Mobile Nuclear Reactor: Japan’s Mitsubishi To Commercialize technology by 2030s

 

Following the Fukushima Daiichi Nuclear Power Plant catastrophe in 2011, Japan is moving ahead to leverage a new technological approach to satisfy the country’s future energy needs.

Leading the effort is Mitsubishi Heavy Industries, which  intends to build and commercialize nuclear reactors small enough to be transported on trucks by the end of the decade, to capitalize on the demand for non-carbon emitting energy, according to Nikkei Asia.

The microreactors, which will be 3 meters tall and 4 meters wide, will weigh less than 40 tons. The reactor and power generation equipment will rest inside a container truck, making it possible to transport it to remote or disaster-stricken locations.

The microreactors’ maximum output will be 500 kilowatts or one-twentieth of the capacity of normal nuclear reactors that generate more than one gigawatt. According to the report, each microreactor will require tens of millions of dollars, significantly less than the $6 billion or more than a 1.2-gigawatt nuclear facility would need.

Mitsubishi Heavy’s microreactors will be able to provide power to remote and disaster-hit areas. (Image courtesy of Mitsubishi Heavy)

The cost of producing one kilowatt-hour will be higher than that of a conventional reactor, but it will be comparable to the cost of providing power to isolated islands now. Remote places will be able to obtain a cost-effective, carbon-free source of energy owing to these micro-reactors.

The reactor as designed will be compact enough to be buried underground to reduce the possibility of a mishap. The technology may also be employed in space exploration. 

Once the company secures clearance from Japan and other governments, Mitsubishi will commercialize the technology in the 2030s at the earliest. However, due to their proximity to inhabited regions, microreactors will need to be made safer than traditional reactors. 

The company has also taken this into account, designing the technology such that all of the nuclear reactor’s components, including the core, coolants, and other equipment, are housed in tightly sealed capsule containers.

Furthermore, highly enriched uranium will be utilized as fuel, and the reactor will not need to be replaced over its 25-year lifespan. The microreactor can be retrieved once the fuel has been used up. The reactors can be installed underground to lessen the danger of natural catastrophes and terrorism because they will only require little maintenance. 

Mitsubishi Heavy will also lessen the chances of catastrophic coolant failure. The microreactors will use a solid-state graphite material that is very thermally conductive rather than liquid coolants.

During normal operation, the graphite surrounds the core and distributes heat to the power generation system. Even when an accident occurs, natural ambient cooling removes excess heat from the core.

Similar trends Around The World

Despite the fact that the technology has yet to be commercialized, multiple designs are ongoing in North America and Europe, with demonstrations scheduled in the next few years.

Oklo, a US-based company, submitted a license application in March 2020 to design and operate a microreactor, with the first reactor expected to start up at Idaho National Laboratory by 2025. 

The US-based companies Westinghouse (0.2-5 MWe), NuScale (1-10 MWe), and UltraSafe Nuclear (5 MWe) are all building reactors with a power output of fewer than 10 MWe, while Sweden’s LeadCold (3-10 MW3) and a UK consortium lead by Urenco (4 MWe) are also developing on comparable systems. 

The Micro Modular Reactor (MMR) system from Ultra Safe Nuclear Corporation is a 4th Generation nuclear energy system. (Credit: Ultra Safe Nuclear Corporation)