ML18102A326

LER 96-018-00:on 960719,potential Performance Impact on ECCS Identified Involving non-safety Related Refueling Water Storage Tank Piping.Caused by Design Discrepancy.Design Reviewed & revised.W/960818 Ltr

ML18102A326
Person / Time
Site:	Salem
Issue date:	08/18/1996
From:	Garchow D, Hassler D Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-96-018-01, LER-96-18-1, LR-N96254, NUDOCS 9608260126
Download: ML18102A326 (6)

Text

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.0.PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit AUG 18 1996 LR-N96254 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:

LER 272/96-018-00*

SALEM GENERATING STATION - UNIT 1 FACILITY OPERATING LICENSE NO. DPR-70 DOCKET NO. 50-272 This Licensee Event Report entitled "Potential Performance Impact on Emergency Core Cooling System due to Non-Safety Related Refueling Water Storage Tank Piping" is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR50. 73 (a) (2) (ii) (B).

Sincerely,

• ~~~9/d::u General Manager -

Salem Operations Attachment SORC Mtg.96-110 dvh/tcp C Distribution LER File 3.7 9608260126 6~836~72

~DR ADOCK PDR The puwer is in \OLir lumds.

95*2168 REV. 6/94

Document Control Desk LR~N96254 Attachment A The following represents the commitments that Public Service Electric

& Gas (PSE&G) made to the Nuclear Regulatory Commission (NRC) relative to this LER (272/96-018-00). The commitments are as follows:

1. The Unit 1 RWST was isolated from the non-seismically qualified piping sections noted in this LER. The quantity of water in the Unit 1 RWST is sufficient to provide makeup water for both Spent Fuel Pools following a seismic event that causes a loss of Spent Fuel Pool cooling at both unit~.

2. Actions will be taken (through administrative controls, design changes, or a combination of both) to ensure that alignment of the reactor drain system or the refueling water purification loop to the RWST will not prevent fulfillment of RWST safety functions.

These actions will be complete prior to alignment of these systems to an operable RWST.

NRCFORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (4-95) EXPIRES 04/30198 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 CT~ ~NUCLEAR (See reverse for required number of REGULATORY COMMISSION, WASHINGTON, DC , AND TO THE PAPERWORK REDUCTION PROJECT ~160-0104), OFFICE OF digits/characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, 20503.

FACILITY NAllE (1) DOCKET NUllBER (2) PAOE(3)

SALEM GENERATING STATION UNIT 1 05000272 1 OF4 TITLE (4)

Potential Performance Impact on Emergency Core Cooling System due To Non-Safety related Refueling Water Storage Tank Piping F'!ENT DATE (5) LER NUMBER (8) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR I SEQUENTIAL NUMBER

'REVISION NUMBER MONTH DAY YEAR FACILITY NAME Salem Unit2 DOCKET NUllBER 05000311 07 19 96 96 - 018 - 00 08 18 96 FACILITY NAME DOCKET NUMBER 05000 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) S~~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)

I CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TONPRDS TONPRDS 1111111111:111:

m~=~=~~=i=~~=;=~=~~=~

SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR SUBMISSION

'YES (If yea, complete EXPECTED SUBMISSION DATE). XINO DATE(15)

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

On July 19, 1996, a design review identified that the alignment, for extended periods, of the non-safety refueling water purification loop to the Refueling Water Storage Tank (RWST) had the potential for impacting the perfor:roance of the ECCS. The refueling water purification loop is not automatically isolated from the RWST during a design basis event. If the purification loop broke during a design basis event, a portion of the RWST inventory would be lost affecting the perfor:roance of the ECCS p~3 assumed in the accident analysis. Subsequent review has identified similar concern for isolating the RWST from the reactor drain pump piping and the supply of cooling water from the RWST for spent fuel cooling.

The cause of this discrepancy is that the Safety Injection System and the Spent Fuel Pool Cooling System design basis did not clearly document the purification system operation limitations. Corrective actions include upgrading the non-safety valve and actions to ensure that alignment of the reactor drain system or the refueling water purification loop to the RWST will not prevent fulfillment of RWST safety functions.

This event is reportable in accordance with 10 CFR 73 (a) (2) (ii); any condition that resulted in the plant being in an unanalyzed condition.

NRC FORM 388 (4-95)

NRC FORM 388A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (8) PAGE (3) 05000272 YEAR I SE.fill~:JkAL I~~ 2 OF 4 SALEM GENERATING STATION UNIT 1 96 - 018 - 00 TEXT (If more ap*ce ia required, use addition*I copies of NRC Form 388A) (17)

PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized water Reactor Safety Injection System {AB/RV}*

Spent Fuel Pool Cooling System {DA/-}

• 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 On July 19, 1996, a design review identified that the alignment, for extended periods, of the non-safety refueling water purification loop to the Refueling Water Storage Tank (RWST) had the potential for impacting the performance of the ECCS.

