ML20024D773
| ML20024D773 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 07/28/1983 |
| From: | Reinaldo Rodriguez SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RJR-83-583, TAC-52047, NUDOCS 8308080178 | |
| Download: ML20024D773 (3) | |
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SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, Califomia 95813; (916) 452-3211 RJR 83-583 July 28, 1983 DIRECTOR OF NUCLEAR REACTOR REGULATION ATTN:
DARRELL G EISENHUT, DIRECTOR DIVISION OF LICENSING
.J U S NUCLEAR REGULATORY COMMISSION j"
WASHINGTON DC 02555 DOCKET N0. 50-312 LICENSE N0. DPR-54 PROPOSED AMENDMENT NO. 98 SUPPLEMENT In accorcance with 10 CFR 59.59, the Sacramento Municipal Utility District hereby proposes to arrend its Operating License CFR-54 fcr Aar,cho Seco Nuclear Generating Station, Unit No. 1; this proposal entitled Proposed Amendment Number 98 is supplemented with this additional information.
The Proposed Amendment No. 98 submitted to you cid not ccntain the detailed "cause and affect" aspects of the request.
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Thc-proposed modification including both the two-out-of-three coincident logic and the new under/overvoltage trip settir.gs with time delays could m
not be installed while operating at power. The district committed and the 9
NRC agreed to installation during the current Cycle 6 refueling outage.
The Commission approved the current Technical Specifications as Amendment No. 46 on March 21, 1983.
The Districts' submittals for the under/overvoltage trip settings and associated time delays complied with Standard Technical Specification i
format for a trip voltage value and delay time and with the format as shown on Table 3, 4-5, Engineered Safety Features Actuation System Instrumentation Trip Values, which was Enclosure 2 of NRC to District letter (Reid to Mattimoe) dated June 3, 1977.
Both~ formats include the trip voltage value with a plus and minus tolerance and the delay time at the trip valve with a plus and minus tolerance. The District's design for undervoltage tripping utilizes a time delay relay with an inverse time characteristic, The District has confirmed during field testing after installation that the inverse time delay relay will repeatably trip only when the voltage value is outside the trip value minus the tolerance. The
" standard" format for technical specifications will not accommodate an inverse time delay relay.
Therefore, the District could not meet the specified time delay at the specified voltage value, the trip set point.
I 8308080178 830728 PDR ADOCK 05000312 p
PDR AN ELECTRIC SYSTEM SERVING MORE THAN 600,000 IN THE HEART OF CAllf0RNIA
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DARRELL G EISENHUT Page 2 July 28, 1983;
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Field testing has verified the time delay band in the proposed technical specifications. The District is presently in compliance to the proposed technical specification.
The district's.submittals as listed below demonstrate that the new settings meet'all the requirements of.the NRC request to review the Adequacy of Station electric Distribution System Voltages and Safety Evaluation and Statement of Staff Positions relative to the Emergency Power Systems for Operating Reactors.
Submittal 1 - District's response to Nuclear Regulatory Commission request to review the adequacy of Station Electric Distribution
' System Voltages (letter from William Gammell to Power Reactor Licer es dated August 8, 1979) Revision 2 dated February 9, 1981.
Submittal 2 - District's "No'Significant Hazards Consideration' Evaluation" attached to Proposed Amendment No. 98, dated. July 26,'1983.
Thus, the margin of safety is not significantly reduced by the proposed over/
undervoltage time delay trip valves.
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'Thus, it has been shown that the proposed Rancho Seco Unit 1 Emergency Power System modification does not:
L 1)
Involve ~a'significant increase in the probability or consequences of an accident previously evaluated; or
- 2) ' Create the possibility.of a new or different kind of accident from any-accident previously evaluated; or-1 3)
Involve a.significant reduction in a margin of safety.
As such, SMUD has determined and submits that the proposed over/undervoltage time delay trip values described herein do not involve a significant safety
. hazard.
These circumstances necessitate a change to DRR-54 without the 30-day notice
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period. ~The 30-day notice period would result in the failure to meet the limiting condition for 0peration. Table 3.7-1 and require Rancho Seco to remain subcritical as-stated in Section 3.7.1 of the Technical Specifications.
This restriction would prohibit operation of Rancho Seco during the peak summer. load when the electric power capacity is greatly needed. Replacement i
capacity, if available, would require conventional power generation requiring approximately-900,000 barrels of oil to produce ~approximately 650,000 megawatt i
hours of electricity, the equivalent output of Rancho Seco during the 30-day l
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DARRELL G EISENHUT Page 3 July 28, 1983 notice period. The Unit is expected to be critical on August 2, 1983.
The State of California was transmitted a copy of the Proposed Amendment No. 98 on July 28, 1983. Dr. Gdrald Wong from the Radiological Health Branch has access to the Proposal and is available for comment.
N
%v R. J. Rodrigue-Executive Director, Nuclear