ML20097E501

Provides Response to NRC Requesting Temporary Waiver of Compliance from Requirements of Units 2 & 3 TS Section 3.5.F.1, Minimum Low Pressure Cooling & Diesel Generator Availability

ML20097E501
Person / Time
Site:	Peach Bottom
Issue date:	06/05/1992
From:	Beck G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9206120209
Download: ML20097E501 (5)

Text

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,' PillLADELPillA El.ECTRIC COMi%NY NUCLEAR OROUP HEADQUARTERS

. 955 65 CilESTERilROOK llLVD.

- WAYNE, PA 19087 5691 (215) 640-6000 NUrtEAR Lt4GINIT.RINO & &LkVICl3 IMTARTMINT Juno 5, 1992 Docket Nos. 50-277 j 50-278 4

License Nos. DPR-44 DPR-56 U.S. Nuclear Regulatory Commission Attn Document Control Desk Washingte,n, DC 20555

SUBJECT:

-Peach Bottom Atomic rower Station, Units 2 & 3 Request for Temporr y Walver of Compliance from the Technical Specifications Section 3.5.F.1, " Minimum Low Pressure Cooling and Diesel Generator Availability"

Dear Sir:

In accordance with the guidance contained in the February 22, 1990 memo from T. E. Murley-(Director, Office of Nuclear Reactor Regulation), Philadelphia Electric Company requests a Temporary Waiver of Compliance irom the requirements of Peach Bottom Atomic Power Station, Units 2 & 3 Technical -

Specifications (TS) Section 3.5.F.1, " Minimum Low. Pressure Cooling and Diesel Generator Availability".

Technical Specif stion 3.5.F.1 states: - "During any period when one diesel gener% sr is inoperable, continued reactor operation is permissible only-during-tho' succeeding seven days unless-such diesel generator is sooner.made operable-provided.

that the :emaining diesel generators and the low; pressure core and containment cooling systems which'are. powered-by the remaining diesel generators are operable. If this requirement cannot be met, an orderly shutdown shall'be initiated and the reactor shall be.placed in the Cold Shutdown Condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />;"'= PECo is. requesting'a Temporary Waiver.of Compliance from this Technical Specification so the E-4.' Diesel' Generator allowable out of service time can be extended.48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

.3 ,Snnnn-9206120209 920605 PDR .ADOCK 05000277

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U.S. Nuclear Rogulatory Commicolon Juno 5, 1992 Tomporary Walvor of Complianco Pago 2 The February 22, 1990 memo requests Licensees to provide the following:

1) A discussion of the requirements for which a waivor in requested Technical Specification 3.5.F.1 states: "During any porlod when one diosol generator is inoperable, continued reactor operation is permissible only during the succooding seven days unless such diosol generator is sooner made operable provided that the remaining diosol generators and the low pressure core and containment cooling systems which are poworod by the remaining diesel generators are operablo. If this requirement cannot be mot, an orderly shutdown shall be initiat.ed and the reactor shall be placed in the Cold Shetdown Condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />." We are requesting that th;9 seven day period be extended 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

2) A discussion of the circumstancos surrounding the situation including the nood for prompt action, and a description of _

why the situation could not have boon avoidod.

The Peach Bottom Atomic Power Station (PBAPS) Emorgency Diosol Generator (E-4) was removed from service on June 1, 1992 at 00:01 hours to replace all 12 cylinder liners as recommended by the manufacturer. In addition to the liner replacement, the mechanical portion of the normal periodic maintenance inspection was scheduled to be performed. The decision to include the mechanical inspection was made in order to reduce future unavailability of the E-4 Diosol Generator during its periodic maintenance inspection.

A detailed schedule was developed, extensive mock-up training was conducted on our training diesel engino, and pre-staging of liners and associated parts was completed prior to taking the E-4 Diosol Generator out of service.

The cylinder liner replacement and mechanical portion of the periodic maintenance inspection would not have required more than the allowable seven days to complete; however, several leaks were identified on the jacket coolant lines and the cylinder inlet adapters and a bearing on the vertical drive was found to be out of tolerance which increased the out of service timo and added an estimated 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to an already aggressive schedule. Up to the point of hydrostatic testing of_the-diosol generator, the outage was progressing well and on schedule. Additional _timo was required to repair the leaks, replace a.boaring on the vertical drive, and perform additional hydrobtatic tests.

Philadelphia Electric is requesting an additional 48. hours-to return the E-4 Diesel Generator to service.- The additional time is needed to complete necessary engine

U.S. Nuciocr Regulatory Commiccion Juno 5, 1992 Temporary Waiver of Compliance Pago 3 run-in tests (36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />) required by the manufacturer '

whenever engine wear-in parts are replaced (e.g. cylinder liners).

