ML19291B125

Forwards LER 79-032/01T-1

ML19291B125
Person / Time
Site:	Peach Bottom
Issue date:	08/20/1979
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19291B126	List: ML19291B125 ML19291B127
References
NUDOCS 7908290444
Download: ML19291B125 (3)

Text

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PHILADELPHIA ELECTRIC . COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 12151 e41-400o August 20, 1979 Mr. Boyce H. Grier, Director Office of Inspection and Enforcement Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvan 1 1 19406

Dear Mr. Grier:

3*dBJECT: Licensee Event Reoort Narrative Descriotion The following occurrence was reported to Mr. Greenman, Region I, Office of Inspection and Enforcement on June 26, 1979.

Reference:

Docket Number 50-277 50-278 Report No: (Update) LER 2-79-32/1T-1 Report Date: (Previous) July 11, 1979 Occurrence Date: June 26, 1979 Facility: Peach Bottom Atomic Power Station R.D. 1, Delta, PA 17314 Technical Specification

Reference:

Technical Specification 6.9.2.a(9) requires reporting

" performance of structures, systems, or components that require remedial action or corrective measures to prevent operation in a manner less conservative than assumed in the accident analysis in the safety analysis report . . ."

Description of the Event:

In response to the analysis required by IE Bulletin 79-02 Revision 1, 1243 seismic class 1 supports have been analyzed. As a result of this analysis, 92 supports have safety factors less than five with the design basis earthquake. Of these, eight have safety factors less than 1; 1.e., may fail during the design basis earthquake. The eight supports are distributed as follows: g dDj/

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Mr. Boyce H. Grier Page 2 August 20, 1979 LER 2-79-32/1T-1 1 on the Unit 2 HPCI System 1 on the Unit 3 HPCI System ,

1 on the Unit 2 RHR System 1 on the Unit 3 RHR System 2 on the Unit 2 Emergency Service Water System 1 on the Unit 3 Emergency Service Water System 1 on the Unit 3 Drywell Inerting System These seismic supports are either single supports in a piping system or are widely separated as in the case of the Unit 2 emergency service water supports. The single HPCI support in each unit is for piping associated with the test flow path which is isolated from the injection flow path except during testing and is automatically isolated if initiation occurs during testing. One of two emergency service water system supports on Unit 2 and the one on Unit 3 are located on the service water side of a normally closed and locked manual valve connecting the emergency service water discharge and service water discharge.

Failure in this location would not interfere with emergency service water delivery. The other Unit 2 emergency service water support is associated with one of the two redundant supply loops which could be isolated if necessary. The single RHR support on each unit is associated with a single subsystem and is not on piping common to the two subsystems. The single drywell inerting system support is on piping at a significant distance and several rigid supports outboard of the outer isolation valve which along with the inner isolation valves is normally closed. These deficiencies constitute less than one percent of the total supports analyzed.

Consequences of Event:

The calculational method used is conservative in that all stresses and loads are combined to obtain the total load during the design basis es.rthquake. Calculations indicate that these supports will withstand an operating basis earthquake.

In light of the conservative nature of the calculation, the Operation and Safety Review (0&SR) Conmittee has concluded that these deficiencies have a minimal safety significance and that the plant can continue operation.

QQ\

. 's Mr. Boyce H. Grier

• Page 3 August 20, 1979 LER 2-79-32/1T-1 Cause of Event:

The cause of this occurrence was inadequate initial support design.

Corrective Act;on:

Design of the necessary modifications has been completed.

The Licensee Event Report dated July 11, 1979, committed to modifying these type supports by July 13, 1979. Completion of these modifications was delayed because design revisions were necessary due to installation interference problens and Q material availability. Modifications of all eight supports were completed on July 19, 1979.

Yours truly,

/

M J. Coo y perintendent Generation Division-Nuclear Attachment ec: Director, NRC - Office of Inspection and Enforcement Mr. Norman M. Haller, NRC - Office of Managenent &

Program Analysfs 77^

2012