The Conceptual Design Study of a TRISO Fueled Compact PWR Core

Abstract

A conceptual study has been carried out for the design of a compact PWR reactor core which employs TRISO fuel particles in zirconium-sheathed fuel rods. This study is focused on reactor core optimization which can be a potential source of energy for a sea going vessel. This compact design can also be used for power production, heating and desalination facilities in a remotely located research facility. This light water cooled and moderated core will be smaller in size as compared to a typical PWR of the same rating. Standard reactor neutronics simulation codes WIMS-D/4 and CITATION have been used for the parametric analysis and to optimize the core. TRISO fuel has been chosen for the current design study because of its superior reliability against the release of fission fragments and high negative temperature coefficient. The selected TRISO fuel particle has 0.40 mm fuel kernel outer diameter in overall 0.870 mm outer diameter. Beryllium has been chosen as reflecting material due to its better reflection properties. Fuel pitch and reflector thickness are optimized to 4 cm and 8 cm respectively. Considering the proliferation issues, a maximum 9% fuel enrichment has been selected with the total fuel inventory of 200kg of uranium. These constraints on fuel enrichment and inventory limit the maximum power to only 25MWth for one year full power operation. This designed PWR core would be compact in size due to the default design of the TRISO fuel; fission neutrons are moderated and reflected by graphite in the fuel itself which causes the increase in reactivity. This additional increment in reactivity would give flexibility to optimize the size of reactor core.