ML20197B727
| ML20197B727 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/05/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20197B725 | List: |
| References | |
| NUDOCS 9803110382 | |
| Download: ML20197B727 (2) | |
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WAsHINeToN, D.C. asset ce01 SAFETY EVALUATION BY THE OFFICE OF NUd FAR REACTOR REGULATION RELATED TO AMENDMENT NO.153TO FACILITY OPERATING LICENSE NO. DPR 28 VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKFF NUCLEAR POWER STATION DOCKET No. 50-271 1,0 INTRODUCTION By letter dated November 20,1997, the *crmont Yankee Nuclear Power Corporation (the licensee) submitted a request to amend M Vermont Yankee Nuclear Power Station (Vermont Yankee) Technical Specification (TS) 3.10 and its associated Bases. The proposed amendment would revise the TS and the Bases to eliminate the use of spare battery charger AB for meeting the TS because it is not a felly capab'e equivalent to either battery charger A or B.
2.0 EVALUATION Vermont Yankee's design basis for 125 volt de power requires: (1) that Vermont Yankee have two redundant 125 volt de power systems, each capable of independently supplying its required loads; and (2) that no single failure shall cause a loss of de power from both redundant de systems. battery chargers are a part of the 125 volt de power systems. The function of the battery chargers is to supply de pcwor during normal plant operations, and to maintain their associated 125 voit station batteries fully charged so that sufficient de power will be available :
during emergency conditions to operate all required equipment. To meet its design basis requirements, the licensee must have at least two independent battery chargers, one for each of the two redundant 125 voit de power systems.
The 125 volt de power systems for Vermont Yankee include two dedicated battery chargers, Charger A and Charger B, and a spare battery charger, Spara Charger AB, Chargers A and B are fully capable battery chargers that are independent of one another. Spare Charger AB can provide sufficient power to operate required equipment,- but it is not independent of Charger A because it is supported by the same emergency diesel generator, and is not fully capable because it is load shed during a loss of normal power and its feeder breaker, which must be locally reclosed, may not be accessible during certain postulated accident scenarios.
- Vermont Yankee TS 3.10.A.2., Battery Systems, presently allows the licensee to operate indefinitely with Charger A or B out-of-service provided Spare Charger AB is available and serving as a substitute. However, because Spare Charger AB is not a fully capable equivalent for either Charger A or Charger B, the licensee has proposed: (1) to modify TS 3.10.A.2. In order to preclude the possibility that Spare Charger AB might be used as a substitute for either Charger A or Charger B; and (2) to modify TS Bases 3.10 in order to clarify that Spare Charger AB is not a substitute for either Charger A or Charger B. Both of these proposed changes are intended to restrict a presently allowed plant operating configuration in order to ensure that Vermont Yankee will be operated in accordance with its design basis, 9803110382 990305 PDR ADOCK 05000271 P_
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2-The TS changes proposed by the licensee are consistent with both NRC requirements aru the Vermont Yankee design basis requirements. Because the proposed changes do not require any equipment modifications, there is no chance that implementation of these proposed changes will create a new or unanalyzed accident scenario.
The NRC staff has reviewed the licensees' proposed changes to restrict a presently allowed plant operating configuration. Based on this review, the staff finds that the changes are acceptable.
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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. 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 occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (62 FR 68319). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(g). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
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 wita the Commission's regu'ations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: V. Beaston, NRR Date: March 5, 1998 o