ML18107A421

LER 99-005-00:on 990605,11 Containment Declared Inoperable. Caused by Valves 11SW72 & 11SW223 Both Leaking.Procedure S1.OP-ST.SW-0010(Q) Was Enhanced to Provide Specific Instructions to Ensure Proper Sequencing.With 990702 Ltr

ML18107A421
Person / Time
Site:	Salem
Issue date:	07/02/1999
From:	Duca P, Garchow D Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-99-005-02, LER-99-5-2, LR-N990321, NUDOCS 9907120210
Download: ML18107A421 (7)

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.O.PS~G-Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit LR-N990321 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 LER 272/99-005-00 SALEM GENERATING STATION -UNIT 1 FACILITY OPERATING LICENSE NO. DPR-70 DOCKET NO. 50-272 Gentlemen:

This Licensee Event Report entitled "11 Containment Fan Coil Unit (CFCU) out of service more than Tech Spec Allowed Time" is being submitted pursuant to the requirements of the Code of Federal Regulations 10 CFR 50.73(a)(2)(i)(B), any operation or condition prohibited by the plant's Technical Specifications.

Sincerely, /l n./), /

0. Ptt{.;~t~~~J D. F. Garqhow General Manager Salem Operations Attachment PJD/

C Distribution LER File 3.7 9907120210 990702 PDR ADOCK 05000272 S PDR

,['he rm\*er is in )'Ollr hands.

95-2168 REV, 6/94

NRC FORM366 U.S. NUCLEAR REGUL RY COMMISSION APPROVED MB NO. 3150-0104 EXPIRES 06/30/2001 (6-1998) Estimated burden per response to comply with this mandatory information collection request 50 hrs. Refeorted lessons learned are incorporated into LICENSE.E EVENT REPORT (LER) the licensing process and ed back to industry. Forward comments r~rding burden estimate to the Records Management Branch b1;-6 F33),

U. . Nuclear RW,ulatory Commission, Washington, DC 20555-00 1, and to (See reverse for required number of the Paperwork eduction Pro~ect (3150-0104), Office of Management and digits/characters for each block) Bud~et, Washin~ton, DC 20 03. If an information collection does not disp ay a current y valid OMB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.

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

SALEM UNIT 1 05000272 1 OF 6 TITLE (4) 11 Containment Fan Coil Unit(CFCU) Out of Service More than Tech Spec Allowed Time EVENT DA TE (5) LER NUMBER (6) REPORT DA TE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR I SEQUENTIAL NUMBER IREVISION NUMBER MONTH DAY YEAR FACILITY NAME DOCKET NUMBER FACILITY NAME DOCKET NUMBER 06 05 99 99 -005 - 00 07 02 99 n.

OPERATING MODE(9) I THTS I<!* vo IK 20.220l{b) 20.2203(a)(l)

TS .<;T 1 ~*

20.2203(a)(2)(v) 20.2203(a)(3)(i) x

• Pl JlHm A. NT TO THF. K II 11 lll<Ml<.NTS {)1' 10 C'FR

50. 73(a)(2)(i) 50.73(a)(2)(ii) rrh *~Ir mP nr mnrp\ {I I\

50. 73(a)(2)(viii) 50.73(a)(2)(x)

POWER 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)(l) 50. 73(a)(2)(v)

Specify in Abstract below or in 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii) NRC Form 366A LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

Philip J. Duca Jr. , Salem Licensinq Enqineer ( 609) 339-2381 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

COMPONE REPORTABLE REPORTABLE CAUSE SYSTEM NT MANUFACTURER TO EPIX CAUSE SYSTEM COMPONENT MANUFACTURER TO EPIX x BI CLR M570 N x BI FCV Fl30 y x BI ISV Ml20 y x BI PT M430 N STTPPT.F.MF.NTAT RFPORT 1'.YPl<.C'TF.O {14\ MONTH DAY YEAR EXPECTED IYES (If yes, complete EXPECTED SUBMISSION DATE). Ix 'NO ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

SUBMISSION DATE(lS)

At 0124 on 5/29/99 after the performance of a valve stroke timing surveillance for the 11 Containment Fan Coil Unit (CFCU), a leak developed in Containment. The CFCU was isolated and Tech Spec(TS) 3.6.2.3 was entered. Containment entry revealed leakage at 3 of the top 4 11 CFCU cooler cover plate gaskets. The CFCU was declared inoperable and the TS action statement was entered. The action statement which expired on 6/5/99 at 0124 required that the unit be in hot standby by 0724 on 6/5/99.

On June 4, 1999, following initial repairs and pressurization of the CFCU with service water, additional cooler leaks developed on the top two coolers. On 6/4/99 PSEG submitted a request for a Notice of Enforcement Discretion (NOED) to the NRC asking for an extension of the allowable outage time for the inoperable CFCU of 5 days or until the CFCU was returned to an operable status. NRC granted this NOED on 6/4/99 (documented via letter A. Randolph Blough, Director Division of Reactor Projects, NRC Region I, NOED No. 99-1-004 dated 6/9/99). This LER is being submitted since the unit operated past the allowable outage time stated in the tech spec action statement.

