March 2005 Report to Congress Regarding the Use of Dedicated Trains for Transportation of High-Level Radioactive Waste and Spent Nuclear Fuel
November 3, 2005
By Robert Fry, NCSL Policy Associate
History
Section 15 of the Hazardous Materials Transportation Uniform Safety Act of 1990 amended section 116 of the Hazardous Materials Transportation Act and directed the secretary of transportation to undertake a study comparing the safety of using “dedicated trains” that are operated exclusively for transporting high-level radioactive waste (HLRW) and spent nuclear fuel (SNF) with the safety of using other methods of rail transportation (“regular trains” or “key trains”) for such purposes. The U.S. Department of Transportation’s Volpe National Transportation Systems Center initiated the safety analysis study--Use of Dedicated Trains for Transportation of High-Level Radioactive Waste and Spent Nuclear Fuel--in the spring of 1992 to determine whether the Federal Railroad Administration (FRA) should require carriers of HLRW and SNF to use dedicated trains. A report on the results of the study was to be submitted to Congress by November 16, 1991, but the report was only recently submitted to Congress on September 27, 2005. Factors leading to the substantial time delay were the lack of congressional funding for the first year, FRA’s continuing desire for the study to be as accurate as possible, and arising issues that showed a need to change certain aspects of the study as it was being developed. The study was near completion by the late 1990s, but by that time more current data was available, as were more accurate and advanced modeling systems, thus leading to further delay. In addition, the events of September 11, 2001, caused a shift in priorities within FRA. Once completed, the study analyzed both non-incident risk from radiation emitted from the cask during transportation and accident risk. After considering the study findings, the secretary is directed to amend existing regulations as deemed appropriate to provide for the safe rail transportation of HLRW and SNF.
Study Analysis
With regard to incident-free risks, transit time is the most significant factor that differentiates the three types of rail service. Risks were lowest for dedicated trains, due mainly to the reduced time in transit because of fewer stops along the transportation route. Although all population groups - such as crew, handlers, escorts, yard personnel and the general public - along the transportation route are subject to radiation exposure even without an accident occurring (continuous emissions of low doses of radiation cannot be totally contained by cask shielding), the total radiation exposure is very low for all three train service types. Dedicated train crew exposures, however, would be higher because the cask is closer to the crew. The amount of low-level exposure depends in part on the number of shipments; specific routes and operating variations, such as the distance from the source; level of shielding provided by intervening equipment or buildings; length of route; number of stops; and travel speed.
With regard to accident-related risks, three issues are relevant when considering radiological risks: the likelihood of an accident, the severity of the accident, and the response or recovery time from the accident. Radiological risks from accidents are based upon the design of the cask; the likely level of loss of shielding; and the effect of radiation on crews, escorts, emergency response personnel, and the general population near the accident site. Safeguards such as Nuclear Regulatory Commission package certification requirements, railroad industry requirements, and FRA’s inspection program largely reduce any chance that a cask might release radioactive material even if an accident does occur.
The study concluded that dedicated trains have the lowest accident probability due to the decreased stopping distance of the shorter consist, fewer number of cars to derail, and fewer yard visits. It also is easier for dedicated trains to avoid higher-risk locations, and the risk of fire is lower because cars carrying hazardous materials are restricted from the consist. Dedicated trains also reduce potential radiation exposure because accident clearing can be expedited with shorter trains. In addition, derailment prevention measures, advanced technology (e.g., the use of electronically controlled pneumatic brakes that can reduce stopping distances by 40 percent to 60 percent), and enhanced operating procedures and training further reduce the risk that any accident will compromise the safety of a cask.
Summary
The non-incident risk from the entire future shipping campaign is approximately one latent cancer fatality for every 40,000 shipments by non-dedicated trains and for every 50,000 shipments by dedicated trains. Thus, the potential exposures to radiation from any rail transportation are benign when compared to normal radiation exposures from such sources as the sun, airplanes and tobacco. The study concluded that more direct routes by dedicated trains reduce both non-incident and accident-related risks. Dedicated train service offers the lowest accident probability and can reduce radiation exposure in the event of an accident by mitigating the consequences and simplifying wreck clearance. Although the study does not address security issues in detail, the use of dedicated trains should enhance security for transportation of HLRW and SNF because dedicated trains will have priority on the railroads, have more precise routes and schedules, and have minimal stops or interruptions along the transportation routes, thus making security arrangements easier to execute.
The FRA now is studying the costs associated with the use of dedicated trains and other special conditions of transportation. After completing this review, the FRA will determine what regulatory changes may be required.
 Hazmat Alliance
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