Advanced Fuel Cycle Initiative

Transmutation System Design

Facility design activities include: (1) a reference plant for fast-spectrum transmutation of the minor actinides and some fission products, (2) a pre-conceptual design of a demonstration facility, and (3) small-scale facilities for performing proof of principle tests.

Initial layouts for reference plant include two plant configurations operating at a power level of 840 MWth. The first uses sodium as the coolant and the second uses lead-bismuth as a coolant. Both metal and nitride fuels are being investigated. The reference designs will evolve as data and information on fuels and materials are obtained from the research programs, and decisions are made on technology options. The designs will be used to provide quantitative requirements to perform small-scale experiments and operate the demonstration facilities. In addition, they will provide practical information and performance limitations for input to the system studies.

The pre-conceptual design of an accelerator driven transmutation system includes a medium-power accelerator, a target and materials test facility, hot-cells for materials and fuels examinations, and a 100-MWth sub-critical multiplier (SCM). The 100-MW SCM operates with a central LBE spallation target surrounded by a sodium-cooled annular core. The design of the SCM is based largely on the experience from EBR-II which operated at a power Level of 62.5 MWth.
 

Conceptual Design Options ( See Image 1 full-size, See Image 2  full-size).

Small-scale test facilities are also under consideration: (1) a low power sub-critical reactor coupled with an electron accelerator-driven neutron source; and (2) a fuels and materials test station at an existing accelerator facility. The first experiment could make use of the TREAT reactor at Idaho National Laboratory. This reactor would be operated in a sub-critical mode with a strong neutron source to perform reactor-accelerator coupling tests. Experiments would be performed at different multiplication levels and power levels to study the effects of reactivity feedbacks in a sub-critical mode. The second experiment would make use of the LANSCE 800-MeV proton beam that operates at 1 mA of current. A test station would be built to include a spallation target that provides neutrons for fuels and materials irradiations. Neutron fluxes up to 1x1015 n/cm2/s are achievable.