ML20039F903
| ML20039F903 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/23/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20039F902 | List: |
| References | |
| NUDOCS 8201140057 | |
| Download: ML20039F903 (3) | |
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o UNITED STATES y
, (, [ gg NUCLEAR REGULATORY COMMISSION I
R W A SHINGTON, D. C. 20555
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v SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 57 TO FACILITY OPEPATING LICENSE NO. D00.-25
_C_0MMONWEALTH EDISON COMPANY DRESDEN STATION, UNIT N0. 3 DOCKET NO. 50-249 1.0 Introduction By letter dated November 23, 1981 Comonwealth Edison Company (CECO) requested a technical specification change deleting that portion of Saecification 4.5.C.2 that requires that the automatic pressure relief subsystem be demonstrated operable daily upon declaring that the High Pressure Coolant Injection System inoperable.
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2.0 Background
Technical Specification 4.5.C.2 requires that:
"When it is determined that HPCI subsystem is inoperable, 4
I the LPCI subsystem, both core spray subsystems, the auto-matic pressure relief subsystem, and the motor operated isolation valves and shell side make-up system for the isolation condenser system shall be demonstrated to be operable immediately. The automatic pressure relief and motor operated isolation valves and shell side make-up system of the isolation ccndenser shall be demonstrated to be operable daily thereafter."
On November 22, 1981 as a result of an apparent faulty valve position indication, CECO personnel determined that the inboard High Pressure Coolant Injection (HPCI) steam supply isolation valve would not properly function. Upoa discovery of the nonfunctioning valve, CECO personnel closed the outboard isolation valve, declared the HPCI system inoperable, and complied with demonstrating the operability of other systems required by Technical Specification 4.6.C.2.
This specification requires, in part, testing the automatic pressure relief subsystem immediately, and daily therea f ter. The testing was completed successfully on November 22, 1981 and the operability of the automatic pressure relief subsystem was i
demonstrated by opening each automatic pressure relief valve, discharging steam to the torus, and reseating the valve.
Il 8201140057 911223 PDR ADOCK 05000249 P
2 Because there have been instances in the past in which relief valves have failed to reseat after opening and because the testing of these valves causes a significant thermal and mechanical shock to the reactor vessel and the suopression chamber (torus), Commonwealth Edison has proposed to delete that portion of the surveillance test that requires the daily testing of these automatic pressure relief valves on subsequent days that the HPCI system continues to be inoperable.
3.0 Evaluation We have reviewed CECO's request and have determined that Commonwealth Edison has adequately demonstrated the operability of the automatic pressure relief subsystem on November 22, 1981 and that there is a low probability that the system would become inoperable during the 7 remaining days that the plant is permitted to remain in operation with the HPCI declared inoperable. We have concluded that the increased probability of having one of the pressure relief valves stick open during the daily testing outweighs the benefits gained by the daily testing and that the safety of the facility will not be adversely affected by deleting the requirement to test these valves daily after the November 22, 1981 demonstration of their operability.
During the_same periodlof;p_ermi_tted. operation _(November 23 through November 29[
1981)_wi_th_the HPCI out of service, _ CECO will. be _reaui_ red to.have two.feedwater pumps operating at power levels in excess of 300 MWe and one feedwater oumo operating as required below 300 MWe and one additional pump operable.
The operation of these feed pumps provided added assurance that a high pressure make up capability is available for transients with offsite power available which do not cause isolation.
Similar relief was provided to CECO under similar conditions for continued Unit 2 operation in Amendment No. 65 to Provisional Operating License No. DPR-19 dated September 15, 1981.
4.0 Environmental Considerations We have determined that this amendnent does 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 this amendment involves 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 this amendment.
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3 5.0 Conclusion We have concluded, based on the considerations discussed above, that (1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does 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 w111 be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: _ December 23, 1981 l
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