Verification of Benchmark Experiments by Determination of the Leakage Neutron Spectrum from the Surface of a Depleted Uranium Sphere with Embedded Radionuclide Sources

Computational validation is presented for previous benchmark experiments designed to determine the energy spectra of the neutron current emanating from the surface of a uranium sphere into which small sources were arranged successively at the center. Such experiments must meet stringent reliability and error requirements, since they are intended for the final check of new or adjusted systems of neutron constants recommended for the calculation of neutron fields. The comprehensiveness of the validation was secured by the fact that experiments with the three sources ²⁵²Cf, Pu–Be, and Pu–B were validated and the calculations were performed using three systems of neutron constants BNAB-78, BBF, and BUGLE-96.