ML18101A844

LER 95-008-00:on 950517,controlled Shutdown Completed Due to Inoperability of Switchgear & Penetration Area Ventilation Sys (Spavs).Three Spavs Supply Fans Will Be Inspected & Fan Motors replaced.W/950714 Ltr

ML18101A844
Person / Time
Site:	Salem
Issue date:	07/14/1995
From:	Pastva M, Summers J Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-95-008-01, LER-95-8-1, NUDOCS 9507260142
Download: ML18101A844 (9)

Text

e OPS~G Public Ser-Vice Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit July 14, 1995 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Attn: Document Control Desk SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT 1 LICENSEE EVENT REPORT NO. 95-008-00 This Licensee Event Report is submitted pursuant to the requirements of Code of Federal Regulation 10CFR50. 73 (a) (2) (i) (A) and 10CFR50. 73 (a) (2) (i) (B). The late submittal of this report, which resulted from additional time required to address corrective actions, was previously discussed with NRC Region I Management.

Sincerely, J.eL J. C. Summers General Manager -

Salem Operations MJPJ:vs SORC Mtg.95-077 C Distribution LER File 9507260142 950714 PDR ADDCK 05000272 S .. - ...... PDR

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• 1 95-2168 REV. 6/94

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF (See reverse for required number of digits/characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

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

Salem Generating Station - Unit 1 05000272 1 OFS TITLE (4) Controlled shutdown following technical specification 3.0.3 entry due to inonerabilitv of switch~ear and nenetration area ventilation svstem EVENT DATE (5) LEA NUMBER (6 REPORT NUMBER (7) OTHER FACILITIES INVOLVED (8)

FACILITY NAME DOCKET NUMBER SEQUENTIAL REVISION MONTH DAY YEAR YEAR MONTH DAY YEAR NUMBER NUMBER 05000 FACILITY NAME DOCKET NUMBER 05 17 95 95 -- 008 -- 00 07 14 95 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more 111)

MODE (9) 1 20.402(b) 20.405(c) 50. 73 (a)(2)(iv) 73.7.1 (b)

POWER 20.405(a) (1) (i) 50.36(c)(1) 50.73(a)(2)(v) 73.i1(c)

LEVEL (10) 95% 20.405(a)(1 )(ii) 50.36(c) (2) 50.73(a) (2) (vii) OTHER 20.405(a) (1) (iii) x 50.73(a)(2)(i) 50. 73(a)(2)(viii)(A) (Specify in Abstract below and in Text, NRC 20.405(a) (1) (iv) x 50.73(a)(2)(ii) 50.73 (a)(2) (viii)(B) Form 366A) 20.405(a)(1 )(v) 50.73(a) (2) (iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LEA 12)

NAME TELEPHONE NUMBER gnclude Area Code)

Michael J. Pastva, Jr. LER Coordinator (609) 339- 165 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

REPORTABLE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER TO NPRDS TO NPRDS x EC FAN Wl20 N x EC FAN Wl20 N SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR I YES (If yes, complete EXPECTED SUBMISSION DATE) )( NO SUBMISSION DATE (15)

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

At 0253 hours0.00293 days <br />0.0703 hours <br />4.183201e-4 weeks <br />9.62665e-5 months <br /> on 5/17/95, a Unit 1 controlled shutdown from Mode 1 to Mode 3 was completed, as required by Technical Specification (TS) 3.0.3, due to inability to justify continued operation with 2 of the 3 Switchgear And Penetration Area Ventilation System (SPAVS) supply fans (Nos. 12 and 13) inoperable. It had been determined that the design basis maximum temperature could be exceeded in areas served by SPAVS, if the remaining operable SPAVS supply fan (No. 11 ) should fail.

