236U and238U radiative-capture cross sections for neutron energies from 10 eV to 50 keV

A task in data support to nuclear power is to measure radiative capture cross sections accurately for 236U (about 4%) and 238U (about 3%). High accuracy in oy2~6U is required because that reaction is the start of a chain leading to 232U accumulation in fast reactors, which plays an important part in optimizing the external fuel cycle because of its hard y rays. There are discrepancies of 1-40% between two recent measurements [i, 2] made in 1982 and 1986 for neutron energies of 3-50 keV.