STUDY OF MODEL OF A CASK AS A SOURCE TERM FOR SKYSHINE CALCULATION

For the skyshine calculation of transport and storage casks, it is not reasonable to use the detailed cask geometry as a source because of the difficulty in modeling of the cask and too long calculation time. The proper source term may be different between radial and axial direction of a cask. A comparison is made for finding the model and normalizing method to be used for actual skyshine calculation. As a result, there is not so much difference between these source terms for the radial direction, but the point source for the axial direction shows a large conservative result compared with the disk source when the source intensity is normalized at 1m from the cask surface. To make a reasonable source term for axial direction, the normalization must be performed at far enough from the cask, such as 100m from the cask.