Swedish company Blykalla, formerly called Leadcold, has announced the closure of its latest funding round to support its lead-cooled SMRs, raising a total of SEK80m ($7.3m). The round was led by Norrsken Launcher together with Nucleation Capital, with participation from Earth Venture Capital, Farvatn, and several private investors.

Norrsken Launcher is an investment fund that works to industrialise, commercialise, and scale innovations that can fundamentally transform the future. Nucleation Capital is a climate-centred venture fund investing promising clean energy and carbon-removal technologies. It primarily focuses on the advanced nuclear and deep decarbonisation sectors. Earth Venture Capital is a global venture capital firm dedicated to investing in early-stage climate-tech startups, pioneering in AI, robotics, satellite technology, and innovative new materials.

The funds will support Blykalla's industrialisation plans for its advanced nuclear reactor design, the SEALER (Swedish Advanced Lead-cooled Reactor), a lead-cooled fast compact reactor with passive safety. Each reactor will have a 55 MWe capacity, which can be increased by installing multiple units at the same location. The reactor designed with the smallest possible core that can achieve criticality in a fast spectrum using 19.9% enriched nitride fuel.

Blykalla says the SEALER is designed for commercial power production in a highly compact format, with unique safety features that are made possible by a number of proprietary innovations. These include corrosion-tolerant steel alloys, which enable the efficient cooling of reactors with liquid lead. “With this technological breakthrough, Blykalla can achieve effective serial production, leading to faster deployment and lower costs than conventional nuclear power.”

The SEALER “also enables nuclear power to be used for decarbonizing industrial applications through hydrogen, biochar, and biofuel production, in addition to providing local electricity production”. Blykalla says the technology helps realise a circular waste model. Compared with conventional nuclear power, the SEALER’s fuel cycle can extract up to 140 times more energy from uranium ore, “thereby producing only a fraction of the waste, which needs to be stored for just 1% of the deposit time”.

Preparatory work is currently underway to license the technology in Sweden. An important step to industrialise and qualify the technology is to build the electric test reactor in Oskarshamn, that is being developed together with OKG (Uniper’s Swedish subsidiary) and KTH (the Royal Institute of Technology). In parallel, the company is in discussions with industrial partners to support building nuclear reactors for off-grid heat and electricity production.

Blykalla says it has developed steel alloys that protect core components from corrosion. Key innovations are three aluminium alloyed steels: a aluminium oxide forming steel for protecting cladding tubes; an austenitic steel for protecting reactor vessels; and a martensitic steel suited for lead pump impellers.

The SEALER is a compact design (five metres by five metres). The fuel residence time is 25 years. It has no overpressure system, no exothermic reaction with structural materials or water, and passive decay heat is removed by natural convection. “The competitive advantage stems from the reactor’s overall compactness and forecasted production volumes, which results in components that are of a size that are more optimally conducive to scalability and repeatability in production.”

The reactor will use uranium nitride fuel, which features 40% more uranium per volume unit, resulting in a 40% longer life for the fuel. Blykalla says this also leads to better safety margins (operating at more than 1,500°C below its melting point), with seven times higher thermal conductivity. “While this fuel is difficult to manufacture using conventional methods, Blykalla has a solution that enables the direct conversion of enriched UF6 [uranium hexafluoride] in streaming NH3 [ammonia]. Using ‘Spark Plasma Sintering’… assisted hot pressing, pellets can be sintered in just three minutes at 1450°C. By comparison, this takes eight hours at 1900°C using conventional methods.”

According to the company website, the SEALER reactor is designed to maintain a maximum temperature of the lead coolant below 450°C, making corrosion of fuel cladding and structural materials a manageable phenomenon, even over a lifespan of several decades. While the website has details of the overall design, fuel and the safety features, it says nothing about the fast reactor technology.

Image: The Swedish Advanced Lead Reactor (SEALER) design (courtesy of Blykalla)