ML18096A807

LER 92-012-00:on 920602,1R11A Radiation Monitoring Sys Channel Spiked Into Alarm Resulting in CP/P-VR Sys Isolation Signal.Caused by Equipment Failure.Sys Returned to Service After Replacement of Warning sys.W/920702 Ltr

ML18096A807
Person / Time
Site:	Salem
Issue date:	07/02/1992
From:	Pollack M, Vondra C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-012, LER-92-12, NUDOCS 9207070369
Download: ML18096A807 (4)

Text

'. *~ e OPS~G Public Service Electric and Gas Company P.O. Box 236 _Hancocks Bridge, New Jersey 08038_

Salem Generating Station Ju1x 2, 1992 U. s. Nuclear Regulatory Commission Document _control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 LICENSEE EVENT REPORT 92-012-00 This Licensee Event Report is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73(a) (2) (iv). This report is required to be issued within thirty (30) days of event discovery.

Sincerely yours,

c. A Vondra General Manager -

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NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION (6-891 APPROVEO OMB NO. 31S0-0104 EXPIRES: 4/30/92 ESTIMATEO BUROEN PER* RESPONSE TO COMP.LY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARO LICENSEE EVENT REPORT (LERJ COMMENTS REGAROING BUROEN ESTIMATE TO THE RECOROS ANO REPORTS MANAGEMENT BRANCH (P-5301. U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, OC 20555, ANO TO THE PAPERWORK REDUCTION PROJECT (31SO-OI041. OFFICE OF MANAGEMENT ANO BUDGET, WASHINGTON. OC 20503.

FACILITY NAME 111 jOOCKET NUMIER (21 I PAGn31 c:i. .. 1 ~.;.. I"! .... - - - . tina Station - Unit 1 Io 1s Io 1o 1 o 1 21 7 12 1 loF o 13 Enaineered Safetv Feature actuation signal initiated from *th.e Radiation Monitoring System.

• EVENT DATE llil LER NUMBER' 161 *REPORT DATE 171 OTHER FACILITIU INVOLVED Iii MONTH DAY YEAR YEAR >t SE~~~~~~AL j) ~~~'::i~ MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI O 1s1010101 I I OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE R~QUIREMENTS OF 10 CFll §: (Clt<<:lc on* or mo,. of th* following! (111 MODE(ll 5 t"""'"'T"::-::'::-:--:--~~~~~-.---,r--~_.:.,~~~~__;-=...:.,.::....:.;~..::;,;:..:;_.::::...:....:.:,..:;:.:_...:.:.:::.;:.::::.:._:~~~~~~~~~~...J t-~~~r-,~.....1.~1--~

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LICENSEE CONTACT FOR THIS LER 1121 lio.731111211wiiillll 50.731111211*1 NAME TELEPHONE NUMBER AREA CODE M ~- n~11~ck - LER Coordinator COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBEO IN THIS REPORT 1131 MANUFAC* COMPONENT MANUFAC*

CAUSE SYSTEM COMPONENT TUR ER. SYSTEM TUR ER I I I I I I I I I I I I I I I I I I I I I I I I I I I I SUPPLEMENTAL REPORT EXPECTEO 1141 MONTH DAY YEAR EXPECTED n ~NO SUBMISSION DATE 1151 YES (If v**. compl*t* EXPECTED SUBMISSION OATEJ I I I This LER addresses an Engineered Safety Feature (ESF) actuation signal initiated through the Radiation Monitoring system (RMS). The signal was for Containment Purge/Pressure-Vacuum Relief (CP/P-VR) System isolation.

On June2, 1992, at 1216 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.62688e-4 months <br />, lRllA RMS channel spiked into alarm resulting in a CP/P-VR System isolation signal. At the time, the associated valves were closed and therefore did not change position~ The root cause of this event is equipment failure. The warning/high alarm light socket was making intermittent contact with the light bulbs due to corroded contacts. The channel spikes could be recreated by tapping the light socket. Other lRllA light sockets did not exhibit this problem.

