BROWN, J.A.CHERRY, R.W.D. KILLEY and D.C. McNAUGHTON. The carbon-isotope geochemistry of a small ground water system innorthern Ontario.

GULENS, J.*, D.R. CHAMP and R.E. JACKSON. Redox processesin ground water.

HENDRIE, L.K. Snowmelt and evapotranspiration in aforested catchment.

INCH, K.J. Phreatophytic evapotranspiration in thePerch Lake area.

OPHEL, I.L.* and J.M. JUDD. Sediment-radionuclide in-teractions in Perch Lake.

PICKENS, J.F.*, J.A. CHERRY, R.W. GILLHAM and W.F.MERRITT. Field determination of the physical contami-nant transport parameters in subsurface flow systems.

ROBERTSON, E. Energy budget studies: Vertical mixingin lakes.

VANDOR, H., P. FRITZ, R.W. GILLHAM and R.M. BROWN*.Environmental isotope studies of the infiltrationprocess.

(B) Science Teachers' Seminar, 25-26 February 1977,CRNL

MARKO, A.M., D.K. MYERS and P.J. BARRY. Everythingyou always wanted to know about biology.

*Given by**Papers in this section are generally not available

in print

- 82 -

3.33.2 Lectures or Seminars*(cont'd)

MERRITT, W.F. and H.C. BIRNBOIM. Radioisotopes: Howthey apply in the life sciences.

OPHEL, I.L. Biological concentration through foodchains.

(C) Other

OPHEL, I.L. Research program of the Environmental Re-search Branch and its relation to the Canadian nuclearpower program. Presented to Treasury Board visitors,5 January 1977, CRNL.

3.33.3 Local Talks*

(A) 19th Annual Health Physics Course, 26-30 September1977, CRNL

MERRITT, W.F. Environmental radioactivity.

OPHEL, I.L. Environment and man.

(B) Other

McMAHON, J.W. Research programs of the EnvironmentalResearch Branch related to the nuclear power program.Presented to University of Toronto students, 15-16February 1977, CRNL.

OPHEL, I.L. Research program of the Environmental Re-search Branch and its relation to the Canadian nuclearpower program. Presented to Biology Branch staff,7 January 1977, CRNL.

ROBERTSON, E. Methods of estimating lake evaporation.Presented at Field Methods in Hydrology, Universityof Waterloo-CRNL field school, 3-9 May 1977, CRNL.

p in this section are generally not availablein print

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3.34 INVITED SPEAKERS*

Dr. T.J. Enright, Chemical Engineering Branch, CRNL- "H9S facilities and safety factors involved at CRNL",2 March 1977.

Dr. J.E. Zajic, University of Western Ontario, London,Ontario - "Chemical and biochemical leaching of coke",24 October 1977.

Mr. R.G. Gallaghar, Applied Health Physics Inc., BethelPark, Pa. - "Management of radioactive wastes resultingfrom processing ores and slags containing traces ofthorium and uranium", 26 October 1977.

Professor J. Kramer, McMaster University, Hamilton, Ontario- "Terrain susceptible to atmospheric deposition",17 November 1977.

*Papers in this section are generally not availablein print

0.4

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0.2

R0LPHT0H 1 3 7 C s

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0.4

pCi/L

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I I I I I I I I

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pCi/L

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I I I I I I

50

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FIGURE 1 OTTAWA RIVER WATER

- 85 -

000

mCi/d

400

MOMIMU.

-

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1230

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15

12

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40

30

20

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-

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FIGURE 2 RADIONUCLIDES DISCHARGED TO OTTAWA RIVER

- 86 -

- 87 -

POPULATION RESEARCH BRANCH

by

Howard B. Newcombe

4.1 Staff ( October - December 1977}

4.2 Aims of the Branch

TUMOUR INDUCTION IN MAMMALS

4.3 Synergistic effects in radiation carcinogenesis

METHODS FOR DERIVING HUMAN DATA ONDISEASES LIKELY TO BE INCREASED BYIRRADIATION -- DEVELOPMENT OF THEINFORMATION SOURCES

4.4 Linking ill-health records for children to birthsummary records

4.5 Linking ill-health records into individual healthhistories

4.6 AECL-UBC collaborative record linkage project

4.7s Collaboration with other outside agencies

4.8 Publications and Invited Speakers

4.9 ' Verbal presentations


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4.1 STAFF

Branch Head - H.B. Newcombe

Hereditary changes and tumour induction in vertebrates

Assistant J. F. McGregor

Methods for deriving human data on diseases likelyto be increased by irradiation

M.E. Smith

Secretarial - C.L. Nagy

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4.2 AIMS OF THE BRANCH

The Branch attempts to obtain biological data withwhich to assess the consequences of exposing largenumbers of people to low levels of radiation. Informationis derived from irradiated and unirradiated populationsof laboratory animals, and new computer methods are beingdeveloped at CRNL for extracting data for man from exist-ing vital and health records.

TUMOUR INDUCTION IN MAMMALS

4.3 SYNERGISTIC EFFECTS IN RADIATION CARCINOGENESIS -H.B. Newcombe and J.F. McGregor

Induced epithelial tumours in the skins of CD whiterats, following different doses of beta irradiation,800-12,800 rads (8-128 Gy), in twofold steps, werestudied to determine the characteristics of the neoplasmsand the associations between these and the likelihood ofeventual malignancy. Growths developing after high dosesof radiation were more likely to be associated withmalignancy and, conversely, lower doses favoured theproduction of benign growths. The maximum yields ofcancers was obtained at 6400 rads (64 Gy), and the peakeffect for benign tumours was at 1600 rads (16 Gy). Thecancers were observed to be the endpoints of three kindsof lesions: warts, cysts and ulcers. Although wartswere more frequent than cysts and ulcers (77%, 14% and 9%)the association of malignancy with the latter two lesionswas stronger (14%, 23% and 23%). Tumours of all threepathologies varied with respect to growth rate, andthose later found to become malignant were the ones whichhad grown most rapidly from the start. This findingsuggests that for the cancers reported here the potentialfor malignant development had been established at the timeof induction, or shortly afterwards. When the combineddata on the cancers was compared with the combined dataon the benign tumours, it was found that the growthsdestined to become cancerous appeared significantlyearlier (p = 0.03). A breakdown of the data revealedthat the interval between the first appearance of thetumour and its subsequent development into an obviouscancer was least for ulcers that became cancerous endgreatest for warts that became cancers, with cysts takingan intermediate position. An account cf the study is inpreparation for submission to the Journal of the National

- 90 -

Cancer Institute. Two related papers will be prepared,the first dealing with tumour latency (i.e. the time fromirradiation to the first observation of the n e o p l a s m ) , andthe second with the effects of localized beta-irradiationon animal growth.

The experimental work for the present long-termstudy on synergism between radiation and certain environ-mental carcinogens, testing the validity of the doublingdose concept as applied to somatic effects by Gofman andTamplin, is now complete. A large volume of data withmany variables is being organized for statistical analyses.Three main papers relating to the production of skintumours are expected from this work, 1) on the combinedeffect of radiation ar.d cigarette tar, the latter beingapplied immediately after the irradiation, 2) as above butwith the cigarette tar being applied two months followingthe irradiation, and 3) on the combined effect of radiationand a dyesfcuff. 2 anthramine.

An experiment is in progress to determine theeffects of a single dose of radiation on the skin ofhairless rats (genetically hypotrichotic, Col 1ip hoodedderived) and their haired sib. There is a view that themajority of skin tumours in haired animals arise from thehair follicles. The present work should confirm this, butthere is also a special interest in the production ofsquamous cell carcinomas. Results to date show that thesehairless animals are far more resistant to skin tumourproduction, at least for 1600 rads (16 G y ) , than are theCharles River CD white rats (Sprague-Dawley d e r i v e d ) .

METHODS FOR DERIVING HUMAN DATA ONDISEASES LIKELY TO BE INCREASED BYIRRADIATION -- DEVELOPMENT OF THEINFORMATION SOURCES

4.4 LINKING ILL-HEALTH RECORDS FOR CHILDREN TO BIRTHSUMMARY RECORDS - H.B. Newcombe and M.E. Smith

An unusually favourable opportunity has arisenat Chalk River for comparing the accuracies with whichcomputers, versus human clerks, were able to link ill-health records for children to the appropriate birthregistration. This test has been possible using n fileof over 44,000 records that had already been linkedmanually in British Columbia, and was subsequently linkedby a CDC 6600 computer at Chalk River, as part of alarger linkage operation, using three alternative filesort sequences.

- 91 -

After visual assessment of both the computer andmanual linkages, the success rate for the computer wasfound to be consistently higher than that achieved byits human counterparts (i.e. 98.5% versus 97 - 0%). Further-more, the proportion of false linkages was much lowerfor the computer operation (0.08% versus 2.3%).

