ML18102A907

LER 97-002-00:on 970210,chilled Water Sys Single Failure Vulnerabilities Identified.Caused by Design Deficiency. License Change Request S97-05 submitted.W/970312 Ltr

ML18102A907
Person / Time
Site:	Salem
Issue date:	03/12/1997
From:	Garchow D, Hassler D Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-97-002-01, LER-97-2-1, LR-N97160, NUDOCS 9703180208
Download: ML18102A907 (4)

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(#1' OPS~G P~blic Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 *

. Nuclear Business Unit MAR 1 2 1997 LR-N97160 U.S. Nuclear Regulatory Commission*

Document Control Desk Washington, DC 20555 LER 272/97-002-00 SALEM ..C~RATING STATION - . UNIT 1 FACILITY OPERATING LICENSE NO. DPR-70 DOCKET NO. 50-272 Ladies & Gentlemen:

This Licensee Event Report entitled "Chilled Water System Single Failure Vuinerabilities" is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR50.73 (a) (2) (ii) (B).

Sincerely, C.ef'~/

David F. Garchow General Manager Salem Operations Attachment DVH c Distribution LER File 3.7 9703180208 970312 PDR ADCCK 05000272 S PDR.

The power is in your hands. 111m1m11J1mm11w1m11m11m~n111

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• 95-2168 REV. 6/94*

NRCFORM366 U.S. NUC EAR REGULATORY COMr.!:SSION A ROVED BY OMB NO. 3150-0104 (4-95) EXPIRES 04/30/98

.} ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 50.0 HRS.

• • • " REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSEE EVENT REPORT (LER) LICENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (T-e ~~NUCLEAR (See reverse for required number of REGULATORY COMMISSION, WASHINGTON, DC , AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF

.digits/characters for each block) MANAGEMENT AND BUDGET, WASttlNGTON, DC 20503.

FACILITY NAME (1) DOCKET NUllBER (2) PAGE (3)

SALEM GENERATING STATION UNIT 1 05000272 1 OF 3 TITLE (4)

CHILLED WATER SYSTEM SINGLE FAILURE VULNERABILITIES EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR I SEQUENTIAL

• 1REVISION MONTH DAY YEAR NUMBER NUMBER Salem Unit 2 05000311 FACILITY NAME DOCKET NUMBER 02 10 97 97 - 002 - 00 03 12 97 OPERATING N THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more) (11)

MODE(9) 20.2201(b) 20.2203(a)(2)(v) 50. 73(a)(2)(i) 50. 73(a)(2)(viii)

POWER 000 20.2203(a)(1) 20.2203(a)(3)(i) *x 50. 73(a)(2)(ii) 50. 73(a)(2)(x)

LEVEL (10) 20.2203(~)(2)(i) 20.2203(a)(3)(ii) 50. 73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50. 73(a)(2)(iv) *' OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(v) SP!IC~ln Abstract below or In C Form 386A 20.2203(a)(2)(iv) 50.36(c)(2) 50. 73(a)(2)(vii)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Are* Code)

Dennis v. Hassler, LER Coordinator 609-339-1989 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) 1*