3) A discussion of compensatory actions Philadelphia Electric Company will continue to demonstrate that all of the remaining diesel generators are operable as required by Technical Specification 4.5.F.1. In addition, activities which may challenge the availability of redundant or critical plant equipment have been minimized. This includes Instrument and Controls (I&C) work, as well as preventative maintenance on the high and low pressuro emergency core cooling systems, station batteries and the battery chargers, Emergency Service Water, Emergency Cooling ,

Water system and discretionary work at the North and South Substations. ,

To further assure reliability of the off site power supply the Load Dispatcher responsible for the two incoming supplies has been requested to minimize switching and other ,

activities which may jeopardize the reliability of the off-site power supplies.

4) A preliminary evaluation of the safety significance and potential consequences of the proposed request Both units are currently operating at steady state.

Initiating a dual unit shutdown would subject the plant to problems / challenges that operating at steady state conditions would not. This is especially relevant because PECo believes the E-4 Diesel Generator will be available for approximately half of the duration of~the extension request ,

and will be fully operable within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of exceeding the LCO. If a shutdown were required, both units would be returned to their previous power levels when the Diesel Generator is returned to service. This power cycling is a challenge to the plant which could be avoided by the continued steady state operation of both units.

A probabilistic risk assessment has been conducted to determine the increase in the probability of a core damage ,

accident. There is an insignificant increase in the already extremely low likelihood of a core damage accident with one Diesel Generator out of service for an additional'two days. ,

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U.S. Nuclear Regulatory Commiocion Juno 5, 1992

, Temporary Waiver of Compliance Page 4

5) A discussion which justifies the duration of the request We are requesting a temporary waiver of compliance for an additional two days to the 7 day LCO. Theso two days will allow the staff at Peach Bottom to complete the Diesel Generator maintenance and testing. It is expected that repairs and restoration will be completed by the end of the existing LCO and the run-in testing will take an additional 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. It should be noted in comparison that an orderly shutdown and cooldown as required by Technical Specification 3.5.F would be completed in approximately one day.

6) The basis for the licensee's conclusion that the request does not involve significant hazards consideration The proposed temporary waiver of compliance to Technical Specification 3.5.F does not involve a significant hazards consideration because operation of Peach Bottom Atomic Power Station with this change does nots (1) involve a significant increase in the probability or consequences of an accident previously evaluated.

Continued steady state operation is less of a challenge to equipment and personnel than a required dual unit shutdown. The Peach Bottom standby AC power system is designed with sufficient redundancy such that one diesel generator may be removed from service for testing, inspection, or repairs in the time-provided in the current Technical Specifications. The remaining three diesel generators are still capable of carrying sufficient loads to mitigate the consequences of an accident and maintain the Units in the safe shutdown-condition. Therefore, the probability or consequences of an accident previously evaluated is not significantly increased by the additional time requested.

(2) create the possibility of a new or different kind of accident from any accident previously evaluated. The requested temporary waiver is limited to increasing a LCO and this in and of itself does not create the possibility of a new or different kind of accident.

-(3) involve a significant reduction in a margin of safety.

The Peach Bottom standby AC system is designed with sufficient redundancy such that-one diesel generator may be removed from service-for testing, inspection or repairs and the remaining three diesel generators are capable of carrying sufficient loads to satisfy the Updated Final Safety Analysis Report requirements for shutdown of both units, Considering.this fact, as well as the high reliability of the remaining diesel

U.S. Nuclear Regulatory Commicolon Juno 5, 1992

,'Tomporary Walvor of Complianco Pago 5 generators and off-site power sources, adding two days to the existing LCO does not reduce the margin of safety.

7) Tho basis for the licensoo's conclusion that the roquest does not_involvo irreversible environmental consequences,1 The proposed temporary waivor of compliance to the Technical Specifications does not have an environmental impact sinco the chango will not result in any increase in the amount or result in any chango in the type of offluent which may be released off-sito, and thoro will be no significant increaso in individual occupational radiation exposures.

The Plant Operational Review Committoo hhs reviewed this proposed temporary waivor of comp 11anco and have concluded that it does not involve a significant hazards consideration and will not endanger the health and safety of the public.

Very truly yours, G. JT' Bock Manager Licensing Section Nucleat Enginooring & Services cca T. T. Martin, Administrator, Region I, USNRC J. J. Lyash, USNRC Senior Resident Inspector, PBAPS bcc R. A. Burricelli, Public Service Electric & Gas W. P. Dornsifo, Commonwealth of_ Pennsylvania R. I. McLean, State of Maryland H. C. Schwemm, Atlantic Electric C. D. Schaefor, Dolmarva Power & Light Company D. B. Miller - PB, SMO-1 D. M. Smith - 52C-7 D. R. Holwig - 63C-1 K. P. Powers - PB, A4-1S J. B. Cotton - 53A-1 R. N. Charles - 51A-1 J. A. Basilio/GJS - 52A-5 A. A. Fulvio - PB, A4-1S A. R. Diederich - 62A-3 A. D. Dycus/ISEG - PB, A3-1S-J. M. Pratt - PB, B-2-N C. J.'McDormott - MO, S13-1 J. T. Robb - 62C-3 J. W. Austin - PB, PR-3-2 Commitment Coordinator - 52A-5 Correspondence Control Desk - 61B-3 Document Administration Center (DAC) - 61B-5

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