ML13316B467
| ML13316B467 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/10/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML13316B465 | List: |
| References | |
| NUDOCS 9008150163 | |
| Download: ML13316B467 (2) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.133TO PROVISIONAL OPERATING LICENSE NO. DPR-13 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NO. 1 DOCKET NO. 50-206
1.0 INTRODUCTION
By letter dated October 30, 1987, Southern California Edison Company (SCE or the licensee) requested a change to the Technical'Specifications (TS) appended to Provisional Operating License No. DPR-13 for operation of San Onofre Nuclear Generating Station, Unit No. 1, located in San Diego County, California.
2.0 DISCUSSION In a letter dated October 30, 1987, the licensee submitted a request to revise Section 4.16, "INSERVICE INSPECTION OF STEAM GENERATOR TUBING," of Appendix A of the TS for San Onofre Nuclear Generating Station, Unit 1.
TS Section 4.16 requires periodic inspections of the steam generator tubing to ensure its integrity for continued operation. The specification de lineates the scope of each inspection, frequency of inspections, correct ive actions, and reporting requirements. Included in the scope of requirements is a section that describes special inspections in the areas of antivibration bar (AVB) intersections and dented tubes. These special inspections were instituted as a result of past inspection findings and to monitor these special areas in order to ensure that mitigative actions were effective.
By memorandum dated December 1, 1988, we deferred action on the above request pending resolution of the question of the condition of inservice sleeved tubes in San Onofre Unit 1 steam generators. This issue has since been resolved.
On January 30, 1989, the NRR staff requested additional information with respect to possible active corrosion mechanisms in the steam generators.
During September 1989, an NRR technical reviewer visited the San Onofre site and reviewed the secondary water chemistry program.
P-
-2 3.0 EVALUATION Denting of the San Onofre Unit 1 steam generators apparently occurred during a six-month period in 1971 and 1972 when the unit operated on all volatile chemistry. Since that time, it has been demonstrated that denting is not progressing. Because of improved secondary water chemistry, it is unlikely that denting will progress in the future. Therefore, the special requirement for gauging for indications of denting in A and C steam genera tors can be deleted.
Improved steam generator tubing eddy current testing and evaluation techni ques have allowed AVB wear indications to be quantified in the same manner as other defect indications (greater than 20 percent through wall).
Further, all previously non-quantifiable indications in each steam genera tor have been inspected, evaluated and assigned discrete defect depths.
On this basis, the special inspections for AVB wear indications can be deleted and all AVB wear indications that are greater than 20 percent through wall will be subject to inspection in accordance with TS 4.16, Section A.4.
We therefore conclude that the licensee's application for a steam generator TS change is acceptable.
4.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to a surveillance requirement. The staff has 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 pre viously issued a proposed finding that this amendment involves no signi ficant 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.
5.0 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, (2) such activities will 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 Contributors: H. Conrad S. Koscielny J. Tatum Dated:
August 10, 1990