ML19249A583
| ML19249A583 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/27/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19249A579 | List: |
| References | |
| NUDOCS 7908230660 | |
| Download: ML19249A583 (2) | |
Text
eR RfCg
[
UNITED STATES y,p g
NUCLEAR REGULATORY COMMISSION 3 "'
I
. WASHINGTON, D. C. 20555 E
o 4,
,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR I'EACTOR REGULATION SUPPORTING AMENDMENT'NO. 50 TO PROVISIONAL OPERATING LICENSE NO. DPR-20 CONSUMERS POWER COMPANY PALISADES PLANT DOCKET NO. 50-255 Introduction By letter dated March 6,1979 and supplement dated May 17, 1979, Consumers Power Company (CPC) requested a change to the Technical Specifications for Palisades Plant to allow use of a new in-core detector system. -
Evaluation Palisades Plant uses an in-core neutron detector system with four vertical (axial) segments of detectors to measure core power distribution. The proposed change would allow use of a system which has five segments of detectors.
We have reviewed the enclosures submitted with the May 17, 1979 letter which addresses the reliability and accuracy of the method for determining spatically dependent axial power shapes using a limited number of fixed in-core detectors in an axial string.
In the examples considered in their submittal, the uncertainty using a five segment detector system or six segment system was substantially less thar the uncertainty using four segment detectors.
CPC has stated that the axial fitting algorithm described in their submittal will be incorporated in their in-core data reduction code, INCA. After this change is made, the accuracy indicated in the May 17 submittal will apply to Palisades.
CPC has not proposed decreasing the assumed uncertainties in the measured power distribution which result from the use of a five segment or six segment detector.
Therefore, with the change to five or six segment detectors the actual margins to safety limits will increase.
We find that the use of five segmert or six segment in-core detector system will improve the deter-mination of core power distribution and is, therefore, acceptable.
Based on the above, we conclude that the proposed change to Technical Specifi-cation 3.ll.a which would delete the word "four" and allow use of five detector system or a six detector system is acceptable.
We e also revising the Bases for this section of Technical Specifications to include the reference to the Fay 17, 1979 submittal and to state that a four axial segment system, five segment system or six segment system may be used.
790.828cm o mns
_g_
Environmental Considerations We have determined that the amendment does not authorize a change in effluent types, an increase in total amounts of effluents or an increase in power level and theref ore will not result in any significant environ-mental impact.
Having made this determination, we have concluded, 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.
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 endangere.d by operation in the proposed manner, and (3) such activities will be conducted in complisnce 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.
Date: July 27, 1979
,e J