ML20239A439
| ML20239A439 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 09/11/1987 |
| From: | Zimmerman S CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NLS-87-183, NUDOCS 8709170344 | |
| Download: ML20239A439 (5) | |
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Carolina Power & Light Company SEP 111987 SERIAL: NLS-87-183 10CFR50.90 87TSB07 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 SUPPLEMENT TO REQUEST FOR LIC NSE AMENDMENT FUEL ASSEMBLY / FUEL STORAGE TE iNICAL SPECIFICATIONS Gentlemen:
Conference calls were held on August 17, August 31, September 1, September 2, and September 9,1987, between Carolina Power & Light Company (CP&L) and the NRC concerning the Brunswick Steam Electric Plant Technical Specification amendment request relating to fuel assembly / fuel storage. The NRC acked CP&L to address several items in its significant hazards analysis to help expedite review of the request. A revised significant hazards analysis is provided in the enclosure to this submittal.
If there are any questions concerning this submittal, please ccntact Mr. Stephen D. Floyd a1 (919) 836-690 l.
Yoors very truly, f?
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.Zim erman anager Nuclear Licensing Section BAT /ppo (5272 BAT) asures l
us Mr. Dayne H. Brown Dr. J. Nelson Grace Mr. W. H. Ruland Mr. E. Sylvester
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REVISED SIGNIFICANT HAZARD ANALYSIS l
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SIGNIFICANT HAZARDS ANALYSIS The Commission has provided standards in 10CFR50.92(c) for determining whether a significant hazards consideration exists. A proposed amendment to an operating license l
for a facility involves no significant hazards consideration if operation of the facility in -
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accordance with the proposed amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated,(2) create the i
possibility of a new or different kind of accident from any accident previously evaluated, or (3) involve a significant reduction in a margin of safety. Carolina Power & Light Company has reviewed this request and determined that:
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Specification 5.3.1 was revised to allow for the use of GE 8r8EB fuel (CE8).
The NRC has separately approved GE's high exposure fuel design via a letter from H. N. Berkow (NRC) to 3. S. Charnley (GE) entitled, " Acceptance for Approval of Fuel Designs Described in Licensing Topical Report NEDE-240ll-P-A-6, Amendment 10 for Extended Burnup Operation," dated December 3,1985. Permission to reference this topical report was given in a l
letter from C. O. Thomas (NRC) to J. S. Charnley dated August 13,1985 entitled " Acceptance for Referencing of Licensing Topical Report NEDE-22148-P, ' Extended Burnup Evaluation Methodology."' The impact of high exposure fuel on fuel handling accident evaluations was considered by the NRC as part of these reviews.
Examination of fission yield curves for Pu-239 and U-235 indicates no significant difference in yields of iodine and xenon isotopes, however; U-235 yields are slightly larger for major xenon and iodine isotopes. Examination of Pu-239 fission yields indicates no other volatile radioactive isotope not currently considered would be produced in significant quantities. Therefore, the contribution of fission product gases from Pu-239 at higher burnup will not significantly change the total inventory of fissien product gases generated.
Fuel rod design feature improvements have been introduced as part of the GES high burnup fuel design. These design feature improvements increase the fuel pellet thermal conductivity as well as the thermal conductance between the fuel pellet and cladding, thereby significantly reducing operating fuel temperatures and attendant fission gas release. These features of the GE8 design have been reviewed and accepted by the NRC via a letter from H. N. Berkow (NRC) to J. S Charnley (GE) entitled, " Acceptance for Approval of Fuel Designs Described in Licensing Topical Report NEDE-240ll-P-A-6, Amendment 10 for Extended Burnup Operation," dated December 3,1985.
The overall result of these design improvements is a reduction in the inventory of gaseous fission products released from the fuel pellet to the fuel rod void volume for the GE8 fuel design at its design exposure as compared to the P8x8R fuel design at its design exposure. Therefore the consequences of a fuel handling accident involving GE8 fuel are not increased and are bounded by the existing analysis.
