Validity Assessment of Shielding Design Tools for ITER Through Analysis of Benchmark Experiment on SS316/Water Shield Conducted at FNS/JAERI

To assess validity of the shielding design tools for ITER, the benchmark experiment on SS316/Water shield conducted at FNS/JAERI is analyzed. As far as a simple bulk shield of SS316/Water is concerned, the followings are found assuming that no uncertainty is involved in the response functions of the design parameters. Nuclear data bases of JENDL Fusion File and FENDL/E-1.0 are valid to predict all the design parameters with uncertainties less than a factor of 1.25. At the connection legs between shield blanket modules and back plates, both MCNP and DOT calculations can predict helium production rate with uncertainties less than 10 %. For the troidal field coils on the midplane, all the nuclear parameters can be predicted with uncertainties less than a factor of 1.25 by MCNP and DOT with consideration of self-shielding correction of cross sections and energy group structure of 125-n and 40-γ. The uncertainties for toroidal field coils are considerably smaller than the design margins secured to the shielding designs under ITER/EDA.