ML17286A474

LER 90-025-00:on 901023,during Performance of HPCS Sys Operability Surveillance Test,Test Return Valve to Suppression Pool Failed to Go Full shut.W/901119 Ltr

ML17286A474
Person / Time
Site:	Columbia
Issue date:	11/19/1990
From:	John Baker, Fies C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GO2-90-191, LER-90-025, LER-90-25, NUDOCS 9012120213
Download: ML17286A474 (8)

Text

ACCELERATEO OlSTH UTlobI MLYLONSMA'N S Yh I'Blvd REGULATORY INFORMATION DISTRXBUTION SYSTEM (RZDS)

ACCESSXON NBR:9012120213 DOC.DATE: 90/11/19 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION FIES,C.L. Washington Public Power Supply System BAKER,J.W. Washington Public Power Supply System

.RECIP.NARK RECIPIENT AFFXLXATION

SUBJECT:

LER 90-025-00:on 901023,inoperability of HPCS sys caused by equipment failure.W/901119 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ( ENCL J BISE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL XD CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 ENG,P.L. 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1' NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NRR B8Dl 1 1 NRR/DST/SRXB 8E 1 1 E 02 1 1 RES/DSIR/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 33 ENCL 33

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 Docket No. 50-397 November 19, 1990 G02-90-191 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.90-025

Dear Sir:

Transmitted herewith is Licensee Event Report No.90-025 for the WNP-2 Plant.

This report is submitted in response to the report requirements of 10CFR50.73 and discusses the items of reportability, corrective action taken, and action taken to. preclude recurrence.

Very truly yours, J. Baker (M/0 927M)

WNP 2 Plant Manager JWB:lr

Enclosure:

Licensee Event Report No.90-025 cc: Mr. John B. Martin, NRC Region V Mr. C. Sorensen, NRC Resident Inspector (M/D 901A)

INPO Records Center Atlanta, GA Mr. D. L. Williams, BPA (M/D 399)

NRC Resident Inspector walk over copy

'A< OCK pgppp3~ ~

PDC

NRC FORM 39) U.S. NUCLEAR REGULATORY COMMISSION APPROVEO OMB NO,31504104 (669)

EXPIRES," 4/30/92 ESTIMATED BURDEN PER AESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST( 500 HAS. FOAWARD LICENSEE EVENT REPORT tLER) COMMENTS REGARDING BVAOEN FSTIMATE TO THE RECORDS ANO REPORTS MANAGEMENT BRANCH (F630). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON. OC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTANO BUDGET, WASHINGTON, DC 20503.

DOCKET NUMBER (2l PA E FACILITY NAME (II Washin ton Nuclear Plant - Unit 2 o 5 o o o 39 7 > oF04 TIT<<<<1 Inoperability o the >gh Pressure Core pray ystem Caused by Equipment Failure EVENT DATE (5) LER NUMBER (Sl REPORT DATE (7) OTHER FACILITIES INVOLVED (4)

MONTH OAY YEAR YEAR SEOVCNTtAL '<rPi' NVMbbrl

~

NVMbbrl MONTH OAY YEAR FACILITYNAMES DOCKET NUMBER(3) 0 5 0 0 0 1 2 3 909 0 2 5 00 11 199 0 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT 7 0 THE RLOUI AEMENTS OF 10 CF A (): ICrtrcb onr or morr of tnr follow np) (11 OPERATING MODE ( ~ ) 1 20.402(b) 20.405(c) 50,73(el(2) Dsl 73.71(b)

POWER 20.405( ~ )(1)(il SOM(el(() 50.73(s)(2)(r) 73.71(cl LEvEL OTHER ISprcify in Aottrrct 1 0 0 20.405(el(1)(NI 50.34(el(2) 50.73(el 12)(YN)

Ill(YINI(BI brrow ensf In Ter L HRC Form 20.405(e l(1 )(INI 50.73(el(2)(I) 60.73(el(2) IrNilIAI 366AI 20A05 (e I (I( I Is) 50.73( ~ l(2)(NI 50.73( ~ )

20.405(sl(1) (s) 50.7lN)(2)(NI) 50.73(sl(1) (el LICENSEE CONTACT FOll THIS LER ll2)

NAME TELEPHONE NUMBER AREA CODE C. L. Fies 'Com liance En ineer 50 37 7-COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCAIBED IN THIS REPORT (13)

MANUFAC MANUFAC. EPORTABLE CAUSE SYSTEM COMPONENT CAUSE SYSTEM COMPONENT TUAER TO NPADS TURER X B G 391 YEs Ak$%NMA ting'Fp+x':re SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTFO SUBMISSION DATE II5)

X YES IIIyrt, compirtr EXPECTED SVSMISSIOH DATEI NO 0 90 19 ABSTRACT ILimit to f400 tprcrA I r.. rpproeimetriy fiRrrn tinpir.rprcr typrwri Urn lined (14)

At 0327 hours0.00378 days <br />0.0908 hours <br />5.406746e-4 weeks <br />1.244235e-4 months <br /> on October 23, 1990, during performance of the High Pressure Core Spray (HPCS) system operability surveillance test the Test Return Valve to the Suppression Pool (HPCS-V-23) failed to go full shut. lhe valve light indicated full closed but the HPCS Minimum Flow Valve (HPCS-V-12) did not come open and the flow indication did not go to zero. This condition could cause the undesired diversion of system flow from in-vessel spray which is the primary function of the system.

