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Publication series 3 — Economics & Market

What a First Plant Costs: Inside the $3.15B FOAK Bill of Materials

Credible capital costs are built from the bottom, one subsystem at a time.

MetroVolt's first-of-a-kind direct-cost basis is $3,150M, assembled as a line-item bill of materials — magnets to shield to conversion train to buildings — rather than scaled from someone else's reactor study.

The science

The BOM prices the frozen design point: the ~31,300 km REBCO conductor order and winding, the WC/W₂B₅ shield stack at its computed ≈1.20 m minimum, the vessel in its qualification-target alloy class, the multi-modal DEC train, cryoplant, heating and current-drive systems, and balance of plant — each line carrying its own basis and contingency posture in the finance model.

Dividing through the conservative 0.61 GWe net yields the capex-per-kilowatt figures that seed the published ladder scenarios; the model and the physics deposit quote each other, so the engineering and the economics cannot silently diverge.

Why it matters

A bottom-up BOM is auditable: a supplier can quote against a line, a diligence engineer can challenge one, and cost learning can be tracked line-by-line as the fleet builds. The $3.15B figure is not small — it is simply real, and every rung of the cost ladder stands on it.

The numbers

FOAK direct-cost basis$3,150M (line-item BOM)
Largest linesmagnets · shield · DEC train
Conductor order≈31,300 km REBCO
Feedscapex/kWe scenarios → LCOE ladder
Consistencyfinance model reconciled to the physics deposit
Straight answersFOAK costs carry first-unit risk by definition; the ladder's $6,500–11,500/kWe scenario spread exists precisely to hold that uncertainty in view rather than average it away.
Every figure in this paper traces to the openly deposited 81-simulation programme (S01–S81) behind the Kronos MetroVolt four-paper design series — data and code at DOI 10.5281/zenodo.21248916 (CC BY 4.0). Read the series, run the code, check us.
Kronos MetroVolt is a conceptual design study. Quantitative values are simulation-derived and carry the feasibility gates stated in the series; Tier-2 flagship-code confirmations are deposited as runnable decks pending HPC execution. This document is informational and is not an offer of securities. © 2026 Kronos Fusion Energy, Los Angeles.