The lRllA RMS channel was returned to service after replacement of the failed warning/high alarm light socket.and succe~sful completion of channel functional testing. Other RMS channel light sockets (same type used by the lRllA RMS channel) were inspected. No signs of corrosion or other failure mechanisms were identified. Also, an historical rev.iew of past lRllA RMS channel problems did not show a light socket failure.

NRC Form 366 16-891

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 1 5000272 92-012-00 2 of 3 PLANT AND SYSTEM IDENTIFICATION:

Westinghouse - Pressurized Water Reactor Energy Industry Identification System (EIIS) codes are identified in the text as {xx}

IDENTIFICATION OF OCCURRENCE:

Engineered Safety Feature actuation signal initiated from the Radiation Monitoring System Event Dates: 6/02/92 .

Report Date: 7/02/92 This report was initiated by Incident Report No.92-362.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 5 (Cold Shutdown) 10th Refueling Outage in progress DESCRIPTION OF OCCURRENCE:

This LER addresses an Engineered Safety Feature (ESF) actuation signal initiated through the Radiation Monitoring System (RMS) {IL}.

The signal was for Containment Purge/Pressure-Vacuum Relief (CP/P-VR)

System {BF} isolation.

On June 2, 1992, at 1216 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.62688e-4 months <br />, 1R11A RMS channel spiked into alarm resulting in a CP/P-VR System isolation signal. At the time, the associated valves were closed and therefore did not change position ..

On June 2, 1992, at 1347 hours0.0156 days <br />0.374 hours <br />0.00223 weeks <br />5.125335e-4 months <br />, the Nuclear Regulatory Commission (NRC) was notified of the actuation signal for CP/P-VR System isolation in accordance with Code of Federal Regulations 10CFR

50. 72 (b) (2) (ii).

APPARENT CAUSE OF OCCURRENCE:.

The root cause of this event is equipment f~ilure. The warning/high alarm light socket was making intermittent contact with the light bulbs due to corroded contacts. The channel spikes could be recreated by tapping the light socket. The warning/high alar~ light socket was replaced.

A large sampling of other RMS channe1*1ight sockets (same type used by the 1R11A RMS.channel) were inspected. No signs of corrosion or other failure mechanisms were identified. Also, an historical review of past 1R11A RMS channel problems did not show a light socket failure.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating station DOCKET NUMBER LER NUMBER PAGE Unit 1 5000272 92-012-00 3 of 3 ANALYSIS OF OCCURRENCE:

The 1R11A Co~ta.inment Particulate Monitor, (a NaI scintillation type detector, model LFE MD5B) monitors air particulate gamma radio-activity in the Containment atmosphere. In Modes 1 through 4, it is used to identify Reactor Coolant system (RCS) {AB} leakage in .

conjunction with the containment sump level monitoring system, and either the containment fan cooler condensate.flow rate or the containment atmosphere gaseous (1R12A) radioactivity monitoring system. In Mode 6, it is used to provide indication of a fuel handling accident and early Containment isolation in the event of an accident.

Both the .1R11A and 1R12A RMS channels provide an alarm signal which will cause the automatic isolation of the CP/P-VR System. Isolation of the CP/P-VR System ~s. an ESF to mitigate the release of radioactive material to the environment after a design basis accident.

This event resulted from an equipment failure and not high Containment airborne activity. Therefore, this event did not affect the health or safety of the public; however, due to the automatic actuation signal of an ESF system, .it is reportable in accordance with Code of Federal Regulations 10CFR 50.73(a) {2)(iv).

• A review of past RMS channel failures has identified one similar occurrence which occurred April 30,. 1990 on the 1R1B Control Room

,Ventilation Duct monitor (reference LER 272/90-015-00). The alarm indication bulb filament, on the channel drawer,* shorted to ground.

The alarm indication bulb is in the same circuit as the ESF actuating relay.*

• CORRECTIVE ACTION:

The 1Rl1A RMS channel.was returneq to service after replacement of the failed warning/high alarm light socket and successful completion of channel functional testing.

Other RMS channels warning/high alarm light sockets (the same type which failed) were inspected. They did not exhibit any signs of corrosion nor were.other failures found.

~JP:pc SORC Mtg.92-072