ML18095A640

LER 90-034-01:on 901005,1101 & 12,containment Purge/Pressure Vacuum Relief Sys Isolation Signals Actuated as Result of Channel Spike on Containment Particulate Monitor 1R11A. Caused by Personnel error.W/901205 Ltr

ML18095A640
Person / Time
Site:	Salem
Issue date:	12/05/1990
From:	Labruna S, Pollack M Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-034, LER-90-34, NUDOCS 9012180079
Download: ML18095A640 (6)

Text

Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station December ~. 1.9.90 U. S. Nuclear Regulatory Commission Documerit Control Des.k Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE.NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 LICENSEE EVENT REPORT 90-034-01;. SUPPLEMENT This Supplemental Licensee Event Report is being submitted pursuarit to. the requirements of. 10CFR 50. 7 3. The orignal LER addressed Engineered Safety Feature signal actuations (i.e., Containment Ventilation Isolation) .. That report did not identify the rqot cause of the event(s): .This tER sup~lement, in addition to addressing another ESF signal actuation, identifies the root cause of the events and the appropriate corrective actions taken.

Sincerely yours,

s. LaBruna General* Manager

\,, Salem Operations MJP:pc Distribution*

ThE: Energy People 90121 ::::C>079 S-1 01205 PDR A:OOCI< 05000272

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LICENSEE EVENT REPORT (LEA)

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ESF: Containment Ventilation Isolation Signal: lRllA RMS Channel Spikes IVINT DATl Ill LUI N~Ell Ill llll'OllT DATI 171 OTHlll FACILITlll INVOLVED . .

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>>tSAI TELEPHONE NUMIEll AREA CODE M. J. Pollack - LER Coordinator 6 I 019 3 I 3191- I 210 12 12 COMPLETE ONE LINE FOR EACH COMPONENT FAILUllE D£1CllllED IN THll llEl'OllT 11JI CAUSE SYSTEM COMPONENT MANUFAC- MANUFAC-TURER CAUSE SYSTEM COMPONENT TUREii 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 EXPECTED 1141 MONTH DAY YJAA EXPECTED n YES,,, l'W. COtnp/otl EXPECTED SU/JM/SS/ON DATE}

IUIMIS$10N DATE Cl!I I I I UITllACT (Limit lo 14<<J ~*. I.*.* _,,,,,....,.Ir fiftHtr 11~1**~* ry,,.wrlmn /inocl 1111 On 10/5/90 and 11/1/90, a Containment Purge/Pressure-Vacuum Relief System-(CP/P-VRS) isolation signals actuated as a result of a channel spike on the Radiation Monitoring System {RMS) Containment Particulate Radiation Monitor, lRllA. Technical Specification 3.4.6.1 Action Statement was entered each time. Investigation after each event did not reveal the cause of the channel spikes. Therefore, upon successful completion of a channel calibration, the channel was returned to operable status and Technical Specification 3.4.6.1 Action Statement was exited. On 11/12/90, a third lRllA channel spike occurred resulting in a CP/P-VRS signal. Technical Specification 3.4.6.1 Action Statement was subsequently entered. Investigation revealed that the root cause of the 3 channel spikes is personnel error. Replacement of the detector and its cable connector, on 9/28/90, was substandard and resulted in a broken shield wire. This wire filters electrical noise thereby preventing spurious channel spiking. This event has been reviewed by Maintenance Department management. Those individuals involved in this event have been held accountable. This event will be reviewed with applicable Maintenance Department personnel. This event will be reviewed for inclusion in applicable training programs.

Maintenance Department Continuing Training includes a review of soldering techniques and procedures.

Nl'IC For... JN 19-83)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating St~tion DOCKET NUMBER LER NUMBER PAGE Unit 1 5000272 90.,-034-01 2 of *5 PLANT AND SYSTEM IDENTIFICATION:

Westinghouse Pressurized Water Reactor Energy Industry Identification System (EIIS) codes are identified in.*

t~e text as {xxJ IDENTIFICATION OF OCCURRENCE:

Engineered Safety Feature Actuation - Containment Ventilation Isolation; channel spikes on the lRllA Radiation Monitoring System

.channel due to personnel error Event Dates:. 10/05/90, 11/01/90 arid 11112/~0 Report Date: 12/05/90 This report was initiated by Incident Report Nos.90-754, 90-837 and 90-862.