The revisions to Specifications 5.6.1.1 and 5.6.1.2 impose criticality limitations which ensure that fuel can be safely handled and stored. Basing these limitations on k-infinity rather than the maximum U-235 enrichment and axial gm/cm prevents inadvertent criticality while allowing the handling and storage of higher enrichment GE8 fuel assemblies. Use of such high burnup fuel assemblies will also reduce the probability of a fuel handling accident because, (5272 BAT /ppo)
e over the life of the plant, fewer assemblies will be discharged from the core.
The proposed changes to Specifications 5.6.1.1 and 5.6.1.2 are more restrictive than the existing Technical Specifications. The revision to Specification 5.6.1.1 provides a k-infinity limit to ensure the kgg limits are met. The k-infinity limit established in Specification 5.6.1.'I.a is 1.41, slightly less than the k-infinity determined by General Electric at the lower 2a tolerance for the PWR fue* assembly analyzed. The k-infinity limit established in Specification 5.6.1.2.b for BWR fuel is 1.33, the more restrictive k-infinity limit for General Electric designed, high-density, poisoned BWR storage racks.
Thus, for the reasons described above, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.
2.
As stated in response to item 1, the proposed revisions allow the use of improved, higher enrichment fuel assemblies which have been approved by the NRC. In additior, the revised Specifications 5.6.1.1 and 5.6.1.2 are more restrictive thar! tnose currently existing in the TS. The new fuel design is not l
significantly different than any previously used.
The proposed amendment does not affect the method in which any i
safety-related equipment achieves its safety function. The equipment, methods, and procedures for handling fuel assemblies are not affected by the
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proposed char.ges.
Thus, for the reasons described above, the proposed change does not create the possibility of a new or dif ferent kind of accident from any accident previously evaluated.
3.
The proposed k-infinity limitations provide margin which is equivalent to that
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which currently exists for the PWR. fuel and more restrictive than currently exists for the BWR fuel As stated in response to Items 1 and 2 above, the impact of high exposure fuel was considered by the NRC as part of the review of GE's high exposure fuel j
design. It was concluded that the radiological consequences of a fuel handling accident would be the same as for existing fuel and would be well within the guidelines established in 10CFR100. In addition, pool cleanup and ventilation, as well as heat load, will not be significantly affected by the change.
Progressively higher burnup fuel has been of f-loaded each cycle at BSEP and i
some failed fuel pins have been discharged. Batch average burnup has increased from approximately 12,000 MWD /MT to approximately 29,000 MWD /MT at BSEP-1 and from approximately 9,000 MWD /MT to approximately 25,000 MWD /MT at BSEP-2. Batch average discharge at each of the plants would be expected to increase incrementally to reach approximately 36,000 MWD /MT over the next five cycles. Experience in the BSEP spent fuel pools indicates no long-term trends of substantially increasing activity or heat load as a result of increasing burnup as discharged fuel burnup has increased (other than that attributable to spent fuel capacity and loading expansion). As there is no major change in the GE8 fuel design or manufacturing processes from those currently in use, this prior experience is concluded to be applicable.
Previously implemented fuel design improvements to improve fuel performance and failure resistance are not expected to be compromised by higher burnup applications.
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,F The primary change to heat load results from the number of fuel assemblies discharged from the core. For a given cycle length, fewer assemblies would be discharged in a high burnup fuel cycle thart normally discharged, thereby reducing the probability of a fuel handling accident and potentially increasing the margin of safety. Evaluations indicate that for the highest discharge batch size anticipated in a high burnup scenario in which the entire spent fuel pool is assumed to be filled with high burnup fuel, spent fuel pool heat load is bounded by previously submitted and NRC approved analysis.
Thus, for the reasons stated above, the proposed amendment does not involve a significant reduction in the margin of safety.
4 In conclusion, Carolina Power & Light Company has determined that the proposed 1
amendment does not involve a significant hazards consideration. The proposed fuel j
design has been previously approved for GE by the NRC, and it has been evaluated to determine whether it would impose a significant hazard on a facility. It has been determined that the proposed amendment does not involve a significant hazards consideration.
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