ML18005A402

LER 88-006-01:on 880208,both Emergency Svc Water Sys Declared Inoperable Due to Isolation Valve Failures.Caused by Debris Accumulation.Failed Valves Repaired & Retested. W/880415 Ltr

ML18005A402
Person / Time
Site:	Harris
Issue date:	04/15/1988
From:	Howe A, Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-880092, LER-88-006, LER-88-6, NUDOCS 8804250240
Download: ML18005A402 (7)

Text

'C CELERLTED DMi~ IBUTION DEMONS%ATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:.8804250240 DOC.DATE: 88/04/15, NOTARIZED: NO DOCKET g FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTH. NAME AUTHOR AFFILIATION Light HOWE,A. Carolina Power & Co.

WATSON,R.A. Carolina Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-006-01:on 880208,both emergency svc water sys inoperable due to isolation valve failures.

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

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

NOTES:Application for permit renewal filed. 05000400 ~

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR 'ENCL ID CODE/NAME LTTR ENCL A PD2-1 LA 1 PD2-1 PD 1 1 BUCKLEY,B 1 1 INTERNAL: PCRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/NAS 1 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 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 1 NRR/DREP/RAB 10 1 1 NRR/DREP/RPB 10 2 2 1 1 NRR/PMAS/ILRB12 1 1 G FIB 02 1 1 RES TELFORD,J 1 1 RES/DE/EIB 1 1 RES/DRPS DIR .1 1 RGN2 FILE 01 1 1 EXTERNAL: EG&G GROH,M 4 4 FORD BLDG HOY,A 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS,J 1 1 NSIC MAYS,G 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 45 ENCL 44

NRC Form 346 U.S. NUCLEAR REQULATORY COMMISSION (94)3)

APPROVED OMB NO. 31504104 EXPIRES: 5/31/SS LICENSEE EVENT REPORT tLER)

FACILITY NAME (1) DOCKET NUMBER (2) PA E 3 0 5 0 0 0 1 OF

'(') BOTH EMERGENCY SERVICE WATER SYSTEMS INOPERABLE DUE TO ISOLATION VALVE FAILURES AND DESIGN DEFICIENCY EVENT DATE (5) LER NUMBER (5) REPORT DATE (7) OTHER FACILITIES INVOLVED (EI MONTH DAY YEAR YEAR @y'EQUENTIAL REvtertX MONTH OAY YEAR FACll.lTYNAMES DOCKET NUMBER(S)

WOI N UM B E R 4g NUMBER 0 5 0 0 0 0 2 088 88 8 0 0 6 01 04 1 5 8 8 0 5 0 0 0 THIS REPORT IS SUBMITTED PUASUANT TO THE REQUIREMENTS OF 10 CFR $ : (Check One or more of the fellovflnPI (11)

OPER AT INC MODE (0) 20.402(b) 20.405(c) 60.73( ~ I (2) (iv) 73.71 01)

POWER 20.405( ~ )11)(l) 60M(cl(ll 50.73(e) (2) (v) 73.71(cl 1 0 0 20405(e) (1)(ll) 50.35(c)(2) 60.73(e) (2) (vll) OTHER ISpeclfy In Atrrtrect helorrr end In Tent NRC Form 20.405(e) (1)(ill) X 50.73(e)(2)(l) 50,73(e) 12) (vill)IA) 3BBAJ 20.405(e) II)(ivl 50.73(el(2) (ii) 50.73( ~ l(2) (vlE) IS) 20.405( ~ ) II) (vl 60 73(e) 12) IIII) 60.73(el(2) (rr)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER ANDREW HOME SENIOR ENGINEER REGULATORY COMPLIANCE AREA CODE 19 362 -2 1 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC REPORTABLE: e )r . s-.+~~4 CAUSE SYSTEM COMPONENT MANUFAC. El'ORTABLE TURER TO NPRDS fg~r~'3 TURER TO NPADS p)~>4@'c~~'WN SUPPLEMENTAL REPORT EXPECTF D (14) MONTH DAY YEAR EXPECTED SU 5 M I SS ION DATE (16I YES Ilfyei, complete EXPECTED SUBMISSION DATEI NO ABSTRACT ILlmlt to te00 rpecer, I.e., epprorrlmetely fifteen rlnple rpece typevrrltten lintel (16)

