Experiences with CR-39 SSNTD in monitoring neutrons emitted from spent reactor fuel

Abstract

Abstract Neutron emission from spent fuel assemblies was studied using Hungarian made CR-39 for monitoring the transuranium content as the burnup parameter. To detect thermal and fast neutrons Boron loaded and polyethylene radiators were applied. It was recognized that the high gamma backgroung in the spent fuel ponds causes sometimes a drastic change in the bulk etch rate and in the particle detection sensitivity. An empirical formula was deduced to estimate the change of the bulk etch rate: V B ʒ  V Bo = f ∗ t ∗ B T − 1 2 , where factor f depends on the etching conditions, t is the exposure time, B is the burnup parameter and T is the cooling time after removing the fuel from the reactor core. In addition, Co-60 and LINAC irradiation facilities combined with Pu-Be neutron sources were used to study the effect of the high gamma dose on the bulk etch rate and proton and alpha sensitivity of the Hungarian CR-39.