ML20247F030
| ML20247F030 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 09/07/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20247F006 | List: |
| References | |
| NUDOCS 8909180067 | |
| Download: ML20247F030 (2) | |
Text
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o UNITED STATES g
E NUCLEAR REGULATORY COMMISSION o
3 I
WASHINGTON, D. C. 20855
- f SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.115 TO FACILITY OPERATING LICENSE NO. DPR-28 VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKEE NUCLEAR POWER STATIO,N_
DOCKET NO. 50-271
1.0 INTRODUCTION
By letter dated February 2,1989, Vermont Yankee Nuclear Power Corporation requested an amendment to Appendix A, Technical Specification (TS), of Facility Operating License No. DPR-28 regarding primary containment '
isolation valve testing in the Head Spray Subsystem of the Residual Heat Removal (RHR) system at the Vermont Yankee Plant. The licensee stated that the Reactor Yessel Head Spray process line was permanently disconnected and isolated from the reactor vessel inside the primary containment during December 1981, and, therefore, they requested deletion of the TS surveillance requirement for the isolation valves in the above disconnected process-line.
Proposed changes Vermont Yankee proposed to modify the surveillance requirements in Technical Specifications, Table 4.7.2.b, pertaining to primary containment isolation valves not subject to Type C leakage tests. The proposed change deletes valves RHR-32, RHR-33 and Reactor Head Spray Valve 10-29 from Table 4.7.2.b which requires surveillance tests of stroke time on Valves RHR-32 and RHR-33.
Review Criteria / Requirements NUREG-0800 Standard Review Plan Section 6.2.4.
2.0 DISCUSSION AND EVALUATION The' licensee states that the Reactor Vessel Head Spray System, which is a subsystem of the Residual Heat Removal System, was deactivated to reduce the number of reactor vessel penetrations and because the system was identified as being susceptible to intergranular stress corrosion cracking.
The Reactor Vessel Head Spray process line was permanently disconnected and isolated from the reactor vessel inside the primary containment. A blind flange was installed on this line inside the containment. The valves RHR-32 and RHR-33 are administrative 1y controlled, maintained, and monitored to be in the closed position at all times.
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i Further, the control switches for these valves have been recently removed L
which ensures the valves cannot be opened during operation. As'long as these valves remain installed, position indication will be provided in the Control Room to allow remote verification that the valves are i
closed. The licensee intends to permanently remove these valves and cap this penetration at some future time. The removal of the Reactor Head l
Spray check valve (10-29) from Table 4.7.2.b is also necessary to ensure i
consistency in the Technical. Specification table in recognizing that the Reactor Head Spray function has been disconnected.
The staff was concerned that the blind flange was bolted and not sealed; however, the RHR-32 and RHR-33 valves on this line. located on either side of the containment boundary are still containment isolation valves. Even though the line is not in use and the valves are in the closed position, the flange and the valves are still possible radioactivity leakage paths, and should be periodically leakrate tested.
The staff agrees to the licensee's proposed deletion of the valves RHR-32 and RHR-33 from TS Table 4.7.2.b to eliminate the unnecessary) surveillance of valve stroke time, and to deletion of the check valve (10-29 from TS Table 4.7.2.b to ensure TS consistency.
In a discussion with the licensee, they stated that these valves are listed with all the other containment isolation valves, in a separate Containment Leakrate Testing Program, and are being leakrate tested periodically.
Based on the above evaluation the staff concludes the proposed change is acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change in the surveillance requirements of facility components located within the restricted area, as defined in 10 CFR Part 20. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released off site, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Comission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable e.:surance 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 this amendment will not be inimical to the common defense and security or to the health and safety of the public.
PRINCIPAL CONTRIBUTOR: Angela T. Chu DATE:
September 7, 1989
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