ML20080C690

Responds to NRC Re Violation Noted in Insp Repts 50-352/94-23 & 50-353/94-23.Corrective Actions:On 940912, ERP-300 Was Temporarily Changed to Provide Guidance in Editing Erroneous Inputs to Computer Dose Assessment

ML20080C690
Person / Time
Site:	Limerick
Issue date:	12/09/1994
From:	Helwig D PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9412190204
Download: ML20080C690 (7)

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g' Vice President -

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Umerick'Orneratmg' Station -

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f' :PECOlENERGYJ Peco ene,or cemPaer.

Umerick Generating station -

PO Box 2300 :

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. Sanatoga,' PA 19464-0920 f 610 3271200, Ext. 3000 -

10 CFR 2.201:

December 09,1994 Docket No. 50-353 -

. License No. NPF-85 t

U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC. 20555

SUBJECT:

Limerick Generating Station, Unit 2 Reply to a Notice of Violation NRC Combined Inspection Report Nos. 50-352/94-23 and.

50-353/94-23 Attached is the PECO Energy Company reply to a Notice of Violation for

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Limerick Generating' Station, Unit 2, that was contained in your letter dated November 9,1994. The attachment to this letter provides a restatement of the 1

violation followed by our reply.

if you have any questions or require additional information, please contact us.

Very truly yours,

' k f.c D.ra. Wet.f an.

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.T. T. Martin, Administrator, Region I, USNRC w/ attachment -

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i N. S. Perry, USNRC Senior Resident inspector, LGS

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941219o2o4 9412o9 iPDR' ADOCK 050oo352

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s Attachment Docket No. 50-353 December 09,1994 Y

Page 1 of 8 '

s Raniv to a Nr*irm of Viniatinn' Pantatament of the Viniatinn

.l During an NRC inspection conducted on September 27,1994 through October 31,

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1994, a violation of NRC requirements was identified, in accordance with the " General' Statement of Policy and Procedure for NRC Enforcement Actions," 10 CFR Part 2, Appendix C, the violation is listed below:

10 CFR 50.54(q) requires in part that a licensee authorized to possess and operate a nuclear power reactor shall follow and maintain in effect emergency L'

plans which meet the standards in 10 CFR 50.47(b).

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- 10 CFR 50.47(b) requires in part that the onsite and offsite. emergency respnse :

plans for nuclear power reactors must meet the following standards: a standard emergency classification and action level scheme, the bases of which include facility system and effluent parameters.

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ERP-101, Classification of Emergencies, written to comply with_10 CFR 50.47(b),.

requires in part that the Emergency. Dire # r classify 'an event based on selected categories and most severe Etw (Emergency Action Level).

j Contrary to the.above, on September 12,1994, with Unit 2 at 100%' power, the Shift Manager, acting as the Emergency Director, did not classify an event l

based on selected categories and most severe EAL ' An unusual Event (UE) declaration was not made after the Shift Manager was informed that dose j

assessment, performed by the shift health physics technician in respcnse to an e

'f alarm received on the south vent stack noble gas monitor, indicated that the projected offsite dose was 8.98 E-2 mrem /hr TPARD (Total Protective Action Recommendation Dose), in excess of the EAL for a UE of 5.7 E-2 mrem /hr l

TPARD.

This is a Severity Level IV Violation (Supplement Vill).

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RESPONSE

4 LAdmlaminn of the Viniation PECO Energy Company acknowlsdges the violation.

Ramann for the Vinfatinn

" On September 12,1994, at 0404 hours0.00468 days <br />0.112 hours <br />6.679894e-4 weeks <br />1.53722e-4 months <br />, with Unit 2 at 100 percent power, the South Stack gaseous effluent radiation monitors alarmed. Operations personnel were backwashing resin from the Reactor Water Cleanup (RWCU) System at the time of the i

alarm. The operators entered Transient Response implementation Plan (TRIP)'

procedure T-104, " Radioactivity' Release Control," which directed the performance of Surveillance Test (ST) procedure ST-6-104-880-0, " Gaseous Effluent Dose Ratte Determination." This ST procedure directed Health Physics (HP) to perform a dose assessment of the release using Emergency Response Procedure E. P-300, R

. TSC/MCR Dose Assessment Team," since the threshold value in the ST was exceeded. The shift HP technician reported to the main control room to perform the dose assessment.

