Blue Capsule Technology begins construction of high-temperature sodium installation

18 February 2026 | Blue Capsule Technology announces the start of construction of “ELISE”, a new test rig for sodium at high temperatures. Construction began this week at Peyrolles-en-Provence, in collaboration with France’s CSTI Groupe.

• ELISE is the first installation on Blue Capsule Technology’s development roadmap and is set to run for several years.

• New milestone funded by fresh investment by the company’s historical investors, as well as CSTI Groupe, Robatel and Helionix.

“ELISE will replicate the conditions of the Blue Capsule high-temperature reactor (HTR), with temperatures reaching 750°C,” said the company’s Technical Director, Domnin Erard. 

“This full-size installation will stand at nine metres high when completed, and provide valuable data on thermo-hydraulics and the natural circulation of liquid sodium at high temperatures,” he added. 

President of Blue Capsule Technology, Edouard Hourcade, said the ELISE installation will be the “first of its kind" in France, and will be opened to other players in the field, “either institutional or commercial”. 

“It is important that the broader nuclear energy sector can benefit from ELISE. But it’s also a milestone for our company and a sign of steady progress.” 

Background:

Blue Capsule Technology is developing a high-temperature reactor (or “HTR”) for energy-intensive industries such as cement and metal refining (e.g. alumina), hydrogen production, and chemical sites (for fertiliser and soda ash production).

These vital industries increasingly need a reliable source of fossil-free heat, steam and electricity.

The Blue Capsule HTR will provide all three: heat to 700°C, steam/vapour to 650°C, and 50 megawatts of electricity as needed by the customer.

The sodium-cooled reactor is to use robust TRISO fuel for optimal safety, while the design is also optimised for more favourable economics due to the lower volume of building materials compared with traditional high-temperature gas-cooled reactors.

Last November, Blue Capsule Technology announced an agreement with Framatome to advance our cooperation on TRISO fuel. We aim to deploy low-enriched TRISO fuel at less than 5% in our reactors, given the wide use of low-enriched uranium in the industry, and the export potential of reactors that use LEU.

To date, Blue Capsule Technology has announced partnerships with the CEA, Framatome, Egis, CSTI Groupe, DigIntel, Robatel and BJS, as well as strategic subcontractors such as Veolia Nuclear Solutions, Laborelec and Mersen.

The company’s “historical investors” include Eren Groupe S.A., Exergon, AUDACIA Coinvest, and CEA Investissement.

The first-of-a-kind Blue Capsule reactor is scheduled for deployment at the beginning of next decade.