The bulk of the manual mistakes are due to either:a) errors in copying the birth registration numbers ontothe ill-health source document after the clerical search,or in the keypunching of this number to cards, so that afalse extraneous linkage is indicated by en incorrectbirth registration number, or 2) incomplete searching ofthe birth registration file so that no linkage at all isachieved, or a false linkage is accepted instead of thecorrect one. Both kinds of linkages are readily recognizedon visual inspection when the correct linkage has beenfound by the computer. Only in a minority of instanceswas inadequacy of the combined identifying information thecause of the human error.

In contrast to the manual linkages, errors in thecomputer linkages are almost entirely caused either byinsufficient or discrepant identifying information, andalmost always take the form of failures to achieve alinkage, i.e. false linkages are exceedingly rare. Visualexamination of the records has suggested that an additionalfile sort sequence for linkage might improve the computerperformance. Thus, the matching of the 44,000 recordsto the one million births was repeated, using for thelinkage operation the new CYBER 175 computer, and fouralternative sort sequences for the file, namely:1) Soundex (surname phonetic code) birth date, 2) Soundexforename, 3) birth date alone, and 4) Soundex birth year.A threshold weight of zero or greater was set for theacceptance of a linkage at each step. Analysis of theefficiency, cost, and speed of using four sequences forlinking ill-health records to birth records is now inprogress.

4.5 LINKING ILL-HEALTH RECORDS INTO INDIVIDUALHEALTH HISTORIES -- H.B. Newcombe and M.E. Smith

British Columbia hospital admission-separation,health surveillance, and death records have been linkedinto individual health histories in order to obtain data

concerning the magnitude of the personal and social burdenof cancer and of hereditary and congenital disorders.The British Columbia Health Surveillance Registry "cardimage" and "extended format" records were updated toreflect 75 recent changes, made in British Columbia,mainly involving the disease and aetiology codes forindividuals represented on our files. Modifications weremade to a computer program used to condense the 160-column"extended-format" individual health event records into40-column "Z-records", and the production job of creatingthe 325,000 updated individual summaries has been completed.

Three alternative statistical treatment methods,along with their respective biases, have been investigatedand tested for calculating age-specific death rates. Totest these methods it was advantageous to further consolidatethe "Z-records" for the particular events into a single40-column record for each personal history. This workhas been completed, and computer programs prepared tocalculate the three alternative age-specific death rates,namely where the population "at risk" in the nth year oflife is defined as being: 1) all those registered, regard-less of their age at registration, and still alive at thebeginning of their nth year of life (TOTAL CASE METHOD);2) those registered prior to their nth year of life andstill alive at the beginning of that year (PRIORREGISTERED CASE METHOD), and 3) as in (2), but also usinga fraction of the current year at risk for individualswho were registered as handicapped during their nth yearof life and who were therefore at risk for only a part ofthat year (PRIOR AND CURRENT REGISTERED CASE METHOD).

4.6 AECL-UBC COLLABORATIVE RECORD LINKAGE PROJECT -H.B. Newcombe, M.E. Smith, J.R. Miller and B.K. Trimble

The Population Research Branch of CRNL and theDepartment of Medical Genetics of the University ofBritish Columbia are currently collaborating on a projectthat involves designing computer systems for the linkageof vital and health records into individual, sibship,cousin, and multi-generation histories, employingBritish Columbia birth, death, marriage, and healthsurveillance records, as well as hospitilization records.Since Dr. Trimble's death, in December, the work is beingcontinued in B.C. by Mr. Soo Hong Uh under Dr. Miller.

The linkage of approximately 3/4-million 1946-70birth records with 1/4-million 1946-70 marriage records,into sibship histories, was completed at the Universityof British Columbia -- the cost of the final linkage runsbeing about $2500 using an IBM 370/168. The updated

- 93 -

system is based on methods and rules that are similarto those devised earlier at CRNL.

Particulars of the parents of a bride and groomare available on the original marriage registration sourcedocuments. About 585,000 marriage "parental" cards werekeypunched earlier at Statistics Canada, relating toall marriages that occurred in British Columbia between1946-47. Linkage weights were derived for surnames,parental initiais, and birth provinces and cities. Asample file was used to test new linkage rules and weights,and the final production job has been completed. Thelinkage of marriage parental cards brings together intosibship groupings the marriage registration numbers andSoundex codes for any brothers and/or sisters who gotmarried in British Columbia during the period. Thus,retrieval of cousin groupings from the sibship-1inkedfile is now feasible.

In order to obtain some quantitative measureof the social burden and cost due to childhood dominantand recessive diseases, and congenital malformations,linked individual health histories from CRNL have beenused as a source of data on the risks of early mortality,the frequencies of admissions to hospital, and thedurations of utilization of hospital services associatedwith these groups of diseases.

All three categories of affected children aremuch more likely to die, to be admitted to hospital, andto stay for longer periods, than is normal for livebornsas a whole. It appears that children with congenitalmalformations are the most likely to die as infants, haveslightly smaller per capita risks of hospital admission,and tend to stay for somewhat shorter period, than dochildren with single gene defects.

Individual ill-health summary histories for personswith specific conditions -- namely, central nervous systemdefects, Down's syndrome, haemophilia, and cleft palateand/or harelip -- were extracted from the complete linkedfiles and preliminary tabulations of age-specific ratesof hospital-admission, handicap registration, and deathwere prepared at CRNL for each condition. A detailedanalysis of these results and of the individual healthhistories was started by Dr. Trimble of the Universityof British Columbia, prior to his death.

4.7 COLLABORATION WITH OTHER OUTSIDE AGENCIES - M.E. Smith

Because a new PDP 11/34 Computer is now availableat the Ontario Cancer Treatment and Research Foundation(OCTRF) for use by the Ontario provincial cancer registry,plans are being made to re-write existing linkage programsused at OCTRF. Also manual verification of some earlierlinkage performance. Records from multiple-sources on variousaspects of cancer are being brought together by thecomputer into individual patient health histories.

Dr. Aileen Clarke and Mr. James Darlington fromOCTRF in Toronto visited Chalk River for discussionsregarding the computer linkage techniques being developedat CRNL, and to consider how these methods might be usedin their registry. During this visit: 1) a draft set ofnew linkage rules was prepared for the creation of indiv-idual cancer patient histories; 2) a plan was made forthe calculation of "binit" weights using identifyingitems available on the OCTRF records (such as hospitalcodes, surname spelling, initials, forenames, sex, birthdates, place of residence, disease diagnosis, OHIP numberetc.); 3) steps were outlined for updating existinglinked files; 4) various uses of individual cancer patienthistories for epidemiological studies were discussed; and5) methods for retrieval of information for such studieswere considered.

During a visit at OCTRF in Toronto, detailedinformation was collected regarding the source documentsused by the Ontario cancer registry -- records of hospitaladmission-separations, outpatients, biopsy reports,pathology reports, reports of free drugs supplied byOCTRF, and death registrations -- and regarding the amountof information put into machine readable form from eachof these documents.

Preparation of an updated linkage program byOCTRF is scheduled for 1978.

Statistics Canada keypunched and verifiedapproximately 45,000 marriage "parental" cards for 1970British Columbia marriages. These cards were copied totape and the tape was forwarded to CRNL where sample print-outs, tabulations, and some editing of various fieldson the punch card have been completed. Copies of theoriginal 1970 marriage-parental tape from StatisticsCanada, plus the edited version prepared at CRNL, weresent to the Department of Medical Genetics at UBC.

- 95 -

PUBLICATIONS AND INVITED SPEAKERS

4.8 PUBLICATIONS

Newcombe, H.B. - Methods of obtaining epidemiological datafor mutation risk estimation. Pp. 461-72 in "Handbookof Mutagenicity Test Procedures", B. Kilbey et al (Eds.)E1sevier/North-Ho11 and Biomédical Press, Amsterdam(1977) AECL-5737.

Newcombe, H.B. - Public Health Aspects of Radiation.Atomic Energy of Canada Limited, Report No. AECL-5905.

Newcombe, H.B. - Priorities in assessing the impact onhuman populations of an increased mutation rate.Pp. 122-26 in "Conference on Population MonitoringMethods for Detecting Increased Mutation Rates".Deutsche Forschunsgemeinschaft; Harald Boldt Verlag,Boppard, Germany (1977).

Marko, A.M., Myers, D.K., Ophel , I.L., Cowper G. andNewcombe, H.B. - Research in Radiation Biology, inthe Environment and in Radiation Protection at CRNL.Atomic Energy of Canada Limited, Report No. AECL-5911.

Smith, M.E. - The use of computers for studying the originsand social costs of ill-health. Pp. 37-41 in "MEDINFO 77:the Second World Conference on Medical Informatics",D.B. Shires and H. Wolf (Eds.) North Holland Publ . Co.,Amsterdam (1977) AECL-5740.

Trimble, B.K. and Smith, M.E. - The incidence of geneticdisease and the impact on man of an altered mutationrate. Can. J. Genet. Cytol. 19, 375-385 (1977)AECL-5857.



Newcombe, H.B. - Records, confidentiality and the detectionof delayed industrial risks. Presented at a Conferenceon Occupational Health and Safety, organized by CorpusPublishing for the Science Council of Canada, Toronto,16-17 Nov. 1977- INVITED.

