Fixed-Source Perturbation Worth Calculations

摘要

Material worth measurements are routinely performed in fast reactor critical programs. Until recently, such measurements were usually made by inserting cylindrical samples via stainless steel tubes. Such measurements pose difficult problems for the analyst since the geometry is very complicated. An alternative measurement utilizes a drawer oscillator to remove or insert a fuel plate. In such a measurement, samples are large enough to cause significant distortions of the local flux. Consequently, it is important to account for local flux distortions when calculations of such experiments are performed. Traditional analysis techniques have not addressed many of the complicated phenomemon associated with the measurements, and large (10 to 20%) discrepancies exist between calculated and experimental sample worths. The intent of this paper is to describe new analysis techniques which have been developed to compute accurately sample worths for complicated geometries and large perturbing samples. (ERA citation 09:040065)