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Thesis: For nuclear power to play a large role in future energy needs, there needs to be substantial innovation and infrastructure development in the industry. Microreactors, able to be mass-produced in a factory, pose an alternative solution to the coming energy crisis, effectively producing flexible, limitless energy.

If you haven’t read my Nuclear Energy Primer, I’d highly recommend it before reading this article as some of the terminology can be difficult to understand.

Credit Oak Ridge National Laboratory

Micro-Nuclear Reactors

Everything is better smaller, right?

That’s the thought with modern designs for nuclear microreactors.

Microreactors, also known as “Very Small Modular Reactors” (vSMRs) are starting to be designed as key projects for the nuclear industry. Designs could be ready to roll out within the next decade.

What’s the difference between microreactors and normal reactors?

Microreactors are smaller, more efficient designs than normal reactors. On a simple note, they look like normal reactors but scaled down. They have 3 key advantages:

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Factory Fabricated

Given regulatory approval, all components of a microreactor could be fully assembled in a factory, verified, and then shipped out to a location on a semi-truck. This model has many key advantages over traditional reactors:

Reduces up-front capital costs:

Traditional nuclear reactors take around $5 - $10 billion to develop. On average, nuclear reactors produce around 1 GW of energy. This means that it currently costs around $5 - $10M per megawatt of energy capable of being produced.

A couple of microreactor projects have been proposed and are currently going through regulatory testing and defense development. These reactors are estimated to cost around $100 - $300 million to produce the first reactor. As these reactors are from 1 - 5 megawatts total, it’s estimated to cost anywhere between $20 - $100M per megawatt of energy capable of being produced.

However, this doesn’t include the idea of economies of scale due to mass manufacturing. Around $2 - $3 billion in traditional costs for a reactor go into regulatory approval processes. With mass development, once a factory gets regulatory approval, it can begin to mass produce reactors.

This leads the cost of future energy to be estimated around $60 - $120 million, or around $12 - $25M per megawatt hour. But, being able to produce a nuclear reactor for 1% of the cost is significantly beneficial as raising billions of dollars of capital is extremely difficult.

Decreases regulation waiting period:

Traditional nuclear reactors take years on average to achieve regulatory approval, with many reactors failing to pass this stage, taking too much time or bankrupting companies.

With microreactors, a company simply needs to get regulatory approval to build a small prototype reactor, then once that reactor is completed the company can seek a license for a factory to mass-produce the reactors.

This dramatically reduces the regulatory waiting period for future reactors, as they can be licensed as quickly as they can be constructed. This rapidly decreases the time of construction and deployment of nuclear energy.

Credit Department of Energy

Transportable

Current microreactor designs have been constructed in a way that allows the reactor to be easily transported in a shipping container on the back of a semi-truck. This model has many key advantages over traditional reactors:

Flexible Deployment:

Being able to be transported by truck, train, airplane, or ship, these reactors can be deployed at any time, anywhere. Examples could include military applications (see Project PELE below), rural applications, disaster relief, etc.

Compare this to normal nuclear reactors that are stuck in place and generally only near large metropolitan areas as the cost of energy transportation is still widely expensive.

Scalable Power Generation:

In addition to flexibility, microreactors can be deployed by themselves (as a forward military operating base or a rural community), or in groups to provide power ranging from a few megawatts up to hundreds and potentially thousands of megawatts of energy.

This type of technology and scalability can be applied in any situation. Compared to traditional nuclear reactors where their power generation capabilities are widely fixed in place and in measure, these flexible technologies are infinitely better options.

Credit iStock

Self-Adjusting

Innovation in the size of nuclear reactors has necessitated innovation in the type of reactors capable of providing power at a smaller scale.

Traditional reactors, like the popular pressurized water reactor, are less efficient at a smaller scale. Modern “gen IV” reactor designs are more efficient at a smaller scale.

In addition, these newer reactor designs have design benefits for enhanced safety. Microreactors can automatically adjust output or even shut down if conditions approach safety limits. This vastly reduces accident risk, especially as these reactors can and will be deployed near populated areas.

Self-regulation and automated control systems allow microreactors to maintain optimal performance without continuous oversight by nuclear technicians. These additional safety measures allow microreactors to seamlessly handle faults, power fluctuations, weather events, or human errors while continually supplying reliable electricity.

If these reactors are so beneficial in comparison to traditional reactors, why haven’t they been developed before now?

Well, in some ways we’ve had microreactors for decades.

Credit Blue Moon Patent Print

Submarines powered by nuclear reactors have been around since the 1950s. For more advanced militaries, nuclear submarines provide key advantages over a traditional submarine. As they don’t need to be refueled, the range is virtually unlimited, only subject to factors such as restocking food and consumables. In addition, nuclear submarines are able to operate at high speeds for much longer periods.

There are currently over 160 nuclear-powered operating today, comprising around 200 small nuclear reactors. Most of these are submarines, but there are also some cruisers and ice-breakers.

