Commonwealth Fusion Systems in talks with Japan over tech use after $863M raise backed by Nvidia.

Commonwealth Fusion Systems, a company that recently raised $863 million from investors including Nvidia, is in talks with the Japanese government about using its technology. The company's CEO, Bob Mumgaard, discussed the talks in an interview with Bloomberg. No further details were provided about the nature of the discussions or the potential outcomes.

Commonwealth Fusion Systems (CFS), a company that recently raised $863 million from investors including Nvidia (NASDAQ:NVDA), is in dialogue with Japanese government officials regarding the use of its fusion technology. The company's CEO, Bob Mumgaard, disclosed the ongoing discussions in an interview with Bloomberg in Tokyo on Wednesday [1].

CFS, which spun out from MIT in 2018, is developing a 400-megawatt commercial fusion power plant in Virginia, with plans to commence operations in the early 2030s. Google (GOOG) has committed to purchasing half of the plant's energy output [2]. The company is also building a prototype reactor called Sparc in a Boston suburb, aiming to get it operating by next year and achieve scientific breakeven in 2027 [2].

The Japanese government has shown interest in CFS's technology, with a consortium of 12 Japanese companies, led by trading houses Mitsui & Co. and Mitsubishi Corp, expressing interest in the startup's fusion reactor technology [1]. Japan revised its national strategy in June to support fusion deployment and build a demonstration plant by the end of the decade [1].

While Mumgaard did not provide specific details about the nature of the discussions or potential outcomes, he noted that starting a reactor in Japan in the late 2030s or early 2040s would be a "great scenario" [1]. He also mentioned plans to meet with officials to exchange information about the global fusion market and updates about his company.

Fusion power, which involves combining atoms to release massive amounts of energy, has long been considered a nearly limitless energy source. However, achieving and maintaining a sustained fusion reaction has proven challenging. CFS's latest funding round, which includes investments from Nvidia, Google, and Bill Gates-backed Breakthrough Energy Ventures, aims to accelerate the development of commercial fusion power [2].

References:
[1] https://seekingalpha.com/news/4491538-commonwealth-fusion-in-talks-with-japan-on-tech-use-after-863m-raise-backed-by-nvidia
[2] https://americanbazaaronline.com/2025/08/29/nvidia-google-bill-gates-join-863-million-funding-round-for-commonwealth-fusion-systems-466895/