Smith, M.E. - The use of computers for studying the originsand social cost of genetic disease. Presented atMEDINFO 77, Toronto, Ontario, 8 August 1977.

- 96 -

Smith, M.E. - Medical record linkage -- its present statein Canada. Presented at the Ontario Hospital Associationfall convention, Toronto, Ontario, 7 November 1977.INVITED.

4.9.2 Lectures or seminars

Newcombe, H.B. - Mutagenesis, carcinogenesis and the liferecords of man. Presented at the Department of Biology,York University, Toronto, 24 January 1977. INVITED.

Newcombe, H.B. - Radiation and effects on man. Presentedat the seminar for government officials, on ProposedCanadian Fuel Cycle program, Ottawa, 28 February 1977.

Newcombe, H.B. - Risk-benefit analysis. Presented tothe Foods Directorate, Health Protection Branch,Health and Welfare Canada, Ottawa, 4 November 1977.INVITED.

Smith, M.E. -Medical record linkage -- its present statein Canada. Presented at the Ontario Cancer Treatmentand Research foundation, 9 November 1977. INVITED.

4.9.3 Local talks

Newcombe, H.B. - Radiation risks. Presented at the 19thAnnual Health Physics Course, CRNL, 26-28 September 1977.

- 97 -

BIOLOGY BRANCH

by

D.K. Myers

5.1 Staff

5.2 Aims of the Branch

BIOCHEMISTRY AND MOLECULAR BIOLOGY

5.3 Distribution of Sites of Repair in Human DNA FollowingUltraviolet Light Irradiation

5.4 Relative Positioning of Polypyrimidines WithinNucleosomes of Mouse L-cell Chromatin

5.5 Organization of Polypyrimidine Segments in DNA FromMouse L-cells

5.6 Survey of the Arrangement of Polypyrimidine Segments inthe Genomes of Various Eukaryotic Cells

5.7 Repair of Double-Strand Breaks in Micrococcusradiodurans DNA

5.8 Ionizing Radiation Damage to Micrococcus radioduransCell Wall

5.9 Direct Measurement of Recombinational Repair Exchangesin Micrococcus radiodurans

5.10 Radiation Protection of Micrococcus radiodurans by Pre-Induction of Recombinational Repair

5.11 Synergistic UV-Ionizing Radiation Interaction inSchizosaccharomyces pombe is Due to a RecombinationalRepair Process

5.12 Effect of Radical Scavengers on the y-Su^vival ofM. radiodurans; Identification of Hydroxy Radical as thePrimary Lethal Species

5.13 Y~Ray Response of Cells Cultured from Patients withCancer-Associated Diseases

GENETICS AND POPULATION STUDIES

5.14 Radiation Sensitivity of Temperature-Sensitive Mutants ofUstilago maydis Blocked in DNA Synthesis

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5.15 Control Mechanisms in the Cellular Metabolish of Ustilagomaydis

5.16 A Genetic Assay Using Saccharomyces cerevisiae for LamageAssociated with Low Doses of Ionizing Radiation

5.17 Radiation Sensitivity of Bacteriophage T4 - Mapping theSite of the X Gene

5.18 Effect of Near UV (>300 nm) Radiation on BacteriophageT4: Recognition of a Photoproduct by T4 UV Endonuclease

5.19 Effect of Near UV (>300 nm) Radiation on BacteriophageT4: Attempt to Identify the Endonuclease V-SensitivePhotoproduct

5.20 Radiation-Induced Tumors in Rats

5.21 Assessment of Radiation Hazards to Human Populations

5.22 Publications

5.23 Verbal Presentations


5.24 Invited Speakers

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5.1 STAFF

Branch Head - D.K. Myers

Biochemistry of DNA and RNAH.c. Birnboim

Radiation BiochemistryD.K. Myers

Radiation Damage in Cell Wallsand Membrane

R.E.J. Mitchel

Enzymatic Repair of RadiationDamage to DNA

N.E. Gentner

DNA Repair in CultivatedHuman Cells

M.C. PatersonP.J. Smith1

DNA Replication and Repair in FungiP. UnrauD.P. Morrison2

Bacteriophage T4 GeneticsJ.D. Childs

SecretarialC.I. Walters

Laboratory AttendantsM.A. Jones and B.A. Ruhnke

Assistants J.J. JevcakA.G. Knight

Assistant L.D. Johnson

Assistant K.M. Baird

Assistant M.M. Werner

Assistants B.P. SmithP.A. Knight

Assistant R. Pilon

XP.J. Smith, a Visiting Postdoctoral Fellow, from PatersonLaboratories, Christie Hospital and Holt Radium Institute,Manchester, England, joined the Biology Branch on 28 December, 1977.

2D.P. Morrison, a Visiting Postdoctoral Fellow, from Departmentof Genetics, University of Alberta, Edmonton, Alberta, joinedthe Biology Branch on 2 December, 1977.

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5.2 AIMS OF THE BRANCH

Research in the Biology Branch is directed towardsan understanding of the effects of ionizing radiation onliving organisms, with a particular interest in assess-ment of the genetic and carcinogenic hazards of low-level radiation to human populations. Attention isgiven to the entire chain of events by which the initialradiation-induced changes in the living cell aretranslated into significant biological effects. Themost critical target for damage by radiation or radio-mimetic chemicals in the environment appears to be DNA,the carrier of hereditary information in all livingcells. The harmful consequences of this initial damageto DNA can be diminished 1000-fold or more by the combinedaction of multiple enzymatic repair processes in theliving organism. An improved understanding of the DNArepair mechanisms would thus seem to be crucial for aproper interpretation of the shape and position ofradiation dose-effect curves and consequently forassessment of the hazards of low-level radiation tohumans and other living organisms. Research activitiesin the Branch are currently focussed on this area.

BIOCHEMISTRY AND MOLECULAR BIOLOGY

5.3 DISTRIBUTION OF SITES OF REPAIR IN HUMAN DNA FOLLOWINGULTRAVIOLET LIGHT IRRADIATION - H.C. Birnboim,M.C. Paterson, B.P. Smith, and J.J. Jevcak

These experiments are described in Atomic Energy ofCanada Limited, Report AECL-5806, p. 60, Section 5.4.This work has been completed and submitted for publication.

5.4 RELATIVE POSITIONING OF POLYPYRIMIDINES WITHIN NUCLEOSOMESOF MOUSE L-CELL CHROMATIN - H.C. Birnboim, R.M. Holford,(Health Physics Branch), and V.L. Seligy3

These experiments are described in Atomic Energy ofCanada Limited, AECL-5855, p. 57, Section 5.3. Thiswork has been completed and will be published shortly.

5.5 ORGANIZATION OF POLYPYRIMIDINE SEGMENTS IN DNA FROMMOUSE L-CELLS - H.C. Birnboim, J.J. Jevcak, and A.G. Knight

We have shown earlier that polypyrimidine segmentscan be found in DNA from many higher organisms, includingmouse cells. Over the past two years we have beendeveloping a procedure for separating DNA fragments which

3Cell Biochemistry Group, National Research Council of Canada,Ottawa, Ontario KlA 0R6

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contain a polypyrimidine segment from fragments which donot. This procedure has allowed us to fractionate thegenomes of higher organisms in a new way, and it thereforecomplements other existing fractionation procedures,such as density gradient sedimentation and reassociationkinetics.

The technique involves dénaturâtion of the DNA,chemical modification of guanine residues with glyoxal(Birnboim and Mitchel, in press) and annealing withpoly r(A,G). Under the conditions used, poly r(A,G)forms a specific complex with polypyrimidine segments inthe DNA and this complex can be bound to hydroxyapatite.DNA fragments which do not contain polypyrimidine segmentsdo not bind to hydroxyapatite. Factors which influencethe formation of the poly r(A,G)/DNA complex and itsbinding to hydroxyapatite have been studied in detail(H.C. Birnboim, submitted for publication).

The ability to separate DNA fragments on the basis oftheir content of polypyrimidines has allowed us to explorethe spacing of polypyrimidine segments in DNA. This isdone by examining the relationship between DNA size andpercent binding to hydroxyapatite. If polypyrimidines wereclustered at a relatively few locations in the genome,thsn only a small proportion of the DNA would bind, evenif the size of the DNA were relatively large. Alternatively,if polypyrimidines were maximally scattered throughoutthe DNA (at a few hundred thousand separate sites), thena large proportion of the DNA could be bound tohydroxyapatite. By studying in detail the relationshipbetween DNA size and percent binding, we were able todeduce that, in the mouse genome, polypyrimidine segmentsoccur at intervals of about 15,000 nucleotides in about60% of the DNA.

The poly r(A,G) binding technique was also used toshow that polypyrimidines are "hot spots" in human DNAfor damage by ultraviolet (UV) irradiation (Atomic Energyof Canada Limited, Report AECL-5703, p. 104, Section 5.5;Birnboim and Paterson, submitted for publication). Inthese experiments, repair synthesis following exposureof human cells to UV was found to occur preferentiallyin polypyrimidine-containing fragments of DNA.

