ML19253A784
| ML19253A784 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 08/13/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19253A764 | List: |
| References | |
| NUDOCS 7909110317 | |
| Download: ML19253A784 (2) | |
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UNITED STATES
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 44 TO FACILITY OPERATING LICENSE NO. DPR-19 AMENDMENT NO. 39 TO FACILITY OPERATING LICENSE NO. DPR-25 AMENDMENT NO. 53 TO FACILITY OPERATING LICENSE NO. DPR-29 AMENDMENT NO. 50 TO FACILITY OPERATING LICENSE N0. DPR-30 COMMONWEALTH EDISON COMPANY DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 QUAD CITIES NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-237, 50-249, 50-254 AND 50-265 INTRODUCTION By letter dated May 16, 1977 and supplemented with additional information in a letter dated November 3,1978, Cormonwealth Edison Company (CEC 0) submitted an application to amend the Technical Specifications appended to Facility Operating Licenses DPR-19 and DPR-25 for Dresden Units Nos. 2 and 3, and DPR-29 and DPR-30 for Quad Cities Units Nos. I and 2.
The requested changes would modify the withdrawal schedules of the pressure vessel material surveillance capsules to be in accordance with 10 CFR 50, Appendix H.
DISCUSSION Neutron irradiation causes the pressure vessel reference nil ductility temperature, NDT, to increase with time, and the material fracture toughness properties to RTdecrease with time. These irradiated properties are used to establish cafe pressure-temperature operating limits for the life of the pressure vessel.
10 CFR Part 50, Appendix H, " Reactor Vessel Material Surveillance Program Require-ments," requires a material surveillance program to monitor changes in the fracture toughness properties of ferritic materials in the vessel beltline Under this region resulting from neutron irradiation and high temperatures.
program, fracture toughness test data are obtained from material specimens periodically withdrawn from the vessel. Appendix H gives withdrawal schedules based on the amount of radiation damage predicted at the end of the service lifetime of the vessel. The proposed schedules for the subject vessels are based on the three capsule program defined in Section II.C.3.a of 10 CFR 50, Appendix H.
The three capsule program can be used by vessels that have materials whose RTNDT values will not exceed 100 F at end of service life.
Based on the results of tests on materials that have been removed from the vessels thus far, we conclude that RTNDT will be less than 100 F at end of life for the materials in each of the four vessels. Therefore, the three capsule surveillance is considered acceptable.
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Several capsules have already been removed from the subject pressure vessels and tested. These capsules are not considered to be a part of the three capsule program, but are in addition to the three capsules and are in excess of the Code requirements.
From our review of the proposed surveillance capsule withdrawal schedule, we conclude that the schedule is in accordance with 10 CFR 50, Appendix H, and is therefore acceptable.
ENVIRON?1 ENTAL CONSIDERATIONS We have determined that these 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 these amendments involve an action which is insignificant from the standpoint of environmental impact, and pursuant to 10 CFR 651.5(d)(4) that an environmental impact statement, or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of these amendrents.
CONCLUSION We have concluded that:
(1) because the amendments do not involve a significant increase in the probability 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:
August 13, 1979 o ~ ~.o
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