The commercial protype plant will be built at the former West Burton coal-fired power station site in Nottinghamshire, and aims to demonstrate net energy from fusion in the 2040s.

Fusion is based on the same physical reactions that power the sun and stars, combining two hydrogen atoms to release large amounts of energy.

Importantly, the Spherical Tokamak for Energy Production (STEP) plant will also pave the way for an industry capable of delivering commercial fusion for decades.

Both contract terms will be an initial three-year period, followed by three optional extension periods of four, six and seven years.

The successful engineering and construction partners will deliver work in successive packages, cumulatively worth hundreds of millions of pounds during the initial contract period until 2029. Contracts will then build progressively in line with the development of the prototype plant.

According to the tender invitation the maximum contract duration for both contracts will be 20 years with an estimated value of £10bn each across this period.

This appointed teams will work collaboratively with UKAEA, under joint incentivisation mechanisms.

These partners will be core to delivery of the programme, as well as securing market-leading experience and knowledge.

Atkins and energy transition specialists Assystem have been working as engineering delivery partners to develop the concept design for STEP.

The appointed engineering and construction partners will develop a fully-formed major programme to deliver a full plant design, a viable supply chain and seek the consents needed for construction.

The construction partner will be tasked with delivering a site development programme, including innovative building designs focused on cost, schedule, safety and sustainability.

Applications are due in by 17 July with an initial three-year contract start date of May 2026. For more details click here.