At companies Deep Fissionwhich works to develop new types of compact nuclear reactors, has received the prototype box for its underground mini nuclear reactor.
This key piece, but non-nuclear, is essential to validate the installation concept 1.6 km deep. The project Gravity Nuclear Reactor aims to use natural water pressure for cooling and system security.
The element received will make it possible to test and fine-tune the entire logistical and operational chain of a daring idea: installing small modular reactors at dizzying depths to produce electricity.
What is this metal package that is shaking Kansas?
The part arrived on site is the caisson prototype of the future reactor. This is a full-size envelope, manufactured in a factory and having already passed a battery of hydrostatic tests (verification of resistance to pressure with water), but which does not contain no nuclear fuel.
Its role is to serve as a demonstrator for a dress rehearsal. The teams will be able to simulate and validate each stage of the deployment: assembly, descent into the drilling, installation and integration with the surface systems.
This validation program is a key step for derisk technology before handling even the slightest gram of radioactive material. As Mark Pérès, Deep Fission’s nuclear director, explains, the success of the manufacturing and delivery of this equipment already demonstrates the performance of the design and the supply chain reliability.
How does this concept of buried nuclear reactor work?
The Gravity Nuclear Reactor of Deep Fission is an adaptation of the proven technology of pressurized water reactors (REP or EPR in English), but transposed into a radically different environment.
The idea is to place the energetic heart in a forage vertical d’environ 1,6 km depth. The key to the system lies in the use of gravity and fluid physics : the column of water of one and a half kilometers which overlooks the reactor generates a colossal natural pressurewhich is used both to keep the system pressurized and to provide constant passive cooling.
Concretely, the heat produced by the nuclear reactor is transferred via a first closed circuit to a heat exchanger. Then, a second closed circuit, completely independent of the first, transports this thermal energy to the surface.
There, it is converted into electricity with a turbine, on a model very similar to that of a classic geothermal power plant. The design thus seeks to transform a geological challenge into a safety asset by relying on natural forces to contain and control the reaction.
What are the next steps for this audacious project?
With the prototype chamber now on site, Deep Fission is preparing to launch a series of non-nuclear tests. The goal is to ensure that the complex orchestration of the installation goes smoothly.
At the same time, the company is advancing its administrative procedures to obtain necessary permits from the Kansas Department of Health and Environment (KDHE).
This permit is essential to be able to carry out the large diameter drilling which will accommodate future installations.
The development of the first nuclear demonstration drilling Full-scale work also continues behind the scenes, as does the design of the primary heat exchanger.