ABSTRACT:

On February 8, 1988, during surveillance testing of the Emergency Service Water System (ESWS), the nonsafety portion of the ESW pump seal water supply system failed to isolate as required when two solenoid valves stuck open and a check valve failed to seat. Both ESW trains were declared inoperable due to the piping configuration of the seal water supply and the locations of the failed valves. Manual valves were closed,to isolate the nonsafety piping and permit continued operation while repairs took place. Debris was discovered during disassembly of the failed check valve, and is also suspected of causing the solenoid valve failures. Repairs were'ompleted the next day, the surveillance testing was completed and the ESW system was returned to service.

On February 12, 1988, a concern regarding the seal water piping configuration vulnerability to single passive failures was raised, and a manual valve was immediately closed to separate the trains while an evaluation was conducted.

This evaluation concluded on February 25, 1988, that the piping configuration was vulnerable to single passive failures which could disable both ESW trains, in conflict with the system design requirements specified in the Final Safety Analysis Report. The two trains remain isolated by lock closed manual valve pending a permanent design change to the seal water system.

3304250240 880415 PDR ADOCK 05000400 DCD NRC Form 345 (94)3)

NRC Perm 3SSA U.S. NUCLEAR REOULATORY COMMISSION (583 l LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OMS NO. 3150M(Cd EXPIRES: 8/31/88 PACILITY NAME (Il OOCKET NUMSER (21 LER NUM8ER (SI PACE (3)

SHEARON HARRIS NUCLEAR POWER PLANT YEAR SSOVSNtrAL NVMddrr ~ .

rrdVrdrON NVM drl UNIT 1 0 5 0 0 0 OF 0 1 TEXT /5'ore decor /I teqrrder/, rroe /I/Oore/AIRC %%drrrr 38(/AS/ (ITI INITIAL CONDITIONS:

The plant was operating at 100% power, normal operating conditions prior to and throughout this event.

DESIGN INFORNATION:

Refer to Attachment A, which shows the Emergency Service Water (ESM) pump seal and bearing water supply configuration. The ESW pumps are normally not in service, and start automatically on Safety Injection Actuation, loss of off-~ite power, or '.ow service water header pressure (indication of failure of normal supply). During this idle condition, one of the ESM pump Seal/Bearing Mate Booster pumps draws water from the ESW header and supplies cLean water via a cyclone separator to the ESM pumps'eals and bearings to prevent accumulation of debris between the bearing and the shaft sleeves of the ESW pump which can result from the stagnating water in the ESM pump intake bay.

This flow helps to increase the Life of the bearing, but interruption of this flow would not damage either the bearings or the seals.

When the ESW pump is started, the booster pumps trip and the valves close to isolate the nonsafety piping from the safety-related piping. Seal and bearing water is then provided by the safety-related ESW Screen Wash pumps which tie into the seal water supply header downstream from the isolation valves.

DESCRIPTION:

On February 8, 1988, surveillance test OST-1215, Emergency Service Mater System Operability, was in progress. During testing, two solenoid operated, fail close valves, numbers 1SW-1335 and 1SW-1338, failed to close on demand.

These valves are manufactured by Target-Rock, model number 79/-024 (EIIS:BI:ISV). In addition, check valve 1SW-1336 was not properly seating.

This valve is manufactured by Rockwell, model number H6283-BV985 (EIIS:BI:ISV).

