L-MT-11-028, Deviation from BWRVIP-25 Lnspection Requirements
| ML111330208 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 05/12/2011 |
| From: | O'Connor T Northern States Power Co, Xcel Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-MT-11-028 | |
| Download: ML111330208 (2) | |
Text
May 12,201 1 Monticello Nuclear Generating Plant 2807 W County Road 75 Monticello, MN 55362 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket 50-263 Renewed Facility Operating License No. DPR-22 Deviation from BWRVIP-25 lnspection Requirements
References:
Electric Power Research Institute, "Monticello Nuclear Plant (MNGP)
Technical Justification for Deviation from BWRVIP-25," dated March 29,201 1.
- 2)
BWR Vessel and lnternals Project, "BWR Core Plate lnspection and Flaw Evaluation Guidelines (BWRVIP-25)," December 1996.
- 3)
BWR Vessel and lnternals Project, "BWR Vessel and lnternals Project Program Implementation Guide," (BWRVIP-94, Revision I),
December 2005.
The Northern States Power Company - a Minnesota corporation (NSPM), d/b/a as Xcel Energy, submitted a deviation disposition (Reference 1) for the Monticello Nuclear Generating Plant (MNGP) to the Boiling Water Reactor Vessel lnternals Project (BWRVIP) on March 29, 201 1, concerning core plate holddown bolts. lnspection and evaluation guidelines for these bolts are provided in BWRVIP-25, "BWR Core Plate lnspection and Flaw Evaluation Guidelines," (Reference 2). In accordance with BWRVIP-94, "BWR Vessel and lnternals Project Program lmplementation Guide,"
(Reference 3), NSPM is notifying the U.S. Nuclear Regulatory Commission (NRC) of the submittal of this deviation disposition to the BWRVIP.
The deviation is from a "needed" element of the BWRVIP program which is the inspection of the core plate holddown bolts in accordance with BWRVIP-25. Two options are provided by BWRVIP-25: install core plate wedges or inspect the core plate bolts to assure they can prevent lateral displacement of the core plate.
Document Control Desk L-MT-11-028 Page 2 of 2 NSPM as part of license renewal developed an analytical alternative to the options described in BWRVIP-25 that was approved by the NRC. This analysis demonstrated that the core plate holddown bolts would prevent lateral displacement of the core plate through the 20-year license renewal period. Technical justification, and the NRC basis for approval, of this alternative is described in Section 4.8, "Stress Relaxation of Rim Holddown Bolts," in NUREG-1865, "Safety Evaluation Report Related to the License Renewal of the Monticello Nuclear Generating Plant."
This letter is being submitted for your use. NSPM is not requesting any action from the NRC staff.
Should you have questions regarding this letter, please contact Mr. Richard Loeffler at (763) 295-1 247.
Summary of Commitments ew commitments and does not revise any existing icello Nuclear Generating Plant Northern States Power Company - Minnesota cc:
Administrator, Region Ill, USNRC Resident Inspector, Monticello, USNRC Project Manager, Monticello, USNRC BWRVIP Project Manager, USNRC