Application of the Monte Carlo method for neutron shielding analysis of transport casks

The Monte Carlo Method using the next-event surface crossing (NESX) estimator and the Monte Carlo sampling technique were applied to analyse the neutron shielding problems of transport casks and the neutron dose rate distribution in a spent fuel shipping vessel. The subject of the experiment, the shielding of a spent fuel shipping cask, was carried out at the Central Research Institute of Electric Power Industry (CRIEPI), Japan, on-board a spent fuel shipping vessel, the Pacific Swan, in which 13 casks of TN-12A and Excellox-3 were loaded. The optimum shielding arrangement for a cask shielding system was also studied. With the present knowledge of Monte Carlo techniques the method could be employed as an option for analysing the radiation shielding of transport casks. In addition, the present experimental data can be adopted as benchmarks for transport casks and vessel design. (author)