ML17053B988
| ML17053B988 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 09/24/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Dise D NIAGARA MOHAWK POWER CORP. |
| References | |
| NUDOCS 8010080453 | |
| Download: ML17053B988 (6) | |
Text
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Docket No. 50-220
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Mr. Donald P. Disc Vice President - Engineering c/o Miss Catherine R. Seibert
'Niagara Mohawk Power Corporation 300 Erie Boulevard Hest
- Syracuse, New York 13202
Dear Mr. Disc:
Sy our letter dated August 7, 1978, we informed you of deficiencies we identified in the design of the Hatch 2 regulator system for the motor generator (M-6) sets which supply power to the reactor protection system (RPS).
In general, the problem involved the possibility of the M-6 producing power which was of a quality (High/low outage, etc.)
'hat could be outside that for which the RPS has been demonstrated to be acceptable.
Specifically, the deficiencies involved:
('1)
Potential sequence of undetected single corryonent failures which could adversely affect the operability of the RPS; and (2)
Postulated component malfunctions initiated by a seismi c event which could adversely 'affect the operability of the RPS.
Our letter requested that you review your RPS power supply to determine if your system was susceptible to the same adverse possibilities that the staff had identified for Hatch 2.
Me have completed our review of your response to our request and have determined that the power supply RPS design at your facility is such that it could exper ience the same adverse conditions as described 'above.
Accordingly, we have determined that morlifications should be performed to provide fully redundant Class 1E protection at the interface of the non-Class lE power supplies and the RPS.
Re believe that the use of alartts or shift surveillance is acceptable as an interim measure but's not adequate for the long-term solution of our concerns.
Me have found that the conceptual design proposed by the General Electric Compare and the installed modification on Hatch 1 are acceptable solutions to our concern.
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O'U.S. GOVERNMENTPRINTING OFFICE: 1979'289'369
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fir. Donald P. Disc RPTEQBER 2 4 )geo In view of the above, we believe that you should modify the power supply for the RPS at your facility.
This modification should be implemented by the end of the next refueling outage.
Should this. scheduled outage occur within the next six months, the modifications should be accomplfshed by the end of the subsequent refueling outage.
tte wf1'l perform a post-implementation review of your modification and will require appropriate Technical Specifications for the system'e request that you provide within 60 days of your receipt of this letter:
your (1) coranftment to install a Class 1E system, (2) schedule for completion of the modification and (3) schedule for submission of design information and proposed Technical Specifications.
Si neer ely, cc:
See next page Grid signed 5P Thomas A. Ippolito, Chief Operating Reactors Branch
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Mr. Donald P. Disc CC:
Eugene B. Thomas, Jr.,
Esquire
- LeBoeuf, Lamb, Leiby 8 MacRae 1333 New Hampshire
- Avenue, N.
W.
Sui te 1100 Washington, D. C.
20036 Sta'te University College at Oswego Penfield Library - Documents
- Oswego, New York 13126 Mr. Joseph J.
- Sunser, Manager System Security Niagara Mohawk Power Corporation 300 Erie Boulevard Nest
- Syracuse, New York 13202 Resident Inspector c/o U.S.
NRC P.
0.
Box 126
- Lycoming, New York 13093 (Security matters only)
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