ML20029E076
| ML20029E076 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/09/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20029E073 | List: |
| References | |
| NUDOCS 9405160220 | |
| Download: ML20029E076 (2) | |
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UNITED STATES ly
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NUCLEAR REGULATORY COMMISSION (wg,#
WASWNGioN, O C. MSS @m SAFETY EVALVATION BY THE OFFICE OF NVCLEAR REACTOR REGV1ATION RELATED TO AMENDMENT NO. 31 TO FACILITY OPERATING LICENSE NO. NPF-86 NORTH ATLANTIC ENERGY SERVICE CORPORATION SEABROOK STATION. UNIT NO. 1 DOCKET N0. 50-443
1.0 INTRODUCTION
J By application dated September 13, 1993, North Atlantic Energy Service Corporation (North Atlantic /the licensee) proposed an amendment to the Appendix A Technical Specifications for the Seabrook Station, Unit 1 (Seabrook), The amendment would revise certain sensor errors stated in Table j
2.2-1, Reactor Trip System Instrumentation Trip Setpoints.
Specifically, the i
sensor errors specified for the Power Range Neutron Flux High Setpoint (Functional Unit 2.a.) and the Power Range Neutron Flux Low Setpoint (Functional Unit 2.b.) would be changed to incorporate the Nuclear Instrumentation System cabinet percent-full-power meter accuracy and readout error.
This change will allow the use of the cabinet percent-full-power meter during the daily comparison of the calorimetric to excore power.
2.0 EVALVATION The proposed TS change revises Limiting Safety System Settings, Section 2.2, Table 2.2-1, Reactor Trip System Instrumentation Trip Setpoints, to include an error term of 1.42% of span (as a bias) for the Power Range Neutron Flux High Setpoint and Low Setpoint.
North Atlantic has stated that the sensor errors listed in TS 2.2, Table 2.2-1 are consistent with the assumptions in the Westinghouse Protection System Setpoint Study.
This study assumes the protection system rack calibrations are performed using typical measuring and test equipment (M&TE).
Surveillance 4.3.1.1, Table 4.3-1, requires a daily comparison of the indicated power with the power level determined by the calorimetric. A digital voltmeter is connected to a test point to verify the power range neutron flux high and low setpoints.
The Westinghouse setpoint study incorporates the use of a digital voltmeter to perform the above surveillance; the accuracy and readout error of the full power meter was not included in the study.
In order to utilize the percent-full-power meter, North Atlantic proposes to revise the protection system setpoint study to incorporate the percent-full-power meter accuracy and readout error for the power range neutron flux high and low setpoints.
The original setpoint calculation assumed sensor calibration accuracy to be included within the calorimetric allowance process measurement accuracy term (PMA).
9405160220 940509 PDR ADOCK 05000443 P
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i North Atlantic re-calculated the channel statistical allowance incorporating the accuracy and readout error (as a bias) of the Neutron Instrumentation 1
System percent-full-power meter.
North Atlantic asserts that the resulting error continues to be bounded by the setpoint calculation total allowance.
The proposed change revises the sensor error values for Table 2.2-1, Power Range Neutron Flux High and Low Setpoints (Functional Units 2.a. and 2.b).
The present TS value for total allowance, Z, and the allowable value were found to be acceptable by North Atlantic. No change to the TS bases is required.
The staff has reviewed the proposed changes and finds the proposed TS change to use the Neutron Instrumentation System percent-full-power meter in performing the daily calorimetric to excore power comparison to be acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the New Hampshire and Massachusetts State officials were notified of the proposed issuance of the amendment.
The State officials 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 significant hazards consideration, and there has t'een no public comment on such finding (58 FR 52991).
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.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the i
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:
C. Doutt Date: May 9. 1994 1
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