ML20078L947
| ML20078L947 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 10/05/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20078L942 | List: |
| References | |
| TAC-48929, TAC-48930, NUDOCS 8310240125 | |
| Download: ML20078L947 (3) | |
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SAFETY EVALUATION BY THE OFFI'CE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N.'77 TO FACILITY OPERATING i I' CENSE NO. OPR-24 AND AMENDMENT NO. 81 TO FACILITY OPERATING LICENSE NO. OPR-27 WISCONSION ELECTRIC POWER COMPANY POINT BEACH NUCLEAR PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-266 AND 50-301 Background' By a letter dated September 30, 1982, Wisconsin Electric Power Company (licensee) requested a technical specification change which would permit storage of two thermally hot and highly radioactive spent fuel bundles near a divider wall in their spent fuel pool'. This will be done in order to accommodate the existing location of a poison surveillance sample.
Current technical specifications require that al spent fuel bundles placed adjacent to walls are to have been cooled for one year or more. A technical specification change was therefore requested in order to avoid physical changes which would involve exposure of workers to radiation.
Also included with the licensee's submittal were technical. specification changes intended to clarify limiting conditions for operation of the power operated relief valves (PORV) and PORY indication.
Discussion Spent Fuel Pool Surveillance Specimen The spent fuel pool divider wall is approximately 5 feet thick reinforced concrete and divides the spent fuel pool transversely. The two bundles in question will heat a very small portion of the wall above ambient temperature.
The radiating area from each fuel bundle is approximately 0.7 feet X 12 feet.
The licensee has had a study of the potential structural effects on the divider wall prepared by Bechtel Power Corporation.
In this study, it is calculated that the maximum temperature to be expected at a local section rif the divider wall is 190*F. This is within the limitations outlined in para;raph CC-3440 of the ASME Boiler and Pressure Vessel Code,Section III, Division 2.
- Also, it was calculated that the divider wall loads resulting from thermal effects would be insignificant (about 7% of total moment capacity).
8310240125 831005
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. The staff agrees that the potential structural effects of placement of two spent fuel bundles close to the divider wall, as described in the licensee.'s submittals, will be insignificant.
Further, the staff finds that the proposed technical specification change meets the applicable requirements of 10 CFR 50, Appendix A with regard to structures and is therefore structurally acceptable.
PORY Operability Current technical specifications require that if a PORV is inoperable the PORY shall be restored to operation within one hour or the associated block valve shall be shut. The PORV is defined as being operable if leakage past the valve doesn't exceed allowable primary system leakage and if the PORV has met its most recent channel functional test. Shutting the associated block valve removes the PORY from service by isolating it from the reactor coolant system.
In per'orming the channel functional test, a test signal is inserted into the circuitry to ensure that the pressure bistable operate to open the PORY at its setpoint pressure. Failure of the PORV to meet its channel functional test means that the PORV may not open or reseat at the required reactor coolant system pressure (approximately 2335 psig).
The licensee proposes 'n the case of a failure of the channel functional test to place the PORY control switch in the closed position rather than shut the PORY block valve. The purpose of this action is to reduce cycling of the PORY block valve. The licensee has stated that placin'g the PORV control switch in the closed position disables the automatic control circuitry for the PORY operation and the PORV would remain shut regardless of pressure signals sensed by the automatic control circuitry.
We have evaluated the licensee's proposed action and find that the proposed action provides an equivalent protection to that of shutting the block valve; that is, it ensures that spurious PORV openings would not result due to a failure of the channel functional test.
For the requested technical specifications on PORV and PORV block valve indication, the licensee has not provided sufficient justification to relax the allowable time from 48 to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> that indication may be inoperable.
While this relaxation may provide increased operational flexibility to the licensee, it also doubles the duration that PORV or PORV block valve indication may be inope'rable without providing sufficient compensatory measures. Other indications of PORV opening are available, i.e. pressure relief tank temperature and level, but these indications are not addressed in other technical specification limiting conditions for operation or surveillance requi rements.
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, The staff also disagrees that placing the PORY control switch in the closed position vice closing the PORY block valve is an adequate action upon loss
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cf PORV indication.
If indication is unavailable for the PORV, the staff feels that the valve should be removed from service by shutting the block valve. While, in the previously discussed technical specification change, the staff feels that placing the PORV control switch in the closed position performs equivalent protection to shutting the block valve (removing from service the pressure sensing circuitry that has failed its channel functional test), the staff feels that this same action will not provide equivalent protection for loss of PORV indication. The action statement for loss of PORY block valve indication requires shutting the block valve and removing power from it. Placing the PORY control switch in the closed position does not afford this same level of protection for the PORV.
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 environmental impact appraisal need not be prepared in connection with the issuance of the amendments.
Conclusion We have co'ncluded, 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 amendments will not be inimical to the common defense and security or to the health and safety of the public.
Date:
Principal contributor:
- T. Colburn A. Rothburg 6
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