ML20059D050
| ML20059D050 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 08/30/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20059C985 | List: |
| References | |
| NUDOCS 9009060066 | |
| Download: ML20059D050 (4) | |
Text
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UNITED STATES
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 117 'O FACILITY OPERATING LICENSE NO.
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MAINE YANKEE ATOMIC POWER COMPANY PAINE YANKEE ATOMIC POWEP. STATION DOCKET NO. 50-309 INTRODUCTION By letter dated June 19, 1990, the Maine Yankee Atomic Power Company (the licensee) requested an amendment to Facility Operating License No OPR-36 for the Maine Yankee Atomic Power Station. The proposed amendment would establish a specification for maximum reactor coolant primary-to-secondary leakage from any one steam generator of 0.15 gallons per minute, and deletes the current specification for total primary-to-secondary maximum leakage from all steam generators of 1.0 gallons per minute.
In addition, the proposed amendment would add to the baris that primary coolant leakage may be indicated and/or verified by sampling and analysis of steam generator steam samples.
DISCUSSION AND EVALUATION Prior to the shutdown of the Maine Yankee plant on April 7, 1990, for a refueling outage, the licensee detected increased activity levels in steam generators No. I and No. 3.
During the refueling outage, leak testing confirmed two tubes l
in steam generator No. 1.and one tube in steam generator No. 3 were leaking.
These tubes were spiked and plugged. Subsequent non-destructive testing results indicated an additional 23 tubes in steam generator No. I and 13 tubes
-in steam generator No. 3 required plugging.
In addition, testing indicated that four tubes in steam generator No. 2 required plugging. The licensee l_
plugged all appropriate steam generator tubes during the outage.
The licensee has initiated a program to positively identify the mechanism which caused the tube leakage. The program includes a historical materials and fabrication review by the steam generator vendor and a thorough laboratory analysis, crevice chemistry analyses and a Regulatory Guide 1.121 analysis of a tube specimen pulled from one of the steam generators. The licensee indicated I
that until the results of the analysis are completed and assessed, a more i
conservative technical spe-'fication limit for stenir generator leakage is l
appropriate.
At the present time, the Maine Yankee Technical S)ecification (TS) states that total leakage through all steam generator tubes sia11 not exceed 1.0 gallons-value (1.0 gpm))was to provide a reasonable value which conformed to tieThe inten per minute (gpm.
accepted industry standard with the core loaded with pre-pressurized fuel as set forth in the Standard Combustion Engineering Technical Specifications (NUREG-0212, Rev. 2). Decreasing the specification to a more conservative
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2-4 value of 0.15 gpm ser steam generator will continue to satisfy the original intent of the TS wille providing additional assurance that correctivt operator actions would be taken 3efore excessive steam generator tube leakage occurred.
The proposed change to the steam generator leakage TS is conservative in that it requires the licensee to take action to prevent excessive steam generator leakage at a lower indicated leakage rate than currently required.
Operational experience at Maine Yankee has shown that the proposed leakage limit can be implemented using existing leakage determination methods and is not expected to result in unnecessary reactor shutdowns. Accordingly, the proposed TS change involving steam generator leakage is acceptable.
In addition, the proposed amendment would add to the basis that primary coolant leakage may be indicated and/or identified by sampling and analysis of steam generator steam samples.
Sampling and analysis of various gases and effluents in order to identify accepted by the stafr, primary coolant leakage is a comon industry practice For example, the current Maine Yankee Technical Specifications ellow sampling and analysi?. of containment atmosphere, steam generator blowdown and air ejector effluent for radioactive and non-radioactive tracers for indication of reactor coolant system leakage. Accordingly, the proposed addition to the basis that primary coolant leakage may be indicated and/or identified by sampling and analysis of steam generator steam samples is acceptable.
ENVIRONMENTAL CONSIDERATION This amendment involves a change in a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and/or changes to the surveillance requir ments. *The staff has determined that the amendment involves no significant inaease in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is nc significant increase in individual or cumulative occupational radiation exposure. The Comission has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, this amendment meets the eligibility criteria fur cetegorical exclusion set forth in 10CFR51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
CONCLUSION The Comission made a proposed determination that the amendment involves no significant hazards consideration which was published in the Federal Register (55 FR 30302) on July ?S,1990, and consulted with the State of Maine. No public comments were received and the State of Maine did not have any comments.
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3 The staff has concluded, based on the considerations discussed above, that:
i (1) there is reasonable assurance that the health and safety of the public will i
not be rrdengered by operation in the croposed manner, and (2) such' activities will bi
acted in compliance with the Commission's regulations, and (3) the issuant 2 ;f.he amendment will not be inimical to the common defense and
- 1 security or to the health and safety of the public.
Principal Contributor: Eric J. !.eeds b
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Dated: AJgust 30, 1990 l
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. AMENDMENT NO.117 TO DPR MAINE YANKEE ATOMIC POWER STATION DATED ' August 30, 1990 DISTRIBUTION:
m ;pgg P NRC'PDR' Local PDR PDI-3 Reading S. Varge R. Wessman B. Clayton E. Leeds V.~ Nerses OGC - 15 B18 Dennis Hagan - MNBB 3206 E. Jordan - MNBB.3701 B. Grimes - 9 A2' G. Hill (4)-P1-37 Wanda Jones - MNBB 7103 J..Calvo - 11 F23 ACRS (10) - P-315
- GPA/PA - 2 G5 OC/LFMB - MNBB 11104 J. Johnson, Region I t
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