05000254/LER-1988-001, Sanitized Version of LER 88-001-00:on 880114,records Review Found Two Apparent Overexposures of Contractor Personnel During Fourth Quarter 1980.Caused by Inaccurate Secondary &/ or Primary Dosimetry.Dosimetry Sys Upgraded

Sanitized Version of LER 88-001-00:on 880114,records Review Found Two Apparent Overexposures of Contractor Personnel During Fourth Quarter 1980.Caused by Inaccurate Secondary &/ or Primary Dosimetry.Dosimetry Sys Upgraded

ML20196E296
Person / Time
Site:	Quad Cities
Issue date:	01/28/1988
From:	Bax R, Tank R COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-88-001-06, LER-88-1-6, RLB-88-29, NUDOCS 8803010023
Download: ML20196E296 (7)

LER-2088-001, Sanitized Version of LER 88-001-00:on 880114,records Review Found Two Apparent Overexposures of Contractor Personnel During Fourth Quarter 1980.Caused by Inaccurate Secondary &/ or Primary Dosimetry.Dosimetry Sys Upgraded

Event date:
Report date:
2542088001R00 - NRC Website

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$ LICENSEE EvtNT REPCRT (I.ER) 1 Facility came (1) , Occket Number (2) _han f 31 OJAD-f!Titi NUCLEAR POWER staff 0N. UNIT ONE 01 El 01 01 01 21 El 4 1 lofl0 $

Title (4) TWO CONTRACTOR PERSONNEL OvtRExP01URES IN THE FOURTH QUARTER OF 1980 OUE TO DOS! METER INACCURACY R t Date (1) Ltt Number (6) Renart Date (7) Other Facilities Involved (R)

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Ill 213 elo Alt 01 0 ll 0 l0 0l 1 218 Bla of El dl 01 0! l 1 THIS REPORT !$ $UeMITTED PUR$UANT TO THE REQUIREMENTS OF 10CFR

(. Check one er more of the followino) f11) 20.402(b) _ 20.40$(c) 50.73(a)(2)(iv) 73.71(b)

POWER _X., 20.405(a)(1)(1) 50.36(c)(1) _, 50.73(a)(2)(v) _ 73.71(c)

LEvtl _. 20.405(a)(1)(11) 50.36(c)(2) ,_ 50.73(a)(2)(v11) .,_._ Cther (Specify f101 0!0 ! _0 __ _ _ _ 20.405(a)(1)(111) ., 50.73(a)(2)(1) 50.73(a)(2)(vtti)(A) in Abstract below

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LIfthift CONTACT F0P THit LER (12)

Name TELt? HONE NUMBER AREA CODE Randall Tank. Desimetry Records coordinator Ext. 2741 3 1019 611141-l212 l COMPLETE ONE LINE FOR EACH COMP T FAILURE DESCRIRtc IN THIS REPORT f13)

CAU$E SYSTEM COMPONENT MANUFAC- REPORTA8LE / CAU$E SYSTEM COMP 0NENT MANUFAC. REPORTABLE TURER 70 NPROS TURER 70 MPRDS X fIL l MI of M Vl1 11 11 N X I IL IM 10 IN X10 11 11 4 X fIL l MI of N LI 01 61 E N l l l 1 l l }

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l ll l A31 TRACT (Limit to 1400 spaces i.e. approximately ftfteen single-space typewritten lines) (16)

On January 14, 1988 it was determined fiom a records review that two apparent overexposures of contractor personnel occurred during the fourth quarter of 1980.

Since adequate information does not exist today relative to the 1980 cases, these could not be disproved. This identification of apparent overexposures was the result of a special computer program that produced a list of all individuals that had been documented as being overexposed at Commonwealth Edison (CECO) sites. One individual received 3190 mrem / quarter and the second individual received 3180 trem/ quarter based on documented film badge readings. This is in excess of 10CFR20 exposure limits and is reportable per 10CFR20.405(a)(1)(1).

The cause for the apparent overexposure was the inaccuracy of the secondary and/or primary dosimetry in use. Since this event, significant improvements have been made in both secondary and primary dosimetry systems and discrepancies of this magnitude do not occur. In addition, there are improved administrative controls to track individual doses and to provide for immediate recognition of anyone approaching th6 limits.

8803010023 000128 c;d PDR ADOCK 05000254 S PDR

1. l 1174H/03922 i

I LICE 4itt EVENT REPORT fLER) TEXT CONTINUATION FACILITY 4AME (1) 00CKE? CUM 8tR (2) _ ttR MuMa[R f61 pu , (3)

Year // sequential Restston p/pp/

// Number /pp////p/ Number _

oeud citiat unit one 0lEl 0 1 0 1 0 ! fl El 4 8l 8 . O I0I1 - 0 10 012 0F 011

, TEXT PLANT AND SYSTEM IDENTIFICATION:

General Electric - Bolling Water Reactor - 2511 MWt rated core thermal power. Energy Industry Identification System (E:IS) codes are identified in the text as (XX).

