ML20141B985
| ML20141B985 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/13/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20141B981 | List: |
| References | |
| NUDOCS 9705160092 | |
| Download: ML20141B985 (3) | |
Text
s.
en ang y
t UNITED STATES NUCLEAR REGULATORY COMMISSION f
WASHINGTON, D.C. enmas nani SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO ANENDMENT NO. 5I TO FACILITY OPERATING LICENSE NO. NPF-86 NORTH ATLANTIC ENERGY SERVICE CORPORATION SEABROOK STATION. UNIT N M DOCKET NO. 50-443
1.0 INTRODUCTION
By application dated February 18, 1997, as supplemented by letter dated February 26, 1997, North Atlantic Energy Service Corporation (North.
Atlantic /the licensee) pro)osed an amendment to the Appendix A Technical Specifications (TSs) for tie Seabrook Station, Unit 1 (Seabrook) that tould c1ange the reactor core fuel assembly design features requirements contained in Technical Specification 5.3.1, fuel Assemb7fes. The change would tilow for limited substitution (fuel assembly reconstitution) of fuel rods in fuel assemblies with solid stainless steel or zirconium alloy filler rods.
Fuel assembly reconstitution allows the removal of individual fuel rods that are found to be damaged or that have the potential for cladding breach to be replaced by filler rods. Reconstitution permits these fuel assemblies to be reused without the radiological consequences that could result from operation with defective fuel rods.
Reconstituted fuel assemblies would be limited to those fuel designs that have been analyzed with applicable NRC-staff-approved codes.and methods and shown by tests or analyses to comply with all fuel safety design bases. The proposed change also would allow limited number of lead test assemblies that have not completed representative testing to be placed in nonlimiting core regions.
2.0 EVALUATION On July 31, 1992, the staff issued Supplement I to Generic Letter 90-02 (GL 90-02), " Alternative Requirements for Fuel Assemblies in the Design 4
Features Section of Technical Specifications," as a line-item improvement to accommodate limited fuel reconstitution based on NRC-approved generic topical reports. North Atlantic has proposed incorporating the generic letter guidance to provide flexibility to permit timely removal of fuel rods that are found to be leaking during a refueling outage or are determined to be the
{
probable sources of future leakage.
In Supplement I to GL 90-02, the staff stated:
1 9705160092 970513
+
PDR ADOCK 05000443 P
pg 4
.o
. "The staff considers an NRC-approved methodology to be any methodology that the NRC staff has explicitly approved in a written safety evaluation, or a plant-specific technical specification basis. That NRC-approved methodology must be used only for the purpose and the scope of application specified in the reviewed document as approved or modified in the NRC approval documentation.
In general, the 1
scope of application for generic methods is limited to fuel
?
configurations that are represented by fuel assembly test configurations used to validate an approved methodology."
The definition of an NRC-approved methodology assures that the proposed reconstitution has been adequately reviewed by the staff prior to implementation.
1
)
North Atlantic proposes to use filler rods of zirconium alloy or stainless steel to replace damaged or failed fuel rods for reconstituting the fuel assemblies. The North Atlantic specific safety analyses of reconstitution will be performed using NRC-approved methodology as described in the approved topical report WCAP-13060-P-A, " Westinghouse Fuel Assembly Reconstituted Evaluation Methodology," to demonstrate that operation with the reconstituted fuel assembly or assemblies is in compliance with all safety design bases.
In addition, North Atlantic should be aware of and conform to the several restrictions specified in the staff safety evaluation for using the reconstitution methodology described in WCAP-13060-P-A.
t North Atlantic also proposes the use of a limited number of lead test assemblies in non-limiting core positions,for the purpose of completing representative testing of a new fuel design. The staff has reviewed the use
)
i of reconstituted and lead test assemblies with regard to neutronic, mechanical, and themal-hydraulic safety and design requirements.
The staff concludes that the use of reconstituted and lead test assemblies are compatible with the existing core, and there are no safety concerns to the 1
operation of the Seabrook core.
3.0 TECHNICAL SPECIFICATION CHANGE 3.1 Design Features Section 5.3 Reactor Core, Fuel Assemblies North Atlantic has proposed to revise Section 5.3.1 of the Technical Specifications by replacing the existing specification in its entirety with the following new paragraph:
5.3.1 The reactor shall contain 193 fuel assemblies.
Each assembly shall consist of a matrix of cylindrical zircaloy clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (U0 )
2 as fuel material.
Limited substitutions of zirconium alloy or stainless 4
steel filler rods for fuel rods, in accordance with NRC-approved applications of fuel rod configurations, may be used.
Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff-approved codes and methods and shown by tests or
8 *
- i analyses to comply'with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions. Reload fuel shall be similar in physical design to the initial core loading and shall have a maximum enrichment of 5.0 weight percent U-235.
We have reviewed North Atlantic's proposed change to the Technical Specifications, and based on the staff's evaluation, we conclude that the proposed change is consistent with the requirements described in Supplement I to GL 90-02, and, therefore, is acceptable.
4.0 STATE CONSULTATION
h 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.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within ihe 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 emnulative oc upational radiation exposure. The Commission has previously issued a proposed finding that the amendment j
involves no significant hazards consideration, and there has been no public comment on such finding (62 FR 11496). 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 prepa) red in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, i
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
'I activities will be conducted in compliance with the Commission's regulations, et (3) the issuance of the amendment will not be inimical to the common defease and wcurity or to the health and safety of the public.
Principal Contributor:
S. L. Wu Date: May li, 1997