CONDITIONS PRIOR TO OCCURRENCE:

10/05/90 arid ll/01/9Q:.* Mode 1* Reactor Power 100%; Unit Load 1148 Jt!We 11/12/90: Mode 1 *Reactor Power 55%; Unit Load 545 MWe; load reduced to support No. 11 Steam Generator Feedwater Pump maintenance DESCRIPTION OF OCCURRENCE:

On October 5, 1990 at 1306 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.96933e-4 months <br />, a Containment Purge/Pressure-Vacuum Relief System (CP/P-VRS) isolation signal actuated as a result of a*

channel spike on the Radiation Monitoring System (RMS)* {ILJ Containment Particulate Radiation Monitor, 1R11A. Subsequently, Technical Specification 3~4.6.1 Actitin Statement was entered. The isolation valves were closed at _the time of this signal; they did not change position as a resrilt of the isolation signal.

On October 6, 1990 at 2205 hours0.0255 days <br />0.613 hours <br />0.00365 weeks <br />8.390025e-4 months <br />, upon.completion of a successful channel calibration, the channel was declared operable and Technical Specification 3.4.6.1 Action Statement was exited.

On November 1, 1990 at 1845 hours0.0214 days <br />0.513 hours <br />0.00305 weeks <br />7.020225e-4 months <br />, another 1R11A channel spike occurred resulting in a CP/P-VRS signal. A Containment pressure relief was in progress at the time of this event. The associated valves closed, as designed, in response to the isolation signal.

Technical Specification 3.4.6.1 Action Statement was subsequently entered.

Investigation of the two (2) lRllA channel spikes did not reveal a specific cause. On November 6, 1990 at 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />, upon completion of a successful channel calibration, the channel was declared operable and Technical Specification 3~4.6.1 Action Statement was exited.

On November 12, 1990 at 0642 hours0.00743 days <br />0.178 hours <br />0.00106 weeks <br />2.44281e-4 months <br />, another lRllA channel spike

. LICENSEE EVENT REPORT {LER) TEXT CONTINUATION.

Salem Generating Station DOCKET NUMBER LER NUMBER PAGE

.Unit 1 5000272 90-034-01 3 of 5 DESCRIPTION OF OCCuRRENCE: {cont'd) occurred resulting in a CP/P-VRS signal. The isolation valves were

• closed at the time and did not change position as a result of the isolation signal. Technical Specification 3. 4:. 6. i Action Statement was subsequently entered.

Technical Specification 3.4.6.1 states:

"The following Reactor Coolant System leakage detection systems shall be OPERABLE:

a. The containment atmosphere particulate radioact_ivity monitoring system,

b. .The containment pocket suinp level monitoring system, .and

c. . Either the containment fan cooler condensate flow rate or the containment atmosphere gaseous radioactivity monitoring system."

Technical Specification 3.4.6.l Action Statement states:

"With only two of the above required leakage detection systems OPERABLE, operation may continue for up to 30 days provided grab samples of the containment atmosphere are obtained and analyzed at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when the required gaseous and/or particulate radioactivity monitoring system is inoperable;

• otherwise, be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />."

'fhe CP/P-VRS is considered an Engineered Safety System. {ESF).

Subsequently, on October 5, 1990 at 1323 hours0.0153 days <br />0.368 hours <br />0.00219 weeks <br />5.034015e-4 months <br />, November 1, 1990 at 2021 hours0.0234 days <br />0.561 hours <br />0.00334 weeks <br />7.689905e-4 months <br /> and November 12, 1990 at.0834 hours0.00965 days <br />0.232 hours <br />0.00138 weeks <br />3.17337e-4 months <br /> {respectively), the Nuciear Regulatory Commission was notified of the automatic actuation signal for CP/P-VRS isolation in accordance with Code of Federal Regulations 10CFR 50.72(b) (2) (ii).

APPARENT CAUSE OF OCCURRENCE:

The cause(s) of the first and second lRllA channel spike were not identified prior to returning the channel to service.

Troubleshooting had failed to identify a specifi*c equipment concern -

prior to declaring the lRllA channel operable (on October 6,* 1990 and November 6, 1990 respectively), after successful completion of a channel calibration. This.troubleshooting included visual inspection of the channel electrical components, point to point electrical circuit checks (using test equipment) on the ratemeter drawer, and reverification of the high voltage detector setting.

