ML20195G953
| ML20195G953 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/10/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20195G949 | List: |
| References | |
| NUDOCS 9906160233 | |
| Download: ML20195G953 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION
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WASHINGTON, D.C. toteHOO1
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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 197 To l
FACILITY OPERATING LICENSE NO. DPR-51 ENTERGY OP'ERATIONS. INC.
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ARKANSAS NUCLEAR ONE. UNIT NO.1 -
DOCKET NO. 50-313 l
1.0 INTRODUCTION
By letter dated April 30,1998, Entergy Operations, Inc. (the licensee), submitted a roquest for changes to the Arkansas Nuclear One, Unit No.1 (ANO-1), Technical Specifications (TSs).
. The requested changes were to revise the definition of quadrant power tilt (QPT) as defined in Gection 1.6.1 of the TSs. The revised definition of OPT emulates that contained in the i
improved Standard Technical Specifications (ISTS) for Babcock ana Wilcox plants, NUREG-1430, Revision 1,' dated April 1995.
The licensee stated that current ANO-1 procedures establish requirements for periodic 4
monitoring of QPT with both the incore and excore power range detectors. These procedures are based upon a literal reading _of the original TS definition and its implication that excore
. power range detectors are the preferred set of detectors for determining QPT However, industry practice has been to emphasize the use of incore detectors as the preferred measurement source for determining OPT. This preference for using the incore detectors is based upon the incore detectors having less uncertainty associated with their measured values.
2.0 EVALUATION The current TS 1.6.1, Quadrant Power Tilt, provides the following definition:
Quadrant power tilt is defined by the following equation and is expressed in percent.
Powerin any core quadrant j 100
_ Average power of all quadrants The power in any quadrant is determined from the power range channel displayed on the console for that quadrant. The average power is determined from an average of the outputs of the power range channels if one of the power range channels is out of service, the remaining three operable power range channels or the incore detectors will be used to determine the average power.
9906160233 990610 PDR ADOCK 05000313 P
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' - The quadrant power tilt limits as a function of power are stated in Specification 3.5.2.4.
The prooosed amendment would revise TS 1.6.1, Quadrant Power Tilt, as follows:
-Quadrant power tilt shallbe defined by the following equation and is expressed as a percentage.
Powerin any core quadrant j 100
_ Average power of all quadrants The proposed amendment emulates the ISTS by incorporating minor editorial changes (as l
noted above in italics) and by deleting the second pangraph in TS 1.6.1. This paragraph, l
which has not been revised since the original issuance of the ANO-1 TSs on May 21,1974, L
implies that excore power range detectors are to be used for monitoring QPT. The licensee l
stated that there are three independent reactor power measurement systems at ANO-1: the l.
primary incore detector system; the minimum incore detector system; and the excore detector system. The TS limiting conditions for operation associated with QPT and their bases do not spe.ly a preference for which detectors should be used for determining QPT. The licensee t
j stated that its review of both the design basis and the licensing basis for the OPT resulted in a L
conclusion that any one of the three detector systems could be used for measuring QPT. Any of the three detector systems provide' sufficient accuracy for the calculation of quadrant power tilt. The bases for ISTS 3.2.4 also allow any of the three detector systems to measure OPT (with implied preference for the incore detector system). Therefore, revising the current TS 1.6.1 to emulate ISTS would also eliminate any ambiguities associated with the original definition. The proposed amendment would not alter any safety analysis assumptions established and implemented by the TSs.
On the basis of its evaluation, the staff has determined that the proposed amendment is acceptable since it is consistent with the ISTS and any of the three reactor power measurement systems provide sufficient accuracy for the calculation of quadrant power tilt.
3.0 STATE CONSULTATION
t In accordance with the Commission's regulations, the Arkansas State official was notified of the proposed issuance of the amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC 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 Commission has previously issued a proposed finding that the amendment involves no 1significant hazards consideration and there has been no public comment on such finding (64 FR 6694, February 10,1999). ' Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no
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environmental impact statement or environmental assessment need be prepared in connection l
with the issuance of the amendment.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that (1) there is l
i reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such actMties will be conducted in compliance with the
- Commission's regulations, and (3) the issuance of the amendment will not be inimical to the j
common defense and security or to the health and safety of the public.
Principal Contributor: T. J. Kim J
i Date: June 10, 1999 o
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