The 13 SPAVS supply fan failure resulted from breakdown of the fan motor bearing and windings. The No. 12 SPAVS supply fan failure resulted from breakdown of the fan motor bearings. This event is attributed to Management/Quality Assurance Deficiency as a result of: lack of a preventive maintenance (PM) program for SPAVS fan motors, ineffective corrective action to the December 1994 failure of the SPAVS No. 12 supply fan motor, and inadequate organizational performance after failure of the SPAVS supply fan on 5/12/95. The No. 12 and No. 13 SPAVS supply fans have been repaired and returned to service and the No. 11 supply fan motor as well as the corresponding Unit 2 SPAVS supply fan motors will be replaced. Changes will be made to enhance the PM Programs and will place increased emphasis on HVAC systems. Action will be taken to develop and implement a tracking system for Technical Specification related equipment. Appropriate procedures will be implemented to provide guidance related to operability determinations and the removal from and return to service of equipment covered by the technical specifications. The submittal of this report has been discussed with NRC Region I Management.

NRG FORM 366 (5*92)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Docket Number LER Number Page 2 of 8 Unit # 1 50-272 95-008-00 Plant and System Identification:

Westinghouse - Pressurized Water Reactor Energy Industry Identification System (EIIS) codes and component function identifiers appear in the text as {XX/XX}

Identification of Occurrence:

Controlled Unit 1 Shutdown Following Technical Specification 3.0.3 Entry Due To Inoperability Of Switchgear And Penetration Area Ventilation System Event Date: May 17, 1995 Report Date: July 14, 1995 The late submittal of this report, which resulted from additional time needed to address corrective actions, has been discussed with NRC Region I Management.

This report was initiated by Incident Report No.95-630 Conditions Prior to Occurrence:

Mode 1 Reactor Power 95% Unit Load 1090 MWe Description of Occurrence:

At 2122 hours0.0246 days <br />0.589 hours <br />0.00351 weeks <br />8.07421e-4 months <br /> on May 16, 1995, a Unit 1 reactor shutdown was initiated in accordance with Technical Specification (TS) 3.0.3, due to inability to justify continued operation with inoperability of two (2) of the three (3) Switchgear And Penetration Area Ventilation System (SPAVS) supply fans

{EC/FAN}. No. 12 and No. 13 SPAVS supply fans were both inoperable, and it was determined that the design basis maximum temperature of 105° F could be exceeded in areas served by SPAVS, if the remaining operable SPAVS supply fan (No. 11) should fail. At 2149 hours0.0249 days <br />0.597 hours <br />0.00355 weeks <br />8.176945e-4 months <br /> on May 16, 1995, the NRC was notified of the initiation of the reactor shutdown, in accordance with 10CFR50. 72 {b) (1) {i) {A). Subsequently, at 0253 hours0.00293 days <br />0.0703 hours <br />4.183201e-4 weeks <br />9.62665e-5 months <br /> on May 17, 1995, a controlled shutdown to Mode 3

{Hot Standby) was completed in accordance with Technical Specification (TS) 3.0.3.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Docket Number LER Number Page 3 of 8 Unit# 1 50-272 95-008-00 Analysis of Occurrence:

In December 1994, No. 12 SPAVS supply fan failed due to tripping on overload protection. In January 1995, plans were initiated for a Temporary Modification (T-Mod) to support repair of the fan.

On May 12, 1995, at approximately 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br />, a Nuclear Equipment Operator discovered the power supply breaker overloads of No. 13 SPAVS supply fan tripped. On May 13, the No. 13 SPAVS supply fan motor was tested and found to be shorted to ground. The status of the two inoperable SPAVS supply fans and the remaining operable SPAVS supply fan (No.

