UK Fusion Energy missed four of 21 targets in 2025/26, spent £118.8m

UK Fusion Energy (UKFE), the UKAEA Group company developing the STEP prototype fusion plant at West Burton, spent £118.8 million in the year to March 31, 2026 and missed four of its 21 corporate performance measures, according to its annual report and accounts for 2025/26, published October 13, 2026. Sixteen were achieved and one partially.

The four misses sit in three groups of the report's performance table: one under West Burton site development, two under defining the STEP supply chain and one under international and third-party investment proposals. The report's narrative calls each of those groups partially achieved and explains them: the decision on where the tokamak sits on the site was "taken later than planned, though still in year, following further technical due diligence" (it came in November 2025); Board approval and formalisation of some supply chain outputs "extended beyond the reporting period"; and final approvals for international partnership proposals were not concluded within the year. The partial measure covers technology demonstrations, where high-heat-flux testing of plasma-facing components was not fully completed "due to manufacturing and supply chain constraints".

There will be no engineering partner for now. "Following consideration, it was decided not to appoint an Engineering Partner at this time," the report says, with the capability sourced from the market instead. Other system partner contracts are expected in 2026/27, and market testing for an engineering partner will come in later years.

More of the money is going to industry: spend with industry rose to 54% of the total, from 47% in 2024/25, and the UKAEA Board has approved a £167.5 million budget for 2026/27. The 2025/26 outturn, within 1% of budget, was £106.7 million of operating and £12.1 million of capital expenditure. UKFE's release puts the year's investment at nearly £120 million "progressing design".

The construction partner contract with the ILIOS consortium was placed on April 2, 2026, and UKAEA took ownership of half the West Burton site from EDF on March 23, 2026, with the rest to follow in 2028. In September, UKFE said procurement packages for six strategic partner opportunities were in their final stages.