ML20096B688

Responds to RAI Re Exam of Reactor Water Cleanup Sys Welds

ML20096B688
Person / Time
Site:	Limerick
Issue date:	01/05/1996
From:	Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9601160377
Download: ML20096B688 (2)

Text

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4, Ctrllon Support Drpartment YECO ENERGY =Se==L,,

965 Chesterbrook Boulevard Wayne, PA 19087-5691 January 5,1996 Docket Nos. 50-352 50-353 License Nos. NPF-39 NPF-85 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

Subject:

Limerick Generating Station, Units 1 and 2 Response to Request for Additional Information Concerning Examination of Reactor Water Cleanup System Welds Gentlemen:

This letter is being submitted in response to the NRC's request for additional information received during a telephone conversation on January 4,1996, between PECO Energy and NRC representatives. The NRC is currently reviewing our request to revise the Generic Letter (GL) 88-01, "NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping," inspection program for Limerick Generating Station (LGS), Units 1 and 2.

By letter dated June 21,1995, PECO Energy requested that the NRC approve a revision to the GL 88-01 inspection program for LGS, Units 1 and 2, to eliminate 1) the need to perform Ultrasonic Tests (UT) of the Unit 1 Reactor Water Cleanup System (RWCU) piping welds outboard of the primary containment isolation valves, and 2) the need to conduct inservice Inspection (ISI) pressure testing for Unit 2 on the RWCU system piping outboard of the primary containment isolation valves.

The NRC indicated that, in order to continue its review, additional information is necessary.

Specifically, the NRC requested that PECO Energy provide information for LGS that addresses EPRI's information on very high thrust requirements for blowdown valves. Therefore, in response to this request, the following information is provided to support the NRC's continued review of our request.

EPRI Information Reaardina Globe Valves Under Blowdown Conditions The EPRI information regarding globe valves under blowdown conditions has been reviewed, and it does not apply to the PECO Energy Anchor Darling globe valves for the following reasons:

1) The EPRI tested valve (#48) is a small (2") Rockwell Uni Valve design which is significantly different from the Anchor Darling globe valves in several critical design features.

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Rockwell Uni-Valve Anchor Darlina Globe Valve Rising / Rotating Stem Rising /Non-Rotating Stem Piston Type Disc /Gulde Conventional Gulded Plug

2) The EPRI data is based on a single valve test that is uncharacteristic of the globe valves that PECO Energy utilizes in blowdown applications. In addition, PECO Energy's experience with Rockwell Uni-Valves indicates that their characteristic thrust signatures are prone to cyclic loading, thus, making valve factor performance predictions unreliable.

Although the currently available EPRI information regarding globe valves under l blowdown conditions does not apply to PECO Energy's Anchor Darling globe valves, it is our understanding that EPRI is attempting to collect additional test data to provide further Information on this issue. PECO Energy will evaluate this information and apply ,

It, as appropriate, when it becomes available.

This letter also reaffirms similar commitments made for PECO Energy's Peach Bottom Atomic Power Station facility documented in letters dated August 9,1995, and August 16,1995, regarding GL 88-01 Inspection activities at PBAPS related to the inspection of RWCU syste.n welds outboard of the primary containment isolation valves.

If you have any questions, please do not hesitate to contact us.

Very truly yours,

.h. .4 .

G. A. Hunger, Jr.

Director - Licensing cc: T. T. Martin, Administrator, USNRC, Region i N. S. Perry, USNRC Senior Resident inspector, LGS