ML20202H008

Safety Evaluation Supporting Amend 77 to License DPR-61

ML20202H008
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	07/11/1986
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20202G994	List: ML20202G992 ML20202H000 ML20202H008
References
NUDOCS 8607160173
Download: ML20202H008 (4)

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ha a'e ug k, UNITED STATES

[ g NUCLEAR REGULATORY COMMISSION 5 j WASHINGTON, D. C. 20666

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 77 TO FACILITY OPERATING LICENSE NO. DPR-61 CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT DOCKET N0. 50-213

1.0 INTRODUCTION

o By letter dated May 14, 1986, the. Connecticut Yankee Atomic Power Company (CYAPC0) submitted a request for changes to the Haddam Neck Plant technical specifications.

The amendment permits the performance of monthly surveillance tests on valve SI-MOV-24 (on the line from the refueling water storage tank) and on valve RH-MOV-874 (on the residual heat removal system pump discharge). l The monthly surveillance tests on the subject valves are required to assure the operability of a high pressure recirculation cooling mode following a certain range of small line break loss-of-coolant accidents.

A Notice of Consideration of Issuance of Amendment to License and Proposed No Significant Hazards Consideration Determination and Opportunity for Hearing related to the requested action was published in the Federal ,

Register on June 4,1986(51FR20369). No comments or requests for hearing were received.

2.0 BACKGROUND

On March 25, 1986, CYAPC0 reported that the results of analyses of a small limited range of break sizes in one loop of reactor coolant system (RCS) for which safety injection flow during only the high pressure recirculation mode may be insufficient to provide adequate core cooling.

By letter dated April 10, 1986, CYAPC0 identified measures to provide 8607160173 860711 PDR ADOCK 05000213 P PDR

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adequate core cooling in the event of a small break loss-of-coolant accident (LOCA). CYAPCO's proposed imediate corrective action measures included the use of the high pressure safety injection (HPSI) system, the residual heat removal (RHR) system and certain operator actions. However, CYAPC0 noted that two valves, which are used during the HPSI recirculation mode, do not meet the prescribed single failure requirements.

By letter dated April 22, 1986, CYAPC0 requested a temporary exemption from the single failure criteria for two valves outside of containment that would be used under procedurally defined conditions to respond to small break LOCAs. As a part of the exemption, granted on April 28, 1986, CYAPC0 committed to impose a monthly surveillance and, cycling requirement for these valves to assure valve operability.

3.0 EVALUATION By letter dated May 14, 1986, CYAPC0 proposed changes to Technical Specifications 3.6.B and 4.3.B. which currently require MOV-24 and MOV-874 to be locked in their respective positions during plant modes 1 through 3.

To satisfy the commitment made in the exemption, CYAPC0 proposed that during Modes 1, 2 and 3 SI-MOV-24 will be manually cycled approximately 1 inch of stem travel to verify stem movement. During normal operation, RH-MOV-874 will be fully cycled by closing the electrical breaker in the Primary Auxiliary Building, and opening the valve from the full-closed to the full-open position and back to the full-closed position. During this surveillance test, a potential backflow pathway exists from the reactor waterstoragetank(RWST)tothecontainmentsump. To prevent this l possibility, prior to the opening of MOV-874, the licensee's surveillance I procedure requires verification of the leak integrity of several RHR l block and check valves. In addition, if MOV-874 were to be left open followingatestpartofthelowpressuresafetyinjection(LPSI) flow would be diverted back to the RWST. To aswre that the valves are returned to their proper position as part of the surveillance procedure, the licensee proposed that the final valve positions be independently i

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verified. In addition, valve positions of SI-MOV-24 and MOV-874 are verified once per shift. If necessary another manual block valve is available to be closed to maintain LPSI perfomance.

The staff has reviewed the licensee's proposed changes and concludes that the probability of a small break LOCA concurrent with the planned surveillance is extremely low and therefore, the proposed surveillance  ;

testing will have no measureable impact on high pressure safety injection '

availability. In addition, the licensee has provided an independent l

verification that the tests have not only been performed, but that the l l

subject valves have been returned to the proper position to assure the  :

The staff, operation of the high pressure safety injection system.

therefore, concludes that the proposed changes are acceptable until a permanent resolution to the problem of high pressure recirculation following small break LOCAs has been reviewed and approved.

4.0 ENVIRONMENTAL CONSIDERATION

This amendment involves a change to a requirement with respect to the installation or use of facility components located within the restricted l l

area as defined in 10 CFR Part 20 and changes to the survefilance l requirements. 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 offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission 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 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with +.he issuance of this amendment.

5.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) 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 public.

6.0 ACKNOWLEDGEMENT This Safety Evaluation has been prepared by F. Akstulewicz.

Dated: July 11, 1986 1 i

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