In late April 1998, the U.S. Department of Transportation published the long-awaited study addressing concerns about what shippers and carriers of high level radiation and spent nuclear fuel should consider when selecting transportation modes and routes (modes refer to highway, rail, water and intermodal transport options).
The study was mandated by Congress as part of the Hazardous Materials Transportation Uniform Safety Act of 1990. Entitled Identification of Factors for Selecting Modes and Routes for Shipping High Level Radioactive Waste and Spent Nuclear Fuel, it was prepared by the John A. Volpe National Transportation Systems Center for the U.S. DOT.
The study examines three scenarios for assessing safety factors: incident-free radiological exposure -- the exposure to low levels of radiation that normally occurs as a result of the transport of radioactive materials; accident-related radiological exposure -- the radiation exposure attributable to accidents that result in the release of radioactive materials; and non-radiological consequences of accidents -- the fatalities, property damage and other non-radiological consequences that result from accidents involving the transport of nuclear materials.
The study found that overall radiation risk is low under all three scenarios. The study also concluded, however, that there is a sizable variation in the values of primary safety factors across different mode and route combinations, indicating that mode and route choices made by shippers and carriers can affect shipment risks. This conclusion should bolster the long-stated contention of affected state, local and tribal governments that the U.S. Department of Energy should develop standards for choosing routes and modes rather that leaving those choices to the companies that are transporting the material. The study states that under current practices, safety is not usually given as a reason for choosing a particular mode. Other factors -- such as availability, service attributes, and minimizing transit time -- are more important selection factors. Likewise, routing choices currently are made based primarily on operational efficiency.
The most significant safety factor noted in determining risk was shipment duration. The total necessary time to move a shipment from origin to destination affects non-incident radiation exposure levels, and the group most affected by this factor is transport personnel. Basically, the longer the material is in transit, the longer the exposure of the crew and general public.
A second factor is the amount of material to be shipped. The larger capacity of rail and barge casks and the potential for carrying multiple casks on a single train or barge means that such shipping campaigns require fewer trips than moving the same amount by truck, since truck cask capacities are smaller. Fewer trips reduces total risk under all three scenarios.
Emergency response to a radiological accident is probably the most significant concern of state and local officials; however, it is difficult to measure when comparing route and mode choices. Routes with lower general radiation risk often are farther from emergency response due to the remoteness of the routes. The study failed to address emergency response adequately. It did suggest that the measure for this factor ought to be the amount of time for a specially trained radiological responder to arrive at any point along potential route of travel. It also suggested that remote routes selected by shippers should be reassessed or examined for improvements in emergency response coverage.
The study is useful because it emphasizes safety in assessing factors to be considered in choosing routes and modes. The information about state and local oversight of routing is interesting but dated, since no developments after 1990 are cited. A key issue not addressed by the study -- and perhaps not within its scope -- is who makes the decisions about routes and modes. Public safety officials, state legislators and concerned citizens of affected state, tribal and local governments will find useful analysis in this study for arguing for greater oversight and involvement by the U.S. Department of Energy in the shipments it manages.
The U.S. Senate has refused to call H.R. 1270, the bill that would create a temporary centralized interim storage facility near Yucca Mountain, Nevada. Senators Harry Reid and Richard Bryan (NV) had promised to filibuster the bill and had threatened the resolution of the high-priority tobacco bill. House speaker Newt Gingrich also stated that the Senate version of the bill will not be called for a vote in the House of Representatives, citing the crowded calendar and the strong opposition of some members.
Both articles adapted from the National Conference of State Legislatures High-Level Radioactive Waste Newsletter, July 1998