Refractory Metals Under Fusion Neutrons
Tungsten and other refractory metals handle extreme heat but change under neutron bombardment; qualification quantifies that change.
Heat champions, radiation unknowns
Tungsten and related refractory metals tolerate very high temperatures, which makes them candidates for the hottest, most exposed surfaces. Under fast-neutron bombardment, however, they harden and embrittle, and transmutation shifts their composition over time. These effects must be measured before a refractory component can be trusted in service.
What campaigns measure
- Embrittlement and the ductile-to-brittle transition
- Transmutation products from neutron capture
- Retention of thermal and mechanical performance
A fusion-representative answer
Because refractory behavior depends on the neutron spectrum, a 14 MeV source gives a fusion-representative answer that fission testing only approximates. This supports both fusion component design and any high-temperature, high-radiation application.
Kronos offers refractory-materials irradiation as a neutron service, described publicly. The figures reflect a design study, not a built machine.
Transmutation shifts the alloy
Under sustained neutron capture, tungsten slowly transmutes toward rhenium and osmium, changing the very composition being tested. That drift alters both mechanical and thermal behavior over a component's life, so a credible qualification tracks composition as well as damage. A 14 MeV spectrum reproduces the transmutation pathway representative of fusion service, which fission testing only approximates, giving refractory-component designers a more faithful picture of end-of-life behavior. Tracking composition as well as damage over a campaign is what separates a fusion-representative refractory qualification from a fission surrogate that misses the transmutation pathway entirely.
This page describes a design and simulation study, not a built machine. The breeder (Hyperion) begins construction Q2 2027; first-of-a-kind first tritium is targeted near 2030. No hardware net-gain is claimed before then.