ML20211H816
| ML20211H816 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 08/30/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20211H813 | List: |
| References | |
| NUDOCS 9909020178 | |
| Download: ML20211H816 (3) | |
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UNITED STATES l
j NUCLEAR REGULATORY COMMISSION o
WASHINGTON. D.C. 20555-WJC1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.174 TO FACILITY OPERATING LICENSE NO. DPR-28 VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKEE NUCLEAR POWER STATION DOCKET NO. 50-271
1.0 INTRODUCTION
By letter dated May 26,1999, the Vermont Yankee Nuclear Power Corporation (the licensee) submitted a request to amend the Vermont Yankee Nuclear Power Station Technical Specifications (TSs). The proposed amendment would revise the suppression pool water temperature surveillance TS requirements to specify monitoring the temperature every 5 minutes when performing testing that adds heat to the suppression pool. in addition, the amendment revises the TS requirement to check the suppression chamber water level and temperature from "once per shift" to " daily" and specifies that it is the average temperature that is checked.
2.0 EVALUATION The suppression poolis part of the primary containment system. The safety objective of the primary containment system, in conjunction with the core standby cooling systems, is to provide the capacity to limit the release of fission products to the plant environs in the event of a postulated loss-of-coolant accident so that offsite doses would be well below the values specified in 10 CFR Part 100. TS limits exist on the suppression pool temperature to ensure that the safety objective for the system is met. The TS limits on the suppression pool temperature are not changed by this amendment.
The licensee proposed changing TS 4.7.A.1 as follows:
Replace the first sentence "The suppression chamber water level and temperature shall be checked once per shift" with the new sentence " Verify daily that the suppression chamber water level and average temperature are within applicable limits."
Replace the third sentence "Whenever there is indication of relief valve operation which adds heat to the suppression pool, the pool temperature shall be continually monitored and also observed and logged every 5 minutes until the heat addition is terminated" with the new sentence " Verify suppression pool average temperature is within the applicable limits every 5 minutes when performing testing that adds heat to the suppression pool."
Also add paragraph breaks to separate individual requirements within the larger paragraph.
990902017e 990830 PDR ADOCK 05000271 p
l 2-The licensee also proposed TS Bases changes to make the Basis consistent with the proposed TS changes and more clearly specify the Basis for TS 4.7.A.1.
The suppression pool temperature is regularly monitored to ensure that the required limits ara met. The staff considers that use of the average temperature provides an adequate measure of the overall temperature of the suppression pool which ensures that the safety objective of the system can be met with the average temperature within limits. The staff considers daily verification that the suppression chamber water level and average temperature are within applicable limits to be acceptable since operating experience indicates that changes in temperature and level are minimal during normal operation unless performing testing that adds heat to the suppression pool. When performing testing that adds heat to the suppression pool more frequent monitoring is required. The staff considers that the 5-minute frequency proposed by the licensee is adequate based on the rates at which testing adds heat to the suppression pool and this frequency has been shown to be acceptable based on operating history. This increased frequency provides assurance that the allowable pool temperatures will not be exceeded, The frequencies for monitoring the suppression pool parameters are further justified in view of the other indications available in the control room, including alarms, to alert the operators to an abnormal suppression pool condition. The staff considers that the proposed changes will ensure that the suppression pool parameters will be adequately monitored. The proposed changes are, therefore, acceptable. In addition, the staff notes that the proposed changes are consistent with NUREG-1433, Rev.1, BWR Standard Technical Specifications.
The staff has no objection to the proposed Bases change associated with this amendment request.
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 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 (64 FR 40909). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmentalimpact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
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5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there e
is reasonable assurance that thn 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 common defense and security or to the health and safety of the public.
Principal Contributor: R. Croteau Date:
August 30, 1999 h
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