It's ELEMENTary, our dear Watson!

Nelson W. Couch, PhD,CIH, CSP, Col-ret

Triangle Health & Safety, Inc.Durham, NC

(Adjunct Professor: UNC & NCSU)

ncouch8@earthlink.net919-544-2853

J. Daniel Bourland, PhD, DABRAssociate Professor

Dept of Radiation OncologyWake Forest University

Winston-Salem, NCbourland@wfubmc.edu

James E. Watson, Jr.

Quiet charisma, soft spoken, Southern Gentleman» “Jim” to his friends and colleagues

“Dr. Watson” to his students Quiet and unassuming, but very organized

- he seemed to have a plan BS and MS: NC State; PhD: UNC

» 27 years on UNC faculty; many awards for his teaching, research and service

President national HPS - 1985 to 1986 Recipient of the North Carolina’s “Order of

the Long Leaf Pine”, the highest honor awarded by the state of North Carolina to a citizen

James E. Watson, Jr.

Research:» Radon» Radioactive Waste» Dose Reconstruction

Teacher - Mentor, Coach» Emphasized practical, health protection approach» Always had time and eager to help» Encouraged and enabled achievement

– HP & IH program

» His students filled careers in industry, government, academia and military

, Colleague & Friend

Incineration of Radioactive Waste

C-14 C-14

C-14

H-3

H-3

H-3

H-3

Most incinerator licensing criteria

held to 10% MPC top of stack

Atmospheric Meteorology

°

°

°

Dry & Wet Adiabatic Lapse Rate

0

1000

2000

3000

-15 -10 -5 0 5 10 15 20 25

Temperature ºC

Alt

itu

de,

met

ers

Dry Adiabatic ~1ºC/ 100 m

Wet Adiabatic ~ 6ºC/1000 m

Inve

rsion

SuperadiabticUnstable:A, B, C

Subadiabtic

Stable:

E, F

Neutral: D

Visualization of Atmospheric Conditions

Strong Instability

Stable

Stable - Inversion

Stable below, unstable above

Unstable below, stable above

Visualization of Atmospheric Conditions

…sometimes it gets a little strange!

Gaussian Plume Dispersion Model

Y

X

Z

hH

z

y

(x,-y,0)

(x,0,0)(x,-y,Z)

TH = h + d(v/µ)1.4(1+ )T

(x,y,0) = Q exp[-(y2/2y2 + H2/2z

2)] y z µ

Wind Rose (RDU)

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW8

6

4

2

Average AnnualWind Speeds (m/sec)

By Direction

Maximum Ground Concentrations

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

(0.92)

700 m

(0.89)

500 m

(0.74)

700 m

(0.74)

800 m

(0.89)

700 m

(2.32)

800 m (1.80)

6-700 m(2.30)

600 m

(1.70)

500 m(1.80)

500 m

(1.20)

600 m(1.20)

600 m(1.10)

600 m(1.20)

800 m(1.40)

6-700 m (2.20)

700 m

(x10-12 Ci/ml)

H-3

Ground Level Concentrations

1.22.0

1.5

1.0

0.75

0.50.2

1.2

1.5

2.02.0

(x10-12 Ci/ml)

H-3

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

GLC: 105 below top of stack; 103

to 107 below respective MPC

Licensing criteria of 10%

MPC top of stack too

conservative

MSPH: 1981Won NC and HPS Std Awards

Beta Dosimetry

Energetic Beta

Holding vial for 5 minutes

Finger/hand dose from uranium beta

TLD Thickness

- 0.13 mm LiF-Teflon TLD- 0.5 mm LiF-Teflon TLD- 0.78 mm LiF chip- 0.9 mm LiF chip

TLD chip

Beta Dosimetry

Teledyne Isotopes TLD ReaderModel 7300

Donated by Duke Power

Panasonic TLD’s: LiF in Telfon

Very Thin

Gremlin in the Works

1 cm diameter0.13 mm thick Supported by NIEHS

Extrapolation Chamber

Standard Beta SourcesNTIS traceable:

Sr/Y-90; Tl-204, Tc-99NEIHS prepared:

Sr/Y-90; Tl-204, Tc-99, P-32

Electrometer capable of measuring 10-13 A

3 cm dia active volume with 2.6 mg/cm2 window

Extrapolation Chamber

Ioni

zatio

n C

urre

nt (

10-1

3

A)

Chamber Depth (cm)

Extrapolation Chamber

Ioni

zatio

n C

urre

nt (

10-1

3

A)

Chamber Depth (cm)

Extrapolation Chamber

Ioni

zatio

n C

urre

nt (

10-1

3

A)

Chamber Depth (cm)

di

dx

Slope = di/dx

Dtis (mrad/h) = S(1.9x1012)/

Note: 45 to 60 minutes per measurement

Beta Fingertip Dosimeter

Thin flexible backing – like a “band-aid”Up to 4 LiF-Teflon TLD’s

Thin cover to protect TLD’s

Log

Dos

e

Depth

ID Beta

MDD:40 mrem – low E18 mrem – high E

Beta Fingertip Dosimeter

Range:» 0.127 to 1.93 Rem/mo

Peaks:» 3.4 Rem in 1 day» 1.3 to 1.6 Rem in 9 to

14 days Average:

» 0.416 ± 0.486 rem/mo

40 Ci P-32 in an Eppendorf Tube measured 300

mRem/min

PhD: 19862 other std’s earned MSPH’s NIEHS used until 3 yrs ago

Educational Life with Jim Watson“He was the Radiological Hygiene Program”

Assistant Professor, Program Director 1977 Peterson’s Guides

Educational Life with Jim WatsonStudents Always First – Facilitated Education

Educational Life with Jim WatsonSimplicity of Content, Demand for Excellence

Grading Scale

H 95 – 100

P+ 90 < 95

P 75 < 90

P- 70 < 75

L 60 < 70

F < 60

Very difficult to get an Honors, and yet with a personal touch.

Educational Life with Jim WatsonThe North Carolina State University Connection

How did this ever work? NC 54 – “swamp run” Needed courses

» Radiation Biology» Nuclear Engineering

Why? Respected former teachers» Drs. AW Waltner and DS Grosch

Why? Dr Watson made the Program work

Evaluation of a Water Immersible Ionization Chamber (MSPH)

Duke UnivTZ Wong,

F Bagne, PhD

Bragg-Gray Cavity TheoryA Dual-Volume Parallel Plate Chamber

Irradiation GeometryWhere is the measurement point for a parallel plate chamber?

Results: Satisfactory CharacteristicsDeformation of Active Volume Probable

NC HPS Student Presentation;

Oral Presentation, 1980 AAPM

A Finite-Size Pencil Beam Model for Three-Dimensional Photon Dose Calculations (PhD)

Dr. James E. Watson, Jr.Impact on students and their careers

Always start with first principles “True scholar and a gentleman” Simplicity of content, demand for excellence Students always first “10% of the nation’s health physicists” “He was the Radiological Hygiene Program”

“He was in the top three of the best teachers I have ever had….he was a true scholar and a gentleman.” (Don Tyndall, DDS, PhD, Professor - UNC Diagnostic

Sciences and General Dentistry)

Any Questions?