Abstract :
Material test reactor (MTR) is a pressurized, reflected, open pool – type, light – water moderated and cooled heterogeneous system designed for operation at a maximum steady – state power level of 10MW thermal. This reactor regionized by a consultant s group from IAEA member state, which has been meeting regularly to discuss the technical issue of core conversion. A conversion feasibility study, which involves both HEU (93 % U235) and LEU (30 % U235) fuels, is currently being performed. In order to determine core excess reactivity, Wims-D4 and Daixy codes would used to justify the conversion study from HEU to LEU, which limited by two options; the first one depends on increasing the amount of U235 (no redesign of fuel element), the second option depend on decreasing either the plate cladding or fuel meat thickness while increasing the width of the coolant gap (redesign of fuel element).
