ML20004B576
| ML20004B576 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 05/20/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20004B572 | List: |
| References | |
| NUDOCS 8105290058 | |
| Download: ML20004B576 (2) | |
Text
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UNITED STATES y yf
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NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 7.
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 69 T) LICENSE NO. OPR-36 MAINE YANKEE ATOMIC POWER COMPANY MAINE YANKEE ATOMIC POWER STATION DOCKET NO. 50-309 1.0 Introduction By telecopy dated May 5, 1981, Maine Yankee Atomic Power Company requested an emergency change to the Technical Specification appended to Facility Operating License No. DPR-36 for the Maine Yankee Atomic Power Station...
The proposed change involve::
Revising. Technical. Specification 3.19.to. allow the operability of reactor coolant loop No. 2 isolation.vlave breakers RC-M-21'and RC-M-22 during the period between day 5, 1981 and May 9, 1981.
Discussion and Evaluation
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Technical Specification 3.19.b).2. requires that the breakers for reactor coolant loop isolation valves be opened and made inoperable whenever the reactor is critical. This requirement precludes operation of the facility in a two loop mode. Two loop operation has not been covered in the licensee's accident analysis and therefore, is not permitted.
The request is a one time exception to 3.19;to provide the operator'the capability to isolate RCP No. 2 quickly from the control room.. This involves reactivating the breakers for loop No. 2 isolation valves from their normal position.. locked open,and. thermal overload links removed, whenever the.
reactoi is critical.
-ri The need for this capability is related to the degradation of two out of four of the RCP No. 2 seals. While the remaining seals provide redundant and adequate control of the primary coolant leakage, it is prudent to provide this additional ability to control. leakage by rapidly isolating loop two, after plant shutdown, in the event further degradation of the RCB No. 2 seals should occur. Consequently the licensee desirer to activate the capa-bility to isolate the RCP in loop 2 from the control room during the short period remaining until the refueling shutdown on May 9, 1981 during which time the seals will be repaired. The proposed emergency Technical Specification change will provide for rapid isolation of the loop by the reactor operator following a plant shutdown necessitated by degradation of the remaining 8105290OSE
2 seals. The proposed Technical Specification change does not constitute a significnat hazard to the health and safety of the public since the additional capability to control primary coolant leakage will provide additional prctection. The licensee estimates the isolation time improvement of from 30 minutes to 3 minutes.
In addition this change is requested on a one-time basis for limited time until shutdown on May 9,1981 for refueling during which time the RCP No. 2 seais will be repaired.-
Based on the improvement for providing leakage control and the one time only nature of this request, we find the proposed Technical Specification is acceptable and, therefore, it is approved.
3.0 Environmental Conclusion We have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, we have further concluded that the amendment involves an action which is insignificaat from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(4), that an environmental impact statement, or negative declaration and environ-mental impact appraisal need not be prepared in connection with the issuance of this amendment.
4.0 Conclusion l
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 involveta'significant hazards consideration, (2) there is l
reasonable assurance that the health and safety of the public will not
-- -M be endangered by operation in the proposed manner, and (3) such!
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activities will be conducted in compliance with the Commission's ~
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regulations and the issuance of this. amendment will not be inimical l
to the common defense and security or to the health ~and safety of...the
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public.
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Date: May 20, 1981
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