High Precision Neutron Fluence Calculations, Activation Measurements and Spectrum Adjustment for the Rheinsberg Pressure Vessel Steel Irradiation Program

The overall approach comprises the pure calculation part, the gamma spectrometric analyses of fluence monitors and the comparison of theoretical and experimental results using the spectrum adjustment procedure. Monte Carlo methods were used to perform the transport calculations. By application of special measures of variance reduction the statistical errors could be reduced so much that accurate 3-dimensional Monte Carlo methods could be generally used in reasonable calculation time. The uncertainties of the results due to the use of different group values of neutron cross sections were assessed by testing different group sets. In that way it could be shown that the kind of group data is of minor influence.