Neutron fluence calculations and spectrum adjustment for the Rheinsberg pressure vessel steel irradiation program

Monte Carlo neutron transport calculations are well suited to determine the neutron fluence in reactor pressure vessel material. The sensitivity against applied goup data sets is only low at least for regions not so far from the core. Some disadvantages of the Monte Carlo method can be considerably decreased by weight window techniques and exact treatment of scattering angle-energy loss correlation. The accuracy and reliability of the fluence spectrum calculations have been proved by evaluation of activation measurements using a spectrum adjustment method. (orig.)