ML20045G664

LER 93-006-01:on 930401,Train a Svc Water Inoperable Due to Corrosion Product Buildup Between Valve Stem & Packing Follower.Returned SW-V54 to Operable Status & TS 3.7.4 Action D Exited on 930402.W/930701 Ltr

ML20045G664
Person / Time
Site:	Seabrook
Issue date:	07/01/1993
From:	Feigenbaum T, Peschel J NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-006, LER-93-6, NYN-93099, NUDOCS 9307150023
Download: ML20045G664 (5)

Text

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Seabrook ws O3874 Telephone (603)474 9521 j[h [ Facsimile (603)474 2987 Energy Service Corporation Ted C. Feigenbaum Senior Vice President and Chief Nuclear Officer NYN- 93099 July 1,1993 United States Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Document Control Desk

References:

(a) Facility Operating License No. NPF-86, Docket No. 50-443 ,

(b) North Atlantic Letter NYN 93065 dated April 30,1993," Licensee Event Report (LER) 93-006-00: Train A Service Water Inoperability," T.C.

Feigenbaum to USNRC

Subject:

Supplemental Licensee Event Report (LER) 93-06-01; " Train A Service Water Inoperability" '!

Gentlemen:

Enclosed please find Licensee Event Report (LER) No. 93-06-01 for Seabrook Station. This submittal provides supplemental information regarding previous occurrences of the event, root cause determination, and corrective actions.

Should you require further information regarding this matter, please contact Mr-James M. Pe:;chel, Regulatory Compliance Manager at (603) 474-9521 extenden 3772.

Very tr yours, /

g fgds,- tr Ted C. Fei enbaum TCF:MDO/act

Enclosures:

NRC Forms 366/366A i

130064 j

9307150023 930701 }

PDR g

ADOCK 05000443-PDR D@)a member of the Northeast Utilities L. system

i

. United Sta'tes Nucler.r Regulatory Commission July 1,1993 ,

4 Attention: Document Control Desk Page two Mr. Thomas T. Martin

- cc: ,

Regional Administrator United States Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Mr. Albert W. De Agazio, Sr. Project Manager Project Directorate I-4 Division of Reactor Projects U.S. Nuclear Regulatory Commission ,

Washington, DC 20555 Mr. Noel Dudley NRC Senior Resident Inspector

- P.O. Box 1149 Seabrook, nil 03874 INPO -

Records Center +

700 Galleria Parkway Atlanta, GA 30339-5957 P

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NRC FORM 366 U.S. NUCLEAR REGULATORY CDP 9tlSSIC APPROULD IlY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH LLfCTl " "f "E$

LICENSEE EVENT REPORT (LER) $ARD f0 I"f "

S EcAR9xNG BURDlN kS Ti THE INFORMATION AND RECORDS MANAGEMENT BRANCH "k

(MNBB 7714), U.S. NUCLEAR REGUL ATORY COMMISS10N, (See reverse for required nunber of digits / characters for each block) WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE Of MANAGEMENT AND BUDGET, WASHINGTON, DC 20503, FACILITY NAME (1) DOCKLT NUMBER (2) PAGE (3)

Seabrook Station 05000443 1 OF 3 TillE(4) '

Train A Service Water Inoperability EVENI DATE (5) llR NUMillR (6) RIPORI DALE (1) OIHIR FACILIIIf 5 INV0t Vf D (8)

SEQUENTIAL REVISION MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY YEAR 05000 FACILITY NAME DOCKET UMBE 4 1 93 93 -- 006 -- 01 7 01 93 OPERATING y IHIS REPORI IS SUHMllllD PURSUANI 10 THE RIQUIREMINIS Of 10 CFR 9: (Check one or more) (11)

MODE (9) 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)(1)(1) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c) 100 LEVEL (10) 20.405(a)(1)(11) 50.36(c)(2) 50.73(a)(2)(vii) OIHER 20.405(a)(1)(lit) X 50.73(a)(2)(1) 50.73(a)(2)(viii)(A) (Specify in trac ow 20.405(a)(1)(iv) 50.73(a)(2)(li) 50.73(a)(2)(viii)(B) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x) NRC Form 366A) llCIMSIf CONIACT FOR THIS lf R (12)

