The Spherical Tokamak for Energy Production (STEP) is an ambitious programme to accelerate the delivery of sustainable fusion energy.

STEPThe spherical tokamak is a promising type of compact fusion machine, which has been under development since the 1980s. CCFE is about to start operating its new spherical tokamak, MAST Upgrade, opening an exciting new chapter in the drive towards practical fusion energy.

The STEP programme aims to deliver an integrated concept design for a fusion powerplant based on the spherical tokamak. It will develop and identify solutions to the challenges of delivering fusion energy, benefiting from Culham's breadth of expertise and its suite of research facilities – RACE, Materials Research Facility, H3AT and Fusion Technology Facilities.

The technical objectives of STEP are:

  • Deliver predictable net electricity greater than 100MW
  • Innovate to exploit fusion energy beyond electricity production
  • Ensure tritium self-sufficiency
  • Materials and components qualification under appropriate fusion conditions
  • Viable path to affordable lifecycle costs


The UK government has announced £220 million of funding, launching STEP as a collaborative programme that combines the strengths of UKAEA with industry, universities and other organisations.

STEP offers numerous procurement opportunities, set out in the STEP Programme Procurement Plan Schedule. This is published every quarter and sets out procurement opportunities as well as details of the responsible procurement officer who can be contacted for more information. Note that tender dates are subject to change.