ML050670483
| ML050670483 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 02/24/2005 |
| From: | Spina J Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NMPIL 1929 | |
| Download: ML050670483 (3) | |
Text
Constellation Energy P.O. Box 63 Lycoming, NY 13093 Nine Mile Point Nuclear Station February 24, 2005 NMP1L 1929 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
Nine Mile Point Unit 1 Docket No. 50-220 License No. DPR-63 Notification of an Inaccurate Statement Regarding the Increased Spent Fuel Pool Storage Capacity Modification at Nine Mile Point Nuclear Station Unit 1 Gentlemen:
By letter dated May 15, 1998 (NMP1L 1316) and supplements, Niagara Mohawk Power Corporation (NMPC), the former licensee, submitted an application to amend Nine Mile Point Unit 1 (NMPI) Technical Specification (TS) 5.5, "Storage of Unirradiated and Spent Fuel." The changes reflected planned modifications to increase the storage capacity of the NMPI spent fuel pool (SFP). Based on its review and evaluation of NMPC's submittal and the additional information provided regarding the structural evaluations, the Nuclear Regulatory Commission (NRC) staff concluded that NMPC's structural analysis and design of the spent fuel pool rack modules and the SFP structures were acceptable. Accordingly, by letter and enclosed Safety Evaluation Report (SER) dated June 17, 1999, the NRC issued License Amendment No. 167 which increased the SFP storage capacity specified in TS 5.5 from 2776 to 4086 fuel assemblies.
The purpose of this letter is to notify the NRC of a recently identified inaccurate statement in the Licensing Report prepared by Hoitec International (Holtec) supporting the SFP modification.
The Licensing Report incorrectly states that a 72-hour minimum in-core hold time limit exists for transfer of reactor fuel assemblies to the SFP which is governed by radiological requirements.
The Licensing Report was submitted to the NRC as Attachment C to the May 15, 1998 amendment request letter. The incorrect statement was also repeated in the supplemental information provided to the NRC in a letter dated April 1, 1999 (NMP1L 1419) and reflected in the NRC's June 17, 1999 SER for Amendment No. 167 and subsequent correction letter dated July29, 1999.
During a recent review of the Holtec Licensing Report, it was identified that the Report misrepresents the 72-hour minimum in-core hold time limit for fuel assembly offload as being governed by radiological requirements. As subsequently confirmed by Holtec, the 72-hour A-D(
Page 2 NMP1L 1929 in-core hold time was found to be an administrative limit based on past practice at NMP1, and was not derived from any radiological or thermal-hydraulic limitation.
The plant-specific radiological analyses for the postulated fuel handling accident (FHA),
as described in Section XV-C.3 of the NMP1 Updated Final Safety Analysis Report, assume that the earliest fuel could be moved to the SFP is 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after plant shutdown, which is consistent with Standard Review Plan 15.7.4, "Radiological Consequences of Fuel Handling Accidents" for boiling water reactors. Furthermore, the NRC's confirmatory calculations of the FHA radiological consequences, as documented in the SER for Amendment No. 167, assumed a minimum in-core decay time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for any freshly offloaded fuel. In addition, as indicated in the supplemental information provided in a letter dated December 9, 1998 (NMPIL 1389), a spent fuel cooling time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (before transfer to the SFP) is assumed in the calculations confirming that the increased number of fuel assemblies stored in the SFP does not significantly affect the radiation dose levels in the zones surrounding the SFP.
Based on the foregoing information, a minimum in-core fuel decay time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was assumed in the governing radiological analyses for the SFP modification. Thus, contrary to the Holtec Licensing Report, the governing radiological requirements do not limit in-core hold time to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Furthermore, the 24-hour decay time assumed in the governing radiological analyses is conservative with respect to radiological dose considerations when compared to the past-practice decay.time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> since shorter decay times will result in potentially higher radiological consequences for a worst-case FHA and potentially higher radiation dose in the zones surrounding the SFP. Therefore, Nine Mile Point Nuclear Station, LLC (NMPNS) has concluded that the identified inaccurate statement in the Holtec Licensing Report, as reflected in the NRC's SER, has no safety significance and, as such, would not alter the NRC's conclusion that the modification to increase the SFP storage capacity provides reasonable assurance that the health and safety of the public will not be endangered. Accordingly, it is NMPNS's expectation that the NRC staff review this information; however, no correction to the SER or other written response is believed necessary, nor requested.
Sincerely, President Nine Mile Point
Page 3 NMP1L 1929 JAS/CDM/sac cc:
Mr. S. J. Collins, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector Mr. P. S. Tam, Senior Project Manager, NRR (2 copies)
Mr. John P. Spath, NYSERDA