ML20217G204

Safety Evaluation Supporting Amend 179 to License DPR-28

ML20217G204
Person / Time
Site:	Vermont Yankee, 05000221
Issue date:	10/13/1999
From:	NRC (Affiliation Not Assigned)
To:
References
NUDOCS 9910210225
Download: ML20217G204 (3)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.179TO FACILITY OPERATING LICENSE NO. DPR-28 VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKEE NUCLEAR POWER STATION  ;

i DOCKET NO. 50-271

1.0 INTRODUCTION

By letter dated August 18,1999, the Vermont Yankee Nuclear Power Corporation (the licensee) )

submitted a request to amend the Vermont Yankee Nuclear Power Station Technical l

Specifications (TSs). The proposed amendment would revise the TS definition of " Surveillance  !

Frequency" to incorporate provisions that apply upon the discovery of a missed Technical I Specification surveillance. The proposed change allows a delay in performing the actions of the associated limiting conditions for operation for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or up to the limit of the specified frequency, whichever is less, when it is discovered that a surveillance wss not performed within j its specified frequency.

2.0 EVALUATION NRC Generic Letter (GL) 87-09 provided guidance regarding problems that had been encountered with the general requirements on the applicability of limiting conditions for operation (LCO) and surveillance requirements in TSs. One such problem involved ,

unnecessary shutdowns when surveillance intervals are inadvertently exceeded. The solution l was to specify an acceptable time limit for completing a missed surveillance in certain circumstances and to clarify when a missed surveillance constitutes a violation of the operability l of an LCO. The licensee stated that the proposed change is consistent with standard industry  !

practices previously found acceptable to the NRC and contained in Standard TSs,

- NUREG-1433, and GL 87-09.

- The current TS definition for " Surveillance Frequency" states:

Surveillance Frequency - Unless otherwise stated in these specifications, periodic surveillance tests, checks, calibrations, and examinations shall be performed within the specified surveillance intervals. These intervals may be adjusted plus 25% The

operating cycle interval is considered to be 18 months and the tolerance stated above is applicable."

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.The licensee did not propose changing the existing definition, but proposed adding the following

.to the above definition:

- If it is discovered that a surveillance was not performed within its specified frequency,

dec!aring applicable Limiting Conditions for Operation (LCOs) not met may be delayed, from the time of discovery, up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or up to the limit of the specified frequency, 3 whichever is less. This delay period is permitted to allow performance of the  !

surveillance.

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If the surveillance is not performed within the delay period, applicable LCOs must I immediately be declared not met, and applicable LCOs must be entered.

When the surveillance is performed within the delay period and the surveillance is not met (i.e., acceptance criteria are not satisfied), applicable LCOs must immediately be declared not met, and applicable LCOs must be entered."

GL 87-09 states that it is overly conservative to assume that systems or components are inoperable when a surveillance has not been performed because the vast majority of  !

surveillances do in fact demonstrate that systems or components are operable. When a  !

surveillance is missed, it is primarily a question of operability that has not been verified by the performance of a surveillance requirement. Because the allowable outage time limits of some i action requirements do not provide an appropriate time for performing a missed surveillance before shutdown requirements apply, the TS should include a time limit that allows a delay of required actions to permit the performance of the missed surveillance based on consideration '

. of plant conditions, adequate planning, availability of personnel, the time required to perform the surveillance, and, of course the safety significance of the delay in completing the surveillance. The staff has concluded that 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is an acceptable time limit for completing a missed surveillance when the allowable outage times of the action requirements are less than this limit, or when time is needed to obtain a temporary waiver of the surveillance requirement.

Failure to comply with specified surveillance frequencies is expected to be an infrequent occurrence. Use of the delay period established by the proposed TS is a flexibility which is not  ;

intended to be used as an operational convenience to extend surveillance intervals. '

If a surveillance is not completed within the allowed delay period, then the equipment is considered inoperable, or the variable is considered outside the specified limits and the completion times of the required actions for_ the applicable LCO conditions begin immediately

.upon expiration of the delay period. If a surveillance is failed within the delay period, then the equipment is inoperable, or the variable is outside the specified limits and the completion times of the required actions for the applicable LCO conditions begin immediately upon the failure of the surveillance.

The' staff considers the proposed change to be acceptable because it is overly conservative to L assume that systems or components are inoperable when a surveillance has not been performed and the proposed delay period provides adequate time to complete a surveillance that has been missed. The staff notes that the proposed change is consistent with the standard TSs, NUREG-1433, and GL 87-09.

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3.0 STATE CONSULTATION

-In accordance with the Commission's regulations, the Vermont State official was notified of the proposed issuance of the amendment. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in amounts, and no significant change in the types of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative I occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no s!gnificant hazards consideration, and there has been no  !

public comment on such finding (64 FR 48867).' Accordingly, the amendment meets the i eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR

.51.22(b), no environmental impact statement or environmental assessment need be prepared i in connection with the issuance of the amendment.

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5.0 CONCLUSION

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i The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the i common defense and security or to the health and safety of the public.

Principal Contributor: R. Croteau

. Date: Octcber 13, 1999 l

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