ML20045B470

LER 93-021-00:on 930611,determined That RB Ventilation Exhaust Inboard Isolation Valve HV-AOV-261AV Inoperable & Open Due to Personnel Error.Subj Valve Manually Closed. Proposed Change to TS Will Be submitted.W/930611 Ltr

ML20045B470
Person / Time
Site:	Cooper
Issue date:	06/11/1993
From:	Gardner R, Reeves D NEBRASKA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CNSS933138, LER-93-021, LER-93-21, NUDOCS 9306170401
Download: ML20045B470 (4)

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CNSS933138 June 11, 1993 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555

Dear Sir:

Cooper Nuclear Station Licensee Event Report 93-021, Revision 0, is forwarded as an attachment to this letter.

Sincerely, R. L. Gardner Plant Manager RLG/ju Attachment cc: J . L. Milhoan G. R. Horn J. M. Meacham R. E. Wilbur i V. L. Wolstenholm D. A. Whitman

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NAME TE lee'MONE NUM9ER f ARE A CODE Donald L. Reeves, Jr. 41012 8 12 15 l - 13 1811 11 COMPLETE ONE LINE FOR E ACM COMPONENT F AILURE DESCRIBED IN THis REPORT 0131 M C *EP T,A LE M C T CAUSE S YST E M COMPONE NT CAUSE S Y S'E M COMPONENT D PR 1 I I I I I I i i 1 I i l I i l i l I I i l i I i i i l SUPPLEMENT AL REPORT EF.ECTED f1 1 MONTM DAY YEAR SUBMtS5 SON -

YE 6 ftf r.n. vemps.o. En!dCTEO 500 Mis 5*0N OA TEo kO y l l l Ass, R Ac, n ., M ux - . . . .m. , es, , ,,,,, n ,-,,.. a ; n s, On May 12, 1993, at approximately 5:30 am, the Shift Supervisor (SS) determined that [

with Reactor Building Ventilation Exhaust Inboard Isolation Valve HV-A0V-261AV inoperable and open, Technical Specification requirements for Secondary Containment  ;

were not met. The redundant valve in the line, HV-MOV-260MV, was in the closed 3 position and de-energized, isolating the penetration. With that penetration  ;

isolated, a Secondary Containment capability test had been satisfactorily completed  !

prior to declaring Secondary Containment operable. However, in accordance with Technical Specifications, HV-A0V-261AV should.have been closed. Subsequently, the  !

r Spent Fuel Storage Pool gates were removed and stored, and three Local Power Range Monitor assemblies were transferred from the Separator / Dryer Storage' Cavity to the Spent Fuel Storage Pool. These activities have'been conservatively determined to  ;

constitute movement of loads which could have potentially damaged irradiated fuel l stored in the Spent Fuel Storage Pool, violating paragraph 3.7.C.1.d of the i Technicc? Specifications. At the time, the reactor was defueled. -

The cause of this event was personnel error. Technical Specification requirements  ;

for Secondary Containment Integrity had not been verified by the preceding SS. l l

Upon discovery of the condition, HV-A0V-261AV was manually closed. Since its air ,

operator had been removed, it was physically blocked closed. This action  :

established Secondary Containment Inte 71ty as defined in the Technical- .

j Specifications. The SS who had declared Secondary Containment to be operabic was  ;

counselled. A proposed change to the Technical Specifications, clarifying the requirements,-will be submitted. l, NN IONBt M $

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'" . LICENSEE EVENT REPORT (LER) TEXT CONTINUATION ArPaovro oMe uo. mo-eios at (XPIRES: t/31/8B f LCiUTV haut tu DOC # E T NUMBE R L71 PAGE(31 LER NUMBER (6)

• "*a "C'fd!' 47,%l'O Cooper Nuclent Station 0[5l0l0l0l2l9lg 9l 3 OF gl3 o l 2 l1 0 \0 0 (2 tm a na. am a mr=< u= nesemmc in :m4w tm A. Event Description On May 12, 1993, at approximately 5:30 am, the Shift Supervisor determined that with Reactor Building Ventilation Exhaust Inboard ,

Isolation Valve HV-A0V-261AV inoperable and open, Technical Specification requirements for Secondary Containment were not met. The circumstances which led to this condition were as follows: i

1) On April 30, the results of a stroke time test of HV-AOV-261AV were determined to be unsatisfactory. Engineering determined that an evaluation of the air operator and necessary corrective maintenance was required. Following further testing on May 3, plans were made to remove the operator from the valve.

2) On May 8, after verifying that the valve didn't need to be in the closed position, the air operator was removed with the valve in the open position. Operations had correctly concluded that since Secondary Containment was not required, valve position was not of concern.

3) On May 12, at 12:40 am, the redundant valve in the line, HV-MOV-260MV, was verified to be closed and de-energized. This action is consistent with Technical Specification action requirements for inoperable Primary Containment isolation valves. However, it is not consistent with the current definition of Secondary containment Integrity, which requires all automatic ventilation system isolation valves to be operable or secured in the isolated position.

4) On May 12, at 12:55 am, Secondary Containment was declared operable.

Uith Secondary Containment declared operable, the Spent Fuel Pool gates were removed, and components stored within the storage cavity area, including three Local Power Range Monitor (LPRM) assemblies, were moved from the Separstor/ Dryer Storage Cavity to the Spent Fuel Storage Pool.

These activities have conservatively been determined to constitute movement of loads which could potentially damage irradiated fuel in the Secondary Containment.

B. f_lant Status Shutdown for the 1993 Refueling Outage with all fuel off-loaded from the vessel.

C. Basis for Report i

Movement of loads which potentially could damage irradiated fuel in the l Secondary Containment ar,d, therefore, a violation of paragraph 3.7.C.l.d of the Technical Specifications, reportable in accordance with 10CFR50.73(a)(2)(1)(B).

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0 l0 0 l3 0 l3 D. Cause Personnel. Adherance to the provisions associated with the definition of the term " Secondary Containment Integrity" and Technical Specification requirements were not verified.

E. Safety Sirnificance Secondary Containment is designed to minimize any ground level release of radioactive material which might result from a serious accident.

During reactor operation, the Reactor Building serves as Secondary Containment. When the plant is in Cold Shutdown and Primary Containment is not established, the Secondary Containment provides Primary Containment. Initiating Reactor Building isolation and operation of the Standby Cas Treatment (SGT) System to maintain at least -0.25 inches water gauge within the Secondary Containment provides an adequate test of the operation of the Reactor Building isolation valves, leck tightness of the building, and performance of the SGT System.

On May 12, at 12:22 am, a Secondary Containment capability test was satisfactorily completed with HV-A0V-261AV open and HV-MOV-M0260 closed and de-energized. Therefore, while the definition of Secondary Containment Integrity was not met, testing demonstrated Secondary Containment capability.

F. Safety Implications Secondary Containment integrity is required during both power operation and during Cold Shutdown conditions when refueling activities are conducted. Since the Secondary Containment capability test had been satisfactorily performed, this event would not have been any more significant at power.

G. Corrective Action Upon discovery of the condition, the valve was manually closed and blocked in position, establishing Secondary Containment integrity as defined in the Technical Specifications. The Shift Supervisor who had declared Secondary Containment operable was counselled. Additionally, the proposed change to the Technical Specifications developed in response to LER 91-008, which includes provisions similar to those in Standard Technical Specifications for isolation of Secondary Containment penetrations, will be submitted.

H. Similar Events l l

LER 91-008 Technical Specification Violation for Failure to De-Activate an Inoperable Containment Isolation Valve as a Result of  ;

Inconsistent Technical Specifications and Personnel Error l

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