NAME lELEPHONE NUMBER (Include Area Code)

Mr. James M. Peschel, Regulatory Compliance Mngr. (603)474-9521 ext. 3772 COMPIEll DNE t INF IOR LAOf COMPONINI I AltuRF DESCRIHED IN THIS Rf PORI (13)

E E 0 CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER p p 3 SUPPilMINIAI RIPORT EXPICIID (14) EXPECTED MONTH DAY YE AR YES SullMISSION (If yes, complete EXPECTED SUBMISSION DATE). X NO DATE(15)

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

On April 1,1993, while performing surveillance testing, the Train A Cooling Tower Pump discharge valve could not be fully closed utilizing the motor operator attached to the valve. When this valve is not fully closed an interlock prevents starting of the associated train's Senice Water (SW) pumps and Cooling Tower Pump [BI). The pumps would not start automatically follow'mg a Loss of Offsite Power with the valve not fully closed and therefore, the pumps were declared inoperable.

Technical Specification 3.7.4, Service Water System, does not permit plant operation with 3 pumps within one loop inoperable and thus Technical Specification 3.0.3 was entered. The valve failed to close due to a corrosion product buildup between the vah'e stem and packing follower.

Subsequent investigation has determined that on two previous occasions, maintenance was performed on the Train A Cooling I

Tower Pump Discharge Valve which resulted in the inoperability of the Train A SW pumps. . The maintenance was performed on October 23,1990 and May 31,1991. On both of these occasions Technical Specification Action 3.7.4d was entered for one Cooling Tower Senice Water Pump inoperable. The maintenance that was performed did not involve a failure of the valve to close due to corrosion product buildup or over-torquing the packing gland.

There were no adverse safety consequences as a result of the event. Train B SW was OPERABLE and in operation for each I of the occasions that Train A SW was inoperable.

NRC FORM 366 (5-92)

NRC toali 366A U.S. NUCLI AR RLGULA10R7 COMMISSIC^] APPROVLD liY ONU NO. 3150-0104

'(5-92) EXPIRES 5/31/95 ESilMATED BURDEN PER RESPONSE TO COMPLY Wi1H IHIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE 10 LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECOR05 MANAGEMENT BRANCH (MNBB 7714), U.S. NUCtE AR REGULATORY COMMISSION, TEXT CONTINUATION WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104). OFFICE Of MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACIL11Y NAME (1) DOCKLI NUMBlR (?) llR NUMBIR (6? PAGE (3) ygg SEQUENTIAL REVISION Seabrook Station " "

05000443 93 2 OF 3

-- 0 0 6 --

TLK1 (I( Inore space is requfred, use additionai coples of MC l'orm 36M) (l1)

The Service Water (SW) System [Bl] at Seabrook Station is comprised of two redundant trains. Each train has two pumps which supply cooling water from the ocean and one pump which supplies cooling water from a mechanical draft cooling tower.

Operation of any one of the six pumps (2 trains of 3 pumps) is adequate to mitigate the consequences of a design basis event.

On April 1,1993 SW Train A valve testing was being performed. Part of the testing involves transferring SW supply from the ocean to the cooling tower and back to the ocean so that the open and close times for Train A Cooling Tower Pump Discharge Valve, SW-V54, can be measured. At 0300 of the same day, while measuring SW-V54's close time, the valve stopped before the fully closed position was reached. Operators reestablished SW cooling from the cooling tower by opening SW-V54 and sent personnel to investigate the cause of the failure. At 0318 the three pumps within Train A SW were declared to be inoperable because neither the LCO or ACTION requirements for Technical Specification 3.7.4, Service Water System, could be met. Technical Specification 3.03 was entered at this time. At 0330 of the same day SW-V54 was closed manually and SW was transferred back to the ocean cooling supply. Once SW cooling was esteblished from the ocean the two ocean SW pumps were declared to be OPERABLE, Technical Specification 3.03 was exited and Technical Specification 3.7.4 ACrlON d was entered for the Cooling Tower Pump being inoperable.

