Projected environmental impacts of radioactive material transportation to the first US repository site

The relative national environmental impacts of transporting spent fuel and other nuclear wastes to each of nine candidate repository sites in the United States of America were analysed. Two scenarios were examined for each repository: (1) shipment of 5 year old spent fuel and defence high level waste (DHLW) directly from their points of origin to a repository (Reference Case); (2) shipment of 5 year old spent fuel to a Monitored Retrievable Storage (MRS) facility and shipment (by dedicated rail) of 10 year old consolidated spent fuel from the MRS to a repository. Transport by either all truck or all rail from the points of origin were analysed as bounding cases. The computational system used to analyse these impacts included the WASTES II logistics code and the RADTRAN III risks analysis code. The radiological risks for the Reference Case increased as the total shipment miles to a repository increased for truck; the risks also increased with mileage for rail but at a lower rate. For the MRS scenario the differences between repository sites were less pronounced for both modal options because of the reduction in total shipment miles possible with the large dedicated rail casks. All the risks reported are small in comparison to 'natural background'. (author)