ML20245G348
| ML20245G348 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 06/19/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20245G329 | List: |
| References | |
| NUDOCS 8906290109 | |
| Download: ML20245G348 (2) | |
Text
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UNITED STATES
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g NUCLEAR REGULATORY COMMISSION
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WASHINGTON, D. C. 20S55
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 67 TO FACILITY OPERATING LICENSE NO. DPR-22 NORTHERN STATES POWER COMPANY MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263
1.0 INTRODUCTION
By letter dated January 31, supplemented February 3, 1989, Northern States Power Company (the licensee) submitted a proposed license amendment to extend the Maximum Average Planar Linear Heat Generation Rate (MAPLHGR) limit for the Monticello Nuclear Generating Plant.
The proposed amendment would revise the plant Technical Specifications to extend the MAPLHGR for fuel types P8DRB265L and BP80RB265L and permit the plant to operate beyond the current MAPLHGR exposure limit of 40,000 mwd /MTU to 45,000 mwd /MTU.
The licensee identified the methodology used and provided analyses to justify the extension of the exposure limit.
The amendment would allow the licensee to extend the length of the current plant operating cycle through to August 1989 and meet expe::ted power demands during the peak load summer months of 1989.
The staff has reviewed the licensee's submittals and its findings and determinations are discussed below.
2.0 DISCUSSION AND EVALUATION The MAPLHGR value for the P8DRB265 fuel types was determined using the results of calculations using the NRC approved methodology; i.e. General Electric Company's evaluation for the conformance of this type fuel bundle design'for all thermal-mechanical criteria documented in GESTAR II under the category P8X8R fuel design.
The Emergency Core Cooling System evaluations for this fuel bundle are based on the SAFE /REFLOOD/ CHASTE codes while the fuel rod thermal-mechanical evaluations l
were based on the TEXIC0/ CLAM (Appendix C of GESTAR II) methods.
The peak l
pellet exposure for these fuel rod thermal-mechanical licensing evaluations was 50 GWd/MTU.
Subsequent to these initial licensing evaluations for the P8X8R fuel design, the design was re-evaluated using the GESTR-MECHANICAL fuel rod thermal-mechanical methods and criteria.
This evaluation confirms adequacy for this design out to a peak pellet exposure of 50 GWd/MTU.
The fuel thermal-mechanical evaluations and criteria are described in Section 2.0 of GESTAR II (Revision 9 of the base document).
Nuclear Regulatory Commission approval of TEXIC0/ CLAM is documented in the U.S. Supplement to GESTAR II, page US.C-113.
Nuclear Regulatory Commission approval of GESTR-MECHANICAL Is documented on page US.C-183.
The LOCA analysis is described in GESTAR II, page US-28, Section 5.2.2.3.2.
8906290109 8906190 PDR ADOCK 05000263 P
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1.
The licensee analyzed the MAPLHGR extension from 40,000 to 45,000 mwd /MTU using the aforementioned NRC-approved methodology.
The 45,000 mwd /MTU MAPLUGR limit was calculated conservatively from thermal and mechanical consideration.
The results showed that the peak clad temperature (PCT) is less than 1871 F and the oxidation is less than 1% under the LOCA condition.
In view of these analytical. results, and since the MAPLHGR extension (8.3 kW/ft at 45,000 mwd /MTU) meets the 10 CFR 50.46 requirements, the staff, concludes that the proposed MAPLHGR extension limit is acceptable for Monticello. Accordingly, the staff l
accepts the MAPLHGR extension from 40,000 mwd /MTU to 45,000 mwd /MTU in Technical Specification Table 3.11.1 (page 214) for Monticello as proposed.
3.0 ENVIRONMENTAL CONSIDERATION
I Pursuant to 10 CFR 51.21, 51.32, and 51.35, an environmental assessment and finding of no significant impact has been prepared and published in the Federal Register on June 1, 1989, (54 FR 23551).
Accordingly, based upon the environmental assessment, the Commission has determined that the issuance of this amendment will not have a significant effect on the quality of the human environment.
4.0 CONCLUSION
The staff has concluded, based on the considerations discussed 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; and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health an~d safety of the public.
Principal Contributors:
S. Wu J. Stefano Dated:
Jane 19, 1989 J'
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