05000311/LER-1982-141, Forwards LER 82-141/03L-0.Detailed Event Analysis Encl: Difference between revisions

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#REDIRECT [[05000311/LER-1982-141, Updated LER 82-141/03X-1:on 821121 & 1204,P-250 Computer Inoperable Due to Parity Error.Caused by Periodic Increases in Ambient Temp Due to Insufficient Ventilation.Computer Reprogrammed & Action Statement Terminated]]
| number = ML20070L523
| issue date = 12/08/1982
| title = Forwards LER 82-141/03L-0.Detailed Event Analysis Encl
| author name = Midura H
| author affiliation = PUBLIC SERVICE ELECTRIC & GAS CO. OF NEW JERSEY
| addressee name = Haynes R
| addressee affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
| docket = 05000311
| license number =
| contact person =
| document report number = NUDOCS 8301030157
| package number = ML20070L525
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE, UTILITY TO NRC
| page count = 3
}}
{{LER
| Title = Forwards LER 82-141/03L-0.Detailed Event Analysis Encl
| Plant =
| Reporting criterion =
| Power level =
| Mode =
| Docket = 05000311
| LER year = 2082
| LER number = 141
| LER revision =
| Event date =
| Report date =
| ENS =
| abstract =
}}
 
=text=
{{#Wiki_filter:!
l O          >SEG Public Service Electric and Gas Company P.C. t3ox E Hancocks Bridge, New Jersey 08038 Salem Generating Station December 8, 1982 Mr. R. C. Haynes Regional Administrator USNRC Region 1 631 Park Avenue King of Prussia, Pennsylvania                      19406
 
==Dear Mr. Haynes:==
 
LICENSE NO. DP R-75 DOCKET NO. 50-311 REPORTABLE OCCURRENCE 82-141/03L Pursuant to the. requirements of Salem Generating Station Unit No. 2, Technical Specifications, Section 6.9.1.9.b,
,  we are submitting Licensee Event Report for Reportable occurrence 82-141/03L. This report is required within thirty (30) days of the occurrence.
l                                                          Sincerely yours,
                                                                  /', 4      2' l
H. J. Midura General Manager -
i                                                          Salem Operations l
RF:ksf.
CC:    Distribution I
(
8301030157 821208 PDR ADOCK 05000311 S                        PDR l
l The Energy Pecple                                                                    pW 95 215r) 00".O I161
 
Report Number:      82-141/03L Report Date:        12-98-82
  ;    Occurrence Date:    11-21 82
:      Facility:            Salem Generating Station Unit 2 Public Service Electric & Gas Company Hancock's Bridge, New Jersey 98838 IDENTIFICATION OF OCCURRENCE:
Accident Monitoring Instrumentation - Reactor Coolant System Subcooling Margin Monitor - Inoperable.
This report was initiated by Incident Reports 82-482 and 82-486.
1' CONDITIONS _ PRIOR TO_ OCCURRENCE:
Mode 1 - RX Power 81 % - Unit Load 890 MWe.
i DESCRIPTION OF OCCURRENCE:
i' On two separate occasions, at 1420 hours, November 21, 1982, and at 0730 hours, December 4, 1982, during routine operation, the Control Room Operator discovered that the P-250 Computer was inoperable due to
,      a parity error; attempts to bootstrap the computer failed. Since it utilizes the computer for inputs and calculations, the Reactor Coolant System (RCS) subcooling margin monitor in both cases was declared inoperable, and Technical Specification Action Statement 3.3.3.7a was entered. The wide range RCS temperature and pressure indications were operable and steam tables were available in the Control Room throughout both occurrences.
1      APPARENT CAUSE OF OCCURRENCE:
i The malfunctions of the P-250 Computer were apparently due to the l      power supply breaker tripping in association with periodic increases i      in cabinet ambient temperatures (approximately 89 F) . The temperature increases were attributed to inadequate capacity of the cabinet i      cooling system. Previous trips of the breaker had been noted, but had been assumed to be spurious events resulting from de-energizing the unit following a malfunction.
ANALYSIS.OF OCCURRENCE:
l      Operability of the accident monitoring instrun.entation ensures that j      sufficient information is available on selected plant parameters to monitor and assess these variables following an accident. Since, as I
noted, wide range indication and steam tables were available allowing determination of the subcooling margin, the event involved no risk to the health and safety of the public.
Due to the loss of redundancy, the occurrence constituted operation in
,      a degraded mode permitted by a limiting condition for operation. The l      incident is therefore reportable in accordance with Technical l
 
DER 82-141/03L                        ANALYSIS _ OF OCCilREEEE: (cont'd)
Specification 6.9.1.9b.
Action Statement 3.3.3.7a requires:
With the number of operable accident monitoring channels less than the required number-of channels, restore the inoperable channel (s) to operable status within 7 days, or be in at least hot shutdown within the next 12 hours.
CORRECTIVE ACTION:
In each case, following investigation of the problem, the tripped breaker was reset and the bootstrap program was successfully loaded.
In the first instance, the P-250 Computer was returned to service, the RCS subcooling margin monitor was satisfactorily tested, and Action Statement 3.3.3.7a was terminated at 2000 hours, November 21, 1982.
Following the second occurrence, a temporary fan was installed in the cabinet to increase air circulation and improve cooling. The computer was returned to operation, the monitor was satisfactorily tested, and the action statement was terminated for a second time at 1000 hours, December 4, 1982.
Due to recurrent problems with the computer, a replacement breaker has been ordered and will be installed upon receipt of the part.
Improvement of the ventilation system is presentl'y under investigation; a Supplemental Report will be submitted upon final resolution of the problem.
PAILURE DATA:
Previous malfunctions of the P-250 Computer documented in LER 82-131/03L were similar in nature and may be related to the
;  occurrences discussed in this report.
Westinghouse Electric Corp.
PRODAC 250 Computer l
Prepared By  R. Prahm                                b      V Gederal' Manager -
l
'                                                  Salem Operations j
SORC Meeting No. 82-109 l
1 l
                                              . --
}}
 
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