Engineering services.

UK Fusion Energy Ltd (UKFE) is seeking to appoint a supplier to undertake the concept design of a system capable of in-situ quantification of tritium retention within plasma-facing (first wall) materials for the Spherical Tokamak for Energy Production (STEP) programme. STEP is the UK's flagship fusion energy programme, sponsored by the Department for Energy Security and Net Zero (DESNZ), and aims to design and construct the UK's first prototype fusion power plant capable of demonstrating net energy production, fuel self-sufficiency and a viable route to plant maintenance. UKFE, a wholly owned subsidiary of the United Kingdom Atomic Energy Authority (UKAEA), is responsible for delivering the programme.

A key challenge for future fusion power plants is the management of tritium, which serves as a fuel for the deuterium-tritium fusion reaction. Tritium is both radioactive and scarce, making accurate measurement of its retention within plasma-facing components essential to demonstrating fuel self-sufficiency, supporting tritium accountancy, and monitoring the condition of first wall materials throughout plant operation. The successful supplier will develop a concept design for a measurement system capable of operating within the demanding environment of a fusion power plant, taking into account constraints such as neutron radiation, strong magnetic fields, thermal loading, limited installation space, and exposure to radioactive materials.

This procurement represents the initial concept design phase of a wider programme of work. Subject to future funding and programme approvals, the outputs of this contract are expected to inform subsequent detailed design activities, technology maturation, de-risking and testing, and ultimately the development of an integrated tritium measurement system for deployment within the STEP tokamak.