SMR partnership targets Swedish district heating

The partners said the collaboration "leverages Kärnfull's innovative financing structures and delivery models to bring Steady Energy's world-leading district heating reactors to Sweden".

Steady Energy - which was spun out in May 2023 from the VTT Technical Research Centre of Finland - has previously signed letters of intent for the delivery of up to 15 LDR-50 reactors with Helsinki's local utility Helen and Kuopio Energy in eastern Finland. The construction of the first commercial plant is projected to begin in 2028, with the first unit anticipated to be operational by 2030. Construction of the first SMR pilot plant in Finland will begin next year with candidate sites in Helsinki, Kuopio and Lahti.

The LDR-50 district heating SMR - with a thermal output of 50 MW - has been under development at VTT since 2020. It is designed to operate at around 150°C and below 10 bar (145 psi). The LDR-50 reactor module is made of two nested pressure vessels, with their intermediate space partially filled with water. When heat removal through the primary heat exchangers is compromised, water in the intermediate space begins to boil, forming an efficient passive heat transfer route into the reactor pool, the company said. The system does not rely on electricity or any mechanical moving parts, which could fail and prevent the cooling function.

Kärnfull Next - a fully-owned subsidiary of Kärnfull Future AB - aims to have the first commercial SMR operational at a new nuclear site in Sweden by the early 2030s.

"We are delighted to collaborate with Steady Energy to bring their sleek, cost-effective solution to Sweden," said Kärnfull Next CEO Christian Sjölander. "With Steady's reactor in our portfolio, we complement our electricity-focused Re:Firm SMR programme with a new bespoke district heating programme called Re:Heat, targeting municipalities in need of sustainable heating solutions."

Steady Energy CEO Tommi Nyman added: "We are very proud to partner with trailblazers Kärnfull Next. Sweden’s electricity consumption is projected to increase significantly to meet net-zero targets, driven by the electrification of transport and industry. This necessitates corresponding clean heating energy to maintain Sweden's carbon commitments."

According to the partners, Sweden's district heating consumption totals some 50 TWh per year, two-thirds of which comes from biomass, with fuel costs rising sharply in recent years. Generally, the future of biomass within district heating is debated, not least since it is seen to have more valuable alternative uses. Additionally, the combustion of biomass leads to the emission of biogenic greenhouse gases.

"Heating a large city with biomass requires a pile of logs the size of a football field every single day, with a constant stream of trucks around the clock," Nyman said. "It's high time that our societies limit burning wood to heat our homes. By combining our expertise, Steady Energy and Kärnfull Next are poised to bring SMR district heating to Sweden, speeding up ambitious climate and sustainability goals."