Research on design of the fuel lattice of TACR

This work, using WIMS-AECL 2-5d code, has done lots of research on the design of the fuel lattice of the Thorium-based Advanced CANDU Reactor (TACR). A key element of the cost reduction of ACR is the use of H2O instead of D2O as coolant and slightly enriched uranium fuel in a tighter D2O-moderated lattice. Several cases of changing moderator from D2O to H2O or coolant from H2O to D2O are studied. All-uranium and thorium-based fuel load patterns are discussed separately. For all-uranium fuel load pattern, only typical ACR design has good physics characteristics and at the same time relatively lower economical cost. The comparison results of thorium-based lattices by changing coolant or moderator are similar to all-uranium case. The major feature of 71-rods bundle is an increase in the number of fuel elements from 43 in the ACR-700(Canflex) to 71 elements. Main performance parameters of new bundle design are compared with ACR Canflex case in the same bundle power conditions. Results show that new 71-rods design can get deeper average burnup and more reasonable power density distribution. But coolant void reactivity of 71-rods design is not as good as ACR Canflex fuel. (authors)