05000272/LER-1990-033-01, :on 900923,two Channels Made Inoperable Due to Equipment Failure

:on 900923,two Channels Made Inoperable Due to Equipment Failure

ML18095A547
Person / Time
Site:	Salem
Issue date:	10/23/1990
From:	Labruna S, Pollack M Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-033-01, LER-90-33-1, NUDOCS 9010290270
Download: ML18095A547 (7)

LER-1990-033, on 900923,two Channels Made Inoperable Due to Equipment Failure

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
2721990033R01 - NRC Website

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OPS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Statiori 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 90-033-00 October 23, 1990 This Licensee Event Report is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73(a) (2) (vii) (C).

This report is required within thirty (30) days of discovery.

MJP:pc Distribution

• ~10102'?0270 PDR A:OOO=::

The Energy People Sincerely yours, S. LaBruna General Manager -

Salem Operations re:12 95-2189 (10M) 12-89

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TITLE ICI Two channels made inoperable due to common equipment failure.

EVENT OATI (Ill LER. NUMBER Ill REPORT DATE (7)

OTHEll FACILITIEI INVOLVED Ill FACILITY NAMES DOCKET NUMllERISI OP'IRATINO THll llEl'ORT 11 IUIMITTED P'URIUANT'TO THE REQUIREMENTI OF 10 CFll §: (Otedc OM Ill' mon of rtt. fol/Owl"ll 11U t--_-MODE_ll_E..,,C-ll _

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20.409(11111(1111 20.40ll(l llllllYI 20.4Clll(1llllM ll0.731*1121(11 ll0.73(lllZllYI ll0.73(1112111111 LICENSEE CONTACT FOR THll LEll 1121 NAME M. J. Pollack -

LER Coordinator I0.731olC2HwlllllAI lll.7:1(11121111Mllll I0.73(*11211*1 AREA CODE 7J.71i.I 7J.7U*I OTHEll (Sp<<Hy In Ablewr below *nt1 In Te*f, NRC Fonn 3ll6A)

TELEPHONE NUMBER cOMPLETE ONE LINE FOR EACH COMPONENT FAILURE DEICRllED IN THll llEl'OllT (l:SI CAUSE SYSTEM COMPONENT B

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On 9/23/90, a.control Room Operator observed that the 1RllA/1R12A/lR12B Containment Radiation Monitoring System (RMS) pump operability indication was not illuminated.

Since it was questionable as to pump operability, the lRllA, 1R12A and 1R12B RMS channels were declared inoperable and Technical Specification Action Statements 3.4.6.1 and 3.9.9 were entered as per Technical Specification Table 3.3-6 Action 20 (i.e., lRllA inoperable) and Action 22 (i.e., 1R12A inoperable).

The 1Rl2B channel is not taken credit for in the accident analyses.

The lRllA and 1R12A channels provide. automatic isolation of the Containment Purge/Pressure -

Vacuum Relief System upon detection of high activity.

The root cause of this event has been attributed to an equipment/design concern.

Condensation had caused corrosion (rust) which seized the moving vanes of the positive displacement sampling pump.

Upon replacement of the sample pump, the lRllA and 1R12A monitors were declared operable and the appropriate Action Statement were exited.

An inspection program will be initiated to identify the mean time to sample pump failure.

The design of the Containment-1R11A/1R12A/1R12B RMS will be reviewed.

Appropriate design change(s) to address condensation concerns will be made as applicable.

The pump will be replaced with a more reliable pump.

In the interim, preventive maintenance every six (6) months will be performed until a *more reliable pump is approved for use.

In addition, the weekly inspe~tion program for the sample pump and associated equipment (e.g., filter paper motor) will be enhance~ to better predict the the next failure.

NRC Form 3111 (9-631

LICENSEE EVENT REPO~T (LE~) ~EXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 LER NUMBER 90-033-00 PAGE 2 of*6

PLANT AND SYSTEM IDENTIFICATION

.Westinghouse

- Pressurized Water Reactor Energy Industry Identification System (E!IS) codes are identified* in

. the text as {xxl IDENTIFICATION OF OCCURRENCE:

Two (2) channels in a

~ingle system made inoperaple due to common equipment failure Event Date:

9/23/90 Report Date:

10/23/90 This report was initiated by Incident Report No.90-714.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 Reactor Power 97% - Unit Load 1119 MWe DESCRIPTION OF OCCURRENCE:

On September 23, 1990 at 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, a Control Room Operator observed that the 1R11A/1Rl2A/1R12B Containment Radiation Monitoring System (RMS) {!LI pump operability indication was not illuminated.

