ML20070S404
| ML20070S404 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 02/04/1983 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | Miraglia F Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0313, RTR-NUREG-313, TASK-03-05.A, TASK-03-05.B, TASK-3-5.A, TASK-3-5.B, TASK-RR GL-81-04, GL-81-4, IEB-82-03, IEB-82-3, NUDOCS 8302040380 | |
| Download: ML20070S404 (2) | |
Text
P GPU Nuclear gg g7 P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:
& b 5, /,55 Mr. Frank J. Miraglia Assistant Director for Safety Assessment Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Sir:
SUBJECT:
Oyster Creek Nuclear Generating Station Docket 50-219 Generic Letter 81-04, Implementation of NUREG 0313, Revision 1 This is in response to your letter of November 23, 1982 in which you C
expressed concern regarding the recent discoveries of intergranular stress corrosion cracking (IGSCC) at several operating nuclear power plants.
Our letter dated December 1,1982, in response to I & E Bulletin 82-03 described the proposed sample size and basis for sampling selection to be taken during the upcoming outage. In addition, material characteristics and ultrasonic inspection methods were discussed. Because of the requirements to notify you of inspection findings and resulting repairs prior to resuming power operation, we plan on answering your present request in more detail at some time during the upcoming outage.
GPU Nuclear is investigating potential solutions for any contingencies.
Among these are failure analysis / fracture mechanics, backlay weld repairs, Induction Heating Stress Improvement (IMSI), Post Weld Heat Treatment (PWHT),
partical replacement of loop piping, and complete replacement of individual loop piping.
GPU Nuclear (GPUN) shares the NRC's concern for the potential of pipe cracks remaini ng undiscovered in large diameter BWR piping. We consider this issue to be of significance with regard to plant reliability. However, based on the work conducted by the BWR pipe cracking owner's group and General Electric Company in ostablishing the " leak-before-break" argument, GPUN does not consider this to be an immediate safety cc.cern. We are convinced that your questions regarding augmented inservice inspection, replacement of non-conforming material, and general implementation of NUREG 0313 will be much more accurately answered following the planned inservice inspection and the thorough consideration of results, which will follow. Our present intentions with regard to leak detection systems are outlined in the Systematic Evaluation Program (SEP) integrated assessment for Oyster Creek and involves topics III-5.A "Ef fects of Pipe Breaks on Structures Systems and Componets Inside Containment" and III-5.B " Pipe Breaks Outside Containment".
8302040380 830204 PDR ADOCK 05000219 i
O PDR GPU Nuclear is a part of the General Pubhc Utilities Systern
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At this time we wish to amend our June 30, 1981 letter with regard to recirculation system nozzle safe ends. In that letter it was stated that the safe ends had been removed and replaced with safe ends of inconel 600 prior to beginning commercial operation. It is true that a large scale modification was undertaken as a result of safe end cracking. However, the remedy consisted of applying a 308 stainles steel weld clad to the inner and outer surfaces of the existing sensitized safe ends. This is an acceptable crack remedy per NUREG 0313.
In the event that any comments or questions arise, please contact Mr. J. Knubel at (201) 299-2264.
h P.B. Fiedler Vice President and Director Oyster Creek PBF:jal ec: Ronald C. Haynes, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 NRC Rsident Inspector Oyster Creek Nuclear Generating Station Forked River, NJ 08731