ML18095A573

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LER 90-038-00:on 901004,containment Particulate Radiation Monitoring Sys Channel Spiked Resulting in Containment purge/pressure-vacuum Relief Sys Isolation signal.W/901031 Ltr
ML18095A573
Person / Time
Site: Salem PSEG icon.png
Issue date: 10/31/1990
From: Labruna S, Pollack M
Public Service Enterprise Group
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-038, LER-90-38, NUDOCS 9011130340
Download: ML18095A573 (5)
v • d • e


Text

OPS~G Public Service.Electric and Gas Company P.O. Box ~36 Hancocks Bridge, New Jersey 08038 Salem Generating Station October 31~ 1990 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-75 DOCKET NO. 50-311 UNIT NO. 2 LICENSEE EVENT REPORT 90-038-00 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 within thirty (30) days of* discovery.

Sincerely yours, S. LaBruna General Manager -

Salem Operations MJP:pc Distribution 9011130340 901031 PDR ADOCK 05000311 S PNU

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APl'f!OVED OMI NO. 311!0-0104 EXPIAEll: 1/31111 LICENSEE EVENT REPORT (LER)

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l'ACILITY NAME 111 I Salem Generating Statin - Unit 2 0 rs I 0 ., 0 I 0 I 31 111 1 loF 0 I 4 TITLE (41 ESF Signal; Containment Ventilation Isolation Signal Due To Equip./Desiqn concerns EVENT DATE (Ill LER NUMBER (81 REl'ORT DATE 171 OTHER FACILITIES INVOLVED Ill MONTH QAY YEAR YEAR fl SE~~~~~~AL \ \ ~~~~?.: MONTH DAY YEAR FACILITY NAMES DOCKET NUMllEAISI l lo ol 4 9 o 9 lo - o j3 Ia - ol o l lo 311 9 lo OPERATING THll REPORT II IUllMITTED PURSUANT TO THE REQUIREMENTI OF 10 CFll §: (Ch<<:lt OM or man of tlN followl"f} (111 MODE (II l Z0.402(bl Z0.406(11(11111 20 *.ell5(ol(11(UI

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Z0.406(8111 HM ll0.731oll2llUI ll0.73(11(2ll*Ulllll Z0.40lll11111M ll0.731oll21Ulll ll0.73(111211*1 LICENSEE CONTACT FOR THIS LER 1121 NAME TELEPHONE NUMBER AREA CODE M. J. Pollack - LER Coordinator 61 0 19 31 3 19 1 -1 2 10 1 21 2 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRllED IN THIS REl'ORT 1131 CAUSE SYSTEM COMPONENT MANUFAC. MANUFAC.

TUR ER SYSTEM COMPONENT 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 EXPECTED 1141 MONTH DAY Y~AR

!xi EXPECTED

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SUBMl$SION DATE 1151 YES (If res. comp/*lfl EXPECTED SU/JM/SS/ON DA TEI NO I I I AalTRACT (Limlr IO 1400 q>>ca, I.*** *pproxlm*lflly fifrHn 1lng1..,,,.co ry,,.wrlttwn /inn! 11111 On 10/4/90 at 1335 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.079675e-4 months <br />, during normal power operation, the 2R11A Containment Particulate Radiation Monitoring System (RMS) channel spiked resulting in a Containment Purge/Pressure-Vacuum Relief System (CP/P-VRS) isolation signal. At the time of the event, the 2R11A filter paper was being changed. Tech. Spec. 3.4.7.1 Action Statement was therefore in effect at the time of the CP/P-VRS isolation signal actuation. The CP/P-VRS isolation signal is an Engineered Safety Feature (ESF). The root cause of the CP/P-VRS actuation is attributed to design/equipment concerns. As indicated in prior LERs (e.g.,

311/90-019-00) , the Salem Unit 2 RM*s is p_rone to voltage transients.

Investigation of this event did not identify any specific equipment/component failure. The 2R11A channel filter paper change out, in progress at the time of the event, may have contributed to the CP/P-VRS isolation signal actuation. Therefore, a procedure will be prepared which will require placement of the CP/P-VRS feature in "block" (preventing actuation of the CP/P-VRS isolation signal function} when performing a filter change. In the interim a Work Standard, which will require placing the channel in "block", will be issued. On 10/17/90 at 1455 hours0.0168 days <br />0.404 hours <br />0.00241 weeks <br />5.536275e-4 months <br />, Tech. Spec. 3.4.7.1 Action Statement was exited upon completion of troubleshooting and return of the channel to service. As indicated in LER 311/90-019-00; Engineering has investigated the concerns with the Unit 2 RMS channels. It is anticipated that several system design modifications will eliminate the spurious ESF actuation signals (this includes the installation of an uninterruptable power supply}.

