ML20115D757
| ML20115D757 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/04/1985 |
| From: | Musolf D NORTHERN STATES POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-62166, NUDOCS 8504190107 | |
| Download: ML20115D757 (2) | |
Text
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Northem States Power Company 414 Niconet man Minneapons. Minnesota 5s401 Tehonone (612) 330-5500 April 4,1985 Director Office of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Withdrawal of Exemption Request Concerning 10 CFR Part 50, Section 50.46 and Implementation of a Voluntary Peakina Factor Penalty
References:
1.
Letter dated April 2,1985, D M Musolf, NSP, to the Director of NRR, " Request for Exemption from the Requirements of 10 CFR Part 50, Section 50.46-Acceptance Criteria for Emergency Core Cooling Systems' for Light Water Nuclear Power Reactors."
As a result of discussions with the NRC Staff on the afternoon of April 3, 1985, we withdraw our April 2,1985 Exemption Request and associated commitments to reanalyze the Prairie Island K(z) curve within two weeks (Reference 1) and have implemented a voluntary peaking factor (Fe) penalty.
A 0.05 Fa penalty has been implemented on Exxon fuel at Prairie Island as of today, reducing the value of Fe specified in the Prairie Island Technical Specifications from 2.32 to 2.27.
This penalty will remain in affect until the K(z) curve (Technical Specification Figure 3.10-5) has been shown to conform with the requirements of 10 CFR Part 50, Section 50.46 and Appendix K.
At that time, we will submit documentation verifyin'g the validity of the present K(z) curve and remove the peaking factor penalty.
This analytical verification work will be completed in an expeditious manner.
The peaking factor penalty we have agreed to has been found by the NRC Staff to conservatively account for potential differences between Exxon Nuclear fuel and Westinghouse fuel. The Westinghouse fuel has been shown to comply with the requirements of 10 CFR 50.4G and Appendix K with Westinghouse methodology. Exxon has recently demonstrated to the NRC Staff il 8504190107 850404 g(u \\
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.,j.. 2 Dir, NRR Northem States Power Company April 4,1985 Page 2 with Exxon methodology that the Westingh.)use and Exxon fuel types differ by less than 50 degrees F in peak clad temperature LOCA analysis results. The NRC has suggested that 50 degrees F in peak clad temperature is approxi-mately equivalent to 0.05 in Fe space. Therefore, penalizing the Exxon fuel by 0.05 will conservatively resolve the NRC concerns with the inability of Exxon Nuclear to support the current K(z) curve.
D d Mw David Musolf Manager - Nuclear Suppor Services DMM/TMP/tp c: Regional Administrator-III, NRC NRR Project Mnnager, NRC Resident Inspector, NRC G Charnoff 3+
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