ML18094A303

LER 89-004-00:on 890304,containment Purge/Presssure Vacuum Relief Isolation Valves Isolated as Result of Failure of Containment Particulate Radiation Monitor.Caused by Inadequate Sys Design.Channel 2R11A reset.W/890329 Ltr

ML18094A303
Person / Time
Site:	Salem
Issue date:	03/29/1989
From:	Miller L, Pollack M Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-004-02, LER-89-4-2, NUDOCS 8904060153
Download: ML18094A303 (5)

Text

NRC Form 318 U.I. NUCLEAR REGULATOllY COMMISllOfil (9.a31 APl'ROVEO OM! NO. Jl!I0-0104 EXPIRES: Sf.111815 LICENSEE EVENT REPORT (LER)

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FACILITY NAME (11 OOCKET NUM*ER l2l p,.. .. ., I'll Salem Generating Station - Unit 2 o I 5 Io Io I o 13 11 I l 1 loF 014 TITLE (41 ESF Actuation - Containment Vent. Isolation Due To System Design/Equip. Concerns EVENT DATE (Ill LER NUMBllR (Ill REPORT DATE 171 OTHER FACILITIES INVOLVED (II MONTH CAY YEAR YEAR rt ~E~~~~~~AL tt ~~~~~~ MONTH DAY YEAR FACIL.!iV NAMES DOCKET NUMBERISI ol 3 o14 a 9 a I 9 - o I o14 - oI o q 3 2 I9 a I 9 THll REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Chock an* or m<HY of th* fallowing) (111 OPERATING MOOE (II POWER I l 20.402(bl 20.40l5t*lt1lUI -

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366A) 20.40l(11(1 ltlvl 20.40llt*lt1 IM - ll0.73(11(Zl(lll ll0.73toltZltllll LICENSEE CONTACT FOR THIS LER (121 ll0.73(1)(Zl(wlllltll eo.73t*ltZHxl NAME TELEPHONE NUMBER AREA COOE M. J. Pollack - LER Coordinator COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRlllED IN THll REPORT 1131 CAUSE SYSTEM COMPONENT MANUFAC.

TUR ER B IIL DIEITI v111 01 N I I I I I I I I I I I I I I I I I I I I I SUPl'LEMENTAL REPORT EXPECTED (141 MONTH DAY Y~AR EXPECTED n ~

SUBMISSION YES (If yn, oampl*tt EXPECTED SUBMISSI~ DATE/ NO DATE (151 I I I AllSTRACT (Limit ID 14CO IP"C... I.*** *PPf'OKim*ttly flftHn 1/ngl**IPOCO typoWl'lttfn lintni 11111 On March 4, 1989, the Containment Purge/Pressure-Vacuum Relief System

{CP/P-VRS} valves isolated as a result of the failure of the Radiation Monitoring System (RMS) Containment Particl1late Radiation Monitor, 2R11A. With the failure of the 2RllA channel, Technical Specification 3.4.7.1 Action Statement was entered. The root cause of this event has been attributed to inadequate system design. The CP/P-VRS isolation was preceded by the transfer of 2A Vital Bus to the No. 21 Station Power Transformer {SPT). The No. 21 SPT is the normal power supply for the 2A Vital Bus which powers the 2R11A RMS monitor. The transfer to the No. 21 SPT utilizes a "slow" transfer scheme which will drop line voltage to 35% of nominal value. Since the 2Rl1A RMS.

monitor is directly powered from the 2A Vital Bus it will see the voltage drop too causing the channel to "fail". Conservatively, failure of the channel causes CP/P-VRS isolation. As identified in Unit 2 LER 89-002-00, PSE&G System Engineering has initiated an investigation of RMS system concerns. This investigation includes *a review of power supply concerns. The 2R11A channel was reset, the setpoints were verified and a channel check was successfully completed on March 5, 1989 at which time,* the channel was declared operable and the Technic~l Specification 3.4.7.1 Action Statement was exited.

