ML20199K246
| ML20199K246 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/20/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20199K242 | List: |
| References | |
| TAC-60542, NUDOCS 8607090093 | |
| Download: ML20199K246 (2) | |
Text
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g NUCLEAR REGULATORY COMMISSION 5
j WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0.126 TO FACILITY OPERATING LICENSE NO. DPR-57 GEORGIA POWER COMPANY 0GLETHORPE POWER CORPORATION MUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA EDWIN I. HATCH NUCLEAR PLANT, UNIT NO. 1 DOCKET N0. 50-321
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Introduction By letter dated January 7,1986, Georgia Power Company (GPC)' requested modifica-tion of the Hatch Unit 1 Technical Specifications (TSs) regarding the reactor vessel temperature and pressure limits for pressure tests, non-nuclear heatup/
cooldown, core critical operation and vessel stud tensioning. The proposed modifications reflect the decrease in materials fracture toughness as measured in the first surveillance capsule removed from Hatch Unit 1 after Fuel Cycle 10 in November, 1984. As a supporting document to the request, GPC enclosed General Electric Report NEDC-30997 dated October 1985.
Evaluation The capsule received a fluence of 2.4 x 10 n/cm2 (E> 1.0MeV) during 5.75 17 i
effective full power years (EFPY) irradiation, based on dosimetry wire measure-ments. Chemical analyses of reactor vessel materials iridicated the following:
Limiting plate: 0.17% Cu, 0.011% P Limiting weld:
0:28% Cu, 0.013% P Surveillance plate: 0.13% Cu, 0.010% P The shift in fracture toughness properties is a function of fluence and chemical analyses, particularly copper and phosphorus, and is calculated by a specific relationship prescribed in Regulatory Guide 1.99, Revision 1.
The shift in RT in the surveillance plate was 47 F, compared to the calculated shift of 17kusingthemethodologydescribedintheRegulatoryGuide. The shift in g
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RT in the weld metal was not measured because the fracture toughness properties ofbeunirradiatedweldwerenotavailable. Since the measured shift in the N
surveillance plate exceeded the predicted shift by a factor of 47/17, the coefficient representing the materials from the equation in Regulatory Guide 1.99, Revision 1, was increased by an amount equivalent to a factor of 2.76.
The proposed changes to the Technical Specification relating to the pressure-temperature limits for reactor vessel test and operation meet the requirements of 10 CFR 50, Appendices G and H, ASTM E-185, Regulatory Guide 1.99, Revision 1, and Appendix G,Section III of the ASME Code.
8607090093 860620
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PDR ADOCK 05000321 P
. We have reviewed Figure 3.6-1, " Pressure Versus Minimum Temperature for Pressure Tests, Such as Required by ASME Section XI," Figure 3.6-2, " Pressure Versus Minimum Temperature for Non-Nuclear Heatup/Cooldewn and Low Power Physics Tests," and Figure 3.6-3, " Pressure Versus Minimum Temperature for Core Critical Operation (Includes 40 F Margin Required by 10 CFR 50, Appendix G) of NEDC-30997. We conclude that these curves are conservative, preserve a margin of safety for Hatch Unit 1 reactor vessel test and opera-tion and are acceptable.
Although we find the proposed curves acceptable in this case, we do not agree that the methodology used in conducting the analysis would be applicable for general use.
Therefore, our acceptance of these specific limit curves does not constitute generic approval of the methodology.
The staff currently has issued draft Regulatory Guide 1.99, Revision 2, for public comment.
Following the review and issuance of the Regulatory Guide, review of and possible changes to the Technical Specifications may be required.
Environmental Consideration This amendment changes a requirement with respect to installation or use of a facil.ity 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, the 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 the 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 will~be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: June 20, 1986 Principal Contributor:
F. Litton l
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