ML19337B664
| ML19337B664 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/24/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 8010080534 | |
| Download: ML19337B664 (3) | |
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o, UNITED STATES y Yb s. (X,g NUCLEAR REGULATORY COMMISSION
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E WASHINGTON, D. C. 20$55 Y.Pp SEPTEM8ER 2 4 590 Docket Nos. 50-259 50-260 and 50-296 Mr. Hugh G. Parris Panager of Power Tennessee Valley Authority 50CA Chestnut Street, Tower II Chattanooga, Tennessee 37401
Dear Mr. Parris:
Ey our letter dated August 7,1978, we informed you of deficiencies we identified in the design of the Hatch 2 regulator system for the rotor generator (M-G) sets which supply power to the reactor protection system (RPS).
In general, the problem involved the possibility of tne M-G producing power which was of a quality (High/ low outage, etc.)
that could be outside that for which the RPS has been demonstrated to be acceptable.
Specifically, the deficiencies involved:
(1) Potential sequence of undetected single component failures which could adversely affect the operability of the RPS; and (2) Postulated component malfunctions initiated by a seismic event which could adversely affect the operability of the RPS.
Cur 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.
he have completed our review of your response to our request and have cetermined that the power supply RPS design at your facility is such that it could experience the same adverse conditions as described above.
Accordingly, we have determined that modifications should be performed to crovide fully redundant Class lE protection at the interface of the nor.-Class lE power supplies and the RPS. He believe that the use of alarns or shift surveillance is acceptable as an interim measure but is not adequate for the long-term solution of our concerns.
we have found that the conceptual design proposed by the General Electric Coroany and the installed modification on Hatch 1 are acceptable solutions to 6ur concern.
1
g3 Mr. Hugh G. Parris 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 mo'difications should be accomplished by the end of the subsequent refueling outage.
We will perform a post-implementation review of your modification and will require appropriate Technical Specifications for the system.
We request that you provide within 60 days of your receipt of this letter: your (1) commitment to install a Class lE system, (2) schedule for completion of the modification and (3) schedule for submission of design information and proposed Technical Specifications.
Sincerely,
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Thomas
. Ippolito, Chief Operating Reactors Branch #2 Division of Licensing cc:
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Mr. Hugh G. Parris cc:
H. S. Sanger, Jr., Esquire General Counsel Tennessee Valley Authority 400 Commerce Avenue E 11B 33 C Knoxville, Tennessee 37902 Mr. Ron Rogers Tennessee Valley Authority 400 Chestnut Street, Tower II Chattanooga, Tennessee 37401 Mr. H. N. Culver 249A HBD 400 Commerce Avenue Tennessee Valley Authority Knoxville, Tennessee 37902 Robert F. Sullivan U. S. Nuclear Regulatory Commission P. O. Box 1863 Decatur, Alabama 35602 Athens Public Library South and Forrest Athens, Alabama 35611 9
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