The RWST is part of the ECCS system and its function is to supply water to the suction of the ECCS pumps during the injection phase of a LOCA. The refueling water purification loop is not automatically isolated from the RWST during a design basis event. If the purification loop broke during a design basis event, a portion of the RWST inventory would be lost affecting the performance of the ECCS pumps assumed in the accident analysis.

The refueling water purification loop is a subsystem of the Spent Fuel Pool Cooling system. Connections are provided such that the refueling water may be pumped from either the refueling canal or the refueling water storage tank through the demineralizer and the filter and discharged to either the refueling cavity or the RWST. The refueling water purification loop is a non-safety related system.

A review of documentation determined that the original plant design of the purification loop was non-safety related and separated from the RWST by a safety related valve and a non-safety related valve. The purification loop is described in the Updated Final Safety Analysis Report (UFSAR) Section 9.1.3, Spent Fuel Pool cooling in conjunction with refueling activities. No reference is made to the purification loop in UFSAR Chapter 6 where the design of the RWST is described. A review concluded that the original design basis did not include extended operation of the refueling water purification loop to cleanup the RWST during power operation; rather the intent was to provide the capability during refueling operations to purify the refueling water either from the refueling canal or the RWST. Extended use of the system during normal operation was not intended.

NRC FORM 366A (4-95)

~

NRC FORM 366A (4-95)

• LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) 05000272 YEAR I SE,fillJ=:JhAL I=~ 3 OF 4 SALEM GENERATING STATION UNIT 1 96 - 018 - 00 TEXT (If m<<* *P*C* i* required, UH addition** copies of NRC Form 366A) (17)

DESCRIPTION OF OCCURRENCE (cont'd)

Subsequent review identified two additional concerns. One is that the safety related isolation valve isolating the RWST from the reactor drain pump piping may have been left open during past plant operation. However, isolation was provided by a locked closed non-safety valve upstream.

Additionally, the review identified that if the purification line broke during a loss of Spent Fuel Pool cooling, RWST inventory could be lost and could not provide the 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> of cooling assumed in the Updated Final Safety Analysis.

CAUSE OF OCCURRENCE The Safety Injection System and the $pent Fuel Pool Cooling System design basis di'd not clearly document the purification system operation limitations. The Spent Fuel Pool Cooling System Configuration Baseline Document (CBD) identified the purification loop as non-safety related. The CBD also identified that the purification loop would be used during power operation as required by chemistry procedure, but failed to identify the lack of adequate cautions in the operation procedure and failed to identify the impact of the non-safety related isolation valve.

PRIOR SIMILAR OCCURRENCES In the past two years there were no LERs that addressed a similar condition of limiting operation of a system due to its design intent ..

SAFETY CONSEQUENCES AND IMPLICATIONS There were no safety consequences associated with this issue. The implications of the alignment, for extended periods, of the non-safety purification loop to the RWST had the.potential for impacting the performance of the ECCS. In the extreme case of a break in purification line shortly after a design basis LOCA event, a portion of the RWST inventory would be lost through* the break. This could affect flow to the ECCS pumps, and the amount of inventory added to containment which in turn could affect the ability to switch over to the recirculation mode with suction from the sump. Additional mitigating factors which would have reduced the potential impact on ECCS performance are that the piping is Nuclear Class 3 and material is the same as the ECCS system suction piping and the system is a low pressure system. Therefore, catastrophic failure of the piping is highly unlikely. Degradation of the piping if it occurred NRC FORM 366A (4-95)

1 NRC FORM 366A (4-95) *

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LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACIUTY NAME (1) DOCKET NUMBER (2) LER NUMBER 6) PAGE (3) 05000272 SALEM GENERATING STATION UNIT 1 96 - 018 - 00 TEXT (If more apace i1 required, uae additional copies of NRC Form 366A) (17)

SAFETY CONSEQUENCES AND IMPLICATIONS (cont'd) would surface as a leak. Since the RWST level is monitored in the daily logs, any leak would be recognized and the system would be isolated.

If the RWST is not available for spent fuel pool cooling, alternate sources of water for cooling could have been used. The health and safety of the public were not affected.

! t CORRECTIVE ACTIONS

1. The Unit 1 RWST was isolated from the non-seismically qualified piping sections noted in this LER. The quantity of water in the Unit 1 RWST is sufficient to provide makeup water for both Spent Fuel Pools following a seismic event that causes a loss of Spent Fuel Pool cooling at both units.

2. Actions will be taken (through administrative controls, design changes, or a combination of both) to ensure that alignment of the reactor drain system or the refueling water purification loop to the RWST will not prevent fulfillment of RWST safety functions. These actions will be complete prior to alignment of these systems to an operable RWST.

NRC FORM 366A (4-95)