EVENT IDENTIFICATION: Two contractor personnel were overexposed in the fourth quarter of 1980.

A. CONDITIONS PRIOR TO EVENT:

Unit: One Event Date: November 23, 1980 Event Time: NA Reactor Mode: NA Mode Name: NA Power Level: 007.

This report was initiated by Deviation Report 0-4-1-88-006 B. DESCRIPTION OF EVENT:

Ouring the fourth quarter of 1980, two contractors were apparently exposed to radiation in excess of the 10CFR20 exposure limits. Respective amounts of exposure are: Individual A - 3190 mrem / quarter and Individual 8 - 3180 mrem / quarter (See Attachment A and B). This occurrence was not recognized until recently when a special computer program was run to identify personnel overexposures to radiation. .

The following is a chronological history of what apparently transpired. Please note that dates are approximate as records do not exist for many of these actions.

September 15, 1980- The two individuals began their employment at Quad Cities Station. The main source of exposure to these individuals was

. the inboard Hain Steam : solation Valves (SB, ISV) which they were working on. Dose rates were between 100 mR/ hour and 400 mR/ hour. They worked in this particular area intermittently for six weeks.

November 23, 1980 - The two individuals terminated their employment at Quad Cities Stttion. The computer update of their radiation exposure had tht 4 listed as:

Individual A - 2754 mremiquarter consisting of film badge readings of 1240 mrem and 1130 mrem, and secondary dostmetry readings of 384 mrem.

Individual B - 2734 mrem / quarter consisting of film badge

readings of 1100 mrem and 1090 mrem, and secondary dostmetry readings of 544 mrem.

November 29, 1980 - Film badge readings were substituted for secondary readings for the pertoo ending November 23, 1980. As a result:

820 mrem replaced 384 mrem for Individual A, resulting in an exposure of 3190 mrer for the quarter.

l 990 mrem replaced 544 mrem for Individual B, resulting in an exposure of 3180 mrem for the quarter.

1174H/0392Z E

I se _ _ _

L!cENiff EVENT REPORT fLER) TEXT coNTINUAftoN FAc!LITY NAME (1) 00CLit NUMett (2) _ LER NLMER (6)

Year Pieefn _

, /j// sequential /// Revision

/ Number Number ouas cities unit one o I i l o i o I o i 21 11 4. sIa itxT oIoi1 . oIe ol3 or els, Personnel who are terminated are no longer issued film badges.

The computer update lists only individuals who are currently badged.

Since these individuals were no longer badged, they were not listed on the computer update and the overexposure was not recognized.

December 29, 1980 - Termination letters (10CFR20.408) were produced and sent to the individuals and the NRC. Although all letters are reviewed prior to being sent, apparently these overexposures were missed.

August 15, 1986 -

A special computer program, to list all individuals that were overexposed to radiation at all CECO sites, from 1972 to the present, produced a list of 25 individuals. Ten of these occurrences were immediately recognized as being valid but had already been reported to the NRC. The remaining 15 occurrences were not considered to be valid.

March 25, 1987 -

CECO Corporate Health Physics sent a request to the stations asking that these individuals' overexposures be investigated.

Quad Cities Station was responsible for investigating five of the fifteen occurrences.

November 1, 1987 - A review of Quad Cities personnel records revealed that there was a problem with two individuals. Personnel records reviewed included Form-5 microfiche, microfilmed records of badge and dostmeter records, Radiation 00simetry Reports from CECO's film badge contractor, Radiation Occurrence Reports, Investigation Sheets, and termination letters. The apparent overerposures of these two individuals could not be disproved as could the other three individuals' overexposures. An in-depth review of all related records was initiated. Related records included microf timed records- of Exposure Time Worksheets, badge and dosimeter records for co-workers, Radiation Oostmetry Reports for co-workers and Exposure Time Worksheets for co-workers.

December 22, 1987 - CECO's film badge contractor re-read the film badges for these two individuals and reiterated that the original readings were correct.

January 14, 1988 - The apparent overexposures of these two individuals could not be disproved. On this date, this event was determined to be reportable and the NRC was notified by Corporate Health Physics.

C. APPARENT CAUSE OF EVENT:

These overexposures are reportable under 10CFR20.405 "Reports of Overexposures and Excessive t.evels and Concentrations."

The intermediate cause of the event was the substitution of the individuals' secondary dostmetry readings with their substantially higher film badge readings.

The root cause was inaccurate secondary and/or primary (film) dosimetry.

