ML20079Q477
| ML20079Q477 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 01/30/1984 |
| From: | Brooks W Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20079Q461 | List: |
| References | |
| NUDOCS 8402010179 | |
| Download: ML20079Q477 (3) | |
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NUCLEAR REGULATORY COMMISSION L
E WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 71 TO PROVISIONAL OPERATING LICENSE NO. DPR-16 GPU NUCLEAR CORPORATION AND JERSEY CENTRAL POWEP. & LIGHT COMPANY OYSTER CREEK NUCLEAR GENERATING STATION DOCKET NO. 50-219
1.0 INTRODUCTION
By letter dated September 2,1983 as supplemented December 2,1983, GPU Nuclear Corporation (GPU) requested an amendment to Provisional Operating License No. DPR-16 for the Oyster Creek Nuclear Generating Station. This amendment would authorize changes to the Neutron Monitoring System by adding a tenth range to the intermediate range monitors.
A Notice of Consideration of Issuance of Amendment and Proposed No Significant Hazards Consideration Determination and Opportunity for Hearing related to the requested action was published in the Federal Register on November 22, 1983 (48 FR 52814). A request for hearing and public comments were not received.
The supplemental information submitted by letter dated December 2,1983 merely clarifies the meaning of the Technical Specification change.
It provides rewording 6which explicitly states that the minimun recirculation flow of 39.65 x 10 lb/hr. intended for operation in IRM range 10 only, and not for all operation in the Startup Mode as originally subnitted. This was the actual intent of the original submittal, as seen from the analysis of the significant hazards consideration contained in the original application. Thus, the supplemental information did not change the scope of the staff's notice for opportunity for heari'19 2.0 DISCUSSION AND EVALUATION The proposed Technical Specification change would add a tenth range to the Intermediate P,ange Montior (IRM) to permit monitoring of core power up to approxinately 40 percent of full power.
A reactor scran trip would be provided at 38.4% of full power with a rod block at 35 percent of full power.
With the present IRM setpoint of 12 percent full power the switch fron STARTUP to RUN mode occurs at 10 percent of full power and a significant fraction of the LPRM channel responses are below the downsccle setpoints.
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, Frequently the conditions for operability of the APRM rod block circuitry cannot be net for certain rods and considerable ingenuity is required to continue the power increase.
Increasing the power at which the switch from STARTUP to RUN occurs would elininate this problem.
In order to support the increase in power for the switchover it is necessary to reanalyze the low pcwer rod withdrawal event. The APRM rod block is not in operation in the STARTUP mode and it is necessary to show that core thermal limits are not violated in its absence. GPU has performed the analysis under the assumption that the IRM rod block and scram do not function and that a rod withdrawal error results in the complete removal of the rod from the core.
Each rod in the pattern was withdrawn and the core flow required to prevent violation of fuel thermal limits was determined.
For Cycle 9 the maximum required value was found to be 23% of rated flow.
In order to bound future cycles this value would be increased to 65 percent to require this flow rate prior to entering, and while operating in Range 10 on the IRM.
Core-wide transients which are affected by this char.ge include the loss of feedwater heating and the improper startup of an idle recirculation loop.
However, the IRM scram at 38.4 percent of full power is lower than the APRM scram at minimun flow (52.7% of rated power at 30 percent flow).
Thus, the core would be adequately protected.
In addition, under administrative control, the feedwater heaters will not be turned on until the LPRM down-scales have been cleared and the APRM trip is operable. The staff concludes that fuel thermal limits will not be violated during operation and, therefore, the proposed change is acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
The staff has determined that the amendment 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 inpact. Having made this determination, the staff has further concluded that the amendment involves an action which is insignificant from the standpoint of environ-mental 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 this anendment'.
4.0 CONCLUSION
The staff has 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; ar,d (?) such activities will be conducted in compliance with the Conmission's regulations and tne issuance of this amendment will not be inimical to the connon defense and security or to the health and safety of the public.
, 5.0 ACKNOWI.EDGEMENT This evaluation was prepared by W. Brooks.
Dated: January 30, 1984
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