About GEMINI 4.0

Launched in June 2022, GEMINI 4.0 aims to build a low-carbon future for industry based on the experience gained through the operation of HTR and knowledge of hydrogen production processes acquired in the previous H2020 project GEMINI+.

Many industrial processes require heat, large amounts of hydrogen and other energy products. The GEMINI+ project demonstrated that High Temperature Reactor systems can provide a competitive and safe solution for the CO2 free cogeneration of the process heat and electricity needed by industry. The GEMINI 4.0 project aims to demonstrate that the GEMINI+ system can, in addition to CO2 free process heat, provide a global solution for the competitive and safe decarbonisation of industrial activities, and confirm that this new form of poly-generation of various energy products does not negatively affect the safety of the combined plant.

The GEMINI 4.0 project will build on the groundwork laid by GEMINI+ and earlier projects carried out by NC2I, which defined the bases for the design and licensing framework of a HTR addressing European industry needs of process heat reliant on steam distribution networks that are already operated presently on many European industrial sites.


GEMINI 4.0 organisation

The GEMINI 4.0 project is organised into 6 work packages.

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About the GEMINI Initiative

The GEMINI Initiative is a a transatlantic partnership that aims to develop the first commercial High Temperature Gas-cooled Reactor (HTGR).

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Latest news

Access all news about the GEMINI Initiative, GEMINI+ and GEMINI 4.0.


Primary and Secondary circuit
The drawing shows Primary and Secondary circuit characteristics to transfer heat from the nuclear core to the end user application. Primary circuit convoys helium gas at 750°C to the heat exchanger. Secondary circuit convoys water steam to the end user application to provide heat at 565°C. A turbine provides electricity for house load at 6 MWe.

Step one

Consolidate the GEMINI+ system safety demonstration and ensure that its licensing readiness is assessed by regulators and TSOs including the scenario in which it is used in poly-generation mode.

Step two

Develop the capability of the GEMINI+ system to operate in a cost-effective way in poly-generation mode.

Step three

Plan for the development of a consistent fuel cycle for high temperature reactors with respect to fissile resources as well as a safe, acceptable back-end.

Step four

Implement an ambitious communication plan aimed towards political stakeholders, industry stakeholders and the general public, with the goal of removing obstacles to nuclear solutions for the decarbonisation of industry.

Achieving key objectives

The main objective of GEMINI 4.0 is to clear the way towards the safety demonstration and subsequent deployment of high temperature industrial nuclear cogeneration with the system developed in GEMINI+ project through four main steps.

Expected outcomes

Validation of safety options of high temperature reactors as candidate reactors for cogeneration initiatives for high energy-consuming industries.
Confirming whether a generic design for a high temperature reactor can be proposed for licensing, with the early involvement of regulators, and how a licensing process can be launched at the European level
Demonstration of the feasibility of coupled nuclear cogeneration technologies and installations at industrial scale
Socio-economic evaluation of the introduction of cogeneration with temperatures relevant to high temperature reactors in the industrial landscape of European regions with high energy-consuming industries.

GEMINI 4.0 partners

Coordinated by Framatome, the GEMINI 4.0 consortium gathers 21 partners from across Europe, as well as from Japan and South Korea.