ML20215N427

Safety Evaluation Supporting Amend 86 to License DPR-61

ML20215N427
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	10/30/1986
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20215N412	List: ML20215N411 ML20215N421 ML20215N427
References
NUDOCS 8611050392
Download: ML20215N427 (6)

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om UNITED STATES 8 g NUCLEAR REGULATORY COMMISSION r,  ; wAssincrow. o. c. 20sss .

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION I l

, SUPPORTING AMENDMENT N0. 86 TO FACILITY OPERATING LICENSE NO. DPR-61 CONNECTICUT YANKEE ATOMIC POWER COMPANY

! HADDAM NECK PLANT D0CKET N0. 50-213 l

1.0 INTRODUCTION

By letter dated August 29,. 1986, the Connecticut Yankee Atomic Power Company (CYAPC0) submitted a request for changes to the Haddam Neck Plant technical specifications.

The license amendment adds a second note of clarification to the definition of containment integrity in Technical Specification' 1.8.2.b to permit normally closed manual isolation valves SI-V-863 A, B, C, and D to be opened for periodic surveillances. In addition, the amendment permits valve SA-V-413 to be opened, as required, to assure .the operability of the containment continuous leak monitoring system and to allow for additional infrequent maintenance activites when containment integrity may be required.

Yalves SI-V-863 A, B, C, and D are in the high pressure safety injection ,

system. Periodic surveillance of these valves has been determined to be  !

important from a safety standpoint because they can be used to ensure l

that safety injection check valves (SI-CV-862, A, B, C, and U) are passing flow, there is proper boron concentration in the recirculation line, and any precipitated boron in the system is either flushed or redissolved into solution.

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ADOCK 05000213 PDR

Similarly, the licensee has determined that periodic operation of valve SA-V-413 would enhance operability of the containment continuous leak monitoring system and, as necessary, maintain the containment pressure within technical specification limits, by injecting outside air to maintain a slightly positive pressure.

In the August 29, 1986 application, CYAPC0 also requested a temporary waiver of compliance from the previously identified technical specifications, or the issuance of the revised technical specifications, under the exigency provisions of 10 CFR 50.92 in order to continue to perfom the necessary surveillance tests. On September 11, 1986, the NRC granted the temporary waiver of compliance until such time as.the ,

license amendment could be fomalized through the normal review and  !

public notice process.

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 September 24, 1986 (51 FR 33947). No comments or requests for hearing were received.

2.0 EVALUATION In their letter dated August 29, 1986, CYAPC0 has stated that valves l SI-V-863 A, B, C, and D cannot be operated remotely and, therefore, require local manipulation of the subject valves by an operator to perform surveillance tests. Each valve is opened and closed independently so l that during the surveillance tests only one valve is open at'any time.

Further, the licensee has stated that the operators performing the valve surveillance tests are in constant communication with the control room.

In the event of a containment isolation actuation signal, the operator manipulating the subject valves will be promptly notified and the open valve will be isolated within 60 seconds. Further, CYAPC0 has stated

I, that if valves SI-V-863 A, B, C, or D should fail to close for any reason, isolation valve SI-V 865 is inanediately dcwnstream and in close proximity to the subject valves and can be readily isolated to ensure containment integrity.

CYAPC0 performed a probabilistic risk assessment'concerning the unavailability of the subject HPSI valves. Using statistics on the reliability of check valves, a probabilistic assessment quantitatively confirms that increased surveillance testing would improve availability of the HPSI system. A probabilistic risk assessment sensitivity study was conducted to determine the change in core melt frequency if the ECCS check valves were not tested for a period of three (3) months.

The three (3) months interval was selected as a representative amendment approval interval. The evaluation concluded that the unavailability of I the HPSI system increased approximately 9% assuming a three (3) month test interval (compared to a monthly interval) and, the core melt  ;

frequency increased approximately 0.4% (over the core melt frequency I assuming monthly testing).

l In the August 29, 1986 application, CYAPC0 also requested a license amendment authorizing the opening of Service Air Valve SA-V-413. This would allow periodic testing to verify the operability of containment pressure instrumentation, which is required in detennining the operability of the containment continuous air leakage monitoring system. It would-also allow charging of the containment atmosphere, if required, to maintain administrative limits (again, to ensure the operability of the containment continuous air leakage monitoring system) which are bounded by technical specification limits for containment pr&ssure.

The license has also requested that opening of SA-V-413 be permitted for some infrequent maintenance activities. CYAPC0 has stated that this l valve'was previously used to supply air durin'g normal maintenance of reactor coolant pump seals. However, the licensee no longer performs

, the above maintenance with the reactor at power. Further discussions with CYAPC0 indigate that while no routine maintenance activity using this valve is required or foreseen, CYAPC0 believes that there could be instances preceding a startup or shutdown where this valve might be i opened to perfonn some preparatory work prior to containment entry or to complete some ongoing work while the reactor is above the temperature and pressure (200 F, 300 psig) requiring containment integrity according to the current plant technical specifications. - At r.o time will SA-V-413 be opened for maintenance related activities when the reactor is critical.

The staff has reviewed the information presented concerning operation of

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SA-V-413 as requested by the licensee. Valve SA-V-413 requires local manipulation by an operator during the routine maintenance or surveillance activities. The valve is opened and closed independently so that during the surveillance or maintenance operations only this isolation valve is open at any time. Further, the licensee has stated that the j operator performing the valve manipulation is in constant communication I with the control room. In the event of a containment isolation actuation signal, the operator manipulating the subject valve will be promptly notified and the valve can be isolated within 60 seconds.

Further discussions with CYAPC0 indicate that if valve SA-V-413 should fail to close for any reason isolation valves SA-V-410 and SA-V-411 are in close proximity to the subject valve and can be readily isolated by the local operator within 60 seconds to ensure containment integrity.

3.0 CONCLUSION

The staff has reviewed the material provided in the CYAPC0 letter dated

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August 29, 1986, and concludes that CYAPC0 has demonstrated that the routine monthly surveillance of valves SI-V-83 A, B, C, and D provide a net benefit to plant safety and that the monthly surveillance . tests should continue to be conducted. The staff also concludes that the j safety benefits of reducing the potential core melt frequency and l

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1 ensuring the operability of the HPSI system far outweighs the risk associated with, opening of the subject manual isolation valves under the circumstances described above.

Similarly, the staff concludes that the safety benefit associated with operability of the containment continuous air leakage monitoring system far outweighs the potential risk associated with operation of manual isolation valve SA-V-413.

We, therefore, conclude that the proposed license amendment is acceptable given the' licensee's commitment that (1) the valves (SI-V-863 A, B, C, D 4

and SA-V-413) are operated individually. (2) the operators manipulating the subject valves are in constant communication with the control room and (3) that upon a containment isolation signal, these operators are-immediately available to isolate the subject valves within 60 seconds.

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 area as defined in 10 CFR Part 20 and changes to the surveillance requirements. The staff has detennined that the amendment involves no significant increase in the amount::, and nc 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 Comission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuantto10CFR51.22(b)no environmental impact statement or environmental assessment need be i

prepared in connection with the 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

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of the public.

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

Dated: October 30, 1986 1

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