EFFECTS OF FUEL BURNUP ON REACTIVITY AND REACTIVITY COEFFICIENTS IN YANKEE CORE I

摘要

The burnup dependence of moderator' temperature coefficient and excess reactivity in a pressurized-water reactor is analyzed, Caloulations are compared with measurements from the first Yankee core. For the moderator temperature coefficient studies* burnup effects receive a physical interpretation. Comparisons between two calculational models with dissimilar treatments of the thermal energy range (the LASER and LEOPARD codes) are described, and differences evaluated. Finally;specific influences, such as non-uniform material distributions in depleted fuel rods and thermal scattering kernels, are evaluated.