Evaluation of Techniques for Dynamic Measurement of Fuel Motion in Liquid-Metal-Cooled Fast-Breeder Reactor Safety Experiments

摘要

The purpose of the program for evaluation of fuel-motion diagnostics instrumentation is to determine whether fuel-motion monitoring techniques for planned liquid-metal-cooled fast-breeder reactor safety tests can yield information adequate for verification of reactor-safety calculations. Neutron and gamma-ray hodoscope scans of fuel assemblies containing from 1 to 127 pins were obtained. It was found that a single-pin void can be detected in fuel assemblies containing up to 127 pins and that, for both 37- and 127-pin fuel assemblies, the image of a single-pin void varies with the depth of the void within the assembly. The effect of a thick steel casing on image quality and the use of in-core detectors as fuel-motion monitors were investigated. It was shown that PARKA is a suitable driver reactor for static testing of coded-aperture fuel-monitoring systems. The use of PARKA in a pulsed mode to study transient phenomena in safety tests is discussed.