ML20043F525

Requests Temporary Waiver of Compliance from Tech Spec Limiting Condition for Operation Re Operability of Containment Isolation Valves During Quarterly Slave Relay Testing.Evaluation to Support Request Encl

ML20043F525
Person / Time
Site:	Beaver Valley
Issue date:	06/07/1990
From:	Sieber J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9006150088
Download: ML20043F525 (5)

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1. Bea er Vcury Power Station Shippmgport, PA 15077 0004 O.SUAUS ,o, ,

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June 7, 1990 >

i U. S. Nuclear Regulatory Commission Attn: Document control Desk Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. HPF-73 Request for Temporary Waiver of Compliance Gentlemen:

The purpose of this letter is to request NRC approval of a e request for a temporary waiver of compliance in meeting the Beaver ,

Valley Unit No. 2 Technical Specifications. Specifically, the-Limiting Condition for Operation (LCO) for the containment isolation valves requires the containment isolation valves specified in Table 3.6-1 to be operable with the isolation times shown on the Table. The three inside containment isolation valves associated with containment penetration number 28, 2CHS-AOV200A,B, and C have been defined as having a maximum stroke time of 10 seconds. This request is to permit redefining the maximum stroke time for these valves to less than 60 seconds which is consistent with the outside containment isolation valve (2CHS-AOV204).

During the performance of quarterly slave relay testing we observed these valves as having a stroke time of approximately 35 seconds . - As a result, we declared the isolation valves inoperable-and isolated the containment penetration as required by action statement 3.6.3.1.b. A repeat test was conducted to verify that the stroke time exceeded 10 seconds when the actuation signal was initiated from the safeguards test cabinets. It was on this basis that the valves were declared inoperable. These valves are

-normally demonstrated operable by stroke testing from the control room benchboard and have historically stroked in less than 10 seconds. (

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4 B'env0r Vallcy P; wor StGticn, Unit No. 2 '

Docket No. 50-412, License No. NPF-73 Request for Temporary Waiver of Compliance '

Page 2 3

Since these valves have been declared inoperable and the penetration isolated, it has been necessary to operate the station utilizing the excess letdown flowpath. This configuration has in the past resulted in chemistry control problems and could potentially result in a plant shutdown.

As a result of our conference call on June 6, 1990, between members of my staff and NRC staff members, we received verbal approval of this request. Since that time, we have been completing short term commitments made during the conference call which are necessary to restore the normal letdown flowpath to service.

The long term corrective action is to submit a Technical Specification Change Request to revise the stroke time for these valves from 10 seconds to less than 60 seconds. This submittal will be forwarded to the NRC by June 22, 1990.

Therefore, this request for temporary waiver of compliance is ,

to allow Unit No. 2 to operate utilizing the normal letdown -

flowpath while not meeting the existing maximum stroke time identified on Technical Specification Table 3.6-1 for valves 2CHS-A0V200A,B, and C. This request is for the period of time it takes for the Technical Specifications to be revised approving a longer stroke time.

l Additional details supporting this request are located in Attachment 1 which addresses the current understanding of the level of detail required with respect to requesting a temporary waiver of compliance.

If you have any questions regarding this submittal, please call me or members of my staff. l Very truly yours, f

VGr J. D. ieber ka :.) ,

Vice President Nuclear Group Attachment cc: Mr. J. Beall, Sr. Resident Inspector Mr. T. T. Martin, NRC Region I Administrator Mr. A. W. DeAgazio, Project Manager Mr. R. Saunders (VEPCO) l

,. '. ATTACHMENT Evaluation Supporting a Temporary Waiver of Compliance

_(Ret Containment Isolation Valves)

1. Discuss the requirements for which a waiver is requested:

This waiver is addressing Tech Spec. LCO requirement 3.6.3.1

" Containment Isolation Valves"; Table 3.6-1 requires a 10 second maximum stroke time for RCS letdown isolation valves 2CHS-AOV-200A,B & C which serve as the inside containment isolation valves for containment penetration No. 28. We are unable to meet the 10 second stroke time for these valves and have entered the associated action statement (i.e. isolate the  ;

penetration -

closed 2CHS-A0V204, the outside isolation  !

valve). We request permission to operate with the letdown l path in service while not meeting the 10 second stroke time referenced above. We would administratively impose a less than 60 second stroke time (equivalent to 2CHS-AOV-204).

