ML20072V493
| ML20072V493 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/23/1983 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| 83-137, RO-83-28, RO-83-31, NUDOCS 8304110593 | |
| Download: ML20072V493 (2) | |
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P.O. B O X 126 S AN CLEMENTE, C ALIFORNI A 92672 STATION M AN AGE R fiarch 23, 1 983 m.
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U.S.
Nuclear Regulatory Commission Office of Inspection and Enforcement 1
Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention:
Mr.
R.
B.
Engelken, Regional Administrator
Dear Sir:
Subject:
Docket Nos. 50-361 and 50-362 Prompt Reports Licensee Event Report No.83-031 (Docket 50-361)
Licensee Event Report No.83-028 (Docket 50-362)
San Onofre Nuclear Generating Station, Units 2 & 3 Pursuant to Sections 6.9.1.12.i of Appendix A, Technical Specifications to Facility Operating Licenses NPF-10 and NPF-15 for San Onofre Units 2 and 3, respectively, this submittal provides the written confirmation of our March 23, 1983 prompt notification to the NRC of reportable occurrences involving the Reactor Protection Systems (RPS's).
During post-core hot functional testing on Unit 3 and subsequent follow-up troubleshooting, a potential safety concern involving calibration shift of Foxboro 2AO-V3I modules associated with the Core Protection Calculators (CPC's) was identified.
Specifically, this calibration shift, if left uncorrected, could result in erroneous primary loop temperature (T ot and h
Tcold) being transmitted to the CPC's.
This could result in a non-conservative calculation in the CPC's possibly delaying or preventing a reactor trip signal being generated as described in our FSAR.
N 4110593 830323 PDR ADOCK 05000361 S
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s Mr. R. H.
Engelken March 23, 1983 As corrective action, replacement of the Foxboro 2AO-V3I modules with 2AO-v2I modules in Unit 3 will provide assurance that the temperature inputs can be and will remain calibrated.
Although the problem was not identified in Unit 2, a similar change will be instituted.
A 14-day follow-up report with copies of Licensee Event Reports (LER's)82-031 (Docket No. 50-361) and 82-028 (Docket No.
50-362) will be submitted by April 5, 1983 to address these events.
If there are any questions regarding the above, please contact me.
Sincerely, cc:
A. E. Chaffee (USNRC_ Resident Inspector, Units 2 and 3)
R. J. Pate (USNRC Resident Inspector, Units 2 and 3) r