Scaling and cost tradeoffs for ATW: preliminary considerations

The use of accelerator-produced spallation neutrons to transmute actinide and long-lived fission-products portends a means to alleviate requirements for deep-geological disposal. The accelerator performance, target-blanket physics, chemical-processing requirements, and overall systems engineering are closely coupled in determining the economic incentives for the Accelerator Transmutation of Waste (ATW). Preliminary estimates of and insight into the economics of a net-power-producing ATW are provided by a simplified (analytic) cost-based systems model. Even for large-capacity systems, the accelerator dominates the economics and technology for the ATW cases examined. Since the accelerator represents an important (∼50%) add-on cost to an ATW-based power plant, reducing the accelerator requirement by increasing the blanket neutron multiplication, increasing the thermal-conversion efficiency, and reducing neutron leakage and parasitic absorption in the target-blanket assembly are main avenues for improving the economic prospects of an ATW that would be fuelled with low-reactivity, actinide ''waste'' generated by light-water reactors (LWRs). This route to improved systems has strong implications for the thermalhydraulic, neutronic, and chemical-processing design of the ATW. (author) 1 tab., 4 refs