ML20055A871
| ML20055A871 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/25/1982 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20055A868 | List: |
| References | |
| NUDOCS 8207200079 | |
| Download: ML20055A871 (3) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR R 52 TO FACILITY OPERATING LICENSE NO. DPR-66 RELATED TO AMENDMENT NO.
DUQUESNE LIGHT COMPANY OHI0 EDISON COMPANY PENNSYLVANIA POWER COMPANY BEAVER VALLEY POWER STATION, UNIT N0. 1 DOCKET N0. 50-334 Introduction 16, 1982 a temporary Duquesne Light has requested by letter dated Junelicense amendme not be required to meet the normal accuracy requirements when the reactor This temporary coolant system is below the nominal operating temperature.
change to the Tecnnical Specifications would remain in eff report should be submitted by the licensee at the end of July,1982.
Background
11, 1982 that, in Mode 3 The licensee advised us by telephone og June with the reactor coolant system at 350 F, the analog rod po 60 steps below the fully withdrawn position (i.e.,170 steps versus 228 Normal operating temperature is about 550 F and the accuracy When steps).
specification for the analog position instruments is 112 steps.
normal plant operating temperatures were reached, the analog instruments On June 14, 1982 revised Technical all read with the required accuracy.
Specifications were issued, which require that the rod position instru-ments be within the i 12 step accuracy.
during the plant startup, problems with the reactor On June 16, 1982 coolant pumps forced the licensee to cooldown the plant in. order perform repairs.
12-step accuracy requirements.
tion again did not satisfy the 1 The analog rod position instrumentation at this plant has a history of difficulty in being able to satisfy the required performance specifications.
In November 1980, a set of interim Technical Specifications were approved for Operating Cycle 2.
0207200079 820625 PDR ADOCK 05000334 P
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. Evaluation When the licensee reported that the instruments were not within specifi-cations at cold temperatures, several questions were raised relative to the system behavior and the licensee's understanding of the problem.
The licensee assured us that the low indications were due simply to the low coolant temperature and that, when normal operating temperatures are reached, the instruments would be back within specifications. The plant safety committees had been advised of this behavior but had not previously reviewed the matter in detail because the analog rod position instruments were not required to be operable during operation in the low temperature modes.
We checked with former NRC resident inspectors experienced with previous startups at this plant.
Their recollection was that at cold temperatures the rod position instruments did read low but not by significant amounts -
significantly less than 60 steps. We checked with other NRC personnel experienced with plant startups at two similar PWRs. We got the same response.
At our request the licensee has agreed to study the problem with assistance from the equipment designer and meet with us to explain the behavior that was observed.
A tentative meeting date of July 13, 1982 was agreed to.
It is our position that a permanent waiver of the accuracy requirements should not be granted without a better technical understanding of the -
problem.
Knowledge of rod position is important during the shutdown modes because the position of the rods plays an important role in maintaining the core reactivity within the Technical Specification limit, that is, Keff less than 0.99.
A violation of this technical specification or an inadvertent criticality could occur if the rods were not inserted into the core as deeply as the plant operating staff assumed in establishing the critical boron concentration.
These problems can be avoided in one of the following ways.
1.
Provide accurate rod position indication for shutdown modes (the present Technical Specifications provide for this).
2.
Keep the rods in the fully inserted position until operating system temperatures are reached.
3.
For any rods which are not fully inserted (those partially or fully withdrawn) assume they are fully withdrawn when Keff and the critical boron concentration are being calculated.
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. During the effective period of this change, we require that item #3 above We have added this requirement to the Technical Specifi-be adhered to.
With a better understanding of cation change proposed by the licensee.
the instrument behavior and final resolution of the concerns we plan to return to relying upon accurate rod position indication as a long-term solution.
This plant has a history of difficulties in satisfying the performance We conclude requirements for the analog rod position instrumentation.
that a temporary waiver of the accuracy requirements is justified based on the compensatory measure being required relative to method of establish-ing Kef f.
Therefore, under the conditions described earlier, we approve the proposed waiver.
Environmental Consideration We have determined that the amendment does not authorize a change in effluent types er 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 amendment' involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 51.5(d)(4), that an environmental impact statement o-negative declaration and environ-mental impact appraisal need not be prepared in connection with the issuance of this amendment.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the Enendment does not involve a significant increase in the probability or consequences of an accident previously evaluated, does not create the possibility of an accident of a type different from any evaluated previously, and does not involve a significant reduction in a margin of safety, the amendment does not involve a significant l
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 this amendment will not be inimical to the common defense and security or to the health and safety of the public.
This safety evaluation was prepared by Mr. J.T. Beard, Engineering Section, and Mr. Gary Holahan, Systems Section, Operatir.g Reactors Assessment Branch, Division of Licensing.
Date: June 25,1982
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