ML18096B233

Special Rept 93-1:on 930114,RMS Channels 1R45B & 1R45C Declared Inoperable Upon Annuciation of External Fail Alarm.Cause Not Determined.Upon Completion,Corrective Actions Will Be Taken & Channels Will Return to Svc

ML18096B233
Person / Time
Site:	Salem
Issue date:	01/28/1993
From:	Vondra C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
93-1, NUDOCS 9302030101
Download: ML18096B233 (3)

Text

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• ,:.._:,., PS~G Public Service Electric and Gas Company P.O. Box E Hancocks Bridge, New Jersey 08038 Salem Generating Station January 28, 1993

u. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

• near Sir:

SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO~ 50~272 UNIT NO. 1 SPECIAL REPORT 93-1 This Special Report addresses the inoperability of* the Radiation Monitoring System (RMS) channels 1R45B and-1R45C Plant Vent medium and high range noble gas monitors for greater than seven (7) *days.

This report is submitted for informational purposes in accordance with Technical Specification 3.3.3.1 Action 23 pursuant to Specification 6.9.2.

C. A. Vondra General Manager -

Salem Operations MJP:pc Distribution 9302030101 930128 PDR ADOCK 05000272 S PDR

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- e SPECIAL REPORT N'QMBER 93-1 9**

PLANT IDENTIFICATION:

S~lem Generating Station - Unit 1 Public Service Electric & Gas Company Hancock's Bridge, New Jer~ey 08038 IDENTIFICATION OF OCCURRENCE:

Radiation Monitoring Channels 1R45B and 1R45C inoperable for greater than seven days

• E~ent Date(s): 1/14/9~

Report Date: 1/28/93 This report-was initiated by Incident Report No.93-036.

CONDITIONS PRIOR TO OCCURRENCE:

1/14/93: Mode 1 (Hot Standby) 1/21/91: Mode 3 (Startup)

DESCRIPTION OF OCCURRENCE:

_bn January 14, l993 1 at 1-330 hours, Radiation Monitoring System (RMS}

channels 1R45B and 1R45C were declared inoperable upon annunciation of an "External Fail" alarm. This alarm -can be actuated by a signal indicating that the sample pump is not running or by a flow

• obstruction to the low ~low differential pressure switch {1PD6866 manufactured by Ashcroft). These RMS channels are.medium and'high range Plant Vent noble gas monitors.

Initial investigation did not reveal a specific cause of the External Fail alarm. It was suspected that a problem with the microprocessor

~data existed. The RAM data was cleared artd reentered (e.g.,

conve~sioh constants, *** etc.)~ The external fail alar~

subsequently cleared. However, prior to performance of an operability retest, the external fail alarm reactuated. Subsequent investigation has determined that the low flow pressure switch is causing the External Fail alarm. However, the root cause of the switch actuation has not been determined.

Since the channels have not _been returned to service within seven days, this Speqial Report is required i11; accordance with Technical.

Specification 3.3.3.1.b Table 3.3-6 Action 23 which states: *

"With the number of OPERABLE channels less than required by the Minimum Channels OPERABLE requirements, initiate the-preplanned alternate method of monitoring the appropriate parameter(s),

within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, and: *

1. either restore the inoperable Channel(s} to OPERABLE status within 7 days of the event, or * *

2. prepare and submit a Special Report to the Commission pursuant to Specification 6.9.2 within 14 days following

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. UNIT 1 SPECIAL REPORT 93-1 DESCRIPTfON OF OCCURRENCE: (cont'd) the*event outlining the action taken, the cause of the inoperability and the plans and schedule for restoring the system to OPERABLE status."

APPARENT CAUSE OF oc*cURRENCE:

Investigation, to date, has not determined the root cause of the s~itch actuation_ signal. Efforts to determine this ar~ continuing.

ANALYSIS OF OCCURRENCE:

Th"e 1R45B and 1R45C channels monitor the Plant Vent radioactive noble gas releases via representative sampling. The 1R45B monitor is a medium range monitor and the 1R45C channel is a high range monitor.

They are both required in operating modes 1 - 4 (power operation to Hot Shutdown)~ Their purpose is to monitor.significant releases of radioactive materials in compliance with the Updated Final Safety Analysis.Report (UFSAR) and federal regulation.

CORRECTIVE ACTION:

Investigation as to the.causal factors associated with this event is continuing.* Upon completion, appropriate corrective action will be taken and the 1R45B and 1R45C RMS Channels will be returned to service.

General Manager -

Salem Operations MJP:pd SORC Mtg.93-008