ML20045G241
| ML20045G241 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/28/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20045G239 | List: |
| References | |
| NUDOCS 9307130083 | |
| Download: ML20045G241 (3) | |
Text
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[pa arog#'o UNITED STATES l' '
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NUCLEAR REGULATORY COMMISSION g.
.t WASHINGTON, D. C. 20b55
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION t
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'T RELATED TO AMENDMENT NO.148 T0 i
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FACILITY OPERATING LICENSE NO. NPF-6 ENTERGY OPERATIONS. INC..
ARKANSAS NUCLEAR ONE. UNIT NO. 2 g
g DOCKET N0. 50-368 I
1.0 INTRODUCTION
3 By letter dated February 24, 1993, Entergy Operations, Inc. (the licensee) g submitted a request for a change to the Arkansas Nuclear One, Unit No. 2 (ANO-2) Technical Specifications (TSs).
The requested change would revise the flow test acceptance criteria for a single pump in the high pressure safety injection (HPSI) system from a minimum of 196 gallons-per-mineM (gpm) for each injection leg to a total flow of 570 gpm, excluding the F sghest injection leg's flow rate.
2.0 DISCUSSION l
The current TSs require that the HPSI system is demonstrated operable by performing a flow balance test, following modifications to the HPSI system that alter the system flow characteristics, to verify that each of the four injection legs has a flow rate greater than or equal to 196 gpm.
The proposed TSs would require that the HPSI system 4 demonstrated operable by performing a flow balance test, following modifications to the HPSI system that alter the system flow characteristics, to verify that the sum of the injection line flow rates, excluding the highest flow rate, is greater than or equal to 570 gpm.
The licensee states that by specifying a single value consistent with the limiting safety analysis, the change will remove the requirement for unnecessarily extending system testing to exactly balance the line flows.
In addition, the licensee proposes a change to the related Bases for the HPSI
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system ano also for the low pressure safety injection (LPSI) system.
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proposed change would indicate that the acceptance criteria specified in the i
surveillance requirements for HPS1 single pump flow, HPSI differential pressure and LPSI differential pressure does not account for instrument error.
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9307130083 930628 L
PDR ADOCK 05000368 P
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3.0 EVALVATION In the February 24, 1993, letter the licensee states that the accident analysis was revised in 1987 to assume a lower HPSI flow in support of a TS change request (resulting in Amendment No. 86, which lowered the required differential pressure developed by the HPSI pump from 1402.5 psid to 1360.4 psid), but no change in the HPSI injection flow was requested at that time.
Accordingly, the February 24, 1993, request is only providing a new flow balance test to verify a previously established lower HPSI flow requirement.
The licensee's letter says that in order to support current accident analysis, one of the four HPSI injaction cold legs is assumed to break, and 570 gpm is required to be delivered to the remaining three injection legs.
The licensee's proposed TS for the HPSI flow balance test requires that the sum of the flows in the three least flow lines is 570 gpm.
This ensures that, in the event of an accident, any one of the four injection legs can be assumed to break, and the total flow available from the remaining three legs for injection will either meet or exceed the needed flow of 570 gpm. Accordingly, the staff finds that the new flow balance test ensures that the HPSI injected flow rate is sufficient to meet licensing basis analysis assumptions, and is acceptable.
Regarding the proposed Bases change (that the acceptance criteria specified in the Surveillance Requirements for HPSI single pump flow, HPSI differential pressure, and LPSI differential pressure does not account for instrument error), the licensee has indicated (per telecon) that the statement is intended to clarify that the flow values given in TS 4.5.2.h (HPSI System -
Single Pump) are criteria of acceptance which do not include consideration of instrument error. The licensee indicated that, for these parameters which are critical to the safety analysis, ANO Design Engineering will perform instrument error calculations using the established ANO instrument error methodology. Based on the TS limits and the instrument error calculations, ANO Design Engineering will provide the appropriate acceptance criteria for AN0 Operations to include in the testing procedures. The staff finds that the proposed Bases change is acceptable because the established licensee instrument error methodology is included in its surveillance procedure to assure that the subject TS values are met.
4.0 STATE CONSULTATION
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.
5.0 fNVIRONMENTAL CONSIDERATION The amendment changes a requirement with respect to installation or use of a facility component lccated within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements.
The NRC staff has determined that the amendment involves no significant increase in the amounts, m
s 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 pro-posed finding that. the amendment involves no significant hazards consideration, and there has been no public comment on such finding (58 FR 16859).
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 environmental impact statement or environmental assessment need'be prepared in connection with the issuance of the amendment.
6.0 [0NCLUSION The Commission has concluded, based on the considerations oiscussed 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, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
T. Alexion, PDIV-1 Date: June 28, 1993 i