Production of heat source fuel for future NASA missions that could be powered by radioisotope power systems (RPS) has been fully re-activated at the Department of Energy (DOE). Thanks to an updated mode of operations called constant-rate production, the production process for fueled clads is adjustable and can be tuned to match projected NASA requirements.
One Multi-Mission Radioisotope Generator (MMRTG) requires 32 fueled clads, each of which contains 150 grams (0.33 pounds) of plutonium dioxide. A production rate of 10-15 fueled clads per year satisfies NASA’s future projected mission needs, as of 2018.
This chart shows projections of fuel clads being produced each year (blue bars) and the total inventory of fueled clads available to be used for selected and potential NASA missions (orange bars). In most years, the team plans to produce up to 15 clads using constant-rate production. DOE has the ability to surge manufacturing to produce 25 clads in a year to support additional proposed missions if they are selected by NASA. The “drawdown” of the inventory for use on a specific mission is recorded in the year of launch.
Constant-rate production reduces the risk and cost for individual missions through greater efficiency and flexibility, and allows the NASA RPS Program to maintain the skills of production staff and make strategic investments to improve equipment reliability and production predictability, with no need for significant downtime.
As of April 2018, DOE has produced 350 grams of new plutonium dioxide heat source fuel for NASA missions.