The initial projected offsite dose using MESOREM, a computerized dose assessment.

i:i program, was 0,855 mR/hr. The HP. technician informed the Shift Supervisor that the.

offsite dose rate was greater than the 0.057 mR/hr EAL for a UE. The Shift Supervisor

. recognized that the results were inconsistent with the expected results for the plant

' evolution in progress. He directed the HP Technician to verify the calculation. This use of Emergency Director's (ED) judgement was in accordance with guidance in the

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Emergency Procedures, and was considered appropriate by the NRC staff during its review of this event.

The HP technician contacted the Effluent Monitoring Physicist at home who determined that input from an out-of-service' effluent radiation monitor had been used by the computer program yielding a false high offsite dose rate. The HP technician completed a subsequent dose assessment run using the computer's auto data collection mode without the' data from the out-of-service effluent radiation monitor.

This run gave an offsite dose rate of 0.09 mR/hr which again was soove the EAL for a UE.'

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c4 Docket No. 50-353 December 09,1994'.

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Page 3 'of 6 -

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.Whiie the HP technician performed the computerized dose assessment, the Effluent

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Monitoring Physicist performed a hand calculation of the offsite dose rate at home using the methodology ~ outlined in the Offsite Dose Calculation Manual.'(ODCM). This calculation gave an offsite dose rate of 0.018 mR/hr whichis well below the EAL for a -

. UE.

The HP technician gave the Shift Supervisor the results of both the computerized dose assessment calculation and the' hand calculation. At 0548 hours0.00634 days <br />0.152 hours <br />9.060847e-4 weeks <br />2.08514e-4 months <br />, on September 12, 1994, the Shift Manager and the Shift Supervisor decided that s' UE declaration was not required based on the results of the hand calculation and a subsequent telephone conversation with the Effluent Monitoring Physicist at home. The ED is expected to use his Judgement in evaluation of EAL declaration, however, the ED's judgement was influenced by inappropriate input from the Effluent Monitoring Physicist. Although.the ODCM methodology used for the hand calculation is valid for dose assessment, it was not procedurally recognized for determining the offsite dose rate in support of making initial emergency classifications in the event of a release. Additionally,.he used g

. meteorology that was not representative of current conditions in the performance of j

this hand calculation.

The primary cause of this event was a preconditioned response on the part of.

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Operations due to recurring problems with dose assessment' calculations during

' RWCU resin backwash eventa. Previous experience with dose assessment led Operations personnel to believe that UE dose rate levels would not. typically be

' reached during routine RWCU resin backwash activities. Also, past experience showed hat initial dose assessment calculations were not always reliable.'. Previous t

events involved multiple calculations which eventually resulted in the conclusion that ll no UE declaration was required. This combination of experiences undermined the credibility of the initial dose assessment calculations and coindbuted to the reluctance on the part of the shift management to accept the computer calculation results.

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1 Ineffective communication of management expectations concoming the_use of the i

computer dose calculation and additional techniul expertise contributed to this event.

Actions taken in response to previous events included management direction regarding classification of events based on dose assessment calculations. However, this guidance did not clearly define the expectation regarding the use of supplemental

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Docket No. 60 353 4

December 00,1994 -

Page 4 of 6' Procedural deficiencies also'ccidi cuted to'this event. These deficiencies involved

? inadequate instruction and _ ineffective human factoring regarding the method for

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correcting erroneous input ' data to the computer dose model. In addition, the.

< corrective actions from the most recent previous similar event in May 1994 imd not yet.

been fully implemented. These actions included human _ factoring of the' procedures

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and the computer dose model, and a proposed revision to ERP-300 and ERP-101, l

" Classification of Emergencies,". which would allow the use of one (1) hour' averaging'

- j of the release data in lieu of 15 minute averaging. One hour averaging is acceptable m

based on NRC Emergency Preparednes guidance. Tni3 would have resulted in an ~

q offsite dose rate below the EAL for an s3, and would have eliminated some of the confusion between the computer run and the hand calculation.

Corrective Actbna Taken and Rannita Achieved On September 12,1994, ERP-300 was temporarily changed to provide guidance'in editing erroneous inputs to the computer dose assesament program, and.self-checking the dose assessment inputs to the computer dose model.. In addition, the Radiation. Protection Manager personally met with all of the Dose Assessment qualifie l

HP technicians to the discuss this event and expected actions. Also,:the Effluent j

Monitoring Physicist was counseled en the appropriate dose assessment methods to i

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be used in support of an initial emergency classification.