The solenoid valves and the check valve isolate the nonsafety seal water booster pump from the safety-related seal water supply piping. Since both ESW pump seal water supplies were now unisolable from the nonsafety portion of the system, both ESW trains were declared inoperable, and Specification 3.0.3 was entered at 1430. Valves 1SW-1332 and 1SW-1324 (EIIS:BI:ISV) were closed, which restored operability to train A ESW since it was now isolated from the nonsafety piping. Specification 3.0.3 was exited at 1452, and Specification 3.7.4, Emergency Service Mater, remained in effect for the 8 train ESM, due to

/alve 1SM-1338 being unabLe to close.

Nrlc porlM Sddo (0831 e U.S.OPO:10854.524 538/4 55,

NRC P<<NR 38SA VA. NUCLEAR REOULATORY COMMISSION ISSSI LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMS NO. 3150WIOS EXPIRES: 8/3I/88

'ACILIT Y NAME ill DOCKET NUMSER ISI LER NUMSER IS) ~ AOE (SI SSOVSNTIAL REVISION NVM SR NVM SR SHEARON HARRIS NUCLEAR POWER PLANT UNIT 010 1

400 88 0 0 6 3 QF 04 TEXT ///more g>>oe 8 reea<<IRE eoe ~ /I///>>/HhC Anrr ~3/ (ITI DESCRIPTION (continued)

Repairs were made to, the failed valves, and the surveillance test was satisfactorily'completed on February 9, 1988 at 1518. The valves 1SW-1332 and 1SW-1324 were reopened to restore the system to its normal lineup.

On February 12, 1988, a concern was raised regarding the configuration of the safety-related ESW pump seal water supply. The two trains are cross-connected without capability ,to automatically isolate, causing the potential for a single passive failure to affect both ESW pumps. Val.ve 1SW-1324 was closed to separate the two safety trains while an evaluation was conducted. This evaluation was completed on February 25, 1988, and concluded that the seal water supply design was not in accordance with the requirement in the Final Safety Analysis Report (FSAR) that the ESW system be protected from passive failures. The evaluation also concluded that ma'intaining one of the two manual isolation valves (1SW-1332 or 1SW-1324) closed was acceptable to comply with the FSAR requirements.

CAUSE:

The valve failures have been attributed to debris accumulation, discovered during disassembly of the check valve 1SW-1336. As described above, the source of water for this system is the ESW header during ESW pump idle periods, when the normal service water pumps are in service supplying water from the cooling tower basin to the ESW headers. Accumulation of debris in the basin is expected, since raw lake water is the supply.

The design of the seal water supply for the ESW pumps did not consider the requirements in the FSAR for the system to be protected from all passive failures., ANSI Standards 58.9-1981 and 51.1-1983 allow exclusion of passive failure considerations when the probability of such failures piping'rom coincident with a demand for the system to function is sufficiently small.

The seal water piping meets this criteria, but the FSAR requirement is that passive failures must be a design consideration.

SAFETY SIGNIFICANCE:

The failure of the valves to isolate had no direct impact on plant safety since the ESW system was not challenged while the valves were inoperable. Had the ESW system been demanded to operate at that point, a diverging flowpath would have existed from the discharge of the ESW Screen Wash Pumps (EIIS:BI) back through the idle ESW Seal and Bearing Water Booster Pump 1B-NNS to the ESW header, potentially starving the seal water supply to the ESW pumps. The postulated failure of the nonsafety portion of the piping would increase this effect. This condition existed for 22 minut'es, when the A train was isolated from the failed portion of the system.