These three (3) RMS channels analyze a sample of Containment atmosphere provided by this single pump.

Since it was questionable as to pump operability, the lRllA, 1Rl2A and 1R12B RMS channels were declared inoperable and Technical Specification Action Statements 3.4.6.1 and 3.9.9 were entered as per Techriical Specification Table 3.3-6 Action 20 (i.e., lRllA inoperable) and Action 22 (i.e., 1Rl2A inoperable).

The 1Rl2B channel is not taken credit for in the accident analyses and therefore has no.applicable Technical *Specifi_cation.

Technical Specification Table 3.3-6 Action 20 'states:

"With the number of channels OPERABLE-less than required by the Minimum Channels OPERABLE. requirement, comply with the ACTION requirements of Specification 3.4.6.1."

Technical Specification Table 3.3-6 Actio~ 22 states:-

"With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement, comply with the ACTION requirements of Specification 3.9.9."

Technical Specification 3.4.6.1 states:

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

LICENSEE EVENT REPORT (LER)

T~XT CONTINUATION Salem Generating Station Unit 1

• DOCKET NUMBER 5000272 DESCRIPTION OF OCCURRENCE:

(cont'd)

LER NUMBER 90-033-00' PAGE 3 of 6 a.

The containment atmosphere particulate radioactivity monitoring system, b.

The conta1nment sump level monitoring system, and c.

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

Technical Specification Action Statement 3.4.6.1 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 i~ 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 fallowing 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. ;,

Technical Specification 3.9.9 states:

"The. Containment Purge and Pressure-Vacuum Relief isolation system shall be OPERABLE."

Technical Specification Action Statement 3.9.9 states:

"With the Containment Purge and Pressure-Vacuum Relief isolation system inoperable, close each of.the Purge and Pressure-Vacuum Relief penetrations providing direct access frpm the containment atmosphere to the outside atmosphere.

The provision of Specification 3.0.3 are not applicable."

APPARENT CAUSE OF OCCURRENCE:

The root cause of this event is attributed to equipment/design concerns.

Investigation revealed that the sample pump was tripped due to failure of the lRllA channel's filter paper motor.

The paper motor is interlocked with the sample pump.

Instrument.power fuses were found blown due to a shorted filter paper motor.

After replacement of the paper motor and the associated fuses, the technician initiated a system operability check.

He observe.d that the lRllA RMS sample pump was not operating properly.

Subsequently the sample pump and belts were replaced.

The filter paper motor had apparently overloaded due to increased friction caused by condensation oxidizing the rotating surface of the "paper drive drum".

Inspection of the filter paper housing revealed

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION

• . Salem Generating Station Unit 1 DOCKET NUMBER 5000272 APPARENT CAUSE OF OCCURRENCE:

(cont'd)

LER NUMBER 90-033-00 water accumulation (filter paper had swelled).

PAGE 4 of 6 Inspection of the sample pump revealed that the pump vanes*had seized due to corrosion (rust) attributed to condensation.

This is a positive displacement pump which uses graphite vanes.

A system walkdown (by the System Engineer) has revealed that the slope of the sample tubing is towards the pump.

Although the sample is drawn from Containment (130' El.) the sample pump and detectors*

are located outside Containment in the 78' Elevation Electrical Penetration Area.

The sample line Containment penetrati.on is located at 88' Elevation.

The Electrical Penetration Area is ~equired to be maintained between 60°F and 105°F.

Located directly above the radiation monitoring equipment skid (lRllA, 1R12A and 1R12_B) is a.vent which blows directly onto the skid.

Ventilation to the area is not heated

{outside air only).

Also, the filter paper housing and sample and discharge lines are not insulated or heat traced.

These factors contribute to the promotion of condensation.

This area is normally cooler than Containment; therefore, any hlimidity in the Containment air sample readily condenses in the sample line {and filter paper housing) outside Containment.

