Neutronic Analysis of a Reference LEU (Low Enriched Uranium) Core for Pakistan Research Reactor Using Oxide Fuel

摘要

Since the core is comprised of all fresh fuel elements, there is an excess of U-235 loading (i.e., 7.21 kg). As a result the core under consideration becomes critical when all the control rods are at about 40% out position. Although the control rods provide an adequate shutdown margin, the position at criticality is less than 50% out, which is not allowed by the operating policies. Therefore some of the fuel elements will have to be removed and the new configuration has to be analyzed to determine the first operating core.