This report presents a best-estimate probabilistic risk assessment (PRA) to quantify the frequency of criticality accidents during railroad transportation of spent nuclear fuel casks. The assessment is of sufficient detail to enable full scrutiny of the model logic and the basis for each quantitative parameter contributing to criticality accident scenario frequencies. The report takes into account the results of a 2007 peer review of the initial version of this probabilistic risk assessment, which was published as EPRI Technical Report 1013449 in December 2006.

Spent nuclear fuel comprises a fraction of the hazardous materials packages shipped annually in the United States. In fact, at the present time, fewer than 100 packages of spent nuclear fuel are shipped annually. At the onset of spent fuel shipments to the proposed Yucca Mountain, Nevada, repository, the U.S. Department of Energy (DOE) expects to ship 400 - 500 spent fuel transport casks per year over the life of the facility.

This report summarizes the results of EPRI’s multi-year research effort to assess cladding
performance under normal and hypothetical accident conditions of spent nuclear fuel
transportation.

This report evaluates the radiological impacts during postulated accidents associated with the
transportation of spent nuclear fuel to the proposed Yucca Mountain repository, using the
RADTRAN 5.5 computer code developed by Sandia National Laboratories. RADTRAN 5.5 can
be applied to estimate the risks associated both with incident-free transportation of radioactive
materials as well as with accidents that may be assumed to occur during transportation. Incidentfree
transportation risks for transport of spent nuclear fuel to Yucca Mountain were evaluated in

At the request of the U.S. Congress, the National Academies assessed the safety and
security of spent nuclear fuel stored in pools and dry casks at commercial nuclear power
plants in the United States. The public report can be viewed on the National Academies
Press website at http://books.nap.edu/catalog/11263.html.

Goal: Secure the Benefits, Limit the Risk
The extent to which nuclear power will be a broadly accepted option for meeting future global energy needs depends upon cost, safety, waste management and the ability to limit the associated proliferation risks. While all four considerations are important, this report exclusively examines proliferation risks.

The U.S. Nuclear Regulatory Commission (NRC) is responsible for issuing regulations for the
packaging of spent fuel (and other large quantities of radioactive material) for transport that
provide for public health and safety during transport (Title 10 of the Code of Federal Regulations
(10 CFR) Part 71, “Packaging and Transportation of Radioactive Waste,” dated
January 26, 2004). In September 1977, the NRC published NUREG-0170, “Final Environmental
Statement on the Transportation of Radioactive Material by Air and Other Modes,” which