5.6 SURVEY OF THE ARRANGEMENT OF POLYPYRIMIDINE SEGMENTS INTHE GENOMES OF VARIOUS EUKARYOTIC CELLS - H.C. Birnboim,J.J. Jevcak, A.G. Knight, and M.C. Paterson

The poly r(A,G) complexing technique described inSection 5.5 has been used to study the arrangement of

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polypyrimidine segments in the genomes of other organisms.A number of different cell lines were purchased fromcommercial sources and DNA, labelled with I xl*C]thymidine,was prepared from them. Preliminary experiments havenow been carried out with DNA from the following types ofcells: human, rhesus monkey, rabbit, Chinese hamster,cow, pig, dog, and chicken. All show evidence of poly-pyrimidine segments in their DNA, having a distributionrather like that in mouse DNA, although some species differencescan be detected. This general conservation of thepolypyrimidine-spacing pattern in widely differing organismssuggests an important role for these segments. Wespeculate that they may be involved in DNA replication,chromosome folding, or transcription, but as yet thereis no strong evidence to allow us to choose amongst thesealternatives.

5.7 REPAIR OF DOUBLE-STRAND BREAKS IN MICROCOCCUSRADIODURANS DNA - D.K. Myers and L.D Johnson

Experiments were carried out in collaboration withDr. N.E. Gentner to determine the effects of chemicalsand of pre-irradiation on the ability of M. radioduransto repair double-strand breaks in DNA. Repair was ~inhibited by chloramphenicol, an agent which preventssynthesis of new proteins in the cell during post-irradiation incubation. Repair was more effective incells which had been pre-irradiated with a low dose ofradiation and allowed to recover from this initialchallenge. The data thus suggest that the repair ofdouble-strand breaks depends upon the synthesis of enzymeswhich are induced by exposure of the cells to radiation.

5.8 IONIZING RADIATION DAMAGE TO MICROCOCCUS RADIODURANSCELL WALL - R.E.J. Mitchel and K.M. Baird

M. radiodurans' cell wall contains some proteins andpolysaccharides that are selectively released by sublethaldoses of ionizing radiation. One of the releasableproteins is an exonaclease. The work on the isolation,purification and properties of this enzyme from unirradiatedcells is complete and the results have been submittedfor publication. This paper shows that the enzyme isa dimer of about 260,000 molecular weight. We have recentlyfound that hydroxyl radicals generated by ionizingradiation release this enzyme from the cell wall as thedimer, and that further radical attack on the free enzymeconverts it to the 130,000 molecular weight monomer formwithout apparent loss of enzyme activity.

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We have also been examining the mechanism by whichoxygen exerts an unusual protective effect (oxygenenhancement ratio = 0.4) against the loss of these cellwall components. Oxygen protection does not involve thescavenging of primary aqueous radicals since release of the wallcomponents is initiated by hydroxyl radicals which do not reactwith oxygen. This protection appears to result from thereaction of O2 with a secondary radical located in the cell wall.This reaction prevents the displacement of this radicalcenter to the sensitive site which would allow the releaseof the wall component. We have shown that these secondaryradicals are subject to repair by sulfhydryl compounds(probably by a hydrogen transfer mechanism) and thatoxygen competes with sulfhydryl for the same radical centers.Sulfhydryl repair of the secondary radical also protectsthe cell wall.

The finding that the initial *OH damage site isdifferent from the final sensitive site from which the wallcomponents are released raised the question as to thepotential number of initial damage sites relative to thenumber of final sensitive sites. We have now shown thateach wall component molecule can be released by freeradicals propagated to it from many initial damage sites.

Current work is directed toward identification of thenature of the final sensitive site. By comparing theproperties and structure of wall components released byionizing radiation with the same components extracted fromunirradiated cells we hope to detect radiation-inducedchanges. Some evidence indicates that release by radiationis accompanied by a change in hydrophobic character. Thisevidence is consistent with our findings that the releasedcomponents originate from a membrane-like mid-wall layer.

5.9 DIRECT MEASUREMENT OF RECOMBINATIONAL REPAIR EXCHANGESIN MICROCOCCUS RADIODURANS - N.E. Gentner and M.M. Werner

The high ionizing radiation resistance of M. radioduransappears to be due primarily to a prereplicative or sisterchromatid exchange recombinational repair process. Theimportance of prereplicative recombinational repair hasbeen inferred largely from genetic and cell cycle studies,since no biophysical assay of such a process has beenavailable.

We have developed an assay for the occurrence ofprereplicative recombinational repair. Cells grown inthe presence of the "heavy" base analog 5-bromodeoxyuridine(BU) are transferred to "light" medium for one generation;

this last round of replication yields daughter chromatidswhich are unifilarly-BU-substituted. Recombinationalrepair of Y~in<3uceâ damage in cells containing this startingmaterial would give regions of bifilar BU-substitution.Two methods have been developed to follow these exchanges:(1) equilibrium sedimentation in neutral CsCl gradients.This method follows the formation of "heavy-heavy" and"light-light" regions in DNA sheared to pieces about103 base pairs long. (2) 313 nm-induced double strandbreaks. Exposure of BU-substituted DNA to 313 nm lightgives rise to single strand breaks. If recombinationalrepair has put regions of BU opposite each other, doublestrand breaks can be seen on velocity sedimentation inneutral sucrose gradients.

The 313 nm-induced double strand break method affordsthe greater sensitivity. In both methods, the shiftsobserved (as predicted as a consequence of recombinationalexchanges) are not observed under conditions known fromprevious work to prevent the development of, or inhibit,functional recombinational repair activity.

5.10 RADIATION PROTECTION OF MICROCOCCUS RADIODURANS BY PRE-INDUCTION OF RECOMBINATIONAL REPAIR - N.E. Gentner andM.M. Werner

This important recombinational repair process inM. radiodurans appears to be induced as a consequence ofTonizing radiation exposure, since inhibition of post-irradiation protein synthesis by chloramphenicol causesboth increased lethality of cells and abolishes therecombinational repair contribution to repair ofy-induced DNA strand breaks. At highly lethal y-exposures,moreover, recombinational repair activity appears tobe blocked in the majority of cells; this failure may beresponsible for the ultimate inactivation of wild-typecells.

If cells are first given a low "priming" exposurefollowed by incubation under conditions that allow proteinsynthesis, the resultant cells are substantially moreresistant than normal to subsequent y-exposure, even ifrecombinational repair of the initial "priming" damage isincomplete. The increased resistance is seen both as anincreased shoulder of the y-survival curve, and as adecreased limiting slope of the exponential portion.Development of this protection requires conditions thatsupport expression of functional recombinational repairactivity. When the effects of ionizing and ultravioletradiation are compared, only ionizing radiation damage inducesthis protection, and increased resistance is seen only for

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ionizing radiation. In the pre-induced cells, furthermore,recombinational repair of DNA strand breaks now proceedseven in the presence of ehloramphenicol or at (formerly)highly lethal exposures.

An inducible component necessary for recombinationalrepair therefore appears to be a decisive factor in thehigh radioresistance of M. radiodurans.

5.11 SYNERGISTIC UV-IONIZING RADIATION INTERACTION INSCHIZOSACCHAROMYCES POMBE IS DUE TO A RECOMBINATIONALREPAIR PROCESS - N.E. Gentner

A synergistic effect on inactivation of the haploidfission yeast S. pombe is seen on combined UV-Y-rayexposure. This synergistic interaction may now beattributed exclusively to a prereplicative recombinationalrepair process (known to be capable of repairing bothtypes of damage) in this eukaryote since: (1) the rad 1mutant defective in this pathway does not show suchsynergism; and (2) in the presence of the recombinationalrepair inhibitor caffeine, the synergistic interactionin the repair-proficient wild-type strain is abolished.

5.12 EFFECT OF RADICAL SCAVENGERS ON THE Y-SURVIVAL OFM. RADIODURANS; IDENTIFICATION OF HYDROXY RADICAL AS THEPRIMARY LETHAL SPECIES - N.E. Gentner

Information on the relative lethality of variousionizing radiation-induced radical species can be derivedfrom the Y-survival curves of Micrococcus radioduransirradiated in various gases (which give different radicalspecies) in the absence or presence of various radicalscavengers. The two scavengers used in this study wereethanol (which scavenges hydroxy radical) and sodiumformate (which, in oxygen, converts hydroxy radical tosuperoxide anion).

In the absence of scavengers, irradiation in N2 producesequal amounts of hydrated electrons and hydroxy radicals; thehydrated electrons are converted to hydroxy radicals in thepresence of N2O and to superoxide anion in the presence of 02.Y-irradiation in N2O is more lethal to M. radiodurans thanis Y - i r r a d i a t i o n in °2 » which is in turn more lethal thanY-irradiation in N2. From these survival curves it can becalculated that hydroxy radical is twice as likely to causeinactivation as superoxide anion. Similarly, for irradiationin O 2, conversion of hydroxy radical to superoxide anion givessubstantially increased survival; this further supportsa conclusion that hydroxy radical is more lethal than anequivalent amount of superoxide anion. From the Y-survivalcurves in N2O, O2, and 02+formate, curves for theinactivation of M. radiodurans specifically as a functionof either hydroxy radical or superoxide anion can bederived. The curve for hydroxy radical suffices to describethe Y-inactivation curve in N2.