The World Nuclear Association states the following:

The safety record of the US nuclear navy is excellent, this being attributed to a high level of standardization in naval power plants and their maintenance, and the high quality of the Navy's training program. However, early Soviet endeavors resulted in a number of serious accidents – five where the reactor was irreparably damaged, and more resulting in radiation leaks. There were more than 20 radiation fatalities.* Nevertheless, by Russia’s third generation of marine PWRs in the late 1970s safety and reliability had become a high priority. (Apart from reactor accidents, fires and accidents have resulted in the loss of two US and about four Soviet submarines, another four of which had fires resulting in loss of life.) In the US, UK and French navies there has never been a nuclear plant accident.

These reactors have traditionally been slightly larger than the current specifications for newer microreactor designs, but they are great starting points for researchers on how to scale down nuclear projects while still maintaining a decent level of energy output.

Yet, even with all of our expertise in building smaller nuclear reactors, the United States has not managed to develop a microreactor for commercial use.

Current Developments with Microreactors

Demand for innovation within the nuclear community has been relatively large recently given the exasperation over the lack of major developments in the last couple of decades in the United States. The only major developments in the last decade have been 2 overpriced Vogtle reactors.

In addition, especially after the Fukushima disaster in 2011, the regulatory environment in the United States has become especially complicated for new reactor designs. So, newer startups and legacy incumbents alike have become interested in the idea of microreactors as they provide a more simple, cost-effective solution to a difficult problem.

Many projects are currently underway regarding microreactors. The main ones are detailed below:

NASA Kilopower Technology

NASA started its Kilopower project in 2015 as a way to develop a nuclear reactor capable of powering human exploration of the Moon and Mars. In 2018, NASA successfully demonstrated its kilowatt microreactor, showing it was capable of producing enough sustainable power for human space exploration. Granted, this technology doesn’t have true practical applications besides niche small ventures, yet it does show that nuclear power can be successfully scaled down to the micro-scale.

Project PELE

Project PELE is a project by the United States Department of Defense to build a deployable nuclear microreactor for use in the Armed Forces remote operating bases.

In June of 2022, BWX Technologies was awarded a contract by the Department of Defense to build a prototype micro nuclear reactor and deliver it by 2024. This project was estimated to cost around $300 million. This reactor will be the first electricity-generating Generation IV nuclear reactor built in the United States.

Currently, the Department of Defense uses around 30 terawatt-hours of electricity per year. Energy usage on the battlefield is expected to increase significantly over the next few decades with modern warfighting systems (directed-energy lasers, railguns, and UAVs), leading to an increased demand for reliable, high-density energy.

A small, safe, transportable microreactor would provide a resilient, carbon-free energy source that would support mission-critical operations in remote environments.

MARVEL Reactor

The MARVEL reactor (stands for “Microreactor Applications Research Validation and Evaluation”) is a United States Department of Energy project to develop a 100-kilowatt reactor capable of providing the nuclear industry with a dedicated reactor to quickly test, develop, and demonstrate microreactor technologies.

In October of 2023, the reactor achieved 90% final design, meaning that everything is mainly finalized, except for minor changes due to unforeseen complexities. This places the reactor’s estimated completion date in early 2025, though in 2020 estimates said 2023, so this may not be a completely accurate date.

Westinghouse eVinci

Westinghouse has been developing its eVinci commercial microreactor for a couple of years. In October 2023, Westinghouse announced selection by the Department of Energy for an engineering and design contract to support the commercialization of a test eVinci reactor (1/5th the size of a normal eVinci reactor). The Department of Energy plans for the deployment of the eVinci Test Reactor at the Idaho National Lab.

Currently, operation is estimated for 2026.

NANO Nuclear Technology Zeus & Odin

NANO has been developing its Zeus commercial microreactor for a couple of years. Their Odin reactor design was recently announced in early 2023. These reactors are currently in the early design stages.

Currently, commercial output and operation are estimated for the early 2030s.

Radiant Power Kaleidos

Kaleidos is building a 1-megawatt microreactor. They estimate it will be the first new commercial reactor design to achieve a fueled test in over 50 years. Radiant’s primary focus is on a demonstration at the Idaho National Laboratory no later than 2026.

The company hopes to be the first microreactor to complete a fuel test by 2026, with commercial production beginning in 2028.

Credit Fine Art Tutorials

So now what?

As microreactors are so new, the Nuclear Regulatory Commission does not have fully articulated regulations specifically for microreactors.

How do you develop a new technology without knowing how it will be eventually regulated?

It’s like playing a game of hide and seek but the boundaries are the entire world. How do you plan to find them if they could be anywhere?

This makes innovation in this field particularly complicated. As a microreactor hasn’t been produced yet, the regulators don’t know how to approach regulating one, specifically in understanding what measures for risk and safety are necessary more than traditional reactor designs.

Yet, this isn’t a reason to give up on microreactors. Given their large advantages over traditional nuclear reactors, they might be our only hope for achievable nuclear power in the future.

Anywho, that’s all for today.

-Drew Jackson