11) was discussed during the Operations shift turnover on May 14th. Nuclear Engineering (NE) was then requested to determine if the Unit could operate with only the No. 11 SPAVS supply fan operable. In addition, the review was expanded to consider environmental impact on associated equipment, loss of all SPAVS supply fans, and benefits from increased ventilation from the feasibility of opening doors to rooms cooled by the SPAVS. On May 15th, efforts were made to provide an initial operability determination in accordance with Generic Letter 91-18. It was then decided on the same day that the SPAVS condition should be based upon a 10CFR50.59 safety evaluation. Additionally, a procurement request was made to obtain a replacement motor for one of the failed fans. On May 16th, it was determined that a Justification for Continued Operation (JCO) should be prepared instead of the 10CFR50.59 safety evaluation, with a self-imposed deadline for completion of a JCO by 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br /> (same day) . This deadline was based on Operations Management decision that Unit 1 operation beyond 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br />, without a JCO, was unacceptable. The JCO was not completed before 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br /> and Operations subsequently initiated the unit shutdown in accordance with TS 3.0.3, at 2122 hours0.0246 days <br />0.589 hours <br />0.00351 weeks <br />8.07421e-4 months <br />.

Apparent Cause of Occurrence:

This occurrence is attributed to Management/Quality Assurance Deficiency", as classified in NUREG-1022, Appendix B.

The failure of the No. 13 SPAVS supply fan resulted from end of life breakdown of the fan motor bearing and windings.

The failure of the No. 12 SPAVS supply fan resulted from end of life breakdown of the fan motor bearings.

LICENSEE EVENT REPORT 0.,ER) TEXT CONTINUATION Salem Generating Station Docket Number LER Number Page 4 of 8 Unit # 1 50-272 95-008-00 Apparent Cause of Occurrence: (cont'd)

Contributing factors to the failure are:

Lack of a preventive maintenance (PM) program for SPAVS fan motors.

Missed opportunities to establish a PM program for periodic monitoring of the SPAVS supply fan motors following a failure of No. 23 SPAVS fan motor (Unit 2) in April 1990, the failure of No. 12 SPAVS supply fan Unit

1) in December 1994, and periodic review of industry operating experience.

Ineffective corrective action following the No. 12 SPAVS supply fan motor failure in December 1994.

The No. 12 SPAVS supply fan remained inoperable without an initial operability determination and appropriate follow-up from December 1994, until after failure of No.

13 SPAVS supply fan on May 12, 1995.

Inadequate organizational performance prior to May 12, 1995.

When No. 12 SPAVS supply fan failed in December 1994, neither Operations nor the responsible System Engineer recognized that the SPAVS was operating outside the design basis of the system (i.e. the required two (2) fans in automatic and the remaining fan in standby) . A spare motor was available to replace the failed No. 12 SPAVS motor, but at the time documentation that the motor was qualified for installation in a safety-related application could not be located. The station planning department was aware of the need for a T-Mod to resolve the failure of No. 12 SPAVS fan motor. However, the involved work order (WO) was statused as "ON HOLD" in the System Engineer's name instead of being routed to the appropriate work group for action. This contributed to delay of the required repairs.

In April 1990, it was identified that the fan motor assembly was obsolete and could no longer be purchased.

An Operations tracking system did not exist to assure that inoperable TS support systems receive timely and appropriate Management attention.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Docket Number LER Number Page 5 of 8 Unit # I 50-272 95-008-00 Apparent Cause of Occurrence: (cont'd)

Inadequate organizational performance after May 12, 1995.

This occurred when the organization did not exhibit timely, and conservative decision making in supporting the SPAVS operability determination during the time from May 14, 1995, through the decision on May 16 to shutdown the U~it. A contributor was failure to identify design and licensing basis before starting work on the 10CFR50.59 evaluation and the JCO.

Prior Similar Occurrence:

Review of the facility records found that there had been two prior similar occurrences. One in April 1990 on Unit 2, and a second in December 1994 on Unit 1.

Safety Significance:

This event is reportable pursuant to 10CFR50.73(a) (2) (i) (A),

due to completion of reactor shutdown required by TS 3.0.3, and 10CFR50. 73 (a) (2) (ii) (B), due to a condition outside the design basis of the plant.

