European and US nuclear companies contribute to space work

01 September 2021

The European Space Agency (ESA) has awarded a contract to Belgian company Tractebel to evaluate the possibility of producing plutonium-238 (Pu-238) for use in space exploration. Separately, US company X-energy, working as part of a General Atomics Electromagnetic Systems (GA-EMS) team, is to develop key fuel fabrication processes in support of a first-of-a-kind rocket powered by nuclear thermal propulsion under a contract awarded by the US Defense Advanced Research Projects Agency (DARPA).

ESA's EL3 will land on the Moon as part of NASA's Gateway programme (Image: ESA)

Radioisotope power sources - sometimes referred to as nuclear batteries - fuelled with Pu-238 have been used in space missions since the early 1960s. Radioisotope thermoelectric generators and radioisotope heater units  can provide power and heat continuously over long, deep space missions. Pu-238 is made by irradiating neptunium-237, recovered from research reactor fuel or special targets, in research reactors but at present only Russia and the USA have the capability to produce the isotope.

Working in partnership with Orano and SKC-CEN, Tractebel will study the possibility of manufacturing Pu-238 by bombarding neptunium-237 from the La Hague recycling facility in France with the neutron flux of the BR2 research reactor in Mol, Belgium. The work will include the development of a "roadmap" for the creation of a Pu-238 production chain in Europe that will include a timeline and estimated production capacity and costs, as well as evaluating regulatory acceptance, Electrabel said.

ESA is manufacturing the European Large Logistic Lander (EL3) to land on the moon as part of Europe's participation in the NASA-led Lunar Gateway programme, which aims to establish a planned small space station in lunar orbit that will serve as a staging point to send astronauts to Mars. The EL3 equipment may need to survive the lunar night - when it will not be exposed to sunlight - for up to two weeks.

Brieuc Spindler, Tractebel's Product Owner - Space, said the study will contribute to making European space exploration more independent. "With a team of multidisciplinary experts, we will analyse the capability of Europe to develop its own supply chain of plutonium 238," he said. "It has the best technical characteristics for space applications, but has never been developed in Europe. It is our first contract with ESA, and what we hope marks the beginning of a fruitful cooperation."

DRACO fuel

US nuclear reactor and fuel design engineering company X-energy has announced it will develop key fuel fabrication processes to support DARPA's Demonstration Rocket for Agile Cislunar Operations (DRACO) programme, which aims to demonstrate a nuclear thermal propulsion - or NTP - system above low Earth orbit in 2025. General Atomics was selected earlier this year to carry out the reactor development work for the project.

NTP systems use a nuclear reactor to heat propellant to extreme temperatures before expelling the hot propellant through a nozzle to produce thrust, providing greater propellant efficiency compared with chemical rockets.

As part of a team led by GA-EMS, X-energy said it will develop key fuel fabrication processes in support of a first-of-a-kind NTP-powered rocket. This will provide previously unavailable data on the specialised fuel, and will contribute to the design of the system, the company said.

X-energy, which has operated a pilot fuel facility since 2017, has active contracts with the US Department of Energy and Department of Defense to develop terrestrial-based nuclear power systems and has supported NASA in their refinement of NTP reactor concepts. It also has partnerships with sister companies Axiom Space - which is building the first commercial space station - and Intuitive Machines - which is developing the first commercial moon lander, scheduled to launch in 2022.

X-energy Executive Chairman Kam Ghaffarian said the company's delivery of nuclear know-how to the DRACO programme fulfilled a long-held personal goal to apply safe, secure and affordable nuclear solutions to the benefit of space-based systems. "The US Government recognises innovative, mission-enabling value of nuclear to achieve our cislunar and planetary exploration goals and we are thrilled to be part of it," he said.

Researched and written by World Nuclear News