05000277/LER-1978-038, Forwards LER 78-038/01T-0

Forwards LER 78-038/01T-0

ML19289F166
Person / Time
Site:	Peach Bottom
Issue date:	09/22/1978
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19289F167	List: 05000277/LER-1978-038, Forwards LER 78-038/01T-0 05000277/LER-1978-038-01, /01T-0 on 780908:one Point on Piping Outboard MO-12-15 Had Stress During DBE Above Code Allowable. Restraint to Be Added to Code
References
NUDOCS 7906040367
Download: ML19289F166 (3)

LER-1978-038, Forwards LER 78-038/01T-0

Event date:
Report date:
2771978038R00 - NRC Website

text

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3 PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHIA. PA.19101 12151841-4000 September 22, 1975

t r. Soyce H. Grier, Director Office of Inspection and Enforcement 2egion I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

SU3 JECT:

Licensee Event Reoort Narrative Description The following occurrence was reported t o 'Ir. Greenman, Region I,

Office of Inspection and Enforcement on September 8, 1973.

Reference:

Docket number 50-277/278 Report No:

LER 73-038/1T-C Report Date:

September 22, 1978 Occurrence Date:

September 8, 1978 Facility:

Peach Botto Atomic Power Station Unit 2 and 3 2.D.

1, Delta, PA 17314 Technical Soecification Reference:

Technical Specification 6.9 2.a(9) requires reporting of

"... conditions...that require remedial action or corrective ceasures to prevent the existence of development of an unsafe condition."

Descriotion of the Event:

Reactor water cleanup system inboard isolation valve (M0 12-

15) - initial calculation indicating an acceleration during the design basis earthquake in excess of the acceleration that the valve was qualified to withstand. Subsequent calculations and

}/

valve re-evaluation proved the initial conclusion to be in err *.

2236 135

'7 s 79060403gz i

Mr. 2oyce H.

Crier Page 2 September 22, 1973 LOR 78-3S/1T-0 Consequences of Event:

There was no actual deficiency in MO 12-15's capability to perforn its design function.

Confirnatory calculations and valve nanufacturer qualification show that the valve uould function and close if required during the design basis earthquake (330).

Cause of Event

In reco;nition of increasing interest in seisuic docunentation Philadelphia lectric Company undertook a pro 3 ram of acquiring supportive documentation confirning the seiscic qualification of certain equipment installed at Peach 3otton.

A review of the Ocactor "ater Cleanup Systen valves conducted in conjunction with this progras initially indicated an acceleration of "O 12-15, during the design basis earthquake, which was in excess of the acceleration the valve was known, at that time, to be qualified for.

This initial calculation conducted by the Architect Engineer was based on the best inforaation available regarding the physical characteristics for the valve and its associated piping.

The possible deficiency was reported to Mr.

Greennan of I and C Region I, on Septeuber 3, 1973 (confirmed by LE2 2-7S-033/IP, 9/11/73).

Subsequent calculations based on actual valve characteristics and as-built piping configuration in addition to qualification by the valve nanufacturer that the valve will accept a hi;her acceleration (7 2g as compared to the initial 3 0g) showed the initial conclusion to be in error and denonstrated that 'io 12-15 is capable of perfor=ing its design function.

The calculations on Unit 2,

however, showed one point on the ass ociated piping outboard of MO 12-15, which had a calculated stress above code allowable (23,000 psi as co mp a r e d to 23,300 psi code allouable based on cill certification yield stress).

It should be noted that while these calculated stresses are above code allouable, they are uell below the ultinate strength of the piping.

Therefore, the pressure envelope integrity of the piping would most likely have remained intact.

It should be emphasized that such stress would only occur during the unlikely event of a D3E, that the piping has never actually

~oeen e::p o s e d to such stress and that the point of high stress was isolable from the reactor.

2236 136

Mr. Boyce H.

Grier Page 3 September 22, 1978 LE2 70-33/lT-0

Corrective Action

An additional restraint will be added to the piping to reduce the stress value to uithin code allowable before returning Unit 2 to power.

Yours truly, AH d.

J.

Cooney S serintendent 0 neration Division-Uuclear Attachment cc:

Mr. Ernst Volgenau, 'IR C - Office of Inspection and Enforcenent Mr. Uornan M.

Heller, URC - Office of Management &

Progran Analysis 2236 137