ML15112A903
| ML15112A903 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 02/07/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML15112A902 | List: |
| References | |
| NUDOCS 8002200298 | |
| Download: ML15112A903 (3) | |
Text
jpj REGQ, UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 79 TO FACILITY OPERATING LICENSE NO. DPR-38 AMENDMENT NO. 79 TO FACILITY OPERATING LICENSE NO.
DPR-47 AMENDMENT NO. 76 TO FACILITY OPERATING LICENSE NO.
DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS NOS. 1, 2 AND 3 DOCKETS NOS. 50-269, 50-270 AND 50-287 Introduction By letter dated December 21, 1979, Duke Power Company (the licensee) proposed a modification to Technical Specification (TS) Table 4.2-1 of the Station's common TSs.
The submittal proposes to delay by three cycles the material surveillance insertion and withdrawal schedule for Oconee Unit No. 3 capsule OCIII-C in Crystal River Unit No. 3 (CR-3), the host reactor. The rescheduling is necessary to accommodate irradiation requirements for Three Mile Island Unit No. 1 (TMI-1) which also will use CR-3 as the host reactor for material surveillance capsules.
Background
Neutron irradiation causes the reactor vessel material reference nil ductility temperature, RTNDT, to increase with time and the material fracture toughness prop erties to decrease with time. These irradiation properties are used to establish pressure-temperature operating limits in accordance with Appendix G, 10 CFR Part 50.
10 CFR Part 50, Appendix H, "Reactor Vessel Material Surveillance Program Require ments", requires a material surveillance program for reactor vessels to monitor changes in the fracture toughness properties of ferritic materials in the vessel beltline region resulting from their exposure to neutron irradiation and the thermal environment. Under this program, fracture toughness test data are obtained from material specimens periodically withdrawn from the reactor vessel.
This Appendix gives withdrawal schedules based on the amount of radiation damage predicted at the end of the service lifetime of the vessel.
For the Oconee 3 reactor vessel, Appendix H requires a five capsule surveillance program. Oconee 3 has a six capsule surveillance program and thus exceeds the Appendix H requirement. On July 14, 1977, we authorized an exemption to the Appendix H requirements which allowed. Oconee surveillance specimens to be irradiated in a host facility of similar design, CR-3.
The exemption was authorized for a period of five years. At that time, guidance was given on the procedure to follow in the event an extension of the initial exemption period is required.
600223"
-2 Eval uation The Oconee 3 material surveillance program is part of the Babcock and Wilcox (B&W) integrated surveillance program. Our safety evaluation dated July 14, 1977, discusses this program and its application to the Oconee units. The B&W 177FA integrated reactor vessel surveillance program uses three host reactors (CR-3, Davis-Besse 1, and TMI-2) to irradiate the surveillance capsules for the other six 177 FA reactors (Oconee Units 1, 2 and 3, TMI-1, Arkansas Nuclear One Unit 1, and Rancho Seco).
Prior to the TMI-2 incident, TMI-2 had been serving as the host reactor for the TMI-1 capsules. In order that TMI-1 will have an ongoing reactor vessel surveillance program in the event of its restart, it is planned to irradiate a TMI-1 capsule in the CR-3 host reactor since TMI-2 is not available. The insertion of the TMI-1 capsule at CR-3 is scheduled to take place at the end of the current CR-3 fuel cycle (March 1980).
This will cause a delay in the irradiation of Oconee 3 capsule OCIII-C. The OCIII-C capsule was scheduled to be irradiated during the third through the seventh cycle of CR-3 and now it is proposed to be irradiated during the sixth through the tenth cycle.
One capsule, OCIII-A, has been withdrawn from the Ogonee reactor vessel and tested.
This capsule received a fluence of 7.39 x 1017 n/cm.
The present pressure temperature limits for Oconee 3 are applicable to four effective full power years (EFPY) and are based on the test results obtained on this capsule. Capsule OCIII-B is scheduled to be withdrawn from CR-3 at the end T; the urrent CR-3 cycle. The estimated fluence on this capsule will be 3.9 x 10 n/cm.
This fluence corres ponds to about 10 EFPY on the vessel at the one quarter from inside the reactor wall depth location. Thus, the test results on this capsule can be used to calculate the pressure-temperature limits for Oconee 3 to 10 EFPY. Capsule OCIII-D was placed in the CR-3 reactor vessel at the end of the first cycle.and is scheduled to be removed at the end of the ninth cycle. Test data on this capsule should be available before the Oconee 3 reactor vessel reaches 10 EFPY. If the data are needed before the end of Cycle 9 at CR-3 is reached, we will require that the capsule be, withdrawn at an earlier date. Therefore, we conclude that the delay in the irra diation schedule of the Oconee 3 capsule OCIII-C will have no adverse effect on the Oconee 3 material surveillance program and thus the proposed delay is acceptable.
We find that the proposed withdrawal schedule is in accordance with Appendix H, 10 CFR Part 50.
Environmental Consideration We have determined that the amendments 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, or negative declaration and environ mental impact appraisal need not be prepared in connection with the issuance of these amendments
Conclusion We have concluded, based on the considerations discussed above, that: (1) because the amendments do not involve a significant increase in the proba bility 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 Commission's regulations and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Dated: February 7, 1980