ML16341E277
| ML16341E277 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 06/12/1987 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML16341E276 | List: |
| References | |
| TAC-65297, NUDOCS 8706180219 | |
| Download: ML16341E277 (6) | |
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ID UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGLILATION RELATED TO AMENDMENT NO. 12 TO FACILITY OPERATING LICENSE NO. DPR-82 PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON NUCLEAR POWER PLANT UNIT NO.
2 DOCKET NO. 50-323 INTRODUCTION By letter dated March 17, 1987, as supplemented May 6, 1987, Pacific Gas and Electric Company (PG&E or the licensee) reauested an amendment to Facility Operating License No. DPR-82 for the Diablo Canyon Nuclear Power Plant, Unit No. 2.
The proposed amendment would allow an extension of time for the submittal of a steam generator tube rupture (SGTR) analysis.
The extension would allow the analysis to be submitted by April 1988, approximately ten months later than currently required.
EVALUATION In Facility Operating License No.
DPR-82 issued on August 26, 1985, license condition 2.C.(9) stated that:
"Prior to restart following the first refueling outage, PG&E shall submit for NRC review and approval an analysis which demonstrates that the steam generator tube rupture (SGTR) analysis presented in the FSAR is the most severe case with respect to the release of fission products and calculated doses.
Consistent with the analytical assumptions, PG&E shall propose all necessary changes to the Technical Specifications (Appendix A) to this license."
The proposed amendment would extend the time for the submittal from approximately June 15, 1987 (the approximate date for startup from the first refueling outage) to April 1988, an extension of about ten months.
As a result of a SGTR event at Ginna, the staff raised questions about the assumptions used in the SGTR analysis presented in the Diablo Canyon and other Westinghouse-designed FSARs, including the capability of plant operators to terminate the event (terminate break flow) in 30 minutes, and whether systems and components credited to mitigate the accident consequences are safety grade.
Accordingly, all operating licenses issued for Westinghouse-designed reactors in the 1985 time frame and later contained a
condition similar to the one in the Diablo Canyon Unit 2 license.
When the license was issued on August 26, 1985, it was felt that the time for submittal of the analysis would be adequate since the startup from the first refueling would be about June
- 1987, a period of almost two years.
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In response to the staff concerns expressed
- above, a subgroup of utilities in the Westinghouse Owners Group (WOG), of which PG&E is a member, was formed to address the licensing issues associated with the SGTR event on a generic basis.
The subgroup submitted:
(1) WCAP-10698, "SGTR Analysis Methodology.
to Determine Margin to Steam Generator Overfill" in December 1984; (2)
Supplement 1 to WCAP-10698, "Evaluation of Offsite Radiation Doses for SGTR Accident" in May 1985; and (3) WCAP-11002, "Evaluation of Steam Generator Overfill due to SGTR Accident" in February 1986.
The NRC staff has now issued its safety evaluation report (SER) on this matter (March 30, 1987) and the SER has been distributed to all the members of the subgroup (April 1987).
The SER on the generic analysis was issued beyond the time possible for PG8E and others to submit a plant-specific analysis based on the generic reports.
PGEE plans to utilize the results of the Subgroup program for its plant-specific analysis and estimates that one year would be needed to do so.
PG8E further states that the Subgroup's generic evaluation shows that (1) operators can respond to a design-basis SGTR and perform required actions to locate and terminate primary-to-secondary leakage before steam generator overfill occurs, and (2) offsite radiation doses for a design-basis SGTR will be less than the allowable limits.
The staff concludes that there is reasonable assurance that the SGTR analysis can be delayed as proposed without endangering the health and safety of the public because the probability of a design-basis SGTR during the requested period (10 months beyond the first fuel cycle) is low and in the event of the design-basis SGTR, the offsite consequences can be expected to be within 10 CFR 100 guidelines.
This extension of time is similar to that granted other facilities, e. g.
Catawba Unit 1, Amendment No.
12, September 18, 1986.
Based on the foregoing, the NRC staff concludes that the.proposed extension of time for submittal of a plant-specific SGTR analysis is r'easonable, does not adversely affect plant safety and should be granted.
CONTACT WITH STATE OFFICIAL The NRC staff has advised the Chief of the Radiological Health Branch, State Department of Health Services, State of California, of the proposed determination of no significant hazards consideration.
No comments were received.
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-3" ENVIRONMENTAL CONSIDERATION This amendment involves changes in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
We have 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 the 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 the issuance of this amendment.
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 wi 11 be conducted in compliance with the Commission's regulations and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
C. Trammell Dated:
June 12, 1987
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