J On September 15,1994, the Radiation Protection Manager and the Senior Manager of i

Operations reviewed the event with the Shift Manager, Shift Supervisor, and the HP technician emphasizing the fact that primary reliance on the hand calculation was -

1 outside of the existing procedural controls, and that the Shift Manager should have informed Senior Management in a timely manner following the event. :In addition, the Radiation Protection Manager issued a memorandum to the HP Dose Assessment technicians to reinforce management expectations regardire the use of computer dose modeling and the involvement of offsite assistance.

On September 16,1994, the Plant Manager issued a memorandum to the Shift Managers to reinforce management expectations for implementation of the Emergency c

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Plan with respect to Emergency Action Levels. This memo indicates that the Shift Manager is expected to use his best Judgement in evaluating the validity of dose assessment 1.9rmation and that he should not delay the declaration for further counsel or advit

• a offsite personnel. Shift management is expected to make a timely decision he best available information, even though it may later be determined to -

snservative.

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4.On September 22,1994,' emergency procedures _ERP-300 and ERP-101 were revised

. for human factoring, and to allow for one (1) hour averaging of release' data for ;

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a determination of the offsite' dose rate using the computer dose model. This change H

will help to minimize'the impact of short duration offsite _ dose releases during planned,

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. evolutions such as RWCU resin backwashing. ' Also, the change to ERP-300 -

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pj3 permanently incorporated the previous temporary change with. espect to guidance for.

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editing erroneous input to the computer dose model. ' in addition, the computer dose W

model was revised for human factoring.

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Scenarios for use in "tableitop" training exercises have been developed by a team of '

representatives from Operations, Health Physics and Training.' These training -...

1 exercises have been established on a continuing basis, and ensure that the interaction.

a between Dose Assessment HP technicians and shift management is routinely '

practiced and is appropriate.

l On November 8,1994, the offsite release EAL for a UE specified in' ERP-101:was

j revised again to provide clear margin between normal processes and the EALL This

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will minimize the need to perform offsite dose assessment for normal plant evolutions j

r such as RWCU resin backwashing.

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Corrective Ar*Inna to Avnid Fidire Nonmmnliance A review of previous events revealed that implementation'of the offsite dose rate EAL

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for a UE is the only emergency classification area that has presented any problems.

The review of this event incorporated a review of previous similar events involving :

dose assessment during routine plant evolutions. The completed actions described above address the results of this review and will ensure future non-compliance is '

avoided.

1 Data When Full ComM=qce was Achieved

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At the time of this event, one of the corrective actions being pursued as a result of a

'l similar event in May 1994 was a revision to the offsite release EAL for.a UE specified l

in ERP-101 to allow for 60 minute averaging of release data. This proposed revision was based on existing NRC guidance provided in NUREG-0818, " Emergency Action Levels for Ught Water Reactors," which evaluated the adequacy of one hour averaging x

of release data and found it acceptable. In addition, this revision would be consistent with the NRC reporting requirement contained in 10CFR50.72 that involves an airborne l

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Docket No. 50-353 December 09,' 1994 ;

Page 6 of 6 i

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~ radioactive release averaged over a time god of one hour. ' The 10CFR50.54(q) and '

10CFR50.59 reviews for this change were completed on August-15,1994, and i

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ocncluded that the change does not constitute a reduction in the effectiveness'of the Emergency Plan or an Unreviewed Safety Question. The revised ERP-101'was reviewed by the Plant Operations Review Committee on August 25,1994, and was,.

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_ approved by the Plant Manager on September 1,1994.'.However, implementation of ;

this revision was delayed umil September 22,1994,- to coincide with organizational improvemants in the Dose Assessment program.

Even though the approved change to the offsite release EAL was not yet implemented, -

a 60 minute computer run of the offsite dose for this event was performed at 1037

- hours on September 12,1994.' This computer calculation resulted in an offsite dose rate of 0.0269 mR/hr, which is below the EAL for a UE. Therefore, plant management.

concluded that no UE declaration was required.

Full compliance was achieved on September 22,1994, when the approved change to ERP-101 and other associated ptccedures became effective.

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