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE

.TONPRDS TONPRDS

~~~~~~l~~~~~~~~l SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR IYES . XINO SUBMISSION

. * (If yes, con:iplete EXPECTED SUBMISSION DATE). DATE(15)

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten line*) (16)

Recent re-evaluation .of the Chilled Water System has determined that to provide the design support function and assume a single failure, .three chillers and two c::hilled water pumps are required to be operable for each Salem unit~ With less than this configuration, the Chilled Water System may not be able to perform its design support function and withstand a single failure. In the past, the plant has operated with less than three chillers or two chilled water pumps.

The cause of this occurrenGe is that at the time of the original *plant design, the ability to withstand a single failure with a component out of service for maintenance, was not recognized as a design input. Because the system did not have specific Technical Specifications associated with it, the impact of having components out of. service was not recognized. Corrective actions include submission of a License Change request and an op*erabili ty Determination addressing the ac;tions to be taken if less than three chillers or two chilled water pumps are operable.

This event is reportable in accordance with 10 CFR 50.73(a) ( 2) (ii) ( B) ' any condition that resulted in the riuclear plant being outside the design basis of the plant.

NRC FORl!il 366 (4-95)

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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION

.i (4-95)

-*' LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) 05000272 YEAR I SEQUENTIAL NUMBER IREVISION NUMBER 2 OF 3 SALEM GENERATING STATION UNIT 1 11---.L...------JL------11 ~c ,..,

97 - 002 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PLANT AND SYSTEM IDENTIFICATION West:l-nghouse - Pressurized Water Reactor Chilled Water system {KM/-}*

• Energy Industry Identification System (EIIS) codes and component function identifier codes appear as {SS/CC}

CONDITIONS PRIOR TO OCCURRENCE At the time of identification, Sal~m Unit 1 was defueled and Salem Unit 2 was in Mode 5.

DESCRIPTION DF OCCURRENCE Recent re-evaluation of the Chilled Water System {KM/-}. has determined that to provide the design support f~nction and assume a single failure, three chillers

{KM/CHU} and two chilled water pumps {KM/P} are required to be operable for each Salem unit. With less than this configuration, the Chilled Water System may not be able to perform its design support function and withstand a single failure of a chiller or chilled water pump. In the past, the.plant has operated with less than three chillers or two chilled water pumps. .

The Chilled Water System consists of .six closed loop cooling subsystems, each of which p~ovide cooling to the designated plant areas and equipment (three chi+lers and two chilled water pumps for each unit). The closed loop which services the Auxiliary Building is the only portion of the.Chilled Water System that is required to suppo"rt equipment and systems that perform.a safety related function.

The Auxiliary Building chilled water subsystem provides chilled water to the control r*oom air conditioning unit coils, Auxiliary . Building penetration area coolers and main steam line radi.ation monitor enclosures. In addition to* these loads, the Unit 2 chilled water subsystem also supplies cooling water to the primary and secondary laboratory coolers, counting room cooler, post accident sampling room. cooler and the eme.rgency control air compressor.

The re-evaluation of the Chilled Water System also determined that a potential single failure vulnerability existed for valve CH168. The controls for valve CH168 are redundant and meet single failure criteria; however, the valve in its entirety did not meet single failure design. Although the evaluation.determined that failure of this valve is unlikely, a temporary compensatory-- action has been implemented to ensure the operability of valve CH168 to support control room ventilation until a permanent solution is implemented.

NRC FORM 366A (4-95)

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LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE(3) 05 0 0 02 7 2 YEAR I SEQUENTIAL NUMBER IREVISION NUMBER 3 OF 3 SALE¥ GENERATING STATION UNIT 1 97 - 002 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

CAUSE OF.OCCURRENCE The cause of this occurrence is that at the time of the original plant design, the ability to withstand.a single failure with a component out of service for maintenance, was not recognized as a design input. Because the system did not have specific technical specifications associated with it, the impact of having components out of service was not recognized.

PRIOR SIMILAR OCCURRENCES In the past two years there has been 6ne LER that addressed a similar condition.

LER 272/96-038-00 identified a potential condition where a single failure of an Electrical Penetration Exhaust.Fan could place the plant in an unanalyzed condition. Corrective actions in that LER were specific to the identified condition.

SAFETY CONSEQUENCES AND IMPLICATIONS The safety consequences of the failure of a chiller or chilled water pump when the plant.was operating with only two chillers or one chilled water pump *

.operable are that the design basis temperatures could be exceeded in the Relay Rooms, the Control Room and the affected Electrical Equipment Rooms.

Temperatures exceeding the design basis could cause component failures which in turn could render redundant trains of safety related equipment inoperable.

Failure of valve CH168 could result in portions of the control room exceeding the design basis temperatures. No significant temperature problems have been documented while the plant was operated with less than three chillers or two chilled water pumps.

The health and safety of the public was not affected.

CORRECTIVE A~TIONS

1. License Change Request (LCR) S97-05*was submitted on February il, 1997. This LCR proposes to add a Technical Specification for the Chilled Water System.

2. A temporary compensatory action has been implemented to ensure the operability of valve CH168. Resolution of the .CH168 concern will result from

-the .ongoing root cause evaluation.

3. An Operability Determination has been developed to address the actions to be taken if less than three chillers or two chilled water pumps are operable.

This Operability Determination will. remain in effect until the LCR in i tern 1 above is approved and implemented.

. NRC FORM 366A (4-95)