Nuclear energy has long been considered one of the most promising energy sources of the future due to its high efficiency and low carbon emissions. However, despite its obvious advantages, two main challenges remain: the high cost of building nuclear power plants and safety concerns. Deep Fission, an innovative startup in the field of nuclear energy, has proposed a new solution that could change the approach to nuclear energy, making it more accessible and safer.
September 4, 2024
Franc Smidt, Editor
Germany
The Main Idea: Compact Reactors in Boreholes
Deep Fission has developed the concept of a compact nuclear reactor that is only 76 cm wide and will be installed 1.6 km underground in a borehole. This solution significantly reduces construction costs, eliminates many operational risks, and simplifies the technical maintenance processes of reactors.
The key idea is that nuclear fuel costs are relatively low—about 1,663 USD per kilogram—which, when used in a reactor, ensures an electricity production cost of only 0.46¢/kWh. The main expenses are not related to the fuel itself but to the costs of reactor infrastructure and safety, including heavy reactor vessels, concrete shells, complex cooling systems, and pressure compensators.
How the New System Works
The Deep Fission reactor uses the same technology as conventional pressurized water reactors (PWR). It operates under the same conditions: 160 atmospheres of pressure and a temperature of 315°C. However, unlike traditional plants, the reactor design is significantly simplified. It will be lowered into a 1.6 km deep borehole, where natural conditions will provide the necessary safety mechanisms.
Instead of complex pressure compensators, a 1.6 km column of water will exert pressure on the reactor as if it were submerged. This eliminates the need for complex engineering solutions required at the surface to manage pressure and cooling. The cooling system will be passive, meaning it will operate without active intervention, significantly reducing the risk of system failure.
Economic and Technological Advantages
| Advantage | Description |
| Simplified Infrastructure | By lowering the reactor into a borehole, bulky protective structures and heavy constructions are no longer necessary. The elimination of complex civil engineering reduces construction costs. |
| Safety | Since the reactor is placed deep underground, it is protected from external influences, and in the event of an accident, the borehole can simply be filled with earth. This greatly simplifies the safety system and makes the reactor more resilient to accidents. |
| Minimal Operating Costs | Since the reactor has no moving parts (except for remotely controlled control rods), maintenance costs are low. If inspection or repairs are needed, the reactor can be raised to the surface using cables. |
| Self-limiting Design | The Deep Fission reactor has a built-in self-limiting feature—if it overheats, the nuclear reaction automatically shuts down, preventing the risk of a meltdown. |
Implementation Prospects
The idea of small, compact, and safe reactors is becoming increasingly popular in the nuclear energy sector. At a time when there is a massive need for cleaner energy sources, but large nuclear projects face challenges in implementation, proposals like those from Deep Fission could represent a significant step forward, as they substantially reduce costs and improve nuclear safety.
Such innovations could fundamentally change the nuclear energy industry, making it more attractive for investment and implementation in various countries, especially those without existing nuclear infrastructure.
More information about the Deep Fission project can be found on their official website: Deep Fission.
