ML19323B427

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Notifies That Upper Shelf Energy of Core Beltline Region Welds in Reactor Pressure Vessels May Fall Below 50-ft-lb Level in 1983.Requests Info Re Testing of wedge-opening- Loading Specimens of Surveillance Capsules
ML19323B427
Person / Time
Site: Zion  File:ZionSolutions icon.png
Issue date: 05/06/1980
From: Peoples D
COMMONWEALTH EDISON CO.
To: Harold Denton
Office of Nuclear Reactor Regulation
References
NUDOCS 8005120361
Download: ML19323B427 (1)


Text

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(O N) ono First National Ptars. Chic:go, lihnois 8005140 36I Commonwealth Edison l

Addrsss Riply to: Post Office Box 767 Chicago, Ilknois 60690 i

4 May 6, 1980 Mr. Harold R.

Denton, Director Of fice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Zion Station Units 1 and 2 I

Reactor Pressure Vessel Upper j

Shelf Energy - Appendix 10 CFR 50 j

NRC Docket Nos. 50-295 and 50-304

Dear Mr. Denton:

Pursuant to the requirement of Paragraph V.E., of Appendix G of 10 CFR 50, Commonwealth Edison Company hereby informs the NRC Staff that it has estimated that the upper shelf energy of the core beltline region welds in both Zion Reactor Pressure Vessels may fall 1

below the 50 ft.-lb level in 1983.

This estimate is based on preliminary data and appears to be conservative.

Commonwealth Edison has scheduled another surveillance capsule for examination this summer and anticipates that a review of the data from this capsule will verify the conversatism of our estimate.

Upon such a verification, Commonwealth Edison will withdraw this letter.

In addition, the requirements of Paragraph V. C.

of Appendix G of 10 CFR 50 need to be addressed.

Commonwealth Edison will inform the NRC Staff of the status of the program required by this paragraph as the data becomes available.

Please be advised that Zio., Surveillance Capsules contain wedge-opening-loading (WOL) specimens.

The WOL specimens are in storage at Battelle Memorial Institute.

Commonwealth Edison is currently waiting for an NRC Staf f disposition on how these specimens should be tested, i.e.

to measure dynamic or static 1

fracture toughness.

An NRC Staff response with regard to this matter would te appreciated.

Please address any questions that you might have concerning this matter to this office.

One (1) signed original and thirty-nine (39) copies of this letter are provided for your use.

Very truly yours, st D. L. Peoples

'/

Director of Nuclear Licensing 3603A

-,.