The interlock which prevents the SW pumps from starting whcn SW-V54 is not fully closed has two purposes. First it prevents starting the Cooling Towei Pump when its discharge valve is not fully closed and second, it prevents the ocean SW pumps from filling the Cooling Tower with seawater. The three Train A SW pumps were declared to be inoperable because they were not capable of starting automatically following a Loss of Offsite Power (LOP) after the Emergency Diesel Generators re-energize the emergency busses. In addition, Technical Specification Surveillance Requirement 4.7.4b.2) also requires that the SW pumps be capable of starting automatically. Once SW V54 was closed manually, the ocean SW pumps became OPERABLE because they were now capable of starting automatically.

Subsequent investigation has determined that on two previous occasions, maintenance was performed on SW-V54 which resulted in the inoperability of the Train A SW pumps. The maintenance was performed on October 23,1990 and May 31, 1991 On both of these occassions Technical Specification Action 3.7.4d was incorrectly entered for one Cooling Tower Service Water Pump inoperable while Technical Specification 3.03 should have been entered. The maintenance that was performed was not associated with a failure of the valve to close due to corrosion product buildup or over-torquing the packing gland.

There were no occasions where maintenance was performed on the B Train Cooling Tower Pump Discharge Valve (SW-V25),

which resulted in the inoperability of Train B SW.

Root Cause The valve failed to close due to corrosion product buildup between the valve stem and packing follower. This caused increased friction between the valve stem and packing follower which resulted in a higher loading on the valves motor operator. The increased loading on the valve stem prematurely actuated a torque switch which stopped the valve prior to full stroke completion.

A contributing cause for the valve's failure is procedure inadequacy. The torque value specified for the valve's packing gland fastener caused over-torquing of the valve's packing during installation. This caused increased friction and resulting valve stem loading and contributed to the premature actuation of the torque switch.

~i E FORM 366A (5-92)

NRC FGtM 366A U.S. NUClLAR REGULA10RY CurtilSSICQ APPROVLD BY OMO NO. 3150-0104

'(5'-92)' EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REOUESTt 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, TEXT CONTINUATION WASHINGTON, DC 20555-000), AND TO THE PAPERWORK RE0UCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

F ACILI1Y NAME (1) DoCKEl NUMBER (?) if R NUMULR (6: PAGE (3)

SEQUENTIAL REVISION YEAR Seabrook Station """ """ "

05000443 93 0 3 OF 3

-- 0 0 6 --

TLKl (If wre space is required, use additional copies of MC Form 366A) (11)

An additional Root Cause, related to the subsequent investigation, is attributed to personnel error. Specifically that control room personnel failed to identify the need to limit work activities on SW-V54.

Corrective Action L SW-V54 was returned to OPERABLE status and Technical Specification 3.7.4 ACTION d. exited at 0523 on 4/2/93.

2. The diagnostic surveillance frequency for SW-54 will be changed from each refueling to quarterly for the next two quarters.

3. A new maximum packing gland fastener torque value for the 24 inch Service Water butterfly valves will be established.

4. An Engineering Evaluation will be performed to evaluate recommendations made by the valve vendor. These recommendations will be applied to other valves if applicable.

5. Diagnostic testing, to measure opening and closing torque, is scheduled to be completed on 24 inch Service Water motor operated valves during the next refueling outage.

6. The Repetitive Task Sheets associated with the Cooling Tower Pump Discharge Valves will be revised to reflect work limitations during applicable Modes.

7. A Standing Operating Order will be developed and issued discussing the limitations of working on the Cooling Tower Pump Discharge Valves.

8. The event will be discussed with the operators as part of Requalification Training.

Safety Consetiuences There were no adverse safety consequences as a result of this event. The operation of only one train of SW is adequate to mitigate the consequences of a design basis event. Train H SW was operable for each of the occasions that Train A SW was inoperable.

Previous Occurrences This is the second event where personnel error has been the cause of the failure to recognize that maintenance activities would result in equipment inoperability and a condition prohibited by the Technic:d Specifications. A previous occurrence was reported by North Atlantic in LER 92 07 00. On that occassion work activities were permitted which resulted in the inoperability of the Train A Containment Enclosure Emergency Air Cleanup System at the same time that the Train II Emergency Diesel Generator was inoperable.

At the time of the event the plant was in Mode 1 at m0% power.

NRCFORM366A($-92)