NRC Form 3111 (9-831

Salem Generating Station DOCKET. NUMBER LICENSEE EVENT REPORT (LER) TEXT CONTINUATION LER NUMBER PAGE Unit 2 5000311 90-038-00

  • 2 of 4 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: Containment Purge/Pressure-Vacuum Relief System Isolation Due To Equipment/Design Concerns Event Date: 10/04/90 Report Date: 10/31/90 This report was initiated by Incident Report No.90-751.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 Reactor Power 100% Unit Load 1130 MWe DESCRIPTION OF OCCURRENCE:

On October 4, 1990 at 1335 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.079675e-4 months <br />, during normal power operation, the 2Rl1A Containment Particulate Radiation Monitoring System (RMS) {IL}

channel spiked resulting in a Containment Purge/Pressure-Vacuum Relief System (CP/P-VRS) isolation signal. At the time of the event, the 2RllA filter paper was being changed. Technical Specification 3.4.7.1 Action Statement was therefore in effect at the time of the CP/P-VRS isolation signal actuation.

The isolation valves were closed at the time of the signal. They did not change position as a result of the isolation signal.

Technical Specification 3.4.7.1 states:

"The following Reactor Coolant Sy~tem leakage detection systems shall be OPERABLE:

a. The containment atmosphere particulate radioactivity monitoring system,
b. The containment pocket sump level monitoring system, and
c. Either the containment fan cooler condensate flow rate or the containment atmosphere gaseous radioactivity monitoring system."

Technical Specification 3.4.7.1 Action Statement states: -

"With only two of the above required leakage detection systems OPERABLE, operation may continue for up to 30 days provid~d grab

Salem Generating Station

  • DOCKET NUMBER LICENSEE EVENT REPORT (LER) TEXT CONTINUATION LER NUMBER PAGE Unit 2

~~~~~~~~~~~~~~~~~~~~~~~~~~~-

5000311 90-038-00 3 of 4 DESCRIPTION OF OCCURRENCE: (cont'd) 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 />."

The CP/P-VRS isolation signal is an Engineered Safety Feature (ESF).

Subsequently,' at 1448 hours0.0168 days <br />0.402 hours <br />0.00239 weeks <br />5.50964e-4 months <br /> on October 04, 1990, the Nuclear Regulatory Commission was notified of the automatic actuation of CP/P-VRS as required by Code of Federal Regulations 10CFR

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

APPARENT CAUSE OF OCCURRENCE:

The root cause of the CP/P-VRS actuation is attributed to design/equipment concerns. As indicated in prior LERs (e.g.,

311/90-019-00), the Salem Unit 2 RMS is prone to voltage transients.

Investigation of this event did not identify any specific equipment/component failure. The 2Rl1A channel filter paper change out, in progress at the time of the event, may have contributed to the CP/P-VRS isolation signal actuation. Therefore, as stated in the Corrective Action Section, a procedure will be prepared which will require placement of the CP/P-VRS feature in "block" (preventing actuation of the CP/P-VRS isolation signal function) when performing a filter change.

ANALYSIS OF OCCURRENCE:

Isolation of the CP/P-VRS is part of the design Engineered Safety Features (ESFs). It mitigates the release of excessive quantities of radioactive material to the environment after a design base accident.

The 2R11A Containment Particulate Monitor monitor's air particulate gamma radioactivity in the Containment atmosphere. It aids in the identification of Reactor Coolant System {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 (2R12A) radioactivity monitoring system. 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 2Rl1A scintillation detector. After the air sample passes through the filter paper, it passes through a charcoal cartridge (monitored by the 2R12B monitor) and is then mixed into a fixed shielded volume where it is viewed by the 2R12A noble gas monitor. The air sample is then returned to the Containment.

Several area radiation monitors, in addition to the 2R12A monitor, are used to corroborate the 2R11A channel's indications. The 2R12A channel has CP/P-VRS isolation capability; although, the other

Salem Generating Station DOCKET. NUMBER LICENSEE EVENT REPORT (LER) TEXT CONTINUATION LER NUMBER PAGE Unit 2 5000311 90-038-00 . 4 of 4 ANALYSIS OF OCCURRENCE: (cont'd) corroborating area radiation monitors do not. They only have alarm capability.

The inadvertent actuation of the CP/P-VRS isolation signal was apparently caused by an equipment/design concern, not the result of high activity. Therefore, this event did not affect the health or safety of the public. However, due to the actuation of an ESF function, this event is reportable in accordance with Code of Federal Regulations 10CFR 50.73(a) (2) (iv).

CORRECTIVE ACTION:

A procedure will be prepared to address filter change requirements for the 2R11A channel. In the interim a Work Standard, which will require ~lacing the channel in "block", will be issued.

On October 17, 1990 at 1455 hours0.0168 days <br />0.404 hours <br />0.00241 weeks <br />5.536275e-4 months <br />, Technical Specification 3.4.7.1 Action Statement was exited upon completion of 2RllA troubleshooting and return of the channel to service.

As indicated in LER 311/90-019-00, Engineering has investigated the concerns with the Unit 2 RMS channels. It is anticipated that several system design modifications will eliminate the spurious ESF actuation signals. One of these design modifications is the installation of an uninterruptable power supply (UPS), which will be completed by February 1991. The plans for completion of these modifications are included in the current PSE&G Living Engineering Plan for the RMS system.

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