Atherma — Solving the Energy Crisis with Nuclear.

Aditya Dewan
13 min readMay 1, 2021


Pioneering next-generation, scalable nuclear power using nanotechnology and thermoelectricity.

Atherma’s proprietary thermoelectric nuclear reactor prototype.

Let’s take a step back for a minute.

The year is 2060. You’re a loving grandparent to 2 wonderful children, have spearheaded numerous accomplishments, and lived a long and beautiful life.

Yet, despite everything that you’ve done, all of your failures, success, and lessons…there’s a feeling that you can’t quite shake. The feeling of truth. Because you, know for a fact that your grandchildren won’t be able to live that same beautiful life.

Climate change robbed your children of living a normal and healthy life…when there’s has already begun.

Climate change — singlehandedly the worst ecological disaster we’ve faced as a species. In fact, it’s gotten so out of hand that scientists predict that we’ll cross the dreaded 2 degree limit as early as 2030.

The effects? Biodiversity loss on the scale of mass extinctions, global food and water shortages, struggling coastal cities, billions and billions rendered homeless, and natural disasters worse than they’ve ever been. We could die in the next 30 years, at the hands of global warming.

Put simply — climate change is coming for everyone. And we’re not ready for it.

Not even close.

Despite billions invested in renewables (like solar, wind, and hydro), carbon capture, and ecological restoration, greenhouse gas emissions still aren’t going down. Yet unfortunately, renewable energies simply aren’t the solution to this problem. Here’s why.

1) Inconsistency.

Renewables today are just too inconsistent — the sun doesn’t always shine, wind doesn’t always blow, you get the memo. And even if we managed to overcome this, geography and seasonal variations will make it incredibly difficult to use these technologies globally at scale.

For reference, here’s the energy generation of a wind power plant compared to the energy demands of a city:


The energy provided simply fluctuates too much — both on individual months and across seasons (with basically no energy being generated between July and August. Compared with the almost 24/7 need for electricity, we simply can’t use renewables to power cities.

Even if batteries allow us to solve this problem, there are still two more issues that prevent this technology from becoming mainstream:

2) Resource Intensity.

Renewables are environmentally friendly — at least, that’s what they look like on the surface. They may not produce (direct) emissions, but they require significantly more minerals and resources than any other energy production method.

Using electric cars and solar globally would currently take:

What’s worse still, is that most of these materials will end up going to waste at the end of their 20 year lifespan,

This is a critical problem — the resources required to create these technologies would require massive increases to mining operations around the world, significantly increasing net environmental impact.

And, this undoubtedly affects developing economies more — minerals will be extracted en-masse, resulting in more labour-based jobs, pollution, and drastic inequality. In places such as Congo, this has already been found to increase gender divides in communities living near mines — further hampering national development.

3) High land usage.

Perhaps the worst part about renewables is their extremely poor power density — 1000x less than natural gas.

This means that we would have to build 1000 solar farms to produce the same amount of energy as 1 natural gas plant.

This means more deforestation, local community displacement, extinctions, and less land available to feed a growing population. Overcoming this technological challenge is a problem that will take decades — acting as the final nail in the coffin for renewables.

So, what do we do?

We need to find a way to generate electricity without harming the planet (fossil fuels), or the environment (renewables).

And that, is where the nuclear power comes in — a zero-carbon, reliable, and incredibly power dense source. In fact, just a couple of reactors can power entire countries!

The single safest energy production method (in spite of disasters like Chernobyl), this seems like the perfect solution to meeting global energy demands while keeping environment intact.

Unfortunately, current nuclear plants have three critical problems — size, complexity, and scale.

These challenges have singlehandedly decimated the nuclear industry, with only one successful American nuclear plant being built in the last 20 years. Dozens more went significantly over budget and time, eventually being scrapped.


To understand the problem, we need to look at the numbers.

Here’s nuclear power in comparison to natural gas:

As you can see, the average nuclear plant costs 5500 kW and 6 years to come online.

In contrast, the average natural gas plant takes 2 years and 2 billion to start producing electricity. It’s clear that, to truly scale nuclear, we need to bring down cost and construction time — while increasing efficiency.

And that, is exactly what Atherma’s doing. We’re revolutionizing the nuclear industry with next-generation, scalable reactors — using a little something called thermoelectricity.

The Status Quo.

Today’s nuclear reactors operate on a very simple set of steps to produce electricity:

  1. A heavy element (most commonly, Uranium 235) is placed inside of a closed chamber.
  2. This atom is then split, releasing huge amounts of energy and neutrons, which then go onto split more atoms and release more energy. This is known as nuclear fission.
  3. The heat produced by these reactors warm surrounding water to extremely high temperatures, generating high-pressure steam.
  4. This steam is then used to spin turbines, which in turn powers a generator.
  5. Electricity!

As you can see, this is an extremely complex process that requires dozens of moving parts, pumps, and containment systems. In fact, expensive and time-consuming cooling towers (the trademark sign of a nuclear power plant) need to be built to process hot water and steam!

