Jimmy Energy is a French start-up developing modular 10-20MWth micro-reactors based on 4th-generation, high-temperature graphite-gas technology, whose distinctive feature is that they do not produce electricity. In fact, these reactors are intended solely for (industrial) heat production. The company was founded in 2020 by Antoine Guyot and Mathilde Grivet and a number of industrial players, and is advised by a number of high-profile players (e.g. Franck Carré, Scientific Director at CEA, Dominique Vignon, former CEO of Framatome, etc.).
Jimmy reactor technology
Jimmy reactors are 4th-generation high-temperature reactors (HTRs). They use graphite as a moderator and helium as a coolant gas. The latter transfers heat in an exchanger to the secondary circuit, containing CO2, which transmits it to the industrial site. The core temperature would be 600°C, and could rise to 750°C. HTR technology has already been the subject of numerous prototypes, and a small modular reactor using it is even in operation in China(Shidao Bay).
The special feature of Jimmy reactors is that they do not produce electricity, but are designed solely to decarbonize process heat. Graphite reactors are too bulky to produce electricity, but using heat directly would be a novelty.
The fuel used in these reactors is very special: it consists of particles with a uranium core surrounded by resistant cladding. This is the so-called“Triso” fuel. On the downside, the fuel would need to be highly enriched: 19.75% U235!
The safety of the process would be perfect: in the event of an incident, the reactor would stabilize or shut down. The graphite moderator would then passively dissipate the heat(Source)
It’s worth pointing out that dismantling graphite reactors is currently a problem: we don’t know how to do it… for large reactors. In fact, the many projects on the subject(Graphitech, Inno4graph, Cleandem) address the problem of dismantling “big” graphite reactors, which are so huge that new tools are needed. Micro-reactors like Jimmy’s don’t pose any particular problems (to my knowledge, small graphite reactors have already been dismantled).
Progress and funding of the Jimmy startup
Jimmy was founded in 2020 by Antoine Guyot (CEO) and Mathilde Grivet (COO). The company’s main targets are companies in the chemical, food and paper industries.
In February 2022, the startup raised 2.2 million euros, enabling it to lay the foundations of the company (recruiting 20 people, finding a first customer to host the first generator, completing an initial design phase, initiating the regulatory phase)
A second round of financing, in October 2022, amounting to €15 million, should enable us to finalize the design and launch the second and most important regulatory phase
Investors include EREN industries, Noria, Otium Capital and Polytechnique Ventures.
The first generator is scheduled for 2026.
- On TRISO fuel: https://doseequivalentbanana.home.blog/2020/08/10/triso-et-reacteurs-a-haute-temperature/