On November 12, 1990 a third channel spike, resulting in an ESF signal, occurred. Investigation of this event revealed that the root cause of all three (3) channel spikes is attributed to personnel error. Replacement of the detector and its cable connector, on

LICENSEE EVENT REPORT (LER)° TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE

• Unit 1 5000272 90.:...034-01 4 of 5 APPARENT CAUSE OF OCCURRENCE: (cont'd)

September 28, 1990*, was substandard and resulted in a broken shield wire. This wire filters electrical noise thereby preventing spurious channel spiking. It~ is believed that normal generated EM/RFI

.(Electro-Magnetic/Radio Frequency Interference) caused the spurious spiking.

Inspection of the detector cable connector revealed that the shield wire had been inadequately soldered. This condition led to .the failure of the shield wire when the wiring was moved; The lRllA*

detector and its connector had been replaced five (5) days prior to the first ESF actuation.

ANALYSIS OF OCCURRENCE:

The lRllA, Containment Particulate Monitor, (a NaI scintillation .type detector, model LFE MD5B) monitors the air particulate gamma radioactivity in the Containment atmosphere. It is used.to identify of Reactor Coolant System (AB} leakage *in conjunction with the containment pocket sump level monitoring system, .the containment fan cooler condensate flow rate monitors, and the containment atmosphere gaseous radioactivity (1Rl2A) RMS channel~ An alarm signal will cause the automatic isolation of the CP/P-VRS.

Air samples are pulled directly from the Containment atmosphere through a filter paper which continuously moves past the lRllA*

scintillation detector. After the air sample passes through the filter paper, it passes through ~ charcoal cartridge (monitored by the 1R12B monitor) and is then mixed into a fixed shielded volume where.it is viewed by. the 1R12Atnoble gas monitor. The air sample.is then returned to the Containment.

Several area radiation monitors, in addition to the 1R12A monitor, are used to corroborate thelRllA channel's. indications. The corroborating area radiation monitors do not have isolation

• capabilities. They* only have alarm capability. The 1R41A Plant Vent Particulate monitor also corroborates the lRllA chann*e1 indications during Containment purge or pressure-vacuum relief operations. It also has the capability to automatically isolate the CP/P-VRS.

During the inoperable period for the lRllA channel, Containment pressure relief was conducted. The 1R41A channel remai.ned operable during the pressure relief.

During either lRllAchannel spike, RCS leakage within Containment*did not increase. The corroborating RMS channels did not indicate any increase in Containment airborne activity. At the time of the second lRllA. channel. spike, a Containment pressure relief was in progress (via the Plant Vent). The Plant Vent RMS channels did not identify any significant activity increase~ Therefore, these events did not affect the health or safety of the public. However, due to the automatic actuation signal of an ESF system, they are reportable in accordance with Code of Federal Regulations 10CFR S0~73(a) (2) (iv).

.. LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER- LER NUMBER PAGE Unit 1 5000272 90-034-01 5 of 5 ANALYSIS OF OCCURRENCE: (cont'd).

An. histo;rical review of prior lRllA channel failures was conducted.

The channel has been subject to spikes (approximately once or twice a year). The corrective actions for the prior events included. contact cleaning and connector adjustment. No specific failed component was identified for several of the prior events.

CORRECTIVE ACTION:

A previous RMS generic historical review was conducted (reference LER 311/90-031-00) of the RMS ESF related channels. A concern with LFE

_ Analog Ratemeters Models AR~2 and AR-2S power supply circuit filtering capacitors was identified. Subsequently, these capacitors have been ~cheduled to be replaced for the subject RMS channels. The lRllA channel* uses the Model AR-2 ratemeter. The ESF actuations

• identified by this LER were not. attributed to a capacitor component.*

problem. They had been replaced on September 28, 1990 along with the detector and its cable connector.

The broken shield wire was repaired. Upon succesful completion of a channel check, on November 16, 1990 at 0642 hours0.00743 days <br />0.178 hours <br />0.00106 weeks <br />2.44281e-4 months <br />, Technical Specification 3.4.6.l Action Statement was ~xited.

This event has been reviewed by Maintenance* Department management.

Those individuals involved in this event have.been held accountable.

This event will be reviewed with applic~ble Maintenance Department personnel.

This event will be reviewed by the Nuclear Training Center for inclusio~ in applicable tr~ining programs. Maintenance Department Continuing Training,* for 1991, includes a review of the techniques and procedures to be used for the performance of soldering.*

General Manager -

Sale~ Operations MJP:pc SORC Mtg.90-159