Repairs were completed, operability testing was successfully performed and the CFCU was returned to an operable status at 1818 on 6/7 /99.

Sufficient safety system components to mitigate relevant events remained operable during the entire duration of 11 CFCU outage, therefore there was no impact to the health and safety of the public.

This event is reportable in accordance with 10 CFR 50. 73 (a) (2) (i) (B), any operation or condition prohibited by the plant's Technical Specifications.

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION l (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET(2)

FACILITY NAME (1) NUMBER(2) LER NUMBER (6) PAGE (3)

YEAR I SEQUENTIAL NUMBER IREVISION NUMBER SALEM UNIT 1 05000272 99 0 0 5 00 2 OF 6 TEXT (If more space is required, use additional copies ofNRC Form 366A) (17)

PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized Water Reactor Containment Fan Cooling System/Service Water/Coolers{BK/BI/CLR}*

• 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 Unit 1 was Mode 1 (Power Operation) at approximately 78% Power.

DESCRIPTION OF OCCURRENCE On 5/18/99 a scheduled surveillance test was performed on 11 CFCU. This surveillance required stroke timing closed of the CFCU inlet and outlet containment isolation valves (11SW58 and 11SW72 respectively).

Approximately three minutes after stroking the valves, Operations received Overhead Annunciator (OHA) C-38 (Containment Fan Coil Unit 11 Leak Detector High) . It was determined that when the 11SW58 was opened, a pressure transient was experienced. This resulted in cooler cover plate gasket leaks from three of the twelve coolers on the llCFCU. Each CFCU has 12 coolers.

The coolers are arranged in two vertical rows of six. The two coolers in the top row developed gasket leaks along with one in the fourth row down.

The apparent cause of the gasket leaks at this time was attributed to the sequence in which the valves were stroked. Procedure steps were not exact and allowed the operator to interpret them to allow using an improper sequence.

The gasket leaks were repaired, operability testing was successfully performed and llCFCU was returned to service on 5/22/99 within the 7 day LCO allowable outage time (AOT)

Sl.OP-ST.SW-0010(Q) ["Inservice Testing Containment Fan Coil Units (CFCU)

Service Water and Control Air Valves"] tests various service water valves for all CFCUs. Since the surveillances for the other CFCU valves were becoming due, the 11 CFCU surveillance was again performed to reset the sequence of testing. In order to ensure the valves were stroked in the NRC FORM 366A (6-1998)

I NRC FORj\1366A U.S. NUCLEAR REGULA TORY COMMISSION

' (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET(2)

FACILITY NAME (1) NUMBER(2) LER NUMBER (6) PAGE (3)

YEAR ISEQUENTIAL NUMBER IREVISION NUMBER SALEM UNIT 1 05000272 99 0 0 5 00 3 OF 6 TEXT (If more space is required, use additional copies ofNRC Form 366A) (17)

DESCRIPTION OF OCCURRENCE (continued) proper manner, the procedure was revised providing very specific direction on the sequencing of the valves.

At 0124 on 5/29/99 after the performance of the stroke timing surveillance test procedure, OHA C-38 (Containment Fan Coil Unit 11 Leak Detector High) was once again received in the Control Room. This alarm indicated that there was another leak in Containment emanating from 11 CFCU. The 11 CFCU was isolated and Technical Specification 3.6.2.3 was once again entered. An entry into Unit 1 Containment revealed Service Water leakage at 3 of the top 4 CFCU cooler cover plate gaskets.

The CFCU was declared inoperable and the tech spec action statement entered.

Leak repairs were commenced on the leaking cooler cover plates. The 11SW72 valve was opened and inspected resulting in the discovery that the 11SW72 rubber liner was degraded allowing significant leakage through the closed valve. The 11SW223 (a valve downstream of the 11SW72 valve) V-ball was also degraded allowing more than design flow through the seat. The following repair actions were undertaken: 1) the 11SW72 (11 CFCU SW Outlet Air Operated Valve) was replaced with a new valve, and 2) the 11SW223 (11 CFCU SW Outlet Control Air Operated Valve) was replaced with a new ball and seat.

On June 4, 1999, following the repairs listed above, service water was returned to 11 CFCU. During subsequent work on a degraded pressure transmitter another pressure transient occurred resulting in additional cooler leaks on the top two coolers.

The action statement entered on 5/29/99 was a 7 day action statement that expired on 6/5/99 at 0124. The action statement required that the unit be in hot standby by 0724 on 6/5/99. On 6/4/99, PSEG submitted a request for a Notice of Enforcement Discretion (NOED) to the NRC asking for an extension of the allowable outage time for the inoperable CFCU for 5 days or until the CFCU was returned to an operable status. NRC granted this NOED on 6/4/99 allowing the unit to continue to operate. The NOED was documented via a letter from Randolph Blough, Director Division of Reactor Projects, NRC Region I, NOED No. 99-1-004, dated 6/9/99. This LER is being submitted since the unit operated past the allowable outage time stated in the tech spec action statement.

