
Nucleation Capital is pleased to congratulate Blykalla on the close of its $50 million financing round in December 2025 and to confirm its participation as a returning investor. The round was co-led by Oklo, Norrsken Launcher, and Armada Investment, with participation from strategic and financial investors including KDDI, Earth Venture Capital, and the co-founders of CoreWeave.
This marks Nucleation Capital’s second investment in Blykalla, following the $7.3 million Series A completed in the spring of 2024, which Nucleation co-led with Norrsken Ventures. Since that time, Blykalla has continued the development of its SEALER lead-cooled reactor while expanding its commercial and partnership activity across Europe and North America.
Over the course of 2025, Blykalla announced a series of partnerships and project-related agreements tied to Nordic deployment of its SEALER reactor, transatlantic cooperation, and the use of nuclear power for data centers.
In February, Blykalla and Norsk Kjernekraft announced a memorandum of understanding to explore the deployment of the SEALER reactor in Scandinavia, followed later by an agreement to pursue an SMR project in Norway’s Svalbard region. In late September 2025, Blykalla announced a major transatlantic partnership with Oklo to collaborate on reactor technology, supply chains, and regulatory coordination. Subsequently, in October 2025, Blykalla announced a landmark partnership with licensed nuclear site host Studsvik and European hyperscaler evroc to evaluate Sweden's first nuclear-powered data centers at the Studsvik site in Nyköping, Sweden.
The capital from this financing will support continued testing and validation at the Advanced Reactor Testing Site in Oskarshamn, Sweden, further design and engineering work on Blykalla’s first nuclear units, and ongoing commercial and regulatory efforts related to siting and licensing its initial SEALER project.
Nucleation Capital invests in advanced nuclear and nuclear-adjacent companies focused on delivering reliable, zero-carbon energy. Nucleation’s continued participation in Blykalla reflects its long-term view that multiple next-generation reactor designs will be required to meet growing electricity demand from industry, data infrastructure, and other energy-intensive sectors.
A recent report highlights the growing financial and strategic significance of Blykalla’s partnership with Studsvik and Evroc, as the companies move forward on plans to develop Sweden’s first nuclear-powered data centers...
Blykalla, the Swedish developer of lead-cooled reactors and a Nucleation portfolio company, and Norway’s Norsk Kjernekraft have agreed to launch a joint venture to develop an SMR power plants on the Norwegian Artic archipelago of Svalbard.
Swedish nuclear energy company Blykalla, a Nucleation portfolio company, and Norway’s Norsk Kjernekraft have signed a memorandum of understanding (MOU) to collaborate on the possible deployment of Blykalla’s SEALER reactor design in Scandinavia.
Blykalla (formerly LeadCold) – The Swedish developer of the high-temperature, low-cost, lead-cooled reactor called the Swedish Advanced Lead Reactor (SEALER) and currently the only Swedish advanced nuclear developer in a country looking to add more nuclear power.
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