Transmutation and Activation Products

Neutrons transmute nuclei in fuel, structure, and targets; understanding these products matters for services, waste, and honest safety accounting.

Neutrons rearrange nuclei

Any material in a neutron field is transmuted to some degree: nuclei capture neutrons or undergo threshold reactions and become different nuclides. In Hyperion this happens deliberately (breeding tritium, activating chosen targets) and unavoidably (activation of structure, coolant, and the first wall). Both must be understood.

Deliberate transmutation

• Tritium breeding: ⁶Li(n,α)³H — the primary product
• Neutron multiplication: (n,2n) on Be or Pb
• Target activation: chosen (n,x) routes for isotope services

Unavoidable activation

Structural steel, tungsten, coolant, and the hafnium-carbide-protected first wall all activate under 14 MeV irradiation, producing radioactive nuclides with a range of half-lives. This activation is why components have handling and disposal requirements, and why the center post — with its limited lifetime near 0.01 fpy — is a scheduled replacement item. Accounting for activation products honestly is part of the safety and waste case, not a side note.

Why it belongs on a products page

What Hyperion makes includes intended products and unintended activation, and candor requires naming both. The neutronics that predict tritium yield are the same neutronics that predict component activation. Both are design-and-simulation results, confirmed by measurement once the machine runs at FOAK.

This page describes a design-and-simulation study, not a built machine. Construction begins Q2 2027; first-of-a-kind (FOAK) first tritium is targeted near 2030. No net-gain claim is made before FOAK.