Il74H/Os922

LICENitt (VENT etPdRT fLER) fttf CONTINUAffah FAc!LifY NAMC (1) 00CKET NUNGER (2)

• LtR NUMatt f61 Pace (1) 3 Year //

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sequential / Rev151on

/ Number /// Number auaa etties unit one oi1IoIofa 1 21 11 4 aia . oIoi1 - a1o 014 or als_

.itz" The cause for the inability to recognize this situation promptly was a deficiency in the system utilized in 1980 to monitor and track radiation exposure.

D. SAFETY ANALYSIS OF EVENT:

There were minimal safety consequences associated with this event because the overexposures were small in magnitude.

E. CORRECTIVE ACTION:

During the years since this event, both secondary and primary dosimetry systems have been upgraded. Secondary dosimetry at the time of this event consisted of indirect reading pocket ton chambers (Victoreen model 362) and mechanical electronic desimeters (Xetex model 415). These have been replaced by better quality direct reading pocket ion chambers (Stephens model 907-862 and DCA model 862) and state of the art electronic dosimeters (Merlin-Gerin model DM-61), Film badges (R.S.

Landauer Jr. and Co. X, gamma and beta badges) have been replaced with thermo-luminescent dostmeters (TLD) (Panasonic model UD 802). Both replacement systems are considered to be much more accurate than the systems in use at the time of the event. Olscrepancies of this magnitude between primary and secondary dastmetry systems no longer occur due to the use of this state of the art equipment.

In addition, there are improved administrative controls to track individual doses and to provide for immediate recogattion of anyone approaching the limits.

Spectfically, the computer program reports used to track doses provide warning flags as individuals approach station administrative and legal limits.

Several reports are currently in use to allow an immediate recognition of a similar occurrence. The first of these is automatically generated when primary readings replace secondary readings and lists all individuals who exceed any administrative or legal limit. Another report compares primary readings with secondary readings for all individuals and lists the individual if the readings are discrepant.

Individuals A and B would have appeared on both of these reports if they had been in place at the time. Both of these reports include individuals who are no longer badged and thus an occurrer.ce of this type would be immediately recognized.

Letters concerning these apparent overexposures have been sent to the two individuals involved.

F. PREVIOUS EVENTS:

Previous events of this type are documented in Quad Cities Station Deviation Reports 0 6-1-76-25 (Mechanical Maintenance Foreman received quarterly whole body dose overexposure) and 0-4-1-76-53 (Two 18 year old contractor personnel received exposures exceeding 10CFR20 limits). These events were reported in letter

' NJK-76-167 dated April 29, 1976 and letter NJK-76-393 dated October 29, 1976.

1174H/03922

c-Litthitt EVENT'2tPott fLE!) ftXT CoNTINUATIoM FACILITY NAMC (1) DOCKET NUMe(R (2)* LER NUMBER f61 Paan (1)

Year ///

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/ Number cua,1 cities unit one o I E I o I o 1.1,.Ltl 11 4 aIa - oIo11 - oIo als oF ois ,

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G. COMPONENT FAILURE DATA:

The following is provided to indicate what dostmetry was in use at the time this event occurred.

Manufacturer Nomenclature Model Number Victoreen Indirect reading lon chamber 362 Xetex Mechanical electronic dosimeter 415 R.S. Landauer, Jr. Film badge X, gamma, beta sensitive and Company l

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4 PURSUANT TO 10CFR20.405(b). THE-FOLLOWING TWO PAGES, IDENTIFIED AS ATTACHMENTS A AND 8. ARE SEING PROVIDED TO NRC UNDER THIS SEPARATE COVER.

i 1174H

6 Commonwealth Edison owad Cities Nuclear Power Station 22710 206 Avenue North Corcova, ininois 61242 Telephone 309/654 2241 RLB-88-29 January 28, 1988 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Reference:

Quad-Cities Nuclear Power Station Docket Number 50-254, DPR-29, Unit One Enclosed please find Licensee Event Report (LER)88-001, Revision 00, for Quad-Cities Nuclear Power Station.

This report is submitted in accordance with th3 requirements of the Code of Federal Regulations, Title 10, Dart 20.405(a)(1)(1), which recuires the reporting of exposures of individuals to radiation in excess of t*,e applicable limits in 10CFR20.101 or 20.104(a). Pursuant to 10CFR20.405(b), Attachments A and B are provided to detail the information required.

Respectfully, COMMONHEALTH EDISON TANY QUAD-CITIE NUC P,OHER STATION

/ /

C. ,

R. L. Bax

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Station Manager RLB/MSK/cir Enclosure cc: I. Johnson R. Higgins INP0 Records Center NRC Regien III 0370H/0183Z

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