Fast reactor programme

Progress in the evaluation and adjustment of fission product capture cross sections is illustrated by results of a 93Nb cross section evaluation and ratios of adjusted and unadjusted group cross sections for 127I and 93Nb. Out-of-pile transient burst tests on tubes of fuel canning material and initial results of the loss-of-cooling experiment with fuel rod R63-L13 are discussed. The preparation of somewhat larger quantities of UC, UC-UN and U2N3 has begun. The creep strength of reactor vessel material DIN 1.4948 was found considerably affected after a short irradiation of 1023 n.m-2; this was due to embrittlement. The mass concentration decay curves obtained during aerosol experiments in various vessels with a heated layer of water on the floor appear to be in reasonable agreement with the MADCA model. An application of the Laser Doppler Anemometry is being developed to measure the velocity distribution in a sub-channel of a fuel element. Preparations for the sodium boiling experiments in a blocked 28-rod bundle are underway