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LICENSEE EVENT REPORT (LER)

Docket Nunt>er (2) Page (3)Facility Name (1)

LaSalle County Station Unit 1 01 51 01 01 01 31 11 3 1|of|0|4Spurious Anmwia Detector Trip Due to Design Deficiency in the Chemcassette Tape Mechanism

Event Date (5) LER Nunt>er (6) Report Date (7) Other Facilities Involved (8) fYear

{/{/{/Sequential /ffRevision Month Day Year Facility Names Docket Nat>er(s) j

Month Day Year|j/// Nunt>erNat>er

LaSalle Unit #2 01 51 01 01 01 31 71 4

01 6 01 2 81 7 B1 7 0|214 010 017 01 1 81 7 0151010101 I I~~~

T H MN EM M M RWN M MOPERATING (Check one or more of the following) 01) ,

4 20.402(b) _20.405(c) X 50.73(a)(2)(iv) 73.71(b) |M00E (9)

POWER 20.405(a)(1)(i) _50.36(c)(1) 50.73(a)(2)(v) 73.71(c) |

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LEVEL 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) _Other (Specify_

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00) 0|0 |0 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) in At,stract__

/,/,/,/,////,//,/,/,/,/, '//,/,/,/,/,//,//,/, 20.405(a) 0 )(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) below and in ;

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/'/7///f///(' /,T///','ff//' '/'//'//'/'j/ _ 20. 405 (a) 0 ) (v) _50. 73(a) (2) (iii) _

50. 73(a) (2) (x) Text) l__

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LICENSEE CONTACT FOR THIS LER O2)TELEPHONE NUMBER

NameAREA CODE

Paul S. Watford. Technical Staff Engineer, ext. 323 81115 31 51 11 -l 61 71 611

COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 03)CAUSE SYSTEM COMPONENT MANUFAC- REPORTABLE CAUSE SYSTEM COMPONENT MANUFAC- REPORTABLE

TURER TO NPRDS TURER TO NPRDS4

B VII i 01 El i l | | N I | | | | 1 1

I i 1 | | | | | | 1 I I I I

SUPPLEMENTAL REPORT EXPECTED (14) Expected Month | Day | Year

Submission

lyes (If yes, conclete EXPECTED SUBMISSION DATE) X l NO | || ||#

ABSTRACT (Limit to 1400 spaces, i.e, approximately fif teen single-space typewritten lines) 06)

At 2120 hours on June 2,1987, with Unit 1 in Condition 4 (Cold Shutdown) and Unit in Condition 5(Refuel), the "A" Control Room HVAC System (VC) amnonia detector OXY-VCl25YB tripped. AnEngineered Safety Feature (ESF) danper actuation occurred and the mininum outside air danpers,OVC05YA and OVC52YA, went to the closed position per design. The charcoal adsorber bypass danper,0VC13YA, was in the closed position for repairs and air flow was already through the charcoal bedinlet and outlet danpers, DVC11YA and OVCl2YA, respectively. The chemcassette tape was foundbroken in the makeup spool due to a design deficiency in the chemcassette tape mechanism. Thechemcassette tape was readjusted and the detector was reset at 2150 hours the same day.

This event is reportable pursuant to the requirement of 10CFR50.73(a)(2)Uv) due to the actuationof an ESF system.

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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) Pane (3)

j/g/Sequential //J Revision/Year

f// Nwber /T/ Number

taSalle County Station Unit 1 0 | 5 1 0 1 0 1 0 1 31 71 3. 8 1 7 0|214 - 0I O 01 2 0F 01 4-

TEXT

PLANT AND SYSTEM IDENTIFICATION

General Electric - Boiling Water Reactor

Energy Industry Identification System (EIIS) codes are identified in the text as [XX].

A. CONDITION PRIOR TO EVENT

Unit (s): 1/2 Event Date: 6/2/87 Event Time: 2120 hours

Reactorliode(s): 4/5 Mode (s) Name: Cold Shutdown / Refuel Power tevel(s): 05/0%

!8. DESCRIPTION OF EVENT

At 2120 hours on . lune 2,1987, with Unit 1 in Condition 4 (Cold Shutdown) and Unit 2 inCondition 5 (Refuel), the "A" Control Room HVAC System (VC) (VI) "B" anmonia detector(0XY-VCl25YB) tripped. An Engineered Safety Feature (ESF) danper actuation occurred and themininun outside air danpers, 0VC05YA and OVC52YA, went to the closed position per design. Atthe time of the event, the "A" VC system " odor eater" (charcoal adsorber) was operating in theRecirculation Mode with the minimum outside air danpers open.

The Instrument Maintenance Department investigated the event and found that the chemcassette j

tape was broken in the makeup spool. The chemcassette tape was readjusted and the detectorwas reset at 2150 hours on the same day.