NRC SORM SSSA <<U.S.OPO;108bb824 538/odd IQ83I

NRC Fotw 300A U.S. NUCLEAR REOULATORY COMMISSION (043)

LICENSEE EVENT REPORT ILER) TEXT CONTINUATION AFFROVEO OMB NO. 3180&ldl EXPIRES: 8/31/88 FACILITYNAME 11) DOCKET NUMBER (21 LER NUMBER IBI FADE IS)

VEAR BEQVENTIAL AIvrsloN SHEARON HARRIS NUCLEAR POWER PLANT NVM Irl Vr:,, NVM FN UNIT 1 o 5 0 o o OF TEXT W wore N>>oe II reoMFrN/, I>>e ae //I/or>>////IC Form SISEA 0/ (ITI SAFETY SIGNIFICANCE: (continued)

The potential for a passive failure in the safety-related seal water supply, which would have the same effect as described above, has been determined to be improbable and unrealistic as defined in ANSI Standards 51.1-1983, Section 3.2.2, and 58.9-1981, Section 3.6, and would not be a design consideration under these requirements.

Debris accumulation in these valves has occurred previously, but not such that alI. valves were unable to isolate, rendering both ESW trains inoperable.

CORRECTIVE ACTION:

1. The failed valves were repaired and retested, and the ESW system was returned to operable status on February 9, 1988.

2. The two safety trains of ESW seal water supply were isolated on February 12, 1988, and will remain isolated pending design changes to the system.

3. A change to the system configuration is being developed for implementation which will simplify the system configuration and ensure the ESW seal water supply meets the FSAR requirements. This will consist of the following'. (1) isolating the nonsafety portion of the seal water supply by closing and de-energizing valves 1SW-1338 and 1SW-1329, and closing manual valves 1SW-1332 and 1SW-1324; (2) removing power from the ESW Seal Water Booster pumps (NNS); and (3) establishing a flowpath from the ESW header through the normally idle ESW Screen Wash pumps, to the ESW pump seals and bearings, by opening and de-energizing valves 1SW-282 and 1SW-280. This alignment will provide seal and bearing cooling water while the ESW pumps are not running by "freewheeling" the ESW Screen Wash pumps with normal servi'ce water from the cooling tower basin. Since this valve alignment does not change when the ESW pumps start, the problems associated with debris accumulation in the small valves, rendering them unable to close, will be eliminated. In addition, the two safety-related trains of ESW seal -and bearing water will no longer be cross connected, so the concern for vulnerability to single passive failures will be eliminated.

4. A review of other similar applications of small valves required to isolate safety-related lines where poor water quality is expected is being conducted.

NRC FORM SOFA e U.SOFO:10884.824 838/4dd 1083 I

ESW ~ I A-SA ESW PUt1P I 8-SB 11OTOR SEALS BEARINGS BEARINGS IS'-280 ISW-282 tIOH-SEIStIIClfMJ-SAFETYCLASS S S CYCLOID SEPARATOR ISW-1335 z<

w lO 5v S 18-t tttS cx < Q co 8~ ISW-1332 IS W" 1336. FROt1 ESW HEAOER 8 CA I ISW-1338 Q

Zr

~ lO pr

~ CO ISW-1326 C

g S IAHNS ISW-1327' FRQ1ESW HEACER A ISW-1324

'ISW-1329

~-

TOESW TOESW INTAKE STRUCTURE INTAKE STRUCTURE ESV PLt1P SEALOEARIIIG WA1ER 80OSTER PUtPS wrrwc>11'IEt<r A ES'0l PUI'1P SEAL/ BEARltlG 0/ATER SUPPLY Ref. Dwg.: CAR 216S-S-0936 Rev. 8

Carolina Power 8 Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New HiL1, NC 27562 File Number: SHF/10-13510C Letter Number: HO-880092 (0)

U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 88-006-01 Genr.lemen:

In accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. The original report fulfilled the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-1022, September, 1983.

Revision 1 provides additional information regarding the corrective action for a change to the plant design'to correct the reported condition.

Very truly yours, SCPCUM~+w'.

A. Watson Vice President Harris Nuclear Project AJH:acm Enclosure cc'. Dr. J. Nelson Grace (NRC RII)

Mr. B. Buckley (NRR)

Mr. G. Maxwell (NRC SHNPP)

MEM/LER-88-006/1/Osl