ML19282A799
| ML19282A799 | |
| Person / Time | |
|---|---|
| Site: | Indian Point, Beaver Valley  |
| Issue date: | 02/09/1979 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19282A800 | List: |
| References | |
| TAC-7313, NUDOCS 7903070027 | |
| Download: ML19282A799 (2) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
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FEB 9 1979 NOTE FOR:
A. Schwencer, Chief, Operating Reactors Branch #1, DOR FROM:
G. Lainas, Chief, Plant Systems Branch, DOR
SUBJECT:
STEAM GENERATOR WATER HAMMER t
In response to your note of January 29, 1979, (attached) regarding modifications to prevent water hammer at Indian Point 2 and Beaver Valley 1, we found that these modifications were carried out in accordance with the quality assurance programs in effect at the time that the modifications were completed. Construction in accord-ance with these programs provides assurance of continued structural integrity thpt is acceptable to the staff.
In the case of Indian Point Unit No. 2, the licensee stated in its letter of July 25, 1975 to the Comission that "All modifications that were made to the Unit following the incident and test program were performed in accordance with the Con Edison Quality Assurance Program for operating nuclear plants that was currently in effect.
A description of thattQA program was submitted to the Comission on July 6,1973 by a Con Edison letter." The water hamer incident referred to occurred on November 13, 1973 and repairs were made in the interval between then and March 16, 1974. The QA program was approved by the staff as indicated in the staff's safety evalua-tion report of September 21, 1973.
For Beaver Valley, the J-tubes were supplied by Westinghouse as part of the steam generators and all means for preventing steam generator water hamer were installed prior to issuance of the operating license.
Issuance of the operating license subsequent to modifications for water hammer indicates that work perfonned on safety related piping systems during construct.on was in accordance with a quality assurance 79030700 M
. program and codes and standards acceptable to the staff. However, after issuance of the operating license, the staff continued its generic review of the causes and effects of steam generator water hammer and certain questions arose regarding the effectiveness of means being implemented to prevent water hammer.
The purpose of the safety evaluations in question was therefore to determine the effectiveness of means being employed to prevent steam generator water hammer. The staff has not found it necessary to seek additional verification of the structural adequacy of piping modifi-cations associated with steam generator water hammer. The engineering branch has found no unusual circumstances associated with these kinds of modifications that would warrant special verification of structural integri ty. We therefore plan to continue to issue our safety evalua-tions for steam generator water hammer with emphasis on the effectiveness of means to prevent water harmer and to rely on the licensee's committment to make these modifications consistent with the require-ments of their QA program.
Y G. Lainas, Chief Plant Systems Branch Division of Operating Reactors
Contact:
S. NacKay X-27110 cc:
R. Vollmer B. Grimes E. Reeves D. Neighbors L. Olshan D. Wigginton V. Noonan K. Wichman S. MacKay