ANALYSIS OF OCCURRENCE:

The lRllA 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 (ABJ*

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 c.-moni taring system {as per Technical. Specification 3.4.6.* 1). _;,An alarm signal will cause the automatic isolation of the Co#ta~ii.inent Pressure/Purge Vacuum Relief System.

0

._::~~-.

The 1R12A Containment Noble Gas Monitor monitor's the noble_ gas activity in the Containment atmosphere to ensure *the gaseous releases through the plant vent or from containment purges.do.not *exceed Technical Specification 3.11.2.1 limits.

Ari*alarm siQ!lal will cause the automatic isolation of the Containment Pressure/Purge**- ~vacuum

• Relief System {an Engineered Safety Feature). **;.Iii' *Mode 6 (Refueling),

this monitors setpoint is reset to 2 times background in order to provide early isolation and indication of a fuel handling accident.

Air samples are pulled directly from the Containment atmosphere (130' Elevation) through a moving filter paper.

The filter paper continuously moves pas-t the lRllA detector, a scintillation type detector.

After the air sample passes through the moving filter

LICENSEE EVENT REPORT (LER} TEXT CONTINUATION Salem Generating Station Unit 1 ANALYSIS OF OCCURRENCE:

DOCKET NUMBER 5000272 (cont'd}

LER NUMBER

'90-033-00 PAGE 5 of 6 paper, it passes through a charcoal cartridge and is then mixed into a fixed shielded volume where it is viewed by the 1Rl2A monitor, a geiger-mueller detector.

The a1r sample is then returned to the Containment.

The 1Rl2B Containment Iodine Monitor monitors the charcoal cartridge for increases in Containment iodine activity.

The 1Rl2B monitor does not have any safety interlock functions.

Several area r'adiation monitors corroborate the lRllA and 1R12A *

.channels I indications.. The corroborating area radiation monitors do not have isolation capabilities, they only have alarm capability.

The requirements of the applicable Technical Specifications for inoperability of the lRllA and 1Rl2A monitors were complied with.

No Containment release*occurred during the time when the lRllA*and the 1Rl2A monitors were inoperable.

The corroborating area RMS channels did not indicate any significant increase in Containment atmosphere radioactive efflu~nts. Therefore, this event did not affect the health or safety of the public, however, since a single cause (erratic sample air flow} restilted in the lRllA and 1R12A monitors, each of which provide an ESF system actuation signal, to become inoperable this event is reportable in accordance with 10CFR 50.73 (a) (2) (vii).

CORRECTIVE ACTION

The sample pump, the filter paper.motor and the fuses :were replaced.

Subsequently, based upon adjustment of the sample flow and verification of* system operability, on September 26, 1990 at 1626 hours0.0188 days <br />0.452 hours <br />0.00269 weeks <br />6.18693e-4 months <br />,* the lRllA and 1Rl2A monitors were declared operable and the appropriate Technical Specifications were*.exited.

The design of the Containment 1R11A/1R12A/1R12B AtMS:-,will be reviewed.

Appropriate design change (s) t'o.. ~a<idreiiJs,;;c;ondensation *

c::::e:

1:i :: ::e a::~:::i::b::~ pump's d~~y~:i::lication has been previously identified (reference LER 272/~9-010-00). *-The pump is scheduled to be replaced with a more reliable p11mp as part of the RMS Upgrade Project.

In the interim, based upon ~-a review of the failure history of the pump, preventive maintenance every six (6) months will be performed until a more reliable"p\\lmp is approved for use.

In addition, the weekly inspection program for the*sample pump and associated equipment (e.g., filter paper motor) will be enhanced to better predict the the next failure.

The failure history of the paper filter motor was reviewed.

Only one other failure (circa 1984) was identified.

The prior failure could not be shown to be related to the cause of this event.

LICENSEE EVENT REPORT (LER} TEXT CONTINUATION Salem Generating Station Unit 1 FAILURE DATA:

Air Sample Pump:

DOCKET NUMBER 5000272 LER NUMBER 90-033-00 PAGE 6 of 6 Manufacturer:

Conde Milking Machine Co.

MJP:pc SORC Mtg.90-145 Dry Air Rotary Positive Displacement Vacuum Pump Part :ft DA06CWOO General Manager -

Salem Operations