ML19260D538
| ML19260D538 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/17/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19260D534 | List: |
| References | |
| NUDOCS 8002110354 | |
| Download: ML19260D538 (2) | |
Text
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g 5,......p SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING LICENSE AMENDMENT NO. 65 TO PROVISIONAL OPERATING LICENSE N0. DPR-21 NORTHEAST NUCLEAR ENERGY COMPANY DOCKET NO. 50-245
1.0 INTRODUCTION
By letter dated January 9, 1980, Northeast Nuclear Energy Company (the licensee) proposed to amend the Technica' Specifications appended to License No. OPR-21 for the Millstone Nuclear Power Station, Unit No.
1.
This amendment would limit reactor power to a maximum of 40% of full power with the Isolation Condenser inoperable.
This operational restriction has been previously reviewed and approved by our Amendment No. 26 dated April 2,1976, but was removed when it was superseded by Amendment No. 29 dated August 6,1976.
The licensee has, therefore, proposed to replace the current specificatian, which allows operation at 100% power for 14 days when the Isolation Condenser is inoperable, by reinstating the previously superseded restriction which limited maximum power level to 40% of rated power.
2.0 EVALUATION We have reviewed the bases for our previous approval and have concluded that the bases continue to be valid, although a system modification has been made to one of the systems considered in our previous res'ew.
This modification consisted of rerouting the Control Rod Drive (CRD) return line so it injected into a main feedwater line rather than directly into the reactor vessel. We have discussed this modification with the licensee and have agreed that it does not significantly affect the makeup flow rate provided from the CRD system.
However, this rerouting could reduce the amount of water from this source since closure of the feedwater va.ve would also isolate that portion of the flow which passes through the CRD return 'ine.
In our original review of the 40% power restriction, we considered the availability of the CRD return line flow as a desirable source of makeup flow, but the ultimate protection was provided by (1) the Feedwater Coolant Injection (FWCI) system, and (2) the ability to manually depressurize the rer: tor and cooldown with low pressure energency core cooling systems.
The modification to the CRD return line has not affected these core protection features.
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_2-the reactor and/or the operator have sufficient time, capability and indication to respond to potential loss of feedwater events which are normally mitigated by the Isolation Condenser.
The results of our analyses indicate that with a complete loss of feedwater initiated from 40% rated power, the operator has at least 10 minutes to manually depressurize via the Automatic Pressure Relief System and initiate low pressure emergency core cooling without uncovering the core.
This is identical to the previous acceptance of the proposed modification.
Based on the above, we find the proposed amendment acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
S We have detennined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not resul' in any significant environmental impact.
Having made this determination, we have further concluded that the amendment involves an action which is insignificapt from the standpoint of environmental impact and pursuant to 10 CFR s51.5(d)(4) that an environmental impact statement or negative declaration and environmental impact ppraisal need not be prepared in connection with the issuance of thi. amendment.
4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the pu bl ic.
Date: January 17, 1980 f
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