ML17285A155

LER 88-037-00:on 881130,plant Tech Specs Initiated Shutdown Due to Containment Supply Purge Valve (CSP-V-9) Air Leak. Caused by Damaged CSP-V-9 Rubber Seat.Plant Maneuvered to Cold Shutdown Condition & Seat replaced.W/881230 Ltr

ML17285A155
Person / Time
Site:	Columbia
Issue date:	12/30/1988
From:	Arbuckle J, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-88-037, LER-88-37, NUDOCS 8901050269
Download: ML17285A155 (8)

Text

AC CELE P>TED DfTQBU'11 ON DEMON S1keON SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8901050269 DOC.DATE:= 88/12/30 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION ARBUCKLE,J.D. Washington Public Power Supply System POWERS,C.M. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-037-00:on 881130,plant Tech Specs initiated shutdown because of containment supply purge valve air leak.

W/8 DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR.~ ENCL SIZE:

TITLE: 50.73 Licensee Event Report (LER), Inci ent Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 D SAMWORTH,R 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DS P 2 2 ARM/DCTS/DAB 1 1 DEDRO 1 1 NRR/DEST/ADS 7E 1 0 NRR/DEST/CEB 8H 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 7 1 1 NRR/DEST/MEB 9H 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEST/RSB 8E 1 1, NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFB 10 1 1' NRR/DLPQ/QAB 10 1 1 NRR/DOEA/EAB 11 1 NRR/DREP/RAB 10 1 1 NRR/DREP/RPB 10 2 2 1 1 NUDOCS-ABSTRACT 1 1

~R~RsG~~ 02 1 1 RES/DSIR/EIB 1 1 RES/DSR/PRAB 1 1 RGN5 FILE 01 1 1 R

EXTERNAL: EGGG WILLIAMS,S 4 4 FORD BLDG HOY I A 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 I NRC PDR NSIC MAYS,G 1

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TOTAL NUMBER OF COPIES REQUIRED: LTTR 44 ENCL 43 a/~ y~

NRC Form 366 (6.83) ~

LICENSEE EVENT REPORT (LER)

~ t V.S. NUCLEAR, REGULATOAY COMMISSION APPAOVEO OMB NOr 3150-0104 EXPIRES: 6/31/SS DOCKET NUM BE R (2) PAGE (3i FACILITY NAME (II 0 5 0 0 0 1 OF

"'""'lant Technical Specification-Initiated Shutdown Because of Containment Supply P 'A Leak Due to Seal Failure - Cause Unknown EVENT DATE (5) LER NUMBER (6) AEPOAT DATE (7) OTHER FACILITIES INVOLVED (6)

SEOVENTIAL FACILITYNAMES DOCKET NUMBER(S)

MONTH DAY YEAR YEAR NUMBER Z4 MONTH'UMBER DAY YEAR 0 5 0 0 0 0 88' 3 7 00 12 of Ihr follovnr'nPI 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT TO THE REOUIAEMENTS OF 10 CFR (); ICntcss onr or mort (11)

OPERATING POWER LEVEL MODE (5)

(10) 0 20.402(isl 20.405(el(1 l(il 20.405(e)(l)(ii)

'0.405 (c) 50.35(cl(1) 50.35(c)(2) 60,7 3 (e I (2)(iv) 60.73(eH2)(vl 60.73(e) (2)(vii) 73.71(b) 73.71(cl OTHER /Sptcily in Aoslrecs Orlovr erxf in Text, /t/RC Form 20.405(el)1)(iii) 50.73(e) (2)(il 60,73(e) (2) N iii)(A) 3SSAI 20,405(e)ll)(iv) 50,73(e)(2)(I<) 50.73( ~ l(2)(viiil(B) 20,405( ~ ) Illivl S0.7 3 I ~ ) (2)(i ill 50.73(el(2) (xl LICENSEE CONTACT FOR THIS LER 02)

NAME TELEPHONE NUMBER AREA CODE COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCAIBEO IN THIS REPORT (13)

CAUSE SYSTEM COMPONESJT MANVFAC CAUSE SYSTEM COMPONENT MANUFAC.

