ML20116N241
| ML20116N241 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 04/30/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20116N236 | List: |
| References | |
| NUDOCS 8505070077 | |
| Download: ML20116N241 (2) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION 3
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SAFETY-EVALUATION BY THE OFFICE OF NUCLEAR RE 4
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_RELATED TO AMEN 0 MENT NO. 65 TO FACILITY OPE ARKANSAS POWER & LIGHT COMPANY s
q ARKANSAS NUCLEAR ONE, UNIT-2 n
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DOCKET NO. 50-368 Introduction i
i By letter dated December 21, 1984, Arkansas Power and Li proposed a revision to the Technical Specifications (TS)ght Company (AP&L) i -
generator low water level reactor trip setpoint.
for steam t
The proposed amendment would revise the steam generator low water level j
trip setpoint specified in each of Table 2.2-1 and Table 3.3-4 of the TS L;
Specifically, the reactor protective instrument trip setpoint and the A
Engineered Safety Feature Actuation System (ESFAS) trip value for the steam generator low water level would be reduced from 46.7% to 23%.
,i Similarly, the allowable values in these tables would be reduced by the same magnitude from 45.811% to 22.111%.
Reducing these setpoints is j
certain planned operating maneuversexpected to reduce the probability generator water level at low power., such as manual control of steam 4
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_ Safety Evaluation AP&L, the licensee, indicated in the December 21, 1984, letter that the original safety analysis setpoint for the steam generator low water level 1
i trip was 23% of steam generator water level.
been corrected for equipment errors and measurement uncertainties.This ana licensee also stated that during the initial licensing review, questions The concerning asymmetric steam generator events were raised.
resolve this concern, it was necessary to modify the Core Protection In order to Calculator (CPC) software or to establish a new steam generator low water level trip setpoint high enough so that the reactor would trip in the
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event of an asynnetric steam generator transient (ASGT).
I chose to raise the steam generator low water level trip analysis setpoint The licensee l
from 23% to 46.7% rather than modifying the CPC software because of the time constraints of obtaining an operating license.
operating license, AP&L initiated a design change (CPC/LEC SoftwareAfter obtain Modification 28/3), and later incorporated it into the CPC software for Cycle 2 operation.
penalty based on reactor coolant system cold leg tem ratio (DNBR differences) caused by an ASGT, and replaced the pr
- !I; by the steam generator low level trip setpoint of 46.7%.
been reviewed and accepted by NRC in its Safety Evaluation dated JuneThis ch and incorporated into Arkansas Nuclear One Unit 2 Technical Specificati 19, 1981, Amendment No. 24.
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l 368 P
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- Based on our review of the licensee's submittal, we conclude that the proposed Technical Specification change reducing the steam generator low level trip to the original safety analysis setpoint of 23% is consistent with the previous NRC approved design change, and is acceptable.
Environmental Consideration This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Comission has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 951.22(c)(9).
Pursuant to 10 CFR 551.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
Conclusion We have 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, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not ce inimical to the comon defense and security or to the health and safety of the public.
l Date: April 30,1985 Principal Contributor:
V. Leung l
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