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Hydroxy radical therefore appears to be the primarylethal species induced by ionizing radiation. Thedecreased survival of M. radiodurans for irradiation inO2 compared to N2 (the oxygen effect) may be a secondaryeffect of oxygen which causes a fixation of hydroxy radicaldamage.

5.13 y-RAY RESPONSE OF CELLS CULTURED FROM PATIENTS WITHCANCER-ASSOCIATED DISEASES - M.C. Paterson, B.P. Smith,and P.A. Knight

A major project in the human cell culture program isthe search for human diseases linked to abnormal sensitivityto ionizing radiation. The prototype disease is ataxiatelangiectasia (AT), a rare genetic disorder characterizedby neurovascular and immunologie abnormalities in additionto predisposition to lymphoreticular cancers and leukemiaand hypersensitivity to conventional radiotherapy. Theincreased sensitivity to radiation is also observed atthe cellular level ̂ n vitro and studies in this laboratoryhave pinpointed defective enzymatic repair of radiationdamage to the genetic material, DNA, as the underlyingcause.

We were thus prompted to examine diploid cells frompatients with related diseases for their response toionizing radiation. Three diseases have been studied todate: familial acute myelogenous leukemia (AML), vonRecklinghausen's disease (VRD) (neurofibromatosis) andtuberous sclerosis (TS). While, as is implicit in itsname, acute myelogenous leukemia is the predominant cancerin the first disease, the other two are characterized bya tendency to develop tumors in the central nervous systemwhich occasionally undergo neoplastic transformation. Sixmembers of an AML family were tested as sources of cellsto study the first disease: three members (father andtwo sons) were free of cancer whereas the other threemembers (mother and two daughters) had developedmalignancies. (These six strains were a gift ofDrs. R.W. Miller and E.A. McKeen, Clinical EpidemiologyBranch, NCI, Bethesda, Md.) Two strains each from patientswith VRD (GM622 and GM1633) and TS (GM1635 and GM1640)were used to examine the other two diseases. Two strainsfrom clinically normal individuals served as controls.The representative strains were exposed to 80Co y-raysunder anoxic conditions (in a N2 atmosphere) and theirradiation response was evaluated by two criteria:(i) ability to form clones, a biological end-point,and (ii) the capacity to perform yray-inducedrepair replication, a gross measure of the ability

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to carry out enzymatic repair of radiation damage toDNA and therefore a molecular end-point.

Whereas all six strains from the AML familiesexhibited normal levels of y-ray-induced repair replication,the three strains from the female members with cancershowed a reproducible, albeit slight, y-ray sensitivityin colony formation relative to the two control strainsand to the three strains from the male members of theAML families. Therefore it is reasonable that hyper-sensitivity to ionizing radiation may be causally relatedto the appearance of cancer in these persons. Further-more, these data suggest the exciting possibility thathypersensitivity to radiation may serve as a usefulin vitro marker for the detection of members within AMLfamilies who are prone to malignancy.

The two VRD and TS strains formed clones and carriedout repair replication following anoxic y-irradiation toan extent comparable to that observed in the two controlstrains. Thus, cells from VRD and TS patients displaya normal DNA repair response to ionizing radiation. Ittherefore appears that abnormal sensitivity to radiationis not responsible for the patterns of clinical featurescharacteristic of these two neurological disorders.

GENETICS AND POPULATION STUDIES

5.14 RADIATION SENSITIVITY OF TEMPERATURE-SENSITIVE MUTANTS OFUSTILAGO MAYDIS BLOCKED IN DNA SYNTHESIS - P. Unrau

In earlier reports the contributions of C E . Grantand J.M. Rainville to this study have been acknowledged.A suspicion that the initial ts-20 strain was a doublemutant has been strengthened by examining the y-raysensitivity of twenty strains obtained after meiosis(which allows unlinked genes to re-assort at random).Three different sensitivities were observed, consonantwith two mutations segregating into three possible groups.It had been observed that mitotic gene conversion wasdepressed in several diploids obtained by crossing ts-20strains to wild-types. With the new classification~rory-sensitivity, it proved necessary to cross these strainsagain in combination with suitable wild-types. Both"sensitive" segregants and "resistant" segregants, whencrossed, gave diploids which could recombine. Not allcrosses, however, can yield recombinants and this anomalywill require further study. It therefore seems thatts-20 is not truly recombination deficient, in theHeterozygous state, at the permissive temperature. It is

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intended to examine the recombination behavior ofthese diploids at 32 C, where the ts-20 gene productshould be inactivated, and in straTns where the ts-20gene is present in two copies (homozygous) at both22 C and 32 C. These studies have been temporarilycurtailed and will be resumed as soon as possible.

5.15 CONTROL MECHANISMS IN THE CELLULAR METABOLISM OF USTILAGOMAYDIS - P. Unrau and D.R. Champ (Environmental ResearchBranch)

In the past year we have reported on the isolation andpartial characterization of a glycoprotein from Ustilagomaydis which makes DNA soluble in dilute ice-cold"trichloroacetic acid (5% TCA). The first report of thismaterial was by W.K. Holloman (j. Biol. Chem. 250, 1975). Thetruly paradoxical nature of this material is that theDNA is not degraded (the usual prerequisite for solubilityof DNA in acid) and the suspicion is that such materialis more wide-spread than commonly believed. We havetherefore tested for the presence of this material inphage T4 infected bacteria, phage T7 infected bacteria,E. coli, M. radiodurans, £3. cerevisiae, Ankistrodesmusbraunii (a green alga), chick embryos, and human fibro-blasts. In all instances DNA binding material couldeither be extracted and tested, or labelled DNA couldbe extracted which was soluble in acid but insoluble in96% ethanol. We conclude that this material has avery wide distribution, even though we are uncertainas to its precise location in the organism or its functions.

The basic paradox that DNA which is soluble in acidcan be undegraded and insoluble in ethanol calls forfurther comment. Practically all molecular biologydealing with nucleic acid metabolism includes thewashing of reaction products or gradient fractions indilute acid. We feel that this practice may produceserious artefacts, and hope to investigate somepossible gaps in knowledge in the coming year.

5.16 A GENETIC ASSAY USING SACCHAROMYCES CEREVISIAE FORDAMAGE ASSOCIATED WITH LOW DOSES OF IONIZING RADIATION -P. Unrau and L.D. Johnson

There are many assays for the detection of environmentalmutagens and carcinogens. These differ in cost, sensitivity,and the spectrum of end-points which can be scored. Itseemed pertinent to score genetic end-points in a simpleeukaryote as the genetical apparatus and nuclear-cyto-plasmic interactions might be more typical of higher

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organisms, and the spectrum of genetic effects might bemore closely related than those observed in repair-deficient bacteria. F.K. Zimmermann has developed yeaststrains used in environmental mutagenesis assays and ina two-month visit base-lines were established, togetherwith comparable techniques. In the last report we mentionedthat the degree of oxygénation of our cultures was notclear; we have since determined that the initial experimentswere on aerobic cells which became anaerobic during thecourse of the experiment.

The effects of low doses of ionizing radiation havebeen studied on one major genetic end-point, namely arecombination assay based on conversion of mutant to wild-type genes. We have been able to detect the induction ofconvertants in late-log phase cells by X-ray doses of aslittle as 1 rad (.01 Gy). The dose response curve is linear;significant increases have been detected at 5 rads(.05 Gy), and the gene conversion response is saturated inoxygen by 20-30 krads (200-300 Gy).

These results are similar to the observations of Markovich(1952) who observed linear response with yield of X-phagedown to 0.3 rad (0.003 Gy). As the induction of A-phagerequires a recombinational event, it is conceivable thatthe assay used by Markovich is as sensitive as can be obtainedfor the recombinational effects of ionizing radiations.Given suitable low background strains, the sensitivity ofthis new yeast assay method might be extended to about1 rad (0.01 Gy) in O2 and about 3 rad (0.03 Gy) in Nz.

There is a pronounced oxygen enhancement ratio, averaging2.65 between 12.5 and 5,000 rads (0.125-50 Gy); the slopeof yield of convertants in both O2 and N2 is about 1.Further statistical enhancement of the data will bepublished in due course.

