ML20246E634
| ML20246E634 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/07/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20246E630 | List: |
| References | |
| NUDOCS 8907120327 | |
| Download: ML20246E634 (3) | |
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UNITED STATES a
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NUCLEAR REGULATORY COMMISSION.
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WASHINGTON, D. C. 20666 -
,,,e SAFETY EVALUATION BY THE 0FFICE'0F NUCLEAR REACTOR REGULATION s
RELATED TO AMENDMENT NOS.118 ' AND 102 - TO FACILITYOPERATINdLICENSEN05.NPF-4ANDNPF-7 VIRGINI A ELECTRIC AND POER COMPANY OLD DOMINION ELECTRIC COOPERATIVE NORTH ANNA POWER STATION, UNITS N0. l' AND NO. 2 DOCKET NOS. 50-338 ' AND 50-339 INTRODUCTION' By-letter dated July 20, 1988, the Virginia Electric and Power Company (the.
licensee)i requested changes to the Technical Specifications (TS) for the North Anna Power Station Units No. 1 and No. 2 (NA-1&2). The proposed chan clarify. the current NA-1&2 TS regarding reactor coolant system (RCS) ges would leakage detection systems.
DISCUSSION-The changes would clarify the NA-182 TS 3.4.6.1 regarding reactor coolant system leakage detection systems and bring the TS into closer agreement with Regulatory Guide 1.45 and Revision 4 of the Westinghouse Standard Technical Specifications.
The specific changes are discussed below.
The Limiting Condition for Operation (LCO) would be revised to require that both the containment. atmosphere particulate and gaseous radioactivity monitoring system as well as the containment sump level and discharge flow measurenant system should be operable. The current LCO is difficult to understand because it appears to require only two of three. identified leakage detection t
methods (particulate radiation monitor'and gaseous radiation monitor or sump discharge flow asasurement) to be opera 5Te, whereas' the associated action can be interpreted to require three separate and independent methods to be operable.
Further, due to the design considerations, the two radiation monitors cannot be considered as two independent systems. Specifically, the two radiation monitors sham a common piping system, power supply and pumping arrangement, and therefore are not independent. The sump level monitor has been added as a l-required element of the leakage detection systems in accordance with Regulatory
. Guide 1.45 and the related NA-1&2 TS 3/4.4.6.2 regarding reactor coolant system leakage limits. Therefom, the proposed Technical Specification LCO continues to require two separate and independent leakage detection systems.
The action statement would also be modified to achieve consistency with the LCO.
If either of the two required leakage monitoring systems is inoperable, a compensatory leakage measurement using the reactor coolant system water inventory balance method would be specified. The compensatory leakage 1/O3D WOM F
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mes.surement using the inventory balance method replaces the current grab sample method which is employed if one of the radioactivity monitors is inoperable.
This new method is considered to be equivalent in terms of sensitivity to the grab sample method and the capability currently exists to perform an on-line calculation of leak rate using the plant process computer.
In addition, it is noted that the current specification does not require a compensatory leakage measurement if the containment sump discharge flow measurement system is inoperable, whereas the new specification would require a compensatory leakage measurement using. the mass balance method for this case as well. The actions to be taken if one of the two required leakage detection systems is inoperable for more than 30 days, or if both of the required systems are inoperable, are unchanged. Also, the surveillance requirements have been rewritten to require a periodic calibration of the containment sump level monitor.
The proposed TS for leakage detection systems are consistent with the recommendations of Regulatory Guide 1.45 and the TS bases.
The TS require two diverse and redundant means of continuously monitoring leakage, and provides for alternative means of performing a compensatory leakage measurement if one of the two required monitors is inoperable. Thus, Regulatory Guide 1.45, and specifically Regulatory Pcsition 9, which requires "the availability of various types of instruments to assure adequate coverage at all times," are satisfied.
EVALUATION
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The NA-182 TS, as proposed, continue to require two redundant and diverse means of continuously monitoring for reactor coolant system leakage.
In addition, an operability requirement for the containment surnp level monitor has been added to the LCO, and a requirement to implement a compensatory leakage measurement (i.e., inventory mass balance) if either or both of the sump leakage monitors are inoperable has been added to the action statement.
Also, the requirement to obtain and analyze appropriate containment grab samples if one of the radioactivity monitors is inoperable has been replaced with a requirement to perform a compensatory leakage measurement using the mass balance method. This method is considered equivalent to the grab sample method in terms of leakage detection sensitivity and therefore will provide the same level of protection as previously provided.
Finally, the proposed TS continue to require two redundant and diverse means of leakage monitoring as well as a compensatory leakage measurement each 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if either of the two required leakage monitoring systems is inoperable, and therefore the TS bases and the recommendations of Regulatory Guide 1.45 (Regulatory Position 9 regarding TS) continue to be satisfied.
Based on all of the above, the staf f finds the proposed changes to be acceptable.
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1 ENVIRONMENTAL CONSIDERATION These amendments involve a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes to surveillance requirements. The staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the' types, of any effluents that nay 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 amendments involve no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 551.22(c)(9).
Pursuant to 10 CFR 551.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendnents.
CONCLUSION We have 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 the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Date: July 7, 1989 A,
Principal Contributor:
Leon Engle i
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