ML20069M303
| ML20069M303 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/22/1983 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 8305030360 | |
| Download: ML20069M303 (2) | |
Text
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S AN ONOFRE NUCLE AR GENER ATING S T A TION P.o. sox tas S AN C LEMENTE. C ALIFORNI A 92672 STATION M AN AGER (714) 492-7700 April 22, 1983 U.S.
Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention:
Mr. J.
B.
Martin, Regional Administrator
Dear Sir:
SUBJECT:
Docket Nos.50-361 and 50-362 Prompt Reports Licensee Event Report No.83-037 (Docket 50-361)
Licensee Event Report No.83-037 (Docket 50-362)
San Onofre Nuclear Generating Station, Units 2 & 3 Pursuant to Sections.6.9.1.12.b of Appendix A, Technical Specifications-to Facility Operating Licenses NPF-10 and NPF 15 for San Onofre Units 2 & 3, respectively, this submittal provides the written confirmation of our April 21, 1983 prompt notification to the NRC of reportable occurrences involving the Engineered Safety Feature Actuation Systems (ESFAS's).
On April 21, 1983, we received a letter from Combustion Engineering Company which identified a potential safety concern involving erroneous trip setpoints for the high steam generator differential pressure trip function.
The error causes the equivalent voltage for the setpoint tc be one volt higher than the correct value.
This one volt increase causes the setpoint to be.300 psid higher than that assumed in our FSAR.
Specifically, the higher setpoint could result in a failure to stop emergency feedwater to an unisolated steam generator during a steam line break inside the containment.
8305030360 930422 PDR ADOCK 05000361 2 -11 0
Mr. J. B. Martin April 22, 1983 Limiting Condition for Operation (LCO) 3.3.2 specifies operability requirements for the high steam generator differential pressure trip function in Modes 1, 2, and 3.
These requirements have been exceeded, since Unics 2 and 3 have been in Mode 3 (and Unit 2 has also been in Modes 1 and 2).
Both units are currently in Mode 5 and, therefore, the trip function is not required to be operable.
Setpoints will be corrected prior to Mode 3 entry on both units and will be reported in a 14 day follow-up report with copies of Licensee Event Reports (LER's)83-037 (Docket No. 50-361) and 83-037 (Docket No. 50-362) to be submitted by May 5, 1983.
If there are any questions regarding the above, please contact me.
Sincerely, H13h /7YM%
cc:
A.
E. Chaffee (USNRC Resident Inspector, Units 2 and 3)
R. J. pate (USNRC Resident Inspector, Units 2 and 3)