At doses between 5 and 200 krads (50 to 2000 Gy), cellsstart to die. At these doses other genetic end-points be-come more frequent amongst survivors. Both mitotic crossing-over and mutation are easily scoreable in these dose ranges.We have measured gene-conversion, mutation, and mitoticcrossing-over in cells exposed to 5 to 200 krads (50 to2000 Gy). Whereas the yield of gene-convertants rises (inOz irradiated cells) till 20-30 krads (200-300 Gy) and thenfalls, the yield of iso mutations rises till 50-70 krads(500-700 Gy) and then declines. The peak yields also differbetween gene-conversion and mutation in N2-irradiatedcells. It seems reasonable to suppose that both therecombination process (scored as gene conversion) and

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the mutation process (scored as leading to iso colonies)act on DNA damage until they are saturated; when theyboth become saturated, the cell dies. If this were true,correcting recombinant or mutant yields for survivalwould lead to a continued increase in the yield ofrecombinants or mutants with increasing dose of radiation;this prediction is not confirmed by the experimentaldata. Therefore we deduce that a third mechanism whichpromotes survival must exist; when all three mechanismsare saturated, the cell dies. In collaboration withD. Morrison, we intend to examine, using the rad seriesof mutants available in S. cerevisiae, all the componentsof the repair systems which lead to the survival of thiseucaryote. It is hoped that analogues to all these repairsystems will be found in other, higher eukaryotes.

5.17 RADIATION SENSITIVITY OF BACTERIOPHAGE T4 - MAPPING THESITE OP THE X GENE - J.D. Childs and G.D. Chant1*

We have previously shown that the x gene of bacterio-phage T4, which is involved in the repair of UV andy-ray damage to ONA, is located between genes 41 and 42.We have now completed the mapping of this gene withrespect to the gene ggt (g-glucosyl transferase), whichis also located between genes 41 and 42. An x mutantwas crossed to double mutants carrying a mutation ingene 41 or 42 and a ggt mutation. From an analysis ofthe progeny of these crosses we have shown that the xgene is located between genes 41 and ggt.

5.18 EFFECT OF NEAR UV (>300 nm) RADIATION ON BACTERIOPHAGET4: RECOGNITION OF A PHOTOPRODUCT BY T4 UVENDONUCLEASE - J.D. Childs, M.C. Paterson, B.P. Smith,and R. Pilon

Most studies on the biological effects of UV haveinvolved the use of far UV (chiefly 254 nm), but UV from300-320 nm is much more relevant to environmentalcarcinogenesis. The most important 254 nm-induced photo-products, both in yield and harmful effects, are cyclo-butane pyrimidine aimers. However, their relativeimportance following 320 nm irradiation is less certain.For example, the relative UV sensitivity of bacteriophageT4y (a mutant of T4 unable to induce endonuclease V whichis required for initial dimer incision) compared to T4yincreases from 2-fold for 254 nm irradiation to 4-foldfor irradiation above 300 nm. This implies that endo-nuclease V also recognizes a photoproduct only detectableafter near UV irradiation.

"Resigned 22 April, 1977

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We have examined the ability of extracts of T4-infected Escherichia coli cells, lacking the host UVendonuclease, to introduce single-strand breaks intoDNA isolated from 254 nm- and 320 nm-irradiated T4 andhave determined the proportion of these which are adjacentto pyrimidine dimers. The extracted DNA was either photo-reactivated to selectively remove dimers or êft untreatedand then exposed to extracts of T4v- and T4u -infectedcells. The v extract, but not the v~, introduced breaksinto irradiated DNA, presumably at sites containing UVphotoproducts. Photoreactivation decreased the numberof these UV endonuclease-sensitive sites in the 254 nm-irradiated DNA by about 90%, but it only decreased thenumber in the 320 nm-irradiated DNA by about 50%. Thisindicates that an unusual photoproduct is formed during320 nm but not during 254 nm irradiation of T4.

Bacteriophage T4 is unusual in that it has glucosylated5-hydroxymethylcytosine (5HMC) in its DNA insteadof cytosine. Mutants of T4 exist which either fail toglucosylate 5HMC or have cytosine instead of 5HMC in theirDNA. As cytosine gives rise to important UV-inducedphotoproducts we repeated the previous experiments usingthese mutants. We found that virtually all (>95%) of theendonuclease sites induced in both mutants by 254 nm and320 nm irradiation were photoreactivable. Thus glucosyl5HMC appears to be involved in the formation of the non-photoreactivable photoproduct.

As the photoproduct was not detected in the DNA ofnon-glucosylated or cytosine-containing phage, it wasexpected that these phage would be more resistant tonear UV than normal T4 phage. However, we found thatnon-glucosylated and cytosine-containing phage hadsimilar sensitivities to near UV (313 nm) as did normalphage. These results can be explained if the photoproductresponsible for the non-photoreactivable sites is formedfrom glucosylated 5HMC and that a similar photoproduct,which is photoreactivable, is formed from cytosine ornon-glucosylated 5HMC in the appropriate phage strains.

The results of these experiments have been preparedfor publication.

5.19 EFFECT OF NEAR UV (>300 nm) RADIATION ON BACTERIOPHAGET4: ATTEMPT TO IDENTIFY THE ENDONUCLEASE V-SENSITIVEPHOTOPRODUCT - J.D. Childs, R.E.J. Mitchel, R. Pilon,and M.J. Ellison5

The results of the experiments described in theprevious section indicate that a photoproduct of 5HMC

5Summer Student, terminated 2 September, 1977

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is formed during irradiation with near UV but not withfar UV. We have now started to investigate the chemicalnature of this photoproduct. The basic procedure wehave adopted is to radioactively label T4 with llfCcytosine, irradiate the labelled T4 phage or T4 DNA,digest the DNA and then separate the DNA bases from theirphotoproducts by paper chromatography. We have used twomethods to digest the DNA. The first is acid hydrolysisat high temperature and the second is enzyme digestion.The acid hydrolysis method has the advantages that it isrelatively simple and it has been used extensively.Using this method, we could completely digest T4 DNA andthen obtain good separations on paper chromatogramsbetween thymine, hydroxymethylcytosine, thymine dimersand at least one other photoproduct. The main disadvantageof the method is that some photoproducts could be lostduring the treatment. The enzyme digestion method istechnically more difficult but, as the photoproduct wasinitially detected by an in vitro enzymatic assay, it isless likely that it would~He destroyed by an enzymedigestion than by acid hydrolysis. We have been ableto carry out an enzyme digestion of non-irradiated T4DNA and then separate thymine from hydroxymethylcytosineby paper chromatography. However, we have found thatdigestion of irradiated T4 DNA leaves pyrimidine aimersand other photoproducts in small fragments of undigestedDNA. Another enzyme treatment will be necessary torelease the photoproducts from these fragments.

5.20 RADIATION-INDUCED TUMORS IN RATS - D.K. Myers andL.D. Johnson

Data are being accumulated on the development ofbreast cancers and skin tumors in rats that were exposedto radiation plus various chemical agents in November 1976and January 1977. Preliminary data indicate that caffeine,a DNA repair inhibitor, will not increase the number ofbreast cancers induced by gamma-radiation; this resultis in agreement with the theoretical concepts proposedearlier. The number of breast cancers induced by radiationplus two doses of urethane is approximately equal to thesum of the effects of radiation alone and of urethane alone.Thus t* -.s results obtained in this particular system supportthe conventional estimates of absolute risk that are basedon observed numbers of cancers in irradiated humanpopulations, rather than the higher estimates of relativerisk that are based on the notion of a constant doublingdose for radiation-induced cancers regardless of theinitial incidence of cancers in the unirradiated population.

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5.21 ASSESSMENT OF RADIATION HAZARDS TO HUMAN POPULATIONS -D.K. Myers

Activities during the year have been concentratedon review of published literature and collection ofrisk data from various sources. A review of the hazardsof low-level radiation (Atomic Energy of Canada Limited,Report AECL-5715) and a contribution to a document onresearch in radiation biology at CRNL (Atomic Energy ofCanada Limited, Report AECL-5911) were completed.Literature on the toxicology of hydrogen sulfide wasreviewed. Data was collected on environmental agentsbelieved to be responsible for cancer induction in humanpopulations and the first draft prepared of a documenton estimates of fatal cancers and genetic defects inducedin human populations by the utilization of various energysources.

5.22 PUBLICATIONS

Birnboim, H.C. - Contribution to "Objectives of ResearchActivities in Biology Branch, CRNL, 1976". AtomicEnergy of Canada Limited, Report AECL-5613 (1977).

Birnboim, H.C., D.K. Myers, and P. Unrau - "GeneticEngineering and Recombinant DNA - The Controversy andPresent State of the Art". Atomic Energy of CanadaLimited, Report AECL-5822 (1977).

Birnboim, H.C. and R.E.J. Mitchel - The use of glyoxal-modified mouse DNA for the study of sequences whichcomplex with synthetic polynucleotides. Proc. Canad.Fed. Biol. Soc. 20, 187 (1977) (Abstract).

Childs, J.D. - Contribution to "Objectives of ResearchActivities in Biology Branch, CRNL, 1976". AtomicEnergy of Canada Limited, Report AECL-5613 (1977).

Childs, J.D. - Conditional lethal mutants of bacteriophageT4 unable to grow on a streptomycin resistant mutantof Escherichia coli. Mutation Res. £4, 165-176 (1977).

Childs, J.D., B.P. Smith, and M.C. Paterson - Novelendonuclease V-sensitive sites induced in the DNAof bacteriophage T4 by near UV (320 run) irradiation.Abstracts of Second International Conference onEnvironmental Mutagens, p. 208 (1977) (Abstract).