Leak repairs were performed using an improved repair method already being used on Salem Unit 2 CFCUs. Repairs were completed, operability testing was successfully performed and the CFCU was returned .to an operable status at L!=:=================================:======================================================:::::!J NRC FORM 366A (6-1998)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION I (6-1998)

" LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET(2)

FACILITY NAME (I) NUMBER(2) LER NUMBER (6) PAGE (3)

YEAR I SEQUENTIAL NUMBER IREVISION NUMBER SALEM UNIT 1 05000272 99 0 0 5 00 4 OF 6 TEXT (If more space is required, use additional copies ofNRC Form 366A) (17)

DESCRIPTION OF OCCURRENCE (continued) 1818 on 6/7/99.

CAUSE OF OCCURRENCE The apparent cause of the 5/18/99 gasket leaks was attributed to the sequence in which the valves were stroked. The sequence utilized on 5/18/99 allowed the piping between 11SW58 and 11SW72 to become depressurized when the 11SW58 was closed with the 11SW72 opened. It is estimated that draining of approximately 4 gallons would be sufficient to create voids. The pressure transient was believed to have occurred when voids in the fluid formed while the llSW72 valve was open, collapsed when 11SW58 was reopened.

During the evaluation of the 5/18/99 event, the possibility that both the 11SW72 and the 11SW223 valve were leaking through was considered. However, the test had been successfully performed on 2/20/99. Also the probability that both valves were leaking through was deemed to be low. There was no external evidence that the valves were leaking through.

The apparent cause of the second service water leakage event was the 11SW72 and 11SW223 both leaking through, allowing the piping between 11SW58 and 11SW72 to become depressurized when the 11SW58 was closed. Since the proper valve sequencing was utilized during the 5/29/99 test, in hindsight it became apparent that the sequence alone may not have caused the 5/18/99 event. The following repair actions were undertaken: 1) the 11SW72 (11 CFCU SW Outlet Air Operated Valve) was replaced with a new valve, and 2) the llSW223 (11 CFCU SW Outlet Control Air Operated Valve) was repaired with a new ball and seat.

A pressure transient also caused the leaks that occurred on 6/4/99. This pressure transient resulted during the following sequence of events.

Subsequent to repair of the leaks and pressurization of the CFCU with service water, a pressure transmitter associated with the 11SW57 (the 11 CFCU pressure control valve) was removed from service so that it could be repaired. This resulted in both 11SW57 and 11SW223 going to their full open positions. The repositioning of these valves to the full open position was not anticipated. With these valves in their full open position, service water header pressure dropped to the point where the backup service water pump automatically started (90 psig). With the backup pump in service (maximum service water flow of approximately 3500 gpm) a pressure surge (to 135 psig) occurred. It was during this transient that the leaks occurred.

NRC FORM 366A (6-1998

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET(2)

FACILITY NAME (l) NUMBER(2) LER NUMBER (6) PAGE(3)

~ REVISION YEAR I SEQUENTIAL N1.JMBER NUMBER SALEM UNIT 1 05000272 99 0 0 5 00 5 OF 6 TEXT (!j more space is required, use additional copies of NRC Form 366A) (I7)

PRIOR SIMILAR OCCURRENCES LERs and Special Reports for Salem and Hope Creek for 1996, 1997, 1998 and 1999 to date were reviewed for similar occurrences. None were identified.

SAFETY CONSEQUENCES AND IMPLICATIONS There was no safety significance to this event. During the entire duration of 11 CFCU being out of service, the four remaining CFCUs and both containment spray pumps were operable. Salem safety analyses show that three CFCUs in conjunction with one containment spray pump, or two containment spray pumps alone will provide sufficient heat removal capability to mitigate the consequences of relevant accidents.

Additionally risk assessment analyses performed in support of the request for the NOED showed very small increases in core damage frequency and large early release frequency as a result of one CFCU being out of service.

CORRECTIVE ACTIONS

1. Procedure Sl.OP-ST.SW-OOlO(Q) was enhanced to provide specific instructions to ensure proper sequencing and timing of valve manipulations

2. The 11SW72 (llCFCU SW outlet air operated valve) was replaced with a new valve.

3. The 11SW223 (11 CFCU SW outlet control air operated valve) was repaired with a new v-ball and seat.

4. For the leaking coolers, the 1/16 inch gasket material, used on the Unit 1 CFCU coolers was replaced with a 1/8 inch gasket as used on Unit 2 CFCU coolers to provide enhanced sealing of the 11 CFCU cover plates.

5. For the leaking coolers, the RTV (the sealant material used on Unit 1) was replaced with Duratough DL (the sealant material used on Unit 2) to enhance the sealing of the 11 CFCU cover plates.

6. The remaining Unit 1 CFCU cooler cover plate sealing will be evaluated under the corrective action program and appropriate changes will be made.

NRC FORM 366A (6-1998

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET(2)

FACILITY NAME (1) NUMBER(2) LER NUMBER (6 PAGE (3)

YEAR I SEQUENTIAL NUMBER IREVISION NUMBER SALEM UNIT 1 05000272 99 o o* s 00 6 OF 6 CORRECTIVE ACTIONS (continued)

7. The personnel involved in the removal from service of the pressure transmitter associated with 11SW57 were held accountable in accordance with PSE&G policies and procedures.