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Korean Republic SMR district heating explored Finnish start-up Steady Energy is to co-operate with South Korea’s largest district heating provider, Korea District Heating Corp on heat- only small modular reactors (SMRs). Steady Energy, spun out of the VTT


Technical Research Centre of Finland in 2023, is developing the LDR-50 SMR. It is designed to only produce heat and is focused on district heating, as well as industrial steam production and desalination projects. The 50 MWt LDR-50, which has been under development at VTT since 2020, is a simplified pressurised light water reactor specifically designed to operate at around 150°C and below 10 bar (145 psi). The reactor module comprises two nested pressure vessels, with their intermediate space partially filled with water. The system does not rely on electricity or any mechanical moving parts, which could fail and prevent the cooling function. It was awarded a patent in 2021. The LDR-50 reactor design is being assessed


by the Finnish Radiation and Nuclear Safety Authority (STUK – Säteilyturvakeskus). The aim is for construction of the first plant to begin in 2029. Steady Energy has already signed agreements for 15 reactors in Finland and in December 2024 signed a contract with Belgian engineering firm Tractebel to provide engineering services. “The 10m-strong Seoul metropolitan area is


keeping a sharp eye on Helsinki’s progress in adopting small nuclear,” said Steady Energy CEO Tommi Nyman. “Many are particularly interested in the fact that our facility is built underground, which makes clean heat practical in dense cities.” In July, Steady Energy completed a €32m


($37.7m) funding round, most of which will go towards a pilot plant to be constructed at a recently decommissioned coal plant in Helsinki city centre. The pilot plant will not contain nuclear fuel. Instead, water within the reactor loop will be heated by electrical elements providing approximately one-tenth of the LDR-50 reactor power output. It will physically demonstrate the LDR-50 reactor’s key safety features and give detailed advance insight into steps required for the eventual commercial plant. Steady Energy aims to reach the ready-to- build phase by 2028.


United States X-energy begins TRISO-X tests US-based X-energy Reactor Company has begun testing at Idaho National Laboratory (INL) to evaluate the performance of their TRISO-X advanced nuclear fuel. This is a critical step in meeting the requirements of the US Nuclear Regulatory Commission (NRC) for the commercial deployment of advanced reactors that will use the fuel. The test campaign is part of X-energy’s


overall plans to establish the first US commercial advanced nuclear fuel fabrication


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facility to support the deployment of their small modular reactor (SMR) design, the Xe-100, and other commercial reactors. Irradiation testing of TRISO-X fuel will take


place over 13 months at INL’s Advanced Test Reactor (ATR) facility. The experiments will evaluate how the fuel performs at various power levels, temperatures, and burnup conditions to simulate a wide range of operating scenarios. TRISO-X is a specialised type of TRISO (tristructural-isotropic) fuel, which is favoured by many advanced reactor developers. The fuel will be fabricated into billiard ball-sized spheres or “pebbles” developed by X-energy to power high temperature gas-cooled reactors, such as the Xe-100. The first units of the Xe-100 will be built in Texas at Dow Company’s Seadrift manufacturing site. Dan Wachs, the National Technical Director


for the Department of Energy’s (DOE’s) Advanced Fuels Campaign, said: “The test marks INL’s first irradiations of TRISO fuel for advanced reactors since 2020 and the first use a new lead-out test capability at ATR that makes these advanced fuel tests possible.” Once testing in the ATR is complete, post-irradiation examination will begin at INL and Oak Ridge National Laboratory. ■


round up


SPACE FRAMATOME HAS SIGNED a contract formalising collaboration with the European Space Agency (ESA) and partners - Perpetual Atomics and Amentum - for the industrialisation of sealed fuel sources to be used as radioisotope power systems (RPS) for space exploration. This contract supports the ENDURE (European Devices Using Radioisotope Energy) programme, which aims provide Europe with a sovereign industrial production capability of radioisotope-based sealed fuel for RPS.


FUSION UK-BASED TOKAMAK Energy has agreed an international strategic partnership with Saudi Arabia’s King Abdulaziz City for Science and Technology (KACST) during the Future Investment Initiative in Riyadh. The partnership aims to advance and develop national capabilities in fusion energy technologies, including high temperature superconductors, through a series of future projects.


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