Gentner, N.E. - Contribution to "Objectives of ResearchActivities in Biology Branch, CRNL, 1976". AtomicEnergy of Canada Limited, Report AECL-5613 (1977).

Gentner, N.E. and M.M. Werner - Slow UV-recovery and fastY-recovery in wild-type Schizosaccharomyces porabe.Molec. gen. Genet. 154, 123-128 (1977).

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Gentner, N.E. - Evidence for a second "prereplicative G2"repair mechanism, specific for y~induced damage, inwild-type Schizosaccharomyces pombe. Molec. gen.;yc<

) .Genet. 154, 129-133 (1977

Marko, A.M., D.K. Myers, I.L. Ophel, G. Cowper, andH.B. Newcombe - "Research in Radiation Biology, inthe Environment and in Radiation Protection at CRNL".Atomic Energy of Canada Limited, Report AECL-5911 (1977).

Mitchel, R.E.J. - Contribution to "Objectives of ResearchActivities in Biology Branch, CRNL, 1976". AtomicEnergy of Canada Limited, AECL-5613 (1977).

Mitchel, R.E.J. - Micrococcus radiodurans surfaceexonuclease: Dimer to monomer conversion by aqueousfree radicals. Abstracts of Papers for the Twenty-Fifth Annual Meeting of the Radiation Research Society,p. 52, Ee-1 (1977) (Abstract).

Mitchel, R.E.J. - Ionizing radiation damage and oxygenprotection in the cell wall of Micrococcus radiodurans.Book of Abstracts on International Conference onSinglet Oxygen and Related Species in Chemistry andBiology, M - 5 , Session XVIII (1977) (Abstract).

Mitchel, R.E.J. and H.C. Birnboim - The use of girard-Treagent in a rapid and sensitive method for measuringglyoxal and certain other a-dicarbonyl compounds.Analytical Biochem. 8 1 , 47-56 (1977).

Mitchel, R.E.J. - Micrococcus radiodurans surfaceexonuclease: Dimer to monomer conversion by aqueous freeradicals. Radiation Res. 70^ 655 (1977) (Abstract).

Myers, D.K. - "Low-Level Radiation: A Review of CurrentEstimates of Hazards to Human Populations". AtomicEnergy of Canada Limited, Report AECL-5715 (1977).

Myers, D.K., J.D. ChiIds, A.R. Jones - Sensitization ofbacteriophage T4 to 6 0Co-y radiation and to low-energy X radiation by bromouracil. Radiation Res.69, 152-165 (1977).

Myers, D.K. and L.D. Johnson - Oxygen effects on initialyield of double-strand breaks, the failure of repair,and cell death in M. radiodurans following y-irradiation.Radiation Res. 70,~655 (1977) (Abstract).

Myers, D.K., H.B. Newcombe, and J.F. McGregor - Synergismand additivity in radiation carcinogenesis in rats.American Industrial Hygiene Conference Abstracts,p. 55, sl82 (1977) (Abstract).

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Myers, D.K. - Contribution to "Objectives of ResearchActivities in Biology Branch, CRNL, 1976". AtomicEnergy of Canada Limited, Report AECL-5613 (1977).

Myers, D.K. and L.D., Johnson - Effects of oxygen during-irradiation of Micrococcus radiodurans. Int. J.

Radiât. Biol. 32, 277-280 (1977).

Mortelmans, K., J.E. Cleaver, E.C. Friedberg, M.C. Paterson,B.P. Smith, and G.H. Thomas - Photoreactivation ofthymine dimers in UV-irradiated human cells: Uniquedependence on culture conditions. Mutation Res.£4, 433-445 (1977).

Lohman, P.H.M., R. Reynolds, and M.C. Paterson - Excisionrepair in human, hamster and embryonic chick cells,studia biophysica 61, 135-140 (1977).

Paterson, M.C., B.P. Smith, P. Knight, and A.K. Anderson -Ataxia telangiectasia: An inherited human diseaseinvolving radiosensitivityr neoplasia and defectiveDNA repair. In Research in Photobiology (A. Castellani,éd.), pp. 207-21FI Plenum Press, New York (1977).

Paterson, M.C,, B.P. Smith, P.H.M. Lohman, A.K. Anderson,and L. Fishman - Defective excision repair of -ray-damaged DNA in human (ataxia telangiectasia) fibro-blasts. In Year Book of Cancer 1977 (R.L. Clark andR.W. Cumley, eds.), pp. 367-369. Yearbook MedicalPublishers Inc., Chicago (1977).

Paterson, M.C. and B.P. Smith - Ataxia telangiectasia:A model genetic disorder relating radiogenic DNAdamage to human malignancy. Proceedings ofconference on "The Role of DNA Repair and Misrepairin Radiation and Chemical Carcinogenesis", p. 2.Kyoto, Japan, 12-14 December, 1977 (Abstract).

Paterson, M.C. - Enzymatic repair of UV-damaged DNA inmammalian cells: Perspectives. Mutation Res. 46,147-148 (1977) (Abstract). —

Paterson, M.C. and B.P. Smith - Ataxia telangiectasia—the -ray analogue of xeroderma pigmentosum. MutationRes. £6_, 148.

Paterson, M.C. - Contribution to "Objectives of ResearchActivities in Biology Branch, CRNL, 1976". AtomicEnergy of Canada Limited, Report AECL-5613 (1977).

Unrau, P. - Contribution to "Objectives of Research Activitiesin Biology Branch, CRNL, 1976". Atomic Energy ofCanada Limited, Report AECL-5613 (1977).

Unrau, P. - Differential chromosomal and mitochondrial DNAsynthesis in temperature-sensitive mutants of Ustilagomaydis. Molec. gen. Genet. 150, 13-19 (1977).

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5.23 VERBAL PRESENTATIONS*


Birnboim, H.C. and R.E.J. Mitchel - The use of glyoxal-modified mouse DNA for the study of sequences whichcomplex with synthetic polynucleotides. Presentedat the Canadian Federation of Biological Societies20th Annual Meeting, University of Calgary, Calgary,Alberta, 21-24 June, 1977.

Childs, J.D. - Non-photoreactivable endonuclease V-sensitive sites induced in the DNA of bacteriophageT4 by near UV (320 run) irradiation. Presented atthe Genetical Society Meeting, Cambridge, England,5-7 July, 1977.

Childs, J.D., B-P. Smith, and M.C. Paterson - Novelendonuclease V-sensitive sites induced in the DNAof bacteriophage T4 by near UV (320 run) irradiation.Presented at poster session at the Second InternationalConference on Environmental Mutagens, Edinburgh,U.K., 11-15 July, 1977.

Mitchel, R.E.J. - Micrococcus radiodurans surfaceexonuclease: Dirtier to monomer conversion by aqueousfree radicals. Presented at Twenty-fifth AnnualMeeting of the Radiation Research Society,San Juan, Puerto Rico, 8-12 May, 1977.

Mitchel, R.E.J. - Ionizing radiation damage and oxygenprotection in the cell wall of Micrococcus radiodurans.Presented at the International Conference on SingletOxygen and Related Species in Chemistry and Biology,Pinawa, Manitoba, 21-26 August, 1977.

Myers, D.K. and L.D. Johnson - Oxygen effects on initialyield of double-strand breaks, the failure of repair,and cell death in M. radiodurans following Y ~ i i iPresented at Twenty-fifth Annual Meeting of theRadiation Research Society, San Juan, Puerto Rico,8-12 May, 1977.

Myers, D.K., H.B. Newcombe, and J.F. McGregor -Synergism and additivity in radiation carcinogenesisin rats. Presented at American Industrial HygieneConference, Fairmont Hotel, New Orleans, Louisiana,22-27 May, 1977.

*Papers in this section are generally not available in print.

117

Paterson, M.C. - Environmentally induced DNA damage,its faulty repair, and malignant genetic diseases.Overview presented at the Dahlem Konferenzen,"Neoplastic Transformation: Mechanisms andConsequences", Berlin, Germany, 9-13 May, 1977.

Paterson, M.C. and B.P. Smith - Ataxia telangiectasia:A model genetic disorder relating radiogenic DNAdamage to human malignancy. Presented at conferenceon "The Role of DNA Repair and Misrepair in Radiationand Chemical Carcinogenesis", Kyoto, Japan,12-14 December, 1977.

Paterson, M.C. - Chairman's Remarks, Session ,2 on"Genetic Factors in Radiation Carcinogenesis".1st Radiation Biology Center International Symposium,Radiation Biology Center, Kyoto University, Kyoto,Japan, 15 December, 1977.

Champ, D.R., P. Unrau, C.E. Grant, and J.L. Young -The role of acid solubilizing proteins ("HollomanMoiety") in the control of DNA condensation.Presented by P. Unrau at NATO Advanced Study InstituteDNA Synthesis: Present and Future, Santa Flavia,Sicily, 20-29 June, 1977.

