Explanation of Changes in CANDU Coolant Void Reactivity with Creep and Burnup

摘要

The underlying physics phenomena leading to the variation of the effect of pressure-tube creep on CANDU coolant-void reactivity has been assessed in this work. This leads to the following explanation of the reduction in the CVR changes with creep as fuel burnup increases: The main mechanism affecting CVR due to pressure tube creep is the upward shift in thermal-neutron spectrum due to collisions in the hot coolant, which increases with the mass of coolant.