Monte Carlo uncertainty analyses for integral beryllium experiments

The novel Monte Carlo technique for calculating point detector sensitivitie s has been applied to two representative beryllium transmission experiments with the objective to investigate the sensitivity of important responses s uch as the neutron multiplication and to assess the related uncertainties d ue to the underlying cross-section data uncertainties. As an important resu lt, it has been revealed that the neutron multiplication power of beryllium can be predicted with good accuracy using state-of-the-art nuclear data ev aluations. Severe discrepancies do exist for the spectral neutron flux dist ribution that would transmit into significant uncertainties of the calculat ed neutron spectra and of the nuclear blanket performance in blanket design calculations. With regard to this, it is suggested to re-analyse the secon dary energy and angle distribution data of beryllium by means of Monte Carl o based sensitivity and uncertainty calculations. Related code development work is underway. (C) 2000 Elsevier Science S.A. All rights reserved.