No systems or conponents were inoperable at the beginning of the event which contributed tothis event.

This event is reportable pursuant to the requirement of 10CFR50.73(a)(2)(iv) due to theactuation of an ESF system. ,

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C. APPARENT CAUSE OF EVENT

The cause of the event was tape breakage in the chemcassette assembly. Due to the nunber ofprevious chemcassette failures, the root cause of this ever.t has been detennined to be a ;

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design deficiency in the chemtassette tape mechanism.;

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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION

FACILITY NAME (1) DOCKET NUMBER (2) LER NUM8ER (6) Pace (3)Revision

f'//Sequential ///Year

ff Number fff Ntseer

01 0 01 3 0F 01 4LaSalle County Station Unit 1 0 1 5 | 0 1 0 1 0 | 31 71 3 8|7 - 0I2l4 -

TEXT

D. SAFETY ANALYSIS OF EVENT

The anmonia detector actuation would nonnally result in an ESF actuation and place the " odoreater" (charcoal adsorber) in operation and isolate (close) the mininsn outside air danper.The charcoal adsorber bypass damper, OVCl3YA, was in the closed position for repairs and airflow was already through the charcoal bed inlet and outlet danpers, DVC11YA and OVC12YA,respectively. During the event when a single subsystem was inoperable, the "A" VC odor eaterwas operating in the nonnal mode of operation. This event had no effect on the non-operating"B" VC train. The annonia detector chemtassette tape was repaired and restored to service inthirty minutes thus meeting all operational requirements of Technical Specification 3.3.7.8.

E. CORRECTIVE ACTIONS

An Instrument Technician adjusted the chemcassette tape and verified that the cassette tapewas operating properly. The detector was returned to operable service at 2150 hours on June2, 1987.

A preventative maintenance program is presently in place to inprove the perfonnance of theanmonia detectors. This program consists of inspecting and cleaning (all moving parts) of theammonia detectors on an annual basis.

Work Request L69592 and L69593 have been written to upgrade the MDA tape mechanism.Consideration is being given to enlarging the scope of the modification to add an additionaldetector to each train and institute a single failure proof trip logic. A TechnicalSpecification Change request has been submitted that would allow removal of these detectors ifapproved.

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F. PREVIOUS EVENTS|

LER Nunter Title

373/87-018-00 Control Room HVAC ESF Actuation Due to Broken NH3 Chemcassette Tape

373/87-012-00 Spurious Mmonia Detector Trip Due to Broken Chemtassette Tape373/87-004-00 Janmed Chemcassette Tape in Anmonia Detector Causes ESF Actuation

373/86-027-00 Spurious Anmonia Detector Trip Due to Broken Chemtassette Tape373/86-018-00 Spurious Amnonia Detector Trip Due to Broken Chemcassette Tape373/86-014-00 Spurious Anmonia Detector Trip Due to Broken Chemcassette Tape373/86-004-00 Spurious Anmonia Detector Trip Due to Broken Chemtassette Tape

373/85-050-00 Spurious Anmonia Detector Trip Due to Janmed Chemcassette Tape373/85-038-00 Spurious Amnonia Detector Trip Due to Broken Chemcassette Tape

373/84-091-00 Spurious Amnonia Detector Trip Due to Broken Chemcassette Tape373/84-078-00 Spurious Amnonia Detector Trip Due to Broken Chemcassette Tape373/84-066-00 Spurious Amnonia Detector Trip Due to Janmed Chemcassette Tape

373/82-060/03L Spurious Amnonia Detector Trip Due to Broken Chemtassette Tape373/82-157/03L Spurious Mmonia Detector Trip Due to Broken Chemcassette Tape

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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) Page (3)

// Revisionfj/j Sequential /j/j//Yearj// Neber/// Nunber

0| 0 01 4 OF 01 4LaSalle County Station Unit 1 0 1 5 1 0 1 0 1 0 1 31 71 3 8I7 0l2l4 --

TEX 1

G. COMPONENT FAILURE DATA

Manufacturer Nomenclature Model Nunter MFC rart Number

MDA Scientific conpany Cassette Tape 7060-FAN 700005

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i t-- Cnmm:nwenith EdisonLaSalle County Nuclear StationRural Route #1, Box 220

|Marseilles, Illinois 61341 '

Telephone 815/357-6761

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IJuly 1, 1987

U. S. Nuclear Regulatory CommissionDocument Control Desk |Washington, D.C. 20555 |

Dear Sir:

Licensee Event Report #87-024-00, Docket #050-373 is being i'

submitted to your office in accordance with10CFR50.73(a)(2)(iv).

1

.f. O. c aC,. J. DiederichStation ManagerLaSalle County Station

GJD/PSW/kg

Enclosure

xc: Nuclear Licensing AdministratorNRC Resident InspectorNRC Region III AdministratorINPO - Records Center

pbals

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