The uncertainty of performance of HPCS-V-23 made the HPCS system inoperable which is a reportable event.

At 0514 hours0.00595 days <br />0.143 hours <br />8.498677e-4 weeks <br />1.95577e-4 months <br /> Plant operators took action to close the manual block valve for the test return line (HPCS-V-64). Ihis action isolated the faulty valve and would prevent the diversion of system flow.

The root cause of this event is indeterminate at this time. A supplement to this LER will be submitted when further investigations are complete and corrective actions determined.

This event posed no threat to the health and safety of the public or plant personnel.

NRC Form 366 (64)9)

NRC I'ORM SSSA U.S, NUCLEAR REGULATORY COMMISSION (050> ~ APPROVED 0MB NO. 21504(04 EXPIRES: O/20/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REQUEST/ 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENTSRANCH IPJISOI. V.S. NVCLEAR REGULATORY COMMISSION. WASHINGTON. OC 20555, ANO TO THE PAPERWORK REDUCTION PROJECT 121504(04(. OFFICE OF MANAGEMENTANO BUDGET, WASHINGTON, DC 20502 FACILITY NAME (ll DOCKET NUMBER (2l LER NUMSER (Sl PAGE (Sl SEQUENTIAL NVM SA 1$?8 NUMSSR W hin ton Nuclear Plant - Unit TEXT ///more <<>>oe Jr reouked, rr>> er/I/rr/ono/HRC %%dnrr SIISAS/ (12(

2 0 5 0 0 0 3 9 7 9 0 0 5 00 2'" 0 4 Plant Conditions a) Plant Mode - 1 (Power Operation) b) Power Level - 10(C Event Descri tion At 0327 hours0.00378 days <br />0.0908 hours <br />5.406746e-4 weeks <br />1.244235e-4 months <br /> on October 23, 1990, during performance of the High Pressure Core Spray (HPCS) system operability surveillance test (PPM 7.4.5.1.11); the Test Return Valve to the Suppression Pool (HPCS-V-23) failed to go full shut. This test was being performed by Licensed Plant Operators and involved the closure of HPCS-V-23 against full discharge pressure of the HPCS Pump (HPCS.-P-I). The valve light indicated full closed but the HPCS Minimum Flow Valve (HPCS-,V-12) did not come open and the flow indication did not go to zero. This condition could cause the undesired diversion of system flow from in-vessel spray which is the primary function of the system. The uncertainty of performance of HPCS-V-23 makes the HPCS system inoperable which is a reportable event.

Immediate Corrective Action At 0514 hour0.00595 days <br />0.143 hours <br />8.498677e-4 weeks <br />1.95577e-4 months <br /> s Plant operators took action to close the manual block valve for the test return line (HPCS-V-64). This action isolated the faulty valve and would prevent the diversion of system flow. The HPCS Oper ability Surveillance was completed at 0809 hours0.00936 days <br />0.225 hours <br />0.00134 weeks <br />3.078245e-4 months <br /> on October 23, 1990 thereby confirming system operability.

Further Eva'luation and Corrective Action A. Further Evaluation This event is being reported per the requirement of 10CFR50.73(a)(2)(v) as a "condition that alone could have prevented the fulfillment of the safety function of structures or systems that are needed to: (A) Shut down the reactor and maintain it in a safe shutdown condition; (B) Remove residual heat; (C) Control the release of radioactive material; or (0) Mitigate the consequences of an acci'dent.H The inoperability of the HPCS system is a unique event at WNP-2. Unlike the other Emergency Core Cooling Systems, HPCS system inoperability is reportable even though all requirements of technical specification LCO action statements are'being complied with.

This is so because it is a "single train" Emergency Core Cooling System and, as such, is reportable any time it is unable to perform its safety function when it is required to be able to do so by Plant conditions.

2. This requirement was not recognized immediately but after further management review it was reported via the Emergency Notification System (ENS) at 0810 hours0.00938 days <br />0.225 hours <br />0.00134 weeks <br />3.08205e-4 months <br /> on October 23 in accordance with 50.72(b)(2)(iii).

