Canada’s Terrestrial Energy has signed a Letter of Intent with US-based advanced nuclear technology development company TerraPraxis to cooperate on Repowering Coal. TerraPraxis is developing Repowering Coal as a programme to standardise and systematise the replacement of coal furnaces at existing coal-fired power plants with high-temperature heat supplied by Generation IV nuclear technology.

The Repowering Coal report, authored by TerraPraxis, was launched at COP26 in Glasgow in November 2021 in partnership with Microsoft, the Massachusetts Institute of Technology, Bryden Wood, Schneider Electric and others. The programme aims at integrating clean heat sources with existing infrastructure at coal-fired power plants.

TerraPraxis said it selected Terrestrial Energy’s Integral Molten Salt Reactor (IMSR) as the first candidate heat source vendor for the Repowering Coal programme due to its unique capabilities. These include its high-temperature heat supply required for coal-fired boiler replacement, and its capacity to be deployed quickly and at the scale necessary to replace 2TW of global coal capacity by 2050. According to the agreement, Terrestrial Energy and TerraPraxis will work on a standardised systems interface between the IMSR and coal-fired power plant systems, which they will apply to candidate sites as part of the programme to repower coal projects in North America and elsewhere.

“Terrestrial Energy is a developer of a leading, next-generation, nuclear technology with unique capabilities for Repowering Coal,” said Kirsty Gogan, managing director of TerraPraxis. “Terrestrial Energy’s high-temperature reactor technology aligns with the vision and mission of Repowering Coal.”

Simon Irish, CEO of Terrestrial Energy said TerraPraxis “is a visionary leader in climate and energy, focused on practicable, energy-transition pathways”. He added: “Repowering coal with Generation IV nuclear can decarbonize a difficult-to-abate part of the energy system rapidly and cost-effectively.”

Eric Ingersoll, managing director of TerraPraxis, said he was looking forward to incorporating Terrestrial’s technology into the design of the Repowering Coal system “while mindful of regulatory requirements as we conduct feasibility studies with multiple customers”.

The US Department of Energy (DOE) reported in a September study that over 300 coal-fired power plants in the United States alone are candidates for the Repowering Coal programme. DOE estimated that “80% of retired and operating coal power plant sites that were evaluated have the basic characteristics needed to be considered amenable to host an advanced nuclear reactor”. This represents over 260GWe located at more than 300 sites. However, the Terrestrial Energy-TerraPraxis partnership is looking to repower coal plants globally, which is an estimated 2TWe opportunity.

In September 2022, TerraPraxis and Microsoft entered into an agreement to deliver a digital solution that will catalyse significant decarbonisation in areas where global industry has struggled to get results. TerraPraxis will combine its expertise in energy with Microsoft to build and deploy a set of tools to automate the design and regulatory approval needed to decarbonize coal facilities with nuclear power.

Terrestrial Energy is developing a cogeneration plant for global industry using its proprietary IMSR fission technology in an innovative, small and modular plant design. The IMSR is a non-Light Water Reactor of the Generation IV class that operates at the high temperature required for broad industrial relevance.


Image: Still from Terrestrial Energy's animation of a clean hydrid energy system (courtesy of Terrestrial Energy)