The SPAVS is designed to maintain a year around temperatures of less than 105° F and serves lA, lB, and lC 4160VAC, 460VAC, and 230VAC vital buses and transformers, 125VDC battery chargers, lC 125VDC battery and the chilled water pumps and compressors. It is designed with single failure capability without loss of ability to maintain temperatures within the required limits during post-accident conditions.

Each SPAVS supply fan is rated at 50% capacity, based upon 95° F ambient temperature. The Updated Final Safety Analysis Report (UFSAR) states that normally two (2) of the three (3) SPAVS supply fans are operated in automatic with the third fan in standby.

Assessment of the safety signific~nce of this occurrence considered the following:

Operation from December 1994, through May 12, 1995, with the No. 12 SPAVS supply fan out of service, and

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Docket Number LER Number Page 6 of 8 Unit # 1 50-272 95-008-00 Safety Significance: (cont'd)

Operation from May 12, 1995, until May 16, 1995, with both the No. 12 and No. 13 SPAVS supply fans inoperable.

Operation With No. 12 SPAVS Supply Fan Out Of Service During this period, if a failure of No. 11 or No. 13 SPAVS supply fans would have occurred, engineering judgment has concluded the remaining operable SPAVS supply fan would have maintained temperatures less than 105° F. This is based on relatively low ambient temperatures during this time frame and observed room temperatures. Subsequent calculations*

after the failure of No. 13 SPAVS supply fan showed that the required temperature limits could be maintained with a single supply fan in operation.

Operation With No. 12 and No. 13 SPAVS Supply Fans Out Of Service During this period, if failure of the single operating supply fan had occurred during post accident conditions, temperatures may not have been maintained less than 105° F.

However, based upon relatively low ambient outside air temperatures and observed room temperatures from time of discovery that 13 SPAVS supply fan was tripped until entry into TS 3.0.3, engineering judgment has concluded that the single operating fan was providing adequate cooling air flow. Final calculations in support of a JCO determined that if required, Salem Unit 1 could have been safely shutdown with no operating SPAVS supply fans coincident with a LOCA. The final calculation was based upon an assumption of ambient temperatures between 60° F (nighttime minimum) and 80° F (daytime maximum) and the use of additional ventilation paths.

Corrective Action:

Prior to restart of Unit 1:

All three of the SPAVS supply fans will be inspected and fan motors replaced. This activity has been completed.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Docket Number LER Number Page 7 of 8 Unit # I 50-272 95-008-00 Corrective Action (cont'd):

Recurring PM tasks will be implemented to replace fan motor bearings on a regular schedule to preclude future failures. These activities have been completed.

Procedures will be put in place to provide guidance on performing operability determinations and documenting the results. This activity has been completed with the creation of SC.OP-DD.ZZ-OD02(Q), Operability Determinations.

Procedures will be put in place to provide guidance for removal from service and return to service of technical specification related equipment. Procedure SC.OP-DD.ZZ-ODlO (Q) is under development and is expected to be available for use by September 1, 1995. The procedure will provide guidance for ensuring certain steps are considered prior to removing from or returning to service equipment covered by the technical specifications and the tracking of action statements for equipment removed from service for all operational modes.

The corrective action from the internal Safety Evaluation Review Team (SERT) report will be followed up to address the failure to take action when it was identified that fan motor assemblies were obsolete and could no longer be purchased.

Evaluations will be performed to address safety related, important to safety, and support equipment to assess the need for PM activities and implement those activities as needed.

The implementation of the revised Corrective Action Program, NC.NA-AP.ZZ-0006(Q), addresses the issue of immediate corrective actions. This procedure will ensure that corrective actions will be taken in a timely manner.

All SPAVS supply fans on Unit 2 will be inspected and the fan motors replaced prior to restart of the Unit. The maintenance activities identified for Unit 1 will also be implemented for Unit 2.

This occurrence will be reviewed during upcoming licensed operator retraining.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Docket Number LER Number Page 8 of 8 Unit # I 50-272 95-008-00 J. C. ers General Manager -

Salem Operations MJPJ:vs SORC Mtg.95-077