ML19347F681
| ML19347F681 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/15/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19347F680 | List: |
| References | |
| NUDOCS 8105260011 | |
| Download: ML19347F681 (2) | |
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wasmNGTON,0. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMEN 0 MENT NO. 42 TO FACILITY OPERATING LICENSE NO. OPR-66 DUQUESNE LIGHT COMPANY OHIO EDISON COMPANY
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PENNSYLVANIA POWER C0KPANY BEAVER VALLEY POWER STATION, URIT NO. 1 DOCKET NO. 50-334 f
t Introduction
~~ In a letter dated March 13, 1981 Duquesne Light Company'(the licensee) requested changes to the Beaver Valley Power Station. Unit No.1 Techni-cal Specifications to allow a deviation be^ tween rod demand indicators and l
analog rod position indicators of 16 steps and to allow the individual rod position indication system inaccuracy to be increased to 16 steps.
12 steps generically for all These quantities are currently limited to operating Westinghouse reactors. The limits have caused an operational problem at Beaver Valley, and other reactors.. As a result of our verbal request, the licensee submitted detailed results of his analysis of 32 step rod misalignments in a eter dated April 8,1981. The analysis was performed for Cycle 2 opeution only, and the. licensee has proposed these Technical Specification changes for this cycle only.
_ Evaluation To investigate the potential effects of
- 32. step misalignments, the an6 '
lysis, performed by Westinghouse, used coarse mesh 3D-TURTLE calculations with 3D-TURTLE peaking factors coarse mesh corrected to discrete 20-TURTLE.
Calculations were made at various power levels with control rods position-ed'at the appropriate insertion limits. This is conservative for the full power case, where DNB would be of most concern and where the control rods are essentially always maintained s' bstantially further' withdrawn than the u
insertion limits. allow. Each rod in banks D and C (only these banks may l
be inserted during power operation) was misaligned by 32 steps and the resulting effects on peaking factors was determined. This included the radial peaking factor, F the enthalpy rise peaking factor, FaH, and the totalcorepeakingfacto8,F.
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The calculations were performed at 150 MWD /MTh because peaking is a max-
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mum at that burcup. At higher exposures, '.he x-y peaking factors tend to decrease because of burnup.
The calculations assumed equlibrium xenon except at zero power where no xenon was assumed.
The results of the analysis show that the peaking factor penalties result-ing from misalignments of 32 steps are small at significant power levels -
and are within the conservatism used in the Cycle 2 design of Beaver Valley Unit 1. llut penalties are larger at lower power, but DNS is not a concern at low power and the peaking factor limits are larger. Therefore, with a rod misalignment of 32 steps the predicted maximum peaking factors will be below the limits allowed by the Technical Specifications. We therefore conclude all of the proposed Technical Specification changes in the licen-see's March 13, 1981 letter do not result in a loss of safety margins and are acceptable for Cycle 2 operation. These changes allow a deviation of 16 steps between rod demand indicators and analeg rod indication sys-i tem inaccurancy to be increased to
- 16 steps.
1 Environmental Consideration We have determined that the amendment does not authorize a change in effluent types or total a= cunts nor an increase in pcwer level and will not result in any significant environmental impact. Having made this determination, we have further cencluded that the amendment involves an action which is insignificant frcm the standpoint of environmental impact and, pursuant to 10 CFR j51.5(d)(4), that an environmental impact sta:erent er negative declaration and environ-mental impact appraisal need cot be prepared in connection with the i
issuance of this amendment.
Corclusion We have concluded, based on the censiderations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previcusly considered l
and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reascnable 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 corplian:e with :he Ccmmissicn's i_
regulations and the issuance of this amendment will not u6 f.nimical to the common defense and security cr to the health and safety of the public.
Date:
liay 15,1981 l
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