TURER REPORTABLE Kx~>+QN' TURER

+~p+PgQ Q SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SUBMISSION DATE I15)

YES Ill yts, compltlt fXPfCTSO SUSMISSIOII OAyf/

ABSTRACT ILimls so /400 sprees, I e., eporoximtlrly lrllttn sinprt spree sypenrinen lintel (16)

On November 30, 1988 at 2335 hours0.027 days <br />0.649 hours <br />0.00386 weeks <br />8.884675e-4 months <br />, Reactor Operators initiated a Plant shutdown due to a Containment Supply Purge Valve (CSP-V-9) air volume leak which exceeded Plant Technical Specification limits. The leakage was discovered during trouble shooting efforts associated with Containment Supply Purge Valve CSP-V-10; Both CSP-V-9 and 10 are Reactor Building-to-Wetwell vacuum breakers. The purpose of these valves (one of three pairs) is to prevent a vacuum from developing in the primary containment due to condensing steam.

The shutdown was ini tiated because it was determined that repairs to CSP-V-9 could not be made under current plant conditions (Mode 1-100% Power),. As a result of. the shutdown decision, the Shift Manager declared an "Unusual Event". On December 1, 1988 at 0352 hours0.00407 days <br />0.0978 hours <br />5.820106e-4 weeks <br />1.33936e-4 months <br />, Plant Operators manually scrammed the Plant from approximately 23'X power to complete the shutdown, entered Mode 3 (Hot Shutdown) and commenced cooldown. At 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br />, reactor coolant temperature was less than 200'F and, as a result, Plant Operators entered Mode 4 (Cold Shutdown). At 1144 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.35292e-4 months <br />, the Unusual Event classification was

-terminated.

The immediate cause of this event was a damaged CSP-V-9 rubber seat. Although the root cause of the seat failure is unknown at this time, preliminary indications are that the failure mode is material related. A formal root cause analysis and Engineering evaluation are currently being performed to determine the failure mode of the seal. At the completion of the analysis and evaluation, the results will be submitted in a supplemental report.

This event posed no threat to the health and safety of either the public or Plant personnel. 890i0=02('.cr Si230 PB PDR ADOCK 050003'3)'7 CvT rv~

NRC Form 366A U.S. NUCLEAR REOULATORY COMMISSION (94)3)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OM8 NO, 3(60&104 EXPIRES: 8/31/88 FACILITY NAME I'I) DOCKET NUMBER (2) LER NUMBER (6) PACE (3)

YEAR SEOUENTIAL .>>> REVISION P~g NUMBER NUMBER 0 5 0 0 0 3 9 7 8 8 0 3 0 0 0 2 oF 06 TEXT (llmore spese is squired. Use sddiriorrer IVRC %%drm 3664'sl (12)

Plant Conditions a) Power Level - 100K b) Plant Mode - 1 (Power Operation)

Event Descri tion On November 30, 1988 at 2335 hours0.027 days <br />0.649 hours <br />0.00386 weeks <br />8.884675e-4 months <br />, Reactor Operators initiated a Plant shutdown due to a Containment Supply Purge Valve (CSP-V-9) air volume leak which exceeded Plant Technical Specification limits. The leakage was discovered during trouble shooting efforts associated with Containment Supply Purge Valve CSP-V-10. Both CSP-V-9 and 10 are Reactor Building-to-Wetwell vacuum breakers. The purpose of -these valves (one of three pairs) is to prevent a vacuum from developing in the primary containment due to condensing steam.

On November 26, 1988 problems were noted with CSP-V-10 in that it would not indicate full open when cycled. Accordingly, a Maintenance Work Request (MWR) was prepared to trouble shoot and repair the valve. In addition, the appropriate Plant Technical Specification Limiting Condition for operation (14-day LCO) was entered.

On November 29, 1988 Plant Electricians were'orking the MWR on CSP-V-10 to trouble shoot the indication problem, and noted water in the piping between CSP-V-10 and CSP-V-9. The pipe is a 24-inch Reactor Building-to-Wetwell vacuum breaker relief line that provides air for containment pressure stabilization. Although the line does not carry water, the source was condensation due to temperature differences between the Wetwell (approximately 135') and the exposed portion of the line in the Reactor Building (approximately 80') upstream of CSP-V-9. Accordingly, Plant Technical Engineers performed a visual inspection and noted surface disturbance in the water at the base of CSP-V-9. Also at this time a small pressure differential (approximately 2" water gauge) existed between ,the Wetwell and the Reactor Building. As a result, the engineers suspected that the seal may have not been seating properly to prevent air leakage. They did establish that CSP-V-10 was seating properly and could act as a containment boundary for the line.

