ML20151Y660
| ML20151Y660 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 08/19/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20151Y650 | List: |
| References | |
| NUDOCS 8808260510 | |
| Download: ML20151Y660 (3) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION e
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WASHipeGTON. D. C 20068
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 20 TO FACILITY OPERATING LICENSE NO. OpR-21 NORTHEAST NUCLEAR ENERGY COMPANY, ET AL.
MILLSTONE NUCLEAR p0WER STATION, UNIT NO. 1 DOCKET NO. 50-245
1.0 INTRODUCTION
By letter dated September 29, 1987, the Northeast Nuclear Energy Company (NNECO or licensee) submitted a request for changes to the Millstone Nuclear Power Station Unit No. 1.
The amendment will revise the Technical Specifications to incorporate requirements for a halon system in the control room. This halon system is a fulfillment of a comitment made by the licensee and documented in a safety evaluation report issued on November 6, 1985 in support of an exemption to 10 CFR 50 Appendix R.
In addition, several upgrades / changes regarding the other plant gaseous fire suppression systems (not related to the control room halon system) havc been included in the proposed Technical Specification changes.
These include both editorial changes and specific reference to the equipment shutdown requirements associated with each gaseous suppression system actuation.
2.0 EVALUATION The new detection system consists of 28 smoke detectori located throughout the control room directly beneath the suspended ceiling. Upon receipt of a single zone smoke detection signal, the electric range and the lavatory fan HVT-10 automatically shut down and the alarm horn / strobe assemblies in the control room activate on slow pulse.
Receipt of a second zone smoke detection signal will then shut the damper in the supply duct to the cable vault, shut off fan HVT-11, close the damper in its supply duct work, shut off HVH-8, close the intake air damper, and activate strobe alams located above each entrance to the control room. A pre-discharge time delay of 60 seconds will enable manual deactivation of the system. Hence, the operators will have the opportunity to assess the need for discharge of the halon system, and, if the operators choose to abort the halon discharge, an abort switch located next to the halon control panel in the control room would serve this purpose. Should an operator wish to override the abort function, activating any one of three manual pull systems will discharge the halon after a five second delay.
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. The system has been designed to totally flood the control room, including the main control board, with a 7% (by volume) concentration of halon. At this concentration, it is ensured that a postulated fire in the main control board would be suppressed automatically, before significant damage to redundant safe shutdown component instrumentation could occur.
The intent of this license amendment request is to replace provisions for the old control room smoke detection system with the provisions for the new smoke detection system consisting of 28 smoke detectors and the associated new halon detection / suppression system. These provisions are being incorporated into the Millstone Unit No. 1 Technical Specifications to ensure that postulated fires in the control room could be adequately extinguished, as comitted to by the licensee and documented by the staff in a safety evaluation report issued November 6,1985 in support of an exemption to 10 CFR 50, Appendix R.
The staff review and acceptability of this fire detection / suppression system modification are documented in the November 6,1985 safety evaluation report.
The proposed changes to the Technical Specifications reflect the modifications to the control room fire detection / suppression system in the appropriate sections and are acceptable.
In addition, the licensee has included several changes / upgrades regarding other plant gaseous fire suppression systems (not related to the control room halon system) in the proposed Technical Specifications change. The changes are both editorial, for clarity, and to make specific reference to equipment shutdown requirements associated with each gaseous fire suppression system actuation.
These equipment shutdowns include:
a)
Gas turbine, along with its associated engine and gear reduction compartment dampers, b)
Fire pumphouse exhaust fan, and c)
Cable vault smoke exhaust fan and dampers.
The staff has reviewed these proposed changes to the Technical Specifications and find them acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements.
The staff has detemined that the amendment involves no significant increase in the 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 published a proposed finding that the amendment involves no significant hazards
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3-consideration and there has been no public conecnt on such finding, Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 551.22(c)(9).
Pursuant to 10 CTR 65' 22(b),
no environmental impact statement or environmental assessment itadd be prepared in connection with the issuance of the amendment.
4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that will not be endangered by operation in the proposed manner, and (2) public (1) there is reasonable assurance that the health and safety of the such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: August 19, 1988 Principal Contributor:
Michael L. Boyle 1
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