STEP Fusion by UK Fusion Energy: status and timeline

STEP Fusion

Build and operate a working fusion power plant to prove the technology can generate electricity at commercial scale, forming the foundation for UK commercial fusion deployment.

ProtoStage 2 of 5

Construction partner appointed March 2026; building for operation around 2040.

Updated 16 Mar 2026Checked 11 Oct0 updates this week

Milestones

Next · Detailed design and early site preparation (Phase 2)

ILIOS construction partnership appointedMar 2026Complete.
Detailed design and early site preparation (Phase 2)Target 2025Current milestone.
Main construction phase beginsTarget 2032Not yet reached.
First plasma and operationsTarget 2040Not yet reached.

Most important updates

UK appoints ILIOS consortium as construction partner for STEP Fusion at West Burton, £200 million contract16 Mar 2026

Upcoming

2025Detailed design and early site preparation (Phase 2) (next)
2026ILIOS construction partnership mobilized
2032Main construction phase begins
2040First plasma and operations
2040First plasma target

Current obstacles

Engineering the full system at scaleMoving from demonstration devices to a working power plant requires solving hundreds of engineering problems simultaneously, from materials to control systems.
Meeting commercial timelineDelivering a prototype by 2040 requires managing complex construction, regulatory approval, and technical validation in parallel.

Physics limits

Plasma instabilities grow with size and powerAs tokamaks scale up to commercial sizes, plasma becomes harder to control; tiny perturbations can cause disruptions that shut down the reaction.
Neutron activation makes decommissioning hazardousReactor walls become radioactive from sustained neutron bombardment, requiring careful decommissioning and waste management at end-of-life.

How it works

2 parts

Spherical design

Compact tokamak geometry

Spherical shape reduces material use and cost while maintaining confinement.

West Burton site

Former coal power station transformation

The West Burton site is being transformed from fossil fuel power generation to fusion, leveraging existing infrastructure and local expertise.

Spec sheet

Spec	STEP Fusion
Construction contract value	£200 million^R (reported)
Peak construction employment	Up to 8,000 onsite jobs^R (reported)

^R reported by the company

Update log

1 update

Mon 16 Mar

Major: UK appoints ILIOS consortium as construction partner for STEP Fusion at West Burton, £200 million contractPressCommercial

About UK Fusion Energy

The team behind STEP Fusion

UK Fusion Energy

STEP prototype fusion plant, West Burton, UK government fusion

UK Fusion Energy leads the STEP programme to build the UK's first prototype fusion plant at West Burton, appointed ILIOS construction partner for £200 million in 2026, targeting 2040 operations.

STEP transforms West Burton into the UK's prototype fusion plant to demonstrate net power generation.
ILIOS consortium appointed March 2026 for £200 million construction contract; operations targeted for 2040.
Peak construction supports 8,000 onsite jobs and anchors long-term economic growth in the region.

gov.uk (opens gov.uk)Company profile →

Headquarters: United Kingdom
Status: Government
Valuation: government
Works in: EnergyFusion
Coverage: 1 program · 1 updatelatest 16 Mar 2026checked 11 Oct
Partners: ILIOS Consortium (opens gov.uk)UK Atomic Energy Authority
People: Paul MethvenCEO & Senior Responsible Owner for STEP Fusion

Spec

STEP Fusion

Construction contract value

£200 million^R (reported)

Peak construction employment

Up to 8,000 onsite jobs^R (reported)