SoftBank to build massive AI datacentre on former US nuclear weapons site

Steven

SoftBank to build massive AI datacentre on former US nuclear weapons site

Summary

SoftBank’s SB Energy has agreed to lease Department of Energy land at the former Portsmouth Gaseous Diffusion Plant in Piketon, Ohio, to develop a large-scale AI data centre campus. The plan calls for a 10-gigawatt (GW) server farm alongside 10 GW of new generation capacity (about 9.2 GW gas-fired). SB Energy and AEP Ohio will invest in a $4.2 billion transmission upgrade across southern Ohio to supply power to the site, with electricity expected by 2029.

The deal includes a “Portsmouth Consortium” of Japanese and US firms (Hitachi, Mitsubishi Electric, Toshiba, TDK, Sumitomo Mitsui Banking, Bechtel, Morgan Stanley, Goldman Sachs, J.P. Morgan) and SB Energy has committed to accelerating cleanup of uranium contamination at the site. The project is positioned as supporting national AI competitiveness while aiming to protect ratepayers from bill increases tied to soaring AI demand.

Key Points

  • SB Energy will build a 10 GW server farm on leased DOE land at the Portsmouth site in Ohio.
  • The project includes 10 GW of new generation capacity, with at least 9.2 GW gas-fired to serve grid and campus needs.
  • SB Energy and AEP Ohio agreed a $4.2 billion transmission upgrade across southern Ohio; power is expected to reach the site by 2029.
  • SoftBank will fund accelerated cleanup of the former uranium enrichment site as part of the deal.
  • A broad “Portsmouth Consortium” of Japanese and US companies and financiers has been announced to participate in the campus.

Context and Relevance

This project sits at the intersection of big‑scale AI infrastructure, energy policy and post‑industrial site reuse. It reflects a growing pattern of colocation between power generation and data centres, highlights the pressure AI demand places on grids, and shows how federal assets are being repurposed to accelerate private investment. For energy and infrastructure stakeholders, regulators and regional planners, it signals major transmission spending and potential local economic shifts. For tech and AI firms, it underlines the scale of compute being deployed and the trade‑offs between on‑site generation and environmental legacies.

Author style

Punchy: this is a big, consequential deal — huge capacity, huge grid spending, and the awkward bonus of nuclear cleanup on the balance sheet. If you work in infrastructure, energy or AI ops, the details matter. Read the detail if you need to plan around power availability, regulatory fallout or regional supply chains.

Why should I read this?

Because it’s massive and messy — a 10 GW AI hub + 10 GW of generation + a $4.2bn grid overhaul. Someone’s turning a cold‑war nuclear site into the backbone for the AI boom, and that reshuffles risk, cost and opportunity for utilities, data‑centre operators and local communities. We’ve done the skim for you, so you can spot the bits that matter fast.

Source

Source: https://go.theregister.com/feed/www.theregister.com/2026/03/23/softbank_to_put_mega_server/