All of this takes significant capital to be built, in the form of 2 costs:

#1: Capital Costs

These are costs incurred during the building of the plant — things like the reactor, different components, and the hiring of construction teams to bring the plant online. This makes up 60% of the total cost of a nuclear plant.

#2: Operating Costs

This is the cost of operating the reactor on a day-to-day basis — maintenance, ensuring parts are in correct working order, hiring operating personnel, etc. This contributes the remaining 40% of the overall cost.

As we were diving deeper into this issue, we found that the main reason for these high costs was the complexity of nuclear power plants. Each plant is usually custom designed, with each new project requiring a different array of parts and suppliers from around the world.

This, combined with a lack of government subsidies for nuclear power, makes it extremely difficult for development teams to manufacture nuclear power plants at scale and gain experience building reactors (since each one is designed differently).

So, to combat the three problems that we mentioned earlier (size, complexity, and scale) we need to do 3 things:

1. Miniaturize

It’s difficult to scale gargantuan power plants — the added size adds significant construction challenges and billions more to the end total.

To achieve our goal of scaled nuclear power, we need to take advantage of SMRs (Small Modular Reactors) — devices that produce less than 300 megawatts.

While these reactors produce less power individually, multiple can be added to the same power plant — keeping power, while improving scale.

2. Simplify

It’s no surprise that nuclear is one of the most complex ways of generating energy. However, it is this complexity that makes this technology unable to provide power to the world (not to mention increasing manufacturing difficulties).

To handle this, Atherma is eliminating the middle party entirely — getting rid of the need for steam, turbines, and alternators.

We’re converting the heat from nuclear reactors directly into energy using nanotech-enhanced thermoelectric semiconductors, improving efficiency and simplifying reactor design.

Ultimately, this makes it significantly easier to overcome the third challenge — scale.

3. Manufacture

Our end vision is a world where simplified nuclear power can be mass-produced in factories. Current reactors by other SMR companies are too complex to be produced rapidly, resulting in dozens of onsite construction teams and 2x cost overruns.

Due to our simplified thermoelectric design, we will be able to assemble the majority of the reactor inside factories, and build minimal infrastructure to construct the plant itself (no need for giant cooling towers or steam release systems).

By combining existing technologies (SMRs) with a novel approach (simplification + mass manufacturing with thermoelectric reactors), Atherma will be able to pave the path forward for the standardization of nuclear power.


Now that we’ve outlined our general strategy, let’s talk about the how.

First — what is a thermoelectric device?

Thermoelectric devices are just what they sound like — devices that convert heat (thermo) into electricity (electric) using a principle known as the Seebeck effect. Basically, these devices generate a voltage when there is a high enough temperature differential on either side.

Here’s a diagram to explain:


These devices are built on top of small p and n type semiconductors known as thermocouples. As you can see, one side is heated while the other is cooled — resulting in the displacement of electrons and a charge balance on one side. Ultimately, this creates a voltage and allows for electricity!

Thermocouples inside thermoelectric devices. Source

It’s this same principle that Atherma aims to use with thermoelectric nuclear reactors. Rather than needing to convert water to steam, move the steam through a turbine, and then generate electricity via an alternator, we can simply convert fission heat — directly into electricity.

However, our team encountered a core (pun intended) challenge while attempting to bring this vision to reality — current thermoelectric technology was just too inefficient.

This property is measured by the figure of merit, and some estimates suggest that this figure will need to be above 2 in order to take over traditional steam power generation. Currently, the average for the industry is around 1.

Where S = Seebeck coefficient, σ = electrical conductivity of material, and K = thermal conductivity. Source.

In fact, this was one of the primary reasons that this technology still hasn’t been brought to market — radioisotope heat sources are simply too ineffective to use with nuclear fission and were instead used as atomic “batteries” in niche deep space missions.

The reason for this inefficiency? The delicate balance between thermal conductivity and electrical conductivity. To improve efficiency, we need a material that conducts electricity well, but conducts heat poorly. Otherwise, the temperature differential will slowly degrade over time, and reduce the amount of power we can generate.

So, what’s the solution? The answer lies in nanotechnology — specifically, using nanostructures smaller than the wavelength of light to decrease thermal conductivity and increase electrical conductivity.

We’re spearheading development in nuclear-grade thermoelectric devices (potentially in partnership with existing institutions) to put an end to humanity’s reliance on fossil fuels.

Currently, there are three materials we’re taking into consideration for further research and development, with #1 being the most promising.

1. Graphene-based nanoribbons

A carbon-based 2D material, graphene has been found to exhibit a figure of 1.4 when synthesized with various chemical vapours (source), with some scientists believing that it can reach a peak efficiency of up to 6.1 — TRIPLE the threshold needed to become more efficient than current generation methods.

By further facilitating development in this field, we open the possibility of harnessing this gargantuan power in the nuclear field.

2. Carbon Nanotubes

a. CNTs are essentially cylinders made of a single layer of carbon atoms — and, researchers at the US Department of Energy have found that they can be used for both the p and n sides of a thermocouple. This means that the same material can be used for both parts of a thermoelectric device, simplifying the manufacturing process.

