Tritium Decay and Inventory Management

Because tritium decays into helium-3, inventories shrink and generate a co-product; managing both is central to any tritium program.

A stockpile that changes itself

Tritium does not sit still. Every atom of tritium that decays becomes an atom of helium-3, releasing a low-energy beta particle. So a tritium inventory continuously loses tritium and continuously gains helium-3. Managing a program means tracking both the shrinking tritium and the accumulating helium-3 that can be harvested.

The co-product connection

This decay is, in fact, the traditional source of helium-3 for neutron detection. It ties two strategic isotopes together: a tritium program is also, over time, a helium-3 program. A breeder that produces tritium therefore contributes to helium-3 supply twice, through direct co-production and through the later decay of its tritium output.

• ~5% of tritium is lost to decay each year
• Each decay produces one helium-3 atom
• Harvested helium-3 feeds neutron detectors

Public framing

Kronos discusses inventory dynamics only at the level of isotope physics and supply. The design-study production figures, tritium in the 4 kg/yr class and helium-3 near 1.97 kg/yr, describe a machine not yet built.

Accounting for both isotopes

Because decay steadily converts tritium into helium-3, a rigorous program tracks a moving balance: tritium falling by roughly five percent a year and helium-3 rising in step. Well-designed handling captures the helium-3 rather than venting it, turning an unavoidable loss into a second product. Managing the pair together, rather than treating decay purely as attrition, is what lets a tritium program also serve as a helium-3 source over its life.

This is a public overview only. It contains no classified information, no operational detail, and no weapons-design content.