How much does a fusion plant cost?

The interesting answer is not a dollar figure but a structure: for a compact, high-gain machine, much of the naive capital is heating power that shrinks as gain rises. Kronos freezes that structure, not a headline price.

Key insight

Capital must be built by structure, not scaled as a lump

Why

At high gain, auxiliary-heating capital shrinks sharply

Breeder

Economic on frozen structural capital at central availability

Absolute figure

Not frozen — depends on scope and financing

Fusion capital estimates are often a single scaled number, which hides where the money goes. Kronos builds it from structure instead. A large share of a naive anchor is auxiliary heating — and at the breeder's gain (Q 3.424), that line is far smaller than at break-even, because a high-gain plasma needs proportionally less external heating. Building the capital line-by-line gives a very different, lower structural figure than scaling the whole anchor.

That is why the breeder is economic on its frozen structural capital at central availability, even at market tritium prices. Kronos freezes this structure and its levers; it does not freeze an absolute plant price, which depends on final scope (divertor, balance-of-plant) and financing terms that remain open.