3. Organic Thermoelectric Devices

a. Organic TE materials are based off of polymers, and while they’re traditionally meant for room temperature applications (with a figure of merit = 0.42), their potentially low cost and relative ease of manufacturing (such as with additive manufacturing or 3D printing) makes it an attractive investment of time and resources.

All in all, all three of these materials show promise for our purposes in the next 2–5 years, with development in this industry having grown exponentially with the advent of nanotechnology, with over 370 materials found in the last decade alone.

Exponential growth in the thermoelectric industry.

Combined with our own findings, this is a strong indicator that the field of thermoelectric devices will soon overtake traditional power generation methods:

Projected growth in the next 2 decades.

Once the necessarily material has been chosen and modified to withstand the high temperatures of a nuclear reactor, the next step is to integrate this technology with existing reactors.

So, we’ll be placing our layer of thermoelectric semiconductors directly on the uranium fuel rods. This allows the devices to collect as much heat from the core as possible, and convert it to electricity. But, none of this is useful if we can’t get the electricity outside of the reactor. This is accomplished by using lead-layered wires from the sides of the reactor chamber — allowing our design to be directly hooked up to the energy grid.

Lastly, our prototype uses helium gas as a coolant — as opposed to traditional water cooling. Why? Well, the answer comes down to safety.

After talking to some experts in the nuclear field, we found that safety is a critical problem with SMRs — by scaling multiple reactors per plant, we need to ensure that each device is incredibly safe and efficient. Traditional water cooling safety methods are effective — but not small enough to work with our design.

So, we decided to use helium ­– a natural by product of nuclear fission, giving us two core advantages:

#1 Increased density and heat.

Due to its properties, using helium coolant results in higher density and heat capture abilities. We can leverage this added heat, and use thermoelectric devices to remove the heat from the helium!

This way, not only are we extracting heat from fission, but also from the processes used to cool it.

#2 Sustainability.

Helium is a natural by product of fission — meaning, that the core itself generates parts of the coolant! This allows us to use fewer resources to cool the reactor, further cutting costs and requirement for operations personnel.

Ultimately, this means that we can retro fit traditional (water cooled) reactors with one layer of semiconductors, and construct brand new ones with multiple!

Below is a blueprint for our prototype:

Atherma’s reactor — Fermi!

And here’s a more complex diagram for those looking to dive deeper:

Now, let’s talk about the economics of our solution.


As we mentioned, nuclear power costs ~5 500/kW. And, we also know that graphene nanoribbons have a peak efficiency of 6 — making our solution 3x more efficient that current alternatives. This means that for the same price, we can generate 3 kW of energy — compared to 1.

So, our per kW cost is reduced to:

$ 5 500 / kW.

$ 5 500 / 3 kW.

$ 1833.3 / kW

But, we aren’t done reducing cost yet. Drastically reducing the size of nuclear power plants and making them easier to manufacture reduces cost in multiple other areas, which compound to reduce this cost by 50%.


Currently, this is what the cost breakdown for a nuclear power plant looks like:

With our thermoelectric design, we have the ability to cut costs in multiple areas!

  1. Nuclear steam supply system 0% (we get rid of it)
  2. Electrical and generating equipment 3% (no need for alternators or generators — thermoelectric devices directly convert heat, though 1/4th of the cost remains as the expense for the devices themselves)
  3. Mechanical equipment — 14% (Fewer pumps are needed for helium gas, though added pressurizers don’t result in too much of a difference)
  4. Construction materials — 6% (SMRs do not require the construction of towers + are more cost effective)
  5. Onsite labour — 6% (this is the largest estimated reduction at 19% — a lack of complex equipment makes it significantly easier to build these reactors)
  6. PM Services — 2% (Fewer workers = smaller need for PMs and a reduced amount of teams)

Ultimately, this results in a 56% reduction in cost!

Combined with the cost benefits from improving efficiency, this is what the final cost /kW looks like:


$1833.33 * 0.46

= ~806 / kW

And as a result of this reduced cost, lower labour, and decreased complexity, we can drastically reduce overruns — allowing nuclear power plants to meet their targeted completion times.

Based on industry standards and similar companies (such as NuScale), we believe that this time can be cut by more than 50%!

Now, let’s compare nuclear and natural gas again!

Combined, our solution reduces end cost 6x over — becoming competitive with fossil fuels, and finally paving the way for nuclear energy to become scalable long term.

Here at Atherma, our vision is a world.

A world where, nuclear power fuels the globe towards a greener and brighter future.

Where billions don’t have to face the devastating impacts of climate change.

Of air pollution.

And, of massive food and water shortages around the globe. A world where your grandchildren can look back with pride, at the efforts of humanity to save the planet.

And, all this is possible by the next generation of nuclear power — smart, zero-emissions, and large-scale power for the world.




Aditya Dewan

Building companies. Machine Learning Specialist Philosophy x Tech.