ML20002D603
| ML20002D603 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/23/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20002D599 | List: |
| References | |
| NUDOCS 8101210545 | |
| Download: ML20002D603 (3) | |
Text
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 33 TO FACILITY LICENSE NO. DPR-71 AND AMENDMENT N0. 54 TO FACILITY LICENSE NO. DPR-62 CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-325 AND 50-324 I.
INTRODUCTION By letter dated November 5,1980, Carolina Power & Light Company (licensee) requested an amendment to the Brunswick Unit Nos.1 and 2 Operating Licenses.
The proposed amendment would extend certain surveillance intervals to allow required testing to be perfonned during a scheduled Brunswick Unit 1 shut-down. The tests involved included 18-month surveillance normally performed during a refueling outage and a visual snubber inspection required on a 6-month interval.
II. BACKGROUND AND DISCUSSION The licensee's request for an extension of certain surveillance intervals was submitted as a result of extended outages of both Brunswick units during spring and. summer 1980 and the subsequent cancellation of the maintenance outage on Brunswick Unit 1 scheduled for September 1980.
4 The licensee has determined that the optimum alternative is to complete all of the required surveillance during a single Unit 1 outage scheduled in March 1981.
The request has been categorized into three areas:
1.
an extension of between 3% to 7% of the original interval for 18-month surveillance on engineered safety features equipment; 2.
an extension of about 17% of the original interval for inaccessible snuboer functional testing; and 3.
an extension of about 50% of the original interval for inaccessible snubber visual inspections.
The licensee supplied information to show that the systems involved have a sustained record of satisfactory performance during initial testing and subsequent to the end of the previous test intervals. The licensee has concluded that the requested delays will not affect the safe perfonnance of these systems.
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, III. EVALUATION The staff's requirement for 18-month surveillance intervals was set with the nominal refueling outage in mind. The refueling test frequency was intended to routinely demonstrate operability of systems over the service life of the plant. To judge the acceptability of extending the required surveillance intervals, we have taken into account the systems involved, operating history, and amount of extension requested.
The systems involved are: (1) inaccessible safety related snubbers, (2) Drywell-Torus Vaccum Breakers,(3) Main Condenser Low Vaccum, (4)
Unit 1 Diesel Generators, (5) Torus-Drywell CAC Temperature Monitoring, (6) LPCI subsysten, (7) Unit 2 Diesel Generator Load Test, (8) 125 Volt Battery, (9) Core Spray System, (10) Primary & Secondary Lcctainment System, (11) Standby Liquid Control System, and (12) CRD Accumulator Leak Detection Instrumentation. With the exception of item (7) above, all of the systems are associated with Unit 1.
However, all of the above tests must be conducted with Unit 1 shutdown, including item (7).
Only two of the above systems have experienced a previous test failure.
The 125 Volt Battery (LER l-79-09) had failed the capacity test in March 1979. A preventive maintenance program was implemented and the battery was tested satisfactorily in April 1979. The most recent inaccessible snubber visual inspection found one inoperable snubber (LER 1-80-34).
The two previous inspections found four and three inoperable snubbers, respectively. Thus the number of inoperable snubbers found is decreasing as the visual inspection intervals are lengthened.
On the basis of the systems involved and their operating history, a one-time extension in the surreillance intervals appears to be justifiable.
To judge the acceptability of the requested extension we pm #omed a calculation to assess the potential impact on system unavc bility (the fraction of reactor operating time during which a system in an undetected failedstate). We found that granting a 7% increase in 1 18-month surveillance interval could result in a 3% increase in system unavailability.
We found that granting a 17% increase in an 18-month surveillance interval for inaccessible snubbers could result in a 10% increase in the likelihood of having an inoperable snubber identified during the next functional test.
Similarly, granting a 50% increase in a 6-month surveillance interval could result in a 33% increase in likelihood of having an inoperable snubber found during the next visual inspection.
s
. The category (1) extension requests result in a minor increase in unavailability and are acceptable. The category (2) extension request 4
results in a slightly larger increase in unavailability, but is still judged to be acceptable for this one time. The category (3) extension request results in an unacceptable increase in unavailability and cannot be justified on a risk assessment Basis. We have discussed these conclusions witit the licensee in an effort to obtain further justification for the category (3) request. After some deliberation, the Itcensee agreed that adequate justification for extending the snubber visual inspection interval could not be developed in sufficient timt to support the request.
Therefore, we are denying the 6-month interval extension request. We have concluded that the 18-month intenal yttnsion remiests are acceptable for this one-time and therefore, they can fae granted.
IV. ENVIRONENTAL CONSIDERATION We have determined that the a:nenG.. ants do 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 amendments involve an action which is insignificant from the standpoint of environmental impact and pursuant to 10 CFR 551.5(d)(4) that an environmental impact statement, negative declaration, or environmental impact appraisal need not be prepared in connection with the issuance of the amendments.
V.
CONCLUSION We have concluded, based on the considerations discussed above, that:
(1) because the amendments do not involve a significant increase in the prtbability or consequences of accidents previously considered and do not involve a significant decrease in a safety margin, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Consnission's regulations and the issuance of the amendments will not be inimical to the coninon defense and security or to the health and safety of the public.
Dated: December 23, 1980
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