The Safety Case for Transporting Spent Nuclear Fuel

The transportation safety case for transporting of radioactive material is a requirement for licensing in South Africa. The recent repatriation of spent nuclear fuel required the compilation of such a safety case. The transportation safety case has both qualitative and semi-quantitative aspects. The qualitative aspects include transportation regulations, radiation dose limits, role of the transportation package in transportation, transportation package certification process, training, emergency response, the performance of the transportation package in accidents, and the evaluation of past transportation accidents. The quantitative aspects support the qualitative descriptions. Radiation doses accrued by members of the public and by workers are calculated using the code RADTRAN. Dose from both routine, incident-free highway transportation and from highway transportation accidents are part of the safety case and will be compared with both background doses and the regulatory safety criteria. The radiation doses from routine transportation are calculated for: • The maximally exposed member of the public. • Doses to vehicle escorts. • Doses to vehicle crew Collective doses to populations are calculated for representative routes. Collective dose depends on the number of people affected as well as on the extent of the radiation from the source to which reference groups are exposed. Accidents involving loss of gamma shielding and loss of confinement integrity are discussed, as are accidents in which there is no impact on the cargo. Based on the safety case a license was successfully granted for the transport of spent nuclear fuel. The presentation will conclude with a reflection on the experience and the outcomes of the transport actions. Keywords: transport safety assessment, spent fuel transport, RADTRAN, radiation dose, collective dose