Abstract
The production of 238Pu as a heat generation source for radioisotope thermoelectric generators (RTGs) was ongoing at the Savannah River Site (SRS) from the 1960s-1990s. Stockpiles of this valuable radioisotope have decreased over the last few decades and it is clear that more material must be produced to support future deep space exploration missions. The Oak Ridge National Laboratory (ORNL) has initiated efforts to establish a reliable production facility to replenish this resource. Like the SRS, ORNL uses a mechanically pressed ceramic/metallic (cermet) pellet that blends 237Np (in the form of ceramic NpO2 powder) and aluminum powder. A “Generation I” target containing 52 such pellets has been qualified for irradiation at the High Flux Isotope Reactor at the ORNL reservation. The next “Generation II” target design incorporates lessons learned from the initial qualification exercise to develop a further optimized irradiation vehicle design. This paper discussed the evolution of the cermet targets at ORNL and provides details on the Generation II design.
