ML20085G167

Responds to NRC Re Violations Noted in Insp Repts 50-277/91-21 & 50-278/91-21 on 910709-0803.Corrective Actions:Task Force Formed to Establish Testing Plans & Configuration Controls to Evaluate ESW Performance

ML20085G167
Person / Time
Site:	Peach Bottom
Issue date:	10/18/1991
From:	Miller D PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CCN-91-14170, NUDOCS 9110240168
Download: ML20085G167 (4)

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k #1 - Delta, Itnrnyhania 17314 p.m terrnas-une km e a os e untsw a pl?) 4% 7014 D. B. Miller, Jr.

' Vice Preildent october 18, 1991 l l

Docket Nos. 50-277 l 50-278  !

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. U. 4. Nuclear 'legulatory Commission ATTN: Document Control Desk

- Washington, DC- ?0555 l

SUBJECT:

Peach Bottom Atomic Power Station - Units 2 & 3 Response to Request for ESW Corrective Actions -

_ (CombinedInspectionReportNos. 50-277/91-21: 50-278/91-21)

Dear Sirl in response to your leu.er dated August 26, 1991, which transmitted the ,

subject inspection Report and a request for a description of corrective  !

actions to control testing and troubleshooting activities, and evaluation and- l trending of ESW tests results, we-submit our planned corrective actions. The subject inspection Report concerned a routine-resident safety inspection conducted July 9, 1991, through August 3, 1991.

If you have any questions or require additional:information, please do not hesitate to contact us.

Sincerely V SF-Y 9,t\'

cci R. A. Burricelli, Public Service Electric & Gas '

T. M. Gerusky, Commonwealth of. Pennsylvania J.lJ. Lyash..USNRC Senior Resident inspector T.'T.-Martin, Administrator, Region.I. USNRC 4

'H..C. Schwemm. Atlantic Electric R.-1. McLean, State of Maryland J. Urban Delmarva Power-9110240168 91101G

'PDR ' ADOCK 05000277 -

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, Document Control Desk

, Page 2 bcc: J. W. Austin A4-4N Peach Bottom J. A. Basilio 52A-5, Chesterbrook G. J. Beck 52A-5, Chesterbrook J. A. Bernstein SIA-13. Chesterbrook R. N. Charles SIA-1. Chasterbrook Commitment Coordinator 52A-5, Chesterbrook Correspondence Control Program 618-3, Chesterbrook J. B. Cotton 53A-1, Chesterbrook G. V. Crenston 63B-5, Chesterbrook E. J. Cullen $23-1, Main Office A. D. Dycus A3-IS, Peach Bottom A. A. Fulvio A4-15. Peach Bottom D. R. Helwig SIA-ll, Chesterbrook R. J. Lees, NRB 53A-1. Chesterbrook C. J. McDer.nott 513-1, Main Office D. B. Miller, Jr. SM0-1, Peach Bottom PB Nuclear Records A4 25 Peach Bottom K. P. Powers A4-IS, Peach Bottom J. M. Pratt B-2-S. Peach Bottom J. T. Robb SlA-13, Chesterbrook D. M. Smith 52C-7, Chesterbrook

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i Document Control Desk  !

. Page 3 IJackground During July 1991, testing of the Emergency Service Water (ESW) system identified several Emergency Core Cooling System (ICCS) and Reactor Core isolation Cooling (RCIC) room coolers and Residual lleat Removal (RllR) seal coolers to be inoperable due to low flow. Troubleshooting to restore flow to the room and seal coolers resulted in inoperability declarations for two diesel generators and a plant shutdown was initiated. Subsequently, a diesel generator with indicated high flow was throttled down which increased flow to the two marginal diesel generators and plant shutdown activities.were terminated. It was later determined that the diesel generator with indicated high flow had been inappropriately throttled down due to an inaccurate high flow determination. This resulted in the diesel generator being declared inoperable due to low flow. flow was increased to the diesel generator and  !

operability was restored. The inoperable ECCS and RCICs room coolers were i returned to operable status by increasing flow to the in-service room coolers and isolating appropriate redundant room coolers. Additionally, a safety evaluation for the RilR seal coolers was performed and approved by the plant ,

Operations Review Committee (PORC) to allowed continued operations with l reduced ESW flow through one RilR pump seal cooler on each WlR loop.

Subsequent engineering evaluations determined that diesel generator l operability had not been impacted during the event based on diesel generator  :

loading and actual cooling water inlet temperatures available during the event '

time interval.

i inspection Concerns Weaknesses were noted in the ability to monitor LSW system performance, and the control of testing and troubleshooting activities. This resulted in declaring core cooling systems and multiple diesel generators inoperable. 1he concern exists that these weaknesses could impact future LSW system operability.

Response and Corrective Actions An ESW task force has been formed to establish testing plans and appropriate configuration controls to effectively evaluate ESW performance. This task force will focus on ESW issues and will address the ability of the system to perform its design function while minimiting the impact nn the technical staff and engineering work force. The formation of the ESW task force in conjunction with the experience gained as a result of this event and the resultant corrective actions will ensure that testing and troubleshooting activities are conducted in a controlled manner which will prevent future inappropriate inoperability determination 3, will minimize the utilltation of the plant technical staff and will increase the ability to adequately monitor and evaluate ESW system performance.

The following actions have been taken in the areas of testinq, troubleshooting and monitoring of the ESW system:

The most recent performance test data has been incorportted into the current test so that in-field comparison can be made between past as left flow values and current flow indication. This comparison will serve to validate the current test data or indicate if any change in l component flow has 0: curred. This will improve reliability of the I test data and will enhance ESW system trending and monitoring.-

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. Document Control Desk

Page 4 System flow rate adjustments are being perf ormed by a f low balaricitig procedure rather than a Troubleshooting Control form.

Testing procedures have been revised to eliminate throttling of valves prior to obtaining as found component flows. 1his ensures that component flows are not altered before as found values are recorded. As found flow values are now obtained prior to any valve adjustment or throtiling.

flow testing on the diesel generator coolers, idlR seal toolers, LCCS and RCIC room coolers is now performed on a monthly basis to ensure continued oper ability. lest data will be reviewed and evaluated prior to making any future frequency changes. 1his testing frequency provides early indication if degradation should begin to occur. In addition to the monthly testing, monitoring and trending of limiting components Is performed on a bi-weekly basis. This monitoring and trending program verifies that degradation does not occur between testing intervals.

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