Nuclear Power's Challenges in less than 1000 Words

2023 March 24 Twitter Substack See all posts

There are fundamental reasons nuclear power struggles with cost.

What Quality of Energy Does Nuclear Fuel Produce?

I often hear statements like "Nuclear fuel's energy density means it should be cheaper" or "Why is nuclear power so expensive when it is just rocks close to each other?" I've written two long posts about these topics, but a shorter answer is needed. The challenge is the quality of energy nuclear fuel produces.

Energy from current nuclear fuel is low quality because it is relatively low-temperature heat, and the radiation and neutrons it emits cause fluid and material compatibility problems that compound the issue. One of the best ways to increase cost-effectiveness is massively scaling up power plants, which increases safety requirements. Nuclear fuel is easy to move but is useless without a large power plant. And massive power plants must transport electricity over inefficient power lines. Coal trains, natural gas pipelines, and oil pipelines can carry orders of magnitude more energy than a high-voltage power line.

Let's consider nuclear-powered aircraft. The military desperately wanted a nuclear-powered bomber and spent over a decade and $15 billion in 2023 dollars trying to create a power plant for one. While the fuel is orders of magnitude more dense than jet fuel, the existing technology to turn low-quality nuclear energy into thrust is fatally heavy. We have primitive battery-powered aircraft flying after R+D programs of a few years and a few million dollars, while blank