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II LICENSEE EVENT REPORT (LER} TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE TJ~i t 2 5000311

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PLA]'.JT AND SYSTEM IDENTIFICATION:

Westinghouse - Pressurized Water Reactor Energy Industry Idez1tification System (EIIS) codes ~re identified in the text as {xx!

IDENTIFICATION OF OCCURRENCE:

Engineered Safety Feature Actuation - Containment Ventilation Isolation Due To System Design/Equipment Concerns Event Date: 3/04/89 Report Date: 3/29/89 This report was initiated by Incident Report No.89-122.

CONDITIONS PRIOR TO OCCVRR~~CE:

Mode 1 Reactor Power 100% - Unit Load 1150 MWe DESCRIPTION OF OCCURRENCE:

On March 4, 1989 at 1620 hours0.0188 days <br />0.45 hours <br />0.00268 weeks <br />6.1641e-4 months <br />, the Containment Purge/Pressure-Vacuum Relief System lCP/P-VRS} valves isolated as a result of the failure of the Radiation Monitoring System (RMS) {ILi Containment Particulate Radiation Monitor, 2R11A. With the failure of the 2R11A channel, Technical Specification 3.4.7.1 Action Statement was entered.

Technical Specification 3.4.7.1 states:

"The following Reactor Coolant System 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 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 />."

The CP/P-VRS is an Engineered Safety System (ESF).

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION

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Salem Generating Station DOCKET NUMBER LER NUMBER PAGE

~-n~i_t~2~~~~~~~~~~~~~~~~~03i_1~~~~~8_9-004-00~~~~3 of 4 The root cause of this event has been attributed to inadequate system design.

The CP/P-VRS isolation was preceded by the transfer of 2A Vital Bus to the No. 21 Station Power Transformer (SPT) {EAi. The No. 21 SPT is the normal power supply for the 2A Vital Bus which powers the 2Rl1A RMS monitor. The transfer to the No. 21 SPT utilizes a "slow" transfer scheme which will drop line voltage to 35% of nominal value.

Since the 2R11A RMS monitor is directly powered from the 2A Vital Bus it will see the voltage drop too causing the channel to "fail.

Conservatively, failure of the channel causes CP/P-VRS isolation.

The No. 21 SPT had been returned to service after completion of a 13 KV leads compartment gasket cover oil leak repair.

ANALYSIS OF OCCURRENCE:

The 2Rl1A Containment Particulate Monitor monitor's the air particulate gamma radioactivity in the Containment atmosphere. It is used as an aid in the identification of Reactor Coolant System fABl 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 tl:e 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 2Rl1A 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 2R11A channel indications.

This monitor also has the capability of automatic isolation of the CP/P-VRS. It remained operable during the course of this event.

During this event, RCS leakage within Containment did not increase.

Additionally, a Containment purge or pressure-vacuum relief was not performed. Therefore, this event did not affect the health or safety of the public. However, due to the automatic operation of an ESF system, this event is reportable in accordance with Code of Federal Regulations 10CFR 50.73(a) (2) (iv).

CORRECTIVE ACTION:

As identified in Unit 2 LER 89-002-00, PSE&G System Engineering has

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 2 ---5000311 89-004-00

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CORRECTIVE ACTION~=-~(~c~o,~n~t-=--'~d~)

initiated an investigation of RMS system concerns. This investigation includes a review of power supply concerns.

The 2R11A channel was reset, the setpoints were verified and a channel check was successfully completed on March 5, 1989. At 0436 hours0.00505 days <br />0.121 hours <br />7.208995e-4 weeks <br />1.65898e-4 months <br /> on March 5, the channel was declared operable and Technical Specification 3.4.7.1 Action Statement was exited.

G:~J~ager -

Salem Operations MJP:pc SORC Mtg.89-026

Public Ser-vice Electric and Gas Company P 0. Box E Hancocks Bridge, New Jersey 08038 Salem Generating Station March 29, 1989 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 89-004-00 This Licensee Event Report is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73 (a) (2) (iv}. ~his report is being submitted within thirty (30) days of discovery.

Sincerely yours,

~!~(~er General Manager -

Salem Operations MJP:pc Distribution The Energy People