Blykalla and NEEXT strengthen cooperation on SEALER Development

Press ReleaseOctober 26, 2026

Belfort, France & Stockholm, Sweden

Blykalla and NEEXT are pleased to announce the expansion of their long-term engineering partnership on Blykalla’s Swedish Advanced Lead Reactor, SEALER, formalised by the signing of a new agreement on 2 October 2026.

The SEALER, developed by Blykalla, is a Generation IV lead-cooled small modular reactor (SMR) designed to deliver fossil-free electricity and industrial heat. It combines liquid lead cooling, passive safety features, and proprietary corrosion-resistant materials to enable safe, long-life, factory-built reactors. The full SEALER program comprises FJÄLL, the first-of-a-kind (FOAK) demonstration reactor, and the SEALER-55 for commercial deployment, recently illustrated by applications for two reactor parks in Sweden: Norrsundet (six units) and Tierp (up to eight units).

Following the successful completion of several engineering assignments together, Blykalla has chosen to expand its collaboration with NEEXT, integrating NEEXT’s design and digital modeling engineers into its own engineering organization to advance the basic design of SEALER’s conventional island.

"NEEXT has demonstrated the technical expertise and collaborative approach we need to advance SEALER’s design. Expanding this partnership is a natural next step. "By integrating their engineers into our team, we bring specialist design and digital modelling capabilities directly into the development of the conventional island. Together, we will translate that expertise into a compact, efficient and competitive power plant, taking SEALER closer to deployment."

— Kristofer Thoresson, VP Engineering of Blykalla

"Being fully integrated into Blykalla’s engineering organization team enables us to work hand in hand from the earliest design stages, bringing greater proximity, faster alignment and better overall integration. "This is key to optimizing plant layout, performance, reliability, modularization, and competitiveness while ensuring seamless integration of digital models to simulate and optimize complex operating scenarios. Working with a client like Blykalla with high expectations for technical and operational expertise also drives NEEXT to continuously raise its engineering standards, strengthen its processes and embed the traceability and design discipline essential to the nuclear industry."

— Jean Maillard, CEO of NEEXT

About Blykalla

Blykalla is a global leader in advanced nuclear technology, commercializing the next generation of clean, reliable energy through its lead-cooled reactor, the SEALER. Blykalla's work builds on an industry legacy of quality, safety, and excellence. By combining decades of specialized research with world-class partners, Blykalla is developing the backbone of the global AI and industrial economy. For more information visit www.blykalla.com.

About NEEXT

Based in Belfort, a global center of excellence for energy technologies, NEEXT was founded in 2022 by a team of experienced energy engineers. With a steadily growing team, NEEXT provides innovative solutions and services for the industrialization of high-performance and sustainable energy production systems. Alongside its R&D programs, SPARTA and REVOLT, aimed at revolutionizing the efficiency of thermodynamic systems through the use of new patented working fluids (“reactive fluids”), NEEXT supports its clients in developing innovative solutions for decarbonized heat production, enabling this heat to be converted as efficiently as possible into electricity or other forms of useful energy. www.neext.energy

Press contacts:

Blykalla:
press@blykalla.com

NEEXT:
press@neext.energy