The following is a chronology for those actions taken on November 30, 1988:

~ 0100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />s: Repairs were completed on CSP-V-10. Plant electricians replaced a proximity switch (Supplier: R. B. Denison Co. Model No. WE74/Ex2).

~ 0730 hour0.00845 days <br />0.203 hours <br />0.00121 weeks <br />2.77765e-4 months <br />s: CSP-V-9 was visually inspected and a small amount of air leakage was observed; The leakage appeared to be minimal and not an indication of gross seal failure.

~ 1029 hour0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.915345e-4 months <br />s: Plant Management determined that a Local Leak Rate Test (LLRT) was needed to ascertain the potential leak rate from CSP-V-9.

NRc FORM SeeA ~ V.S. CPOr IBSS-S2n-SBB,OOO)O (9.83 I

NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION (943)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3) SOW)04 EXPIRES: B/31/BB FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

MII/PIk SEGUENTIAI. ~oP. REVISION YEAR  ; (dig NUMBER $ O) NUMBER Mashin ton Nuclear Plant - Unit 2 o s o o o 9 7 037 0 00 oF0 6-TEXT ///more speseis reqed/ed, Irse eddd)/orre/NRC Form 3NA's/ (17)

~ 2245 hours: After several attempts to perform the LLRT on CSP-V-9, Pl ant personnel were unable'o establish the required pressure between CSP-V-9 and CSP-V-10. As a result, CSP-V-9 was declared inoperable and the appropriate Technical Specification LCO was entered.

2330 hour0.027 days <br />0.647 hours <br />0.00385 weeks <br />8.86565e-4 months <br />s: It was determined that repairs to CSP-V-9 could not be made under

~

Pl' in dd fg d 1 - 1 Og with Plant Technical I d, Specification I, Pl Action 1 d Statement was required accordance (TSAS) 3.6.1.1, "Primary Containment Integrity."

As a result of the shutdown decision, the Shift Manager declared an "Unusual Event" over the Plant PA system.

o 2333 hour0.027 days <br />0.648 hours <br />0.00386 weeks <br />8.877065e-4 months <br />s: The Shift Manager, utilizing the CRASH Network, notified the 1 g OP lll C 1 1 C CMOFCCF 1 1 Event.

e 2335 hour0.027 days <br />0.649 hours <br />0.00386 weeks <br />8.884675e-4 months <br />s: Plant Operators commenced Plant shutdown to bring the Plant into the Cold Shutdown -(Mode 4) condition.

~ 2347 hours: The NRC was notified of the Unusual Event declaration and Plant On December commenced cooldown. 't 1, 1988 at 0352 hours0.00407 days <br />0.0978 hours <br />5.820106e-4 weeks <br />1.33936e-4 months <br />, Plant Operators manually scrammed the Plant from approximately 23% power to complete the shutdown, entered Mode 3 (Hot Shutdown) and 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br />, reactor coolant temper'ature was less than 200'F and, as a result, Plant Operators entered Mode 4 (Cold Shutdown). , At 1144 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.35292e-4 months <br />, the Unusual Event classification was terminated.

Immediate Corrective Action As required by the Plant Technical Specifications, Plant Operators successfully maneuvered the Plant to the Cold Shutdown condition.

Further Evaluation and Corrective Action A. Further Evaluation k

The immediate cause of this event was a damaged CSP-V-9 rubber seat. The Vi ton seal was supplied by I. B. Moore Co. and manufactured in accordance with ASTM D20002HK715A1-10Zl (Shore A 75 Hardness). The seal was procured by the Supply System to fit into the butterfly valve which was manufactured by BIF, Co.

Although the root cause of the seat failure is unknown at this time, preliminary indications are that the failure mode is material related.

