Daily Rules, Proposed Rules, and Notices of the Federal Government
By letter dated March 28, 2008, as supplemented August 29, 2008, Northern States Power Company (NSP), formerly Nuclear Management Company, LLC, submitted a request to the NRC to amend materials license SNM-2506 for the Prairie Island Independent Spent Fuel Storage Installation (PIISFSI). The license amendment request proposes the design modification of the TN-40 cask to the TN-40HT cask. The modified cask design will accommodate the dry
The objective of NSP is to modify the current cask design to the TN-40HT model, which will accommodate dry storage of fuel with higher initial enrichment and higher burnup. The current TN-40 cask limits the fuel that may be stored to that of an initial enrichment of 3.85 wt% of uranium-235 and a burnup of 45,000 Mega Watt-days/Metric Ton of Uranium (MWd/MTU). To accommodate higher uranium-235 enrichment and higher burnup of fuel, modifications to the cask design are required to support operation during the plant life extension. The enhancements involve features that improve heat transfer and neutron absorption. The heat transfer capability of the basket design must be enhanced as well as minor changes to the cask body to accommodate the enhanced basket. The changes being made to the cask design are such that the TN-40HT cask will use existing equipment for lifting, loading, and transporting. The EA addresses the expected environmental impacts associated with the proposed design modification of the ISFSI cask on the Prairie Island site.
The NRC staff has concluded that the proposed action will not result in a significant impact to human health or the environment. To support this conclusion, NRC staff has prepared an EA, which evaluated the direct, indirect, and cumulative environmental impacts of modifying the ISFSI cask design. Based on this assessment, the NRC staff has determined that no significant radiological or non-radiological impacts from normal operations of the ISFSI with the newly designed cask are expected. The ISFSI is a passive facility that produces no liquid or gaseous effluents and requires no power or regular maintenance. The license amendment request does not require altering the site footprint nor does it change the operating processes of the existing facility.
The radiological dose rates from the ISFSI will be limited by the design of the dry storage cask. Occupational dose estimates from routine monitoring activities and transfer of spent fuel for disposal must be maintained as low as reasonably achievable (ALARA) and must be within the limits of 10 CFR 20.1201. The annual dose to the nearest member of the public from ISFSI activities remains significantly below the annual dose limits specified in 10 CFR 72.104 and 10 CFR 20.1301(a). The cumulative dose to an individual offsite from all site activities will be less than the limits specified in 10 CFR 72.104 and 10 CFR 20.1301. Therefore, the NRC staff concludes that the proposed action will not result in a significant impact to human health or the environment.
Because of its proximity to the plant and the uniqueness of the community, the NRC acknowledges that there is the potential for the Prairie Island Indian Community (PIIC) to be disproportionately affected by the PIISFSI. Potential impacts to minority and low-income populations would mostly consist of radiological effects; however, radiation doses from the modified TN-40 cask design at the PIISFSI would be well below regulatory limits. Therefore, based on this information and the analysis of human health and environmental impacts presented in the EA, the proposed modification would not have disproportionately high and adverse human health and environmental effects on minority and low-income populations residing near the PIISFSI.
The consultations ensured that the requirements of Section 7 of the Endangered Species Act and Section 106 of the National Historic Preservation Act were met. The consultations also provided the designated state liaison agency the opportunity to comment on the proposed action. NRC staff consulted with other agencies regarding the proposed action, including the U.S. Fish and Wildlife Service (FWS), the Minnesota State Historic Preservation Office, and the Minnesota Department of Natural Resources (MNDNR). The NRC received responses from the FWS and the MNDNR. The NRC also considered the concerns of interested stakeholders, namely the PIIC, throughout the review process. NRC staff incorporated such responses and concerns from these agencies into the final text of the EA. The conclusions by all agencies consulted were consistent with the staff's conclusions.
On the basis of the EA, the NRC staff concludes that there are no significant radiological or non-radiological impacts associated with the proposed action. The issuance of the license amendment for the design change of the spent nuclear fuel dry storage cask at the Prairie Island ISFSI will have no significant impact on the quality of the human environment. Therefore, pursuant to 10 CFR 51.31 and 51.32, a finding of no significant impact is appropriate and an environmental impact statement need not be prepared for the amendment of materials license SNM-2506.
Documents related to this action, including the license amendment request of SNM-2506 and supporting documentation, are available electronically at the NRC's Electronic Reading Room at
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For the Nuclear Regulatory Commission.