ML20056H243
| ML20056H243 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/24/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20056H241 | List: |
| References | |
| NUDOCS 9309090038 | |
| Download: ML20056H243 (2) | |
Text
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'o UNITED STATES 8'
NUCLEAR REGULATORY COMMISSION i
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..E W ASHINGTON, D. C. 20555
\\....+7 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION 4
RELATED TO AMENDMENT NO. 24 TO FACILITY OPERATING LICENSE NO. NPF-86 NORTH ATLANTIC ENERGY SERVICE CORPORATION j
SEABROOK STATION. UNIT NO. 1 DOCKET NO. 50-443 i
1.0 INTRODUCTION
By letter dated April 8,1993, North Atlantic Energy Service Corporation (North Atlantic) submitted an amendment request for a change to the Technical Specifications (TS). The proposed amendment would revise TS Figure 2.1-1, i
Reactor Core Safety Limit - Four Loops in Operation, to correct non-conservative curves.
North Atlantic identified that the curves were non-conservative as a result of a review of the Technical Specificat. ion values provided to North Atlantic by Westinghouse. North Atlantic determined, through a comparison of Westinghouse design documents to the actual curves on l
TS Figure 2.1-1, that the curves in the region of 80% to 110% of rated thermal power (RTP) do not accurately represent the loci of points upon which the curves are based.
2.0 EVALUATION The curves on TS Figure 2.1-1 show the loci of points of Rated Thermal Power, l
Reactor Coolant System (RCS) pressure, and average RCS temperature for which i
the minimum Departure from Nucleate Boiling Ratio (DNBR) is no less than 1.30, or the average enthalpy at the reactor vessel exit is equal to the enthalpy of l
saturated liquid. Operating the reactor plant within the safety limit ensures l
that the integrity of the fuel is not challenged.
The revision to the curves will accurately reflect the loci of points upon which the curves are based. The new curves will ensure that if the Reactor Protection System trip functions are exceeded, the evaluations made to verify if a safety limit has been exceeded will be accurate. Tha proposed change does not alter the design, function, or operation of the ;ilant. The proposed change does not affect any existing accident analyses, and does not introduce the possibility of any accidents or malfunctions not already analyzed.
Since the proposed change provides more conservative values for TS Figure 2.1-1, it does not reduce the margin of safety as defined in the bases of the Technical Specifications and preserves the margin originally established. The revision ensures that the design basis and the safety limits are accurately 9309090038 930824 PDR ADOCK 05000443 P
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reflected in the Technical Specifications and will allow proper verification that a minimum DNBR of not less than 1.30 is achieved.
Based on the above discussion, the NRC staff finds that the licensee's proposed change meets the regulations and is, therefore, acceptable.
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3.0 STATE CONSULTATION
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In accordance with the Commission's regulations, the New Hampshire and Massachusetts State officials were notified of the proposed issuance of the l
amendment. The State officials had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
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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 i
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 exposures. The Commission has previously issued a proposed finding that the i
amendment involves no significant hazards consider =+ ion, and there has been no public comment on such finding (58 FR 34082). Accoro:ngly, the amendment l
meets the eligibility criteria for a categorical exclusion set forth in 10 CFR j
51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement 1
or environmental assessment need be prepared in connection with the issuance of the amendment.
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5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, 1
j 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.
6.0 REFERENCES
1.
Feigenbaum, Ted. C. " License Amendment Request 93-03: Change to Technical Specification Figure 2.1-1, Reactor Core Safety Limit - Four Loops in Operation," Letter to USNRC from Senior Vice President and Chief Nuclear Officer, North Atlantic Energy Service Corporation, NYN-93056, April 8, 1993.
2.
"Seabrook Station Final Safety Analysis Report," Public Service Company of New Hampshire, New Hampshire Yankee Division.
3.
" Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants, LWR Edition," NUREG-0800, July, 1981.
Principal Contributor:
i N. Dudley Date: August 24, 1993 i
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