Shielding analyses for the REA-2023 and Castor-1C BWR storage casks

A number of casks have been designed and several have been built for the storage of spent nuclear fuel rods. As part of the comprehensive demonstration test programs, spent fuel has been loaded into the REA-2023 and Castor-1C casks and radiation dose rates measured. Point kernel and discrete ordinates methods were used to predict radiation dose rates on the surface of the two casks. The QAD-CG code was used for primary gamma-ray calculations. The DOT-4 code was used for neutron and secondary gamma-ray calculations. Calculated dose rates agree resonably well with the measurements. Calculated neutron dose rates for the REA-2023 cask range from good agreement to a factor of four high. The calculated gamma-ray dose rates ranges from a factor of two high to a factor of four low. Calculated neutron dose rates for the Castor-1C cask range from a factor of two to a factor of four high. The calculated gamma-ray dose rates are a factor of two high. The sensitivity of the dose rates to the details of the calculation is discussed, and the importance of various assumptions made for the calculations is evaluated