ML16337A268
| ML16337A268 | |
| Person / Time | |
|---|---|
| Issue date: | 01/15/1985 |
| From: | Lewis H Advisory Committee on Reactor Safeguards |
| To: | Dircks W NRC/EDO |
| References | |
| Download: ML16337A268 (2) | |
Text
D850115 Mr. William J. Dircks Executive Director for Operations U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Mr. Dircks:
SUBJECT:
DIESEL-GENERATOR FAILURES AT NORTH ANNA POWER STATION, UNIT 2 During its 297th meeting, January 10-12, 1985, the ACRS heard a presentation from representatives of the NRC Staff on an incident involving the diesel generators at North Anna, Unit 2, in which diesel generator testing requirements may have contributed to early damage and reduced reliability of the diesel engines powering these generators. During this briefing, we also became aware that the engine testing requirements being used for Unit 1 were significantly different than those being used for Unit 2, due to the NRC use of a later version of the Standard Technical Specifications which implemented requirements in Regulatory Guide 1.108, "Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants," for the newer unit. The testing differences were not due to any difference in the performance requirements for the two units. This matter was also discussed at a Reactor Operations Subcommittee meeting on January 9, 1985.
The diesel engines for Unit 1 did not experience damage comparable to that found in Unit 2, perhaps due to the less rigorous test requirements for Unit 1; thus, if a real emergency should occur, they would provide more reliable power than those for Unit 2, which were subjected to the more severe start and run tests.
In the attached letter of September 16, 1982, the ACRS suggested that operability of diesel generators may be demonstrated without resorting to the exclusive use of fast start testing. We would like to know what NRC Staff attention is being given to the possibility of modifying the diesel-generator testing requirements.
We were also informed that the Japanese are experiencing unusually successful diesel-engine start experience; if true, there may be valuable lessons to be learned from this data. We would like to hear about this in greater detail.
We wish to be informed concerning the status of this work at an ACRS meeting in the near future.
Sincerely, H. W. Lewis Acting Chairman
Attachment:
Memo for William J. Dircks, EDO, from R. F. Fraley, ACRS,
Subject:
Testing
Requirements for Diesel Generators, dated September 16, 1982