NRC FORM 386A ~U ~ S. OPOr )988-820-889/OOO30 1943)

NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION (9.631 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OM8 NO. 3)60M104 EXPIRES: 8/31/88 FACILITY NAME (1) DOCKET NUMEER (3) LER NUMBER (6) PAGE (3)

N?6 SEOVENTIAL '~ N REVISION

'IEus NUMBER >NB NUMBER Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 7 Q 3 7 0 0 04 o" 0 6 TEXT lllmore specs /s requtred, use eddiriorre/NRC Form 366A'4/ (IT)

B. Further Corrective Action

1. The damaged CSP'-V-9 seat was replaced with new seat material and a post-maintenance LLRT was successfully performed in accordance with Plant Procedure (PPN) 7.4.6.1.2.4, "Containment Isolation Valve and Penetration Leak Test program".

2. A visual inspection was .performed on CSP-V-5 and CSP-V-6. Although CSP-V-6 showed no signs of deterioration, the CSP-V-5 seal was also damaged. The CSP-V-5 seal was replaced and successfully passed a post-maintenance LLRT. In addition, CSP-V-6 was tested and successfully passed an LLRT.

3. As a precautionary measure, an entry was made into the Operations Department Night Orders such that each time one of the vacuum breaker CSP valves or Wetwel-1 Exhaust Purge (CEP) valves are cycled, an LLRT is to be performed on the cycled valve. The valves are: CSP-V-5, CSP-V-6, CSP-V-9, CEP-V-3A and CEP-V-4A.

4. A "formal root cause analysis and Engineering evaluation are currently being performed to determine the failure mode of the seals. At the completion of the analysis and evaluation, the results will be submitted in a supplemental LER.

Safet Si nificance There are three Reactor Building-to-Wetwell relief lines each containing a 24-inch vacuum breaker (check) valve and an air-operated butterfly valve. The check valves are CSP-V-748 and 10; the butterfly valves are CSP-V-5,6 and 9 (Reference Figure 1). These valves prevent a vacuum from developing in the primary containment due to condensing steam. Actuation of the butterfly valves is controlled by the differential pressure between the suppression chamber and the Reactor Building.

Both types of valves are set to open at 0. 5 psid.

Because it was established that CSP-V-10 was seating properly and could act as a containment boundary for the line, and that Plant Operators successfully maneuvered the Plant to a Cold Shutdown condition, this event posed no threat to the health and safety of either the Public or Plant personnel.

Similar Events None NRC FORM 346A re 6 ~ GPOr )988-830 889/00070 19SIS I

NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION (943)

LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVED OMB NO. 3150&)04 EXPIRES: 8/31/68 FACILITY NAME (1) DOCKET NUMBER (3) LER NUMBER (6) PAGE (3)

YEAR

."" SEQUENTIAL .89)'EVISION NUMSER gN NUMBER Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 7 8 8 3 7 0 0 05 DF 0 6 TEXT /// mart tptot /t rtr/udtd, u>> odd/0'or>>/IVRC Form 3864'9/ (17)

EIIS Information Text Reference EIIS Reference System Component Butterfly Valves CSP-V-5, 6 and 9 VB PDCV Vacuum Breaker (Check) Valves CSP-V-7, 8 and 10 VB PDCV Wetwell Exhause Purge Valves CEP-V-3A and 4A VB PDCV NRC FOAM 366A ~ V.S. CPOr 1988-530-589r00010 (9 S3)

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WASHINGTON PUBLIC POWER SUPPLY SYSTEiVI P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washinglon 99352 Docket No. 50-397 December 30, 1988 Document Control Desk U,S, Nuclear, Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.88-037

Dear Sir:

lransmitted herewith is Licensee Event Report No.88-037 for the WNP-2 Plant.

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

Very truly yours,

~/] tf+~~>>

C.M. Powers (MID 927M)

WNP-2 Plant Manager CMP lc

Enclosure:

Licensee Event Report No.88-037 cc: Mr. John B. Hartin, NRC Region V Hr. C.J. Bosted, NRC Site (M/D 901A)

INPO Records Center Atlanta, GA Hs. Dottie .Sherman, ANI Hr. D.L. Williams, BPA (M/D 399)