[Federal Register Volume 64, Number 208 (Thursday, October 28, 1999)] [Notices] [Pages 58106-58107] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 99-28228] ======================================================================= ----------------------------------------------------------------------- NUCLEAR REGULATORY COMMISSION [Docket No. 50-423] Northeast Nuclear Energy Company, et al.; Millstone Nuclear Power Station, Unit No. 3, Environmental Assessment and Finding of No Significant Impact The U.S. Nuclear Regulatory Commission (the Commission) is considering issuance of an amendment to Facility Operating License No. NPF-49, issued to Northeast Nuclear Energy Company (NNECO or the licensee), for operation of the Millstone Nuclear Power Station, Unit No. 3 (MP3), located in New London County, Connecticut. Environmental Assessment Identification of the Proposed Action The proposed action would revise the analysis for the design basis loss-of-coolant accident (LOCA) to include the dose contribution from a previously unevaluated radioactivity release pathway to the environment. The licensee identified a potential pathway for post accident back-leakage of highly radioactive containment sump water from the Recirculation Spray System (RSS) to the Refueling Water Storage Tank (RWST). Since the RWST is [[Page 58107]] vented to the atmosphere, this pathway could contribute to an inadvertent release of radioactivity not previously accounted for in offsite dose calculations. Previously, the licensee had assumed no radiological consequences due to back-leakage. This revision adds the dose from RWST back-leakage to the LOCA analysis, as documented in the Final Safety Analysis Report (FSAR). The proposed action is in accordance with the licensee's application for amendment dated May 7, 1998, as supplemented by letter dated January 22, 1999. The Need for the Proposed Action Pursuant to 10 CFR 50.59 licensees are required to obtain prior NRC approval of changes to the facility that involve an unreviewed safety question. The licensee determined that the back-leakage from RSS to the RWST involves an unreviewed safety question. Therefore, the licensee was required to obtain prior NRC approval for changes to the LOCA analysis and the FSAR to incorporate the dose consequences of the potential for back-leakage from the RSS to the RWST that had not been previously accounted for in offsite dose calculations. Environmental Impacts of the Proposed Action The NRC has completed its evaluation of the proposed action and concluded that the contribution to the LOCA dose to the thyroid (most limiting organ) from the RWST back-leakage as calculated by the licensee is small (2.1 rem at the Low Population Zone (LPZ) and 0.9 rem at the Control Room). When added to the licensee's previously calculated doses, the affected LOCA doses to the thyroid are 11 rem at the LPZ and 12 rem at the Control Room. The increase are small when compared to, and these results continue to meet the acceptance criteria in, 10 CFR Part 100 for the offsite dose consequences and in 10 CFR Part 50, Appendix A, General Design Criterion (GDC) 19 for the control room. All other offsite and control room doses were unchanged. On this basis the staff determined there is no significant radiological environmental impact. The proposed action will not increase the probability or consequences of accidents, no changes are being made in the types of any effluents that may be released off site, and there is no significant increase in occupational or public radiation exposure. Therefore, there are no significant radiological environmental impacts associated with the proposed action. With regard to potential non-radiological impacts, the proposed action does not involve any historic sites. It does not affect non- radiological plant effluents and has no other environmental impact. Therefore, there are no significant non-radiological environmental impacts associated with the proposed action. Accordingly, the NRC concludes that there are no significant environmental impacts associated with the proposed action. Alternatives to the Proposed Action As an alternative to the proposed action the staff considered requiring the licensee to maintain zero back-leakage from the RSS to the RWST. Since this is the original analysis condition, this alternative is the same as the staff denying the proposed action (i.e., the ``no-action'' alternative). Zero back-leakage cannot be ensured for the valves between the RSS and the RWST; therefore, this alternative is impractical. Denial of the proposed action would result in no change in current environmental impacts. The environmental impacts of the proposed action and the alternative action are similar. Alternative Use of Resources This action does not involve the use of any resources not previously considered in the ``Final Environmental Statement Related to the Operation of Millstone Nuclear Power Station, Unit No. 3,'' dated December 1984 (NUREG-1064). Agencies and Persons Consulted In accordance with its stated policy, on September 23, 1999, the staff consulted with the Connecticut State official, Mr. Fred Scheuritzel of the Department of Environmental Protection, regarding the environmental impact of the proposed action. The State official had no comments. Finding of No Significant Impact On the basis of the environmental assessment, the NRC concludes that the proposed action will not have a significant effect on the quality of the human environment. Accordingly, the NRC has determined not to prepare an environmental impact statement for the proposed action. For further details with respect to the proposed action, see the licensee's letter dated May 7, 1998, as supplemented by letter dated January 22, 1999, which are available for public inspection at the Commission's Public Document Room, The Gelman Building, 2120 L Street, NW., Washington, DC, and at the local public document rooms located at the Learning Resources Center, Three Rivers Community-Technical College, 574 New London Turnpike, Norwich, Connecticut, and the Waterford Library, 49 Rope Ferry Road, Waterford, Connecticut. Dated at Rockville, Maryland, this 22nd day of October 1999. For the Nuclear Regulatory Commission. John A. Nakoski, Sr., Project Manager, Section 2, Project Directorate I, Division of Licensing Project Management, Office of Nuclear Reactor Regulation. [FR Doc. 99-28228 Filed 10-27-99; 8:45 am] BILLING CODE 7590-01-P