6 start-ups innovating in the field of nuclear energy

27 Feb 2020

A nuclear power plant in Bavaria, Germany. Image: © pwmotion/Stock.adobe.com

We have gathered six start-ups around the globe that are developing solutions to make nuclear energy safer and more affordable.

As the climate crisis continues, energy is a major topic of concern worldwide. Nuclear energy has been touted as an alternative to fossil fuels, however, fission reactors can be expensive, generate large amounts of waste and come with safety risks.

Nuclear fusion, meanwhile, could usher in an age of near-limitless, cheap and clean energy. However, stability is the issue here, and companies and international bodies are investing heavily in trying to develop this tech as a feasible alternative.

Here, we take a look at six start-ups that are trying to disrupt this industry, developing solutions using magnets, molten salt and other technologies in the hopes of making nuclear energy a greater option in the future.

Commonwealth Fusion Systems

Commonwealth Fusion Systems is an MIT Plasma Science and Fusion Center (PSFC) spin-out that was founded in 2018 and is led by CEO Bob Mumgaard.

This start-up is focusing on the development of nuclear fusion, or the “holy grail” of energy sources, as it’s often described. While there are numerous companies striving to achieve the same goal, Commonwealth Fusion wants to achieve it sooner and at a lower cost by building “smarter”, rather than building bigger.

In order to accomplish this, Commonwealth Fusion Systems has assembled a team of experts in magnets, manufacturing and plasma physics, and hopes to someday deliver clean, limitless fusion power.

Last year, the Massachusetts-based company raised $115m in funding, with investors such as Italian energy company Eni, Schooner Capital, Lowercase Capital, Khosla Ventures and Beni VC.

General Fusion

Founded in 2002, Canadian company General Fusion may be more established than the start-ups on this list, but it began raising seed capital in 2007 and raised its most recent round of VC funding in December 2019, when it closed $65m in Series E financing. The firm has now raised more than $200m to date.

The company was founded by Michael Laberge and is now led by CEO Christofer Mowry. General Fusion is currently developing a fusion power device, based on magnetised target fusion. In 2017, the company said that it was developing subsystems for use in a prototype that could be built within five years.

The company’s latest funding round was led by Singapore’s Temasek, and saw additional investment from DLF Group, Gimv, Hatch and Bezos Expeditions, which is the investment firm of Amazon boss Jeff Bezos.


Founded in Sweden in 2013, LeadCold is a spin-out from the KTH Royal Institute of Technology in Stockholm, and is led by a team that has been researching the design and safety analysis of lead-cooled nuclear reactor systems since 1996.

Co-founders Janne Wallenius, Peter Szakalos and Jesper Ejenstam lead a team of experts in fast reactor core design, transient analysis, corrosion and materials science, nuclear fuel development, lead coolant chemistry, radiation damage and severe accident analysis.

In 2014, the start-up received a funding grant from the Swedish Innovation Agency to develop tools for safety-informed design of lead-cooled reactors, and in 2015 signed an agreement with KIC InnoEnergy.

In 2016, LeadCold received $18m in funding from Dubai-based Essel Group Middle East, and in June 2018, the UK government awarded the start-up a contract to produce a feasibility study for its Sealer reactor.

Flibe Energy

Flibe Energy was founded in 2011, with the aim tackling the future of nuclear energy by researching and developing the liquid fluoride thorium reactor (LFTR), which is a modern incarnation of molten salt reactor technology. Flibe energy was founded by Kirk Sorensen, who has spent more than a decade studying and exploring the technical basis and design of molten salt reactors.

Flibe claims that the properties of fluoride salts used in the LFTR offer safety benefits over existing reactor technologies, while facilitating an “inherently safe, intrinsically stable and self-regulating design that removes the root causes of today’s reactor accidents”, with an abundant supply of thorium available in the Earth’s crust.

Based in Huntsville, Alabama, the company has been backed by the US Department of Energy and Greengage Capital.

Seaborg Technologies

Founded in 2015, Danish start-up Seaborg Technologies aims to make nuclear energy inexpensive and sustainable, offering an alternative source of energy to fight the climate crisis. The company began as a collaboration between a small team of physicists, chemists and engineers with backgrounds at the Niels Bohr Institute, CERN, ESS and DTU Center for Nuclear Technologies.

The company is aiming to develop nuclear reactor technology that is fundamentally different from existing solutions, which Seaborg believes could out-compete fossil fuels. The technology is called the Compact Molten Salt Reactor (CMSR), which the company claims is significantly smaller than existing molten salt reactors and better for the environment.

The CMSR does not need constant cooling with water under high pressure, as conventional nuclear reactors do, as the CMSR’s fuel is mixed in a liquid salt that acts as a coolant and ensures it cannot melt down or explode. The start-up claims that in the case of an emergency, the core can simply be shut down.

Seaborg Technologies has raised around €1.5m in funding from investors including Lars Nielsen, PreSeed Ventures and The Index Project, among others.


Based in the UK and Canada, Moltex was founded by Dr Ian Scott and John Durham. The company is led by chief executive Stephen Haighton, along with North America CEO Rory O’Sullivan, who is a graduate of mechanical and manufacturing engineering from Trinity College Dublin.

Moltex wants to make molten salt reactors (MSRs) the norm, replacing today’s fission reactors, which require expensive measures to ensure that they operate safely. The start-up acknowledges that managing fission reactors is part of what makes nuclear energy so costly, making it unaffordable without significant government or consumer subsidy.

While MSRs have been understood for decades, there were a number of engineering challenges that prevented them from being used in mainstream nuclear power generation. Moltex believes that it has overcome these challenges and has developed a stable salt reactor that can be used to generate clean, cheap and safe electricity.

In 2019, Moltex raised £6m in its Series C, which included a crowdfunding campaign, and received a £3m grant from Canadian utility firm New Brunswick Power. The company has also received funding from the US Department of Energy.

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Kelly Earley was a journalist with Silicon Republic