ML18102A706

LER 96-037-00:on 961125,deficiency in Single Failure criteria-component Cooling Water Sys Occurred.Caused by Failures Were Not Adequately Evaluated During Initial Plant Design.Plant Components Has Been completed.W/961226 Ltr

ML18102A706
Person / Time
Site:	Salem
Issue date:	12/26/1996
From:	Garchow D, Hassler D Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-96-037, LER-96-37, LR-N96434, NUDOCS 9701020214
Download: ML18102A706 (4)

Text

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• Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit DEC 2 6 1996 LR-N96434 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 LER 272/96-037-00 SALEM GENERATING STATION - UNIT 1 FACILITY OPERATING LICENSE NO. DPR-70 DOCKET NO. 50-272 Gentlemen:

This Licensee Event Report entitled "Deficiency in Single Failure Criteria - Component Cooling Water System" is being submitted pursuant to the requirements of the Code of Federal Regulations 1 0 CFR 5 0 . 7 3 ( a ) ( 2 ) ( i ) ( B ) .

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_.I David F. Ga chow General Manager Salem Operations Attachment DVH C Distribution LER File 3.7 9701020214 961226 PDR ADOCK 05000272 S PDR

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' NRC FORM 366 U.S. NUCLE REGULATORY COMMISSION APP OVED BY OMB NO. 3150-0104 (4-95) EXPIRES 04/30198 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 60.0 HRS.

I 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~ F33), U.S. NUCLEAR (See reverse for required number of REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF digits/characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, DC 20603.

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

SALEM GENERATING STATION UNIT 1 05000272 1 of 3 111 E (4)

Deficiency in Single Failure Criteria - Component Cooling Water System EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL I REVISION MONTH DAY YEAR I

NUMBER NUMBER Salem Unit 2 05000311 FACILITY NAME DOCKET NUMBER 11 25 96 96 - 037 - 00 12 26 96 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(a)(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) Spec~in Abstract below or in C Form 366A 20.2203(a)(2)(iv) 50.36(c)(2) 50. 73(a)(2)(vii)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

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

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TONPRDS TONPRDS SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR IYES XINO SUBMISSION (If yes, complete EXPECTED SUBMISSION DATE). DATE (15)

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

A deficiency in the application of the single failure criteria was discovered, in that either a single active failure of the 22 Component Cooling Heat Exchanger Room Cooler, or a single active failure of "C" Vital Bus, concurrent with a Component Cooling Water (CCW) Pump out of service, could potentially cause a loss of all component cooling. Prior to identifying this deficiency, one ccw pump could be out of service without a Technical Specification Action Statement being entered. The cause of this occurrence lS that the vulnerability of the ccw systems to failures of the ventilation system was not adequately analyzed in the original design of the plant.

There were no safety consequences associated with this issue. The safety implications of this occurrence are the ccw is considered an Engineering Safeguards System, since it is required for post-accident removal of decay heat from the reactor.

This event is reportable in accordance with 10 CFR 73(a) (2) (ii) (B) any event or condition that resulted in the nuclear power plant being in a condition that was outside of design basis of the plant NRC FORM 366 (4-95)

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• NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

SALEM GENERATING STATION UNIT 1 96 - 037 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized Water Reactor Closed/Component Cooling Water System {CC/-} *

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

CONDITIONS PRIOR TO OCCURRENCE At the time of identification, Salem Units 1 and 2 were shutdown and defueled.

DESCRIPTION OF OCCURRENCE '

During a recent NRC Inspection of the Component Cooling Water (CCW) {CC/-}

system, questions concerning the application of single failure criteria were raised. PSE&G had identified the CCW Room Coolers as vulnerable to a single failure. In addressing thi*s vulnerability and the NRC questions, a deficiency in the application of single failure criteria was identified. Prior to identifying this deficiency, one CCW pump {CC/P} could be out of service without a Technical Specification Action Statement being entered. The original interpretation of the CCW operability requirements was based on the UFSAR minimum safeguards alignment of one CCW pump and one CCW heat exchanger {CC/HX}.

This interpretation is not supportable given the interdependence of CCW and supporting ventilation systems. For the current design the Technical Specification (TS) Action Statement must be entered for any inoperable CCW pump.

In* March of 1995, administrative controls were developed and implemented to ensure that all three of the Component Cooling Water (CCW) pumps were available.

These controls were initiated to simplify operator actions. These controls better defined the requirements for an independent loop of CCW. With these controls in place the appropriate decisions regarding the independence of the CCW system could be made. Prior to the implementation of these controls, PSE&G assumed a single CCW pump could have been removed from service without entering the Limiting Condition of Op~ration (LCO, TS 3/4.7.3.1) of the Component Cooling system The 21 CCW pump is located in the 21 Component Cooling Pump Room; cooled by the 21 Pump Room Cooler {-/CLR}. The 22 and 23 CCW pumps are both located in the 22 Component Cooling Pump Room; cooled by the 22 Pump Room Cooler. In this arrangement, with the 21 CCW pump out of service, a single failure of the 22 Pump Room Cooler may result in a loss of component water cooling function due to overheating of both the 22 and 23 CCW pumps. To minimize the heat build up in the 22 room, the door has been removed. The maximum room temperature is being evaluated; however, an operability determination based on expected outside temperatures was completed to allow Salem Unit 2 entry into Mode 6.

NRC FORM 366A (4-95)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (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 3 OF 3 SALEM GENERATING STATION UNIT 1 96 - 037 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

DESCRIPTION OF OCCURRENCE (Cont'd)

Another single failure scenario identified that could impact the CCW system was the loss of the "C" Vital Bus {EK/BU}. The "C" Vital bus provides power to the 21 Pump Room Cooler and the 23 CCW Pump. A failure of the "C" Vital Bus, coincidence with an out of service 22 CCW pump, results in the 21 CCW pump operating with no room cooling. The impact of room cooling on equipment operability is being evaluated.

CAUSE OF OCCURRENCE The cause of this occurrence is that ventilation system single failures were not adequately evaluated during the initial plant design.

PRIOR SIMILAR OCCURRENCES In the past two years there were ten LERs that addressed design as the cause.

These LERs are 272/95-014-00, 272/95-020-00. 272/95-029-00, 272/96-001-00, 272/96-010-00, 272/96-012-00, 272/96-018-00, 272/96-019-00, 272/96-020-00, and 272/96-034-00. Corrective actions for these LERs were specific to the particular issue.

SAFETY CONSEQUENCES AND IMPLICATIONS There were no safety consequences associated with this issue. The safety implications of this occurrence are that the CCW is considered an Engineering Safeguards System, since it is required for post-accident removal of decay heat from the reactor. The CCW provides cooling for heat loads such as the residual heat exchangers, the residual heat removal, safety injection, and charging pumps, and the spent fuel pool cooling system.

The health and safety of the public were not affected.

CORRECTIVE ACTIONS

1. A review of the impact ventilation systems have on plant components has been completed. This condition was discovered as a result of these efforts.

2. An operability determination based on expected outside temperatures was completed to allow for Salem Unit 2 entry into Modes 5 and 6.

3. An evaluation to determine the maximum room temperatures and to determine the impact of room cooling on equipment operability will be completed and implemented prior to entry in to Mode 4 for Salem Unit 2.

4. The TS Bases and the UFSAR for Salem Units 1 and 2 will be revised to reflect the relationship between ventilation systems and the CCW system. These revisions will be completed prior to Salem Unit 2 entering Mode 4.

NRC FORM 366A (4*95)