ML19209A710
| ML19209A710 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/28/1979 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7910050260 | |
| Download: ML19209A710 (2) | |
Text
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'# SACRAMENTO MUNICIPAL UTILITY DISTRICT C 6201 S Street, Box 15830. Sacramento, California 95813, (916) 452-3211 September 28, 1979 Director of Nuclear Reactor Regulation ATIN:
Darrell G. Eisenhut Acting Director for Operating Reactors Division of Operating Reactors U. S. Nuclear Regulatory Commission
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20555 Re: Docket No. 50-312 Rancho Seco Nuclear Generating Station Unit No. 1 D. G.
Eisenhut letter to All Pressurized Water Reactors dated June 26, 1979
Dear Sir:
Your letter dated June 26, 1979, requested a review of unnecessary challenges to the reactor trip and safeguards systems at our facility.
The Sacramento Municipal Utility District is hereby subnitting the requested response.
A review of our plant operation history indicates that.atomatic safety injection system actuations have not been a common occurrence at our facility. With a few notable exceptions (reference LER 78-01 and LER-79-01) the majority of reactor trip challenges were not accompanied by automatic safety injection system challenges.
Inadvertent reactor trips were encountered more frequently during the early phases of operation. Approximately SOT. of all reactor trips occurred during our first 14 months of operation (October, 1974, through December, 1975).
Upgrading and modifying specific systems have aided in minimizing inadvertent reactor trips.
The same review indicated that there was no indication that a substantial number of the trips were caused by surveillance testing.
Some of the trips occurred during initial system testing (TP's) and some later ones occurred during the performance of Special Test Procedures (STP's).
- However, trips which occurred due to equipment malfunction or otber operational events (maintenance activities, design changes, etc.) constitute a greater percentage of the total number of trips than those as a direct result of testing.
The District does not concur that there is an apparent sense of complacency toward surveillance requirements which have the pptential of causing inadvertent reactor SCRAMS at the Rancho Seco facility.
Following all reactor trips, plant personnel investigate and analyze the trip and prepare a report.
This report is then reviewed by the Plant Review Committee. :bjor parameters and system (s) responses during the transient are reviewed.
Recommen-dations concerning potential design or procedure changes to prevent recurrence
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Mr. Darrell G. Eisenhut Page 2 September 28, 1979 It is the District's contention that the facility's staff analysis of each reactor trip is sufficient to detect any procedural inadequacies which have the potential of imposing unnecessary challenges to the reactor trip and safe-guards system.
To assure review by plant supervisors, a copy of your letter and this response will be routed to the appropriate group supervisors at our facility.
Respectfully,
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J. J. Mattimoe Assistant General Manager and Chief Engineer JJM:HH: jim es: Region V USNRC 11 (k) 066