! 2. Discuss the circumstances surrounding the situation including the need for prompt action, and why the situation could not have been avoided:

These valves were stroked during performance of our quarterly l slave relay testing. During this test, we observed that the i valve stroke times were greater than 10 seconds. This had not  ;

been previously noted as this test does not time these i valves. Normally these valves are stroke time tested using the benchboard control switches. When tested using the benchboard control switches, these valves have consistently i stroked in less than 10 seconds. The difference in stroke I time between the two tests is a result of different circuit I configurations.  ;

Since these valves' stroke times were longer than 10 seconds during slave relay tests, they were declared inoperable and the penetration was isolated as required by Action statement 3.6.3.1.b.

We are currently operating utilizing the excess letdown flowpath since we have had to isolate all normal letdown flowpaths. Operating in this manner has previously resulted in- RCS chemistry control problems which may result in a plant j shutdown due to out of spec conditions (LCO 3.4.7 - hot standby in less than 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />). Therefore, a temporary waiver I of compliance permitting operation through the normal letdown ,

I flowpath is needed to avoid potential chemistry problems which  ;

l may result in a plant shutdown. 1 l

.. '. ATTACHMENT

2. (Continued)

Testing practices for obtaining valve stroke times had been considered. satisfactory due to repeated acceptable valve stroke times when tested from the benchboard control switch. This was the accepted. practice for demonstrating valve operability in meeting the 10 second maximum stroke time.

3. Discuss compensatory actions (if any):

on the basis that the 200A,B & C valves stroke in less than 60 seconds (which would be reverified upon approval of this request for temporary waiver of compliance), they are capable of satisfying their design requirements and we do not propose any compensatory actions other than defining the maximum stroke time as being less than 60 seconds. l

4. Provide a preliminary evaluation of the safety significance and potential consequences of the proposed request:

The outside isolation valve has a maximum stroke time of less than 60 seconds. If the inside valves were assumed to fail -

containment isolation would still be completed in less than 60 seconds. Revising the inside valves from 10 to less than 60 seconds will result in these valves having a stroke time equivalent to that of the outside containment isolation valves.

The valves are currently stroking at approximately 35 seconds which provides adequate margin to the less than 60 second maximum stroke time. Therefore, there is no increase in the offsite dose consequences of postulated accidents. The 10 second stroke time was implemented as a matter of prudency to assure the inside valve would close before the outside valve, thus preventing the penetration relief valve from lifting. This relief valve is located in containment and discharges to the pressurizer relief '

tank, therefore there would be no release to the environment.

There are no changes to the results of our safety _ analyses and ,

therefore no increase in the potential consequences of any postulated accident.

5. Discuss justification for the duration of the request:

Since the 200A, B and C valves have not stroked in 10 seconds or '

less when stroked during slave relay testing (expected transient response), the LCO cannot be met as written. This Temporary l Waiver of Compliance needs to remain in effect until a Tech Spec L change can be approved by the NRC changing the valve stroke time from 10 to less than 60 seconds.

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6. Provide a basis for the conclusion that the request does not involve a significant hazards consideration:

The change in valve stroke time remains consistent with that which I has been established for the outside valve and therefore does not affect the offsite dose consequences. There is no safety analysis ,

impact as a result of having both the inside and outside i containment letdown orifice isolation valves close in less than 60 I seconds, therefore, based on the above, this request does not  !

involve a significant hazards consideration.

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7. Provide a basis for the conclusion that the request does not involve irreversible environmental consequenccs:

The offsite dose analyses and accident analyses are not affected, therefore, this request does not involve irreversible environmental consequences.

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