Determination of the energy release distribution and temperature in the irt-4m nuclear fuel when changing the configuration of the control and protection system channels in the WWR-SM reactor

Abstract

The objective of this work is to determine the temperature distribution in the IRT-4M type fuel assembly with fuel 19.75% enriched in 235U in the core of the WWR-SM reactor for the case of a square tube with rounded edges and a round hole in the center and the case of a round tube. In the case of installing a round tube inside the fuel assembly instead of a square tube with rounded edges and a round hole in the center, the volume of water in this space increases. On the one hand, this leads to improved heat removal, since the volume of cooling water increases, and on the other hand, an increase in the volume of water leads to an increase in thermal neutrons on this side of the fuel element, and this, in turn, leads to an increase in energy release. To determine these changes, we performed neutron-physical and thermal-hydraulic calculations for a channel with a square tube with rounded edges and a round hole in the center and for a round tube. It has been determined that replacing a square tube with rounded edges and a round hole in the center with a round tube as a guide for installing a compensating control rod will not affect the nuclear safety of the WWR-SM reactor operation.