5.23.2 Lectures or Seminars

Myers, D.K. - Radiation Biology. Presented to a class ofstudents, University of Toronto, Toronto, Ont., 31 Oct/77.

Paterson, M.C. - Ataxia telangiectasia: An inheritedhuman disease involving radiosensitivity, malignancy,and defective DNA repair. Presented to theDepartment of Biology, University of Ottawa, Ottawa,Ontario, 16 February, 1977.

Paterson, M.C. - Radiosensitivity, cancer, and defectiveDNA repair. Presented to graduate students inthe Department of Biology, University of Ottawa,Ottawa, Ontario, 16 February, 1977.

Paterson, M.C. - Environmentally induced DNA damage,its faulty repair, and malignant genetic diseases.Presented to the Department of Physics, M.D.Anderson Hospital and Tumor Institute, Texas MedicalCentre, Houston, Texas, 18 March, 1977.

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Paterson, M.C. - Ataxia telangiectasia: An inheritedhuman disease involving radiosensitivity, neoplasia,and defective DNA repair. Presented to the MedicalBiological Laboratory, TNO, Rijswijk, Z.H., TheNetherlands, 16 May, 1977.

Paterson, M.C. - Ataxia telangiectasia: A model geneticdisorder for human radiogenic malignancy. Presentedto Epidemiology Branch, National Cancer Institute,Bethesda, Md., 17 October, 1977.

Paterson, M.C. - Ataxia telangiectasia: A model geneticdisorder for human radiogenic malignancy. Presentedto Carcinogenesis Branch, National Cancer Institute,Bethesda, Md., 18 October, 1977.

5.23.3 Local Talks

Birnboim, H.C. - Radioisotopes: How they apply in thelife sciences. Presented at the Science Teachers'Seminar, CRNL, 25 February, 1977.

Birnboim, H.C. - DNA Sequencing. Presented to BiologyBranch, CRNL, 29 July, 1977.

Birnboim, H.C. - The genetic engineering controversy.Presented at Deep River Science Association,9 December, 1977.

Childs, J.D. - Genetics of DNA repair. Presented tostudents from the Department of Zoology, Universityof Toronto, CRNL, 15 February, 1977.

Childs, J.D. - Report on "Second International Conferenceon Environmental Mutagens". Presented to BiologyBranch, CRNL, 22 August, 1977.

Gentner, N.E. - Biochemistry of DNA repair. Presentedto students from the Department of Zoology, Universityof Toronto, CRNL, 16 February, 1977.

Gentner, N.E. - How DNA repair processes are studied.Presented to students from Algonquin College, CRNL,24 February, 1977.

Gentner, N.E. - M. radiodurans: Why it survives, andhow it is kiTlecT Presented to Biology Branch, CRNL,25 November, 1977.

Gentner, N.E., P. Unrau, and D. Morrison - A Proposal:Construction of a recombinational intermediate -And what can be done with it. Presented to BiologyBranch, CRNL, 19 December, 1977.

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Johnson, L.D. - Dosimetry. Presented to Biology Branch,CRNL, 15 December, 1977.

Mitchel, R.E.J. - Biological Aspects of the "InternationalConference on Singlet Oxygen and Related Species inChemistry and Biology". Presented to Biology Branch,CRNL, 7 September, 1977.

Mitchel, R.E.J. - Ionizing radiation damage in Micrococcusradiodurans cell wall. Presented to Biology Branch,CRNL, 23 September, 1977.

Myers, D.K. - DNA repair and assessment of radiationhazards. Presented to students from Department ofZoology, University of Toronto, CRNL, 16 February, 1977.

Myers, D.K. - DNA repair and radiation biology at CRNL.Presented to students from Algonquin College, CRNL,24 February, 1977.

Marko, A.M., D.K. Myers, and P.J. Barry - Everything youalways wanted to know about biology. Presented atthe Science Teachers1 Seminar, CRNL, 25 February, 1977.

Myers, D.K. - Radiation biology at CRNL. Presented tostudents from University of Ottawa, CRNL, 15 March, 1977.

Myers, D.K., H.C. Bimbo ira, and P. Unrau - Geneticengineering and recombinant DNA: The controversyand state of the art. Biology and Health Physics DivisionSeminar, CRNL, 18 March, 1977.

Myers, D.K. - Report on ORNL Symposium on "Mechanismsof Tumor Promotion and Cocarcinogenesis". Presentedto Biology Branch, CRNL, 5 April, 1977.

Myers, D.K. - Radiation biology at CRNL. Presented tomembers of Senior Management Committee, CRNL,7 April, 1977.

Myers, D.K. - Radiation biology at CRNL. Presented toProfs. R.L. Clark and R. Morrison, Carleton University,12 April, 1977.

Myers, D.K. - Radiation biology at CRNL. Presented toB. Powell, Commercial Products, 21 April, 1977.

Myers, D.K. - Radiation biology at CRNL. Presented toCRNL Summer Student Guides, 17 May, 1977.

- l'O -

Myers, D.K. - Review from Radiation Rtrear.. . Tw-,:;ty~fifth Annual Meeting and Preview ct paper onRadiation Carcinogenesis in Rats- Presented toBiology Branch, CRNL, 18 May, 1977.

Myers, D.K. - Report on Oak Ridge Workshop on "RepairMechanisms and Exposure Standards". Presented toBiology Branch, CRNL, 8 July, 1977.

Myers, D.K. - DNA repair. Presented to Ontario EducationTV personnel, CRNL, 15 August, 1977.

Myers, D.K. - Biology and Population Research at CRNL.Presented to R & D Program Committee meeting atOttawa, Ontario, 17 August, 1977.

Myers, D.K. - Biological effects of radiation. Presentedat 19th Annual Health Physics Course, CRNL,27 September, 1977.

Paterson, M.C. - Radiosensitivity, cancer, and defectiveDNA repair. Presented to students from theDepartment of Zoology, University of Toronto, CRNL,15 February, 1977.

Paterson, M.C. - Environmentally induced DNA damage,its faulty repair, and malignant genetic diseases.Biology Branch Seminar, CRNL, 22 March, 1977.

Paterson, M.C. - Environmentally induced DNA damage,its faulty repair and malignant genetic diseases.Presented to Biology Branch, CRNL, 18 April, 1977.

Paterson, M.C. - Report on Dahlem Conference on"Neoplastic Transformation: Mechanisms andConsequences". Presented to Biology Branch, CRNL,2 June, 1977.

Paterson, M.C. and B.P. Smith - Recent activities inthe human DNA repair program. Presented at BiologyBranch Staff Meeting, CRNL, 14 June, 1977.

Paterson, M.C. - Ataxia telangiectasia: A modelgenetic disorder relating radiogenic DNA damageto human malignancy. (Rehearsal of talk given inKyoto, Japan.) Presented at Biology Branch Seminar,7 December, 1977.

Unrau, P. - Report on DNA replication meeting in SicilyPresented to Biology Branch, CRNL, 22 July, 1977.

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Zimmermann, F.K. and P. Unrau - Information discussionsof mutations in yeast and plans for experiments.Presented to Biology Branch, CRNL, 6 July, 1977.

Unrau, P. - Low-dose genetic effects in yeast. Presentedto Biology Branch, CRNL, 15 December, 1977.

5.24 INVITED SPEAKERS*

Dr. A. Chan, University of Western Ontario, London,Ontario - "Excision repair of DNA in mammalian cells",18 February, 1977.

Dr. R. Perry, Institute for Cancer Research, Philadelphia,Pa., U.S.A. - "Studies of messenger RNA in animalcells", 24 February, 1977.

Dr. J.A. Heddle, Department of Biology, York University,Toronto, Ontario - "Detection of chromosomeaberrations in human lymphocytes", 21 April, 1977.

Dr. J.A. Raleigh, Health and Safety Division, WNRE,Pinawa, Manitoba - "Radiation chemistry of modelmembranes", 13 May, 1977.

Prof. E. Farber, Department of Pathology, Universityof Toronto, Toronto, Ontario - "Carcinogenesis—ANew Perspective", 16 June, 1977.

Dr. Jean Cadet, Commissariat A L'Énergie Atomique,Centre D'Études Nucléaires De Grenoble, Grenoble,France - "Radiation chemistry of DNA components inaqueous solutions", 18 August, 1977.

Dr. Roger P. Smith, Chairman, Department of Pharmacology,Dartmouth Medical School, Hanover, New Hampshire,U.S.A. - "Toxicology of hydrogen sulfide (biochemicaland pharmacological data)", 31 August, 1977.

Dr. Roger Hand, Department of Microbiology and Immunology,McGill University, Montreal, Quebec - "DNA synthesisin mammalian cells: Evidence for two distinct sizeclasses of replication units", 5 December, 1977.

Dr. Fredericka Eckhardt, Department of Biology,Free University of Berlin, Berlin, Germany -"Mutation induction in yeast by UV radiation",20 December, 1977.

•Papers in this section are generally not available in print.

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ATOMIC ENERGY WjS& L'ENERGIE ATOMIQUE OF CANADA …PROGRESS REPORT October 1 to December 31, 1977...

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