NRC Form SSSA (5801

NRC FORM355A UA. NUCLEAR REGULATORY COMMISSION APPROVED 0M B NO, 3)500106 (080) ~

~ ~ EXPIRES! i/30/02 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REOUESTI 608) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENTBRANCH (P4)30), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, DC 20555, ANO TO THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTANO BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (ll LER NUMBER (5) PAGE (3)

YEAR ~ SEOUSNTIAL NUMBER IIEVISION HUMSCR Washington Nuclear Plant TEXT BYmac ~ ls nqceaf. Vae ~ - Unit NRC Ann KEBAB) (IT) 2 o s 0 0 o 397 90 02 5 0 0 3 OF 0 4

3. The preliminary cause of this. event is believed to be equipment failure associated with HPCS-V-23. The valve was not able to completely close when the line was pressurized to prevent the undesired diversion of system flow.

4. The root cause of this event is indeterminate at this time. However, a recent inspection of the valve internals indicate this is not the problem (See discussion under Similar Events below). A supplement to this LER will be submitted when further investigations are complete.

B. Further Corrective Action

1. Further tests to investigate reasons for inoperability of HPCS-V-23 will be conducted under controlled conditions. Until that time the valve will be red tagged in the closed position and HPCS-V-64 will remain closed.

2. 'The plant policy will be reviewed to identify improvements in the process of identifing reportable events including the inoperability of "single train" safety systems.

Safet Si nificance There is no safety significance associated with this event. The failure of the HPCS system is within the bounds of the ECCS single failure analyses. At all times the ECCS could have performed its safety function in response to a DBA since the Automatic Depressurization System (ADS) and Low Pressure Coolant Injection (LPCI) systems were operational.

The HPCS System Operability Test is performed on a quarterly basis. During this test HPCS-V-23 is opened and closed against the running pump for only a short period of time. Thus, the probability of system inoperability due to the valve not closing against system pressure is quite small. In addition, the HPCS test data collected during the surveillance indicates the system was not completely degraded. The flow through HPCS-V-23 after it closed against the running pump was approximately 1400 gpm at a pump discharge pressure of 1350 psig. With HPCS-V-23 open the flow was measured at approximately 7000 gpm at a pump discharge pressure of 250 psig.

At all times during the event the requirements of the WNP-2 Technical Specifications (Section 3. 5.1I were complied with. The LCO action for this section requires ensuring the operability of the redundant ECCS Divisions 1 and 2 and the Reactor Core Isolation Cooling system while the HPCS system is inoperable (a maximum of 14 days is allowed). Since no safety significance is associated with this event, it posed no threat to the health and safety of the public or plant personnel.

NRC Form 36SA (080)

l'.

N 0 'FORM 245A U.S, NUCLEAR REOULATORY COMMISSION APPROV CO OMS NO, 21400104 (545<

EXP(ASSI t/20/02 ~

~ STIMATCO SUAOEH PEA RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INPORMATION COLLCCl'ION RCOUESTI 500 HAS. I'OAWAIIO COMMENTS AEOA4DINO SUAOCN ESTIMATE TO THE RECORDS TEXT CONTlNUATlON ANO REPOATS MANAOEMCNT SAANCH IP420I, U.5. NUCLEAA REOULATOAY COMMI4SION, WASHINOTON. DC 20545, AND TO THC FAPE4WORK REDUC'TION PROJECT 121504IOtl. OFFICE OF MANAOEMENTANO SUDOET,WASHINOTON, DC 20502.

FACILI'TY NAME Il) DOCKET NUMSCR Il(. LER NUMSEA (4) PAOC (ll ttQVSNTIAL rltvrtlorr YCA" 85 RUM t II rrvMetrr p -U TEXT ///more tutee ls reeckerL uee edcrr/trruro///IIC %%dnn 0554'I/ (lll

't 050((0 3 99P 0 5 p p 4 OFp 4 Similar Events This event is similar to the one that occurred on November 21, 1989 as reported in LER 89-043. In that case, HPCS-V-23 was found to stay approximately 10 percent open when the same operability surveillance was performed. At that time, the problem was thought to be an internal mechanical problem with the valve. During the May 1990 refueling outage the valve was disassembled and inspected (Mork Request AS3203) but no significant problems were discovered. A root cause analysis was performed on the event associated with LER 89-043 and the subsequent inspection on August 31, 1990.

The root cause was judged to be indeterminate.

EIIS Information Text Refe'rence EIIS Reference System 'omponent HPCS System. BG HPCS-Y-23 BG V HPCS-Y-12 BG ~

V HPCS-V-64 BG Y HPCS-P-1 BG P ECCS BM ADS BG LPCI BM RCIC BG NRC Ferel 555A (540)