ML20063D761
| ML20063D761 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/18/1982 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML20063D764 | List:
|
| References | |
| NUDOCS 8208300030 | |
| Download: ML20063D761 (2) | |
Text
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Southern Califomia EdisoNho'iNphy !" l2: ~
gE SAN ONOFRE NUCLE AR GENER ATING ST A TION P.O. B O X 12 8 S A N C LEMENTE. C A LIFOR NI A 92672
. H. B. R A Y tetgesoNg
" " " " ^ " " * * "
August 18, 1982
" " > " 2 "a U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V
_1450 Maria Lane, Suite 210 l
Walnut Creek, Califoirnia 94596-5368 Attention:
Mr. R. H. Engelken, Regional Administrator
Dear Sir:
Subject:
Docket No. 50-361 30-day Reports Licensee Event Report No.82-063 and 82-070 San Onofre Nuclear Generating Station, Unit 2 4
This submittal is in accordance with the reporting requirements of Section 6.9.1.13b of Appendix A to Facility Operating License NPF-10.
It describes two (2) reportable conditions involving Limiting Condition for Operation (LCO) 3.7.1.1 associated with main steam safety valves.
Completed copies of LER 82-063 and 82-070 are enclosed.
While in Mode 3, at 1603 on July 19, 1982, 18-month surveillance testing in accordance with procedures S023-1-2.5 and S023-1-6.44 was in progress.
The pressure setpoint for main steam safety valve 2PSV-8416 was discovered to be below the required setting shown in Table 3.7-1 of the Technical Specifications.
Additionally, the valve did not sear properly. As required by the LCO, the valve was declared inoperable and the Action Statement associated with LCO 3.7.1.1, was entered.
LER 82-063 addresses this event.
This Action Statement allows operation to continue with one or more main steam safety valves inoperable provided that, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, either the Inoperable valve is restored to operable status or the power level-high trip setpoint is reduced in accordance with Table 3.7-2.
Otherwise the plant must be placed in hot standby (Mode 3) within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The inoperable valve was gagged closed and the power level-high trip setpoint verified to be less than 98.9%, allowing operation to continue.
Valve 2PSV-8416 has since been repaired.
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.R. H. Engelken August 18, 1982
'On the following day, July 20, 1982 at 0135, surveillance testing on the remaining 17. valves was performed. _ Review of this test data indicated that 9 of the safety valves had thelr setpoints slightly lower (0.5% to.
2.9%) than the acceptance band._ required by Table 3.7-1.
.These variations
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-from the acceptance band required by Table 3.7-1 are attributable to instrument drift and the fact that the approved procedure for valve setpoint verification does not. consistently result in a setpoint accuracy equivalent to the 1% tolerance permitted by the Technical Specifications.
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- . An evaluation of this valve 'setpoint verification procedure will be undertaken to determine whether modification can be made.to consistently produce setpoint accuracles commensurate with the 1% tolerance permitted by the Technical Specifications.
The pressure setpoints for the 9 valves were reset within allowable Technical. Specification tolerance by'0635 on.the same day. LER 82-070-addresses this event.
During this period,17 of the 18 safety valves would have been relied -
upon to provide'for system pressure relief had there been a need.
If there are any questions regarding the above, please contact me.
Sincerely, dy
Enclosure:
LER 82-063 and 82-070 cc:
A. E. Chaffee (USNRC Resident inspector, San Onofre Unit 2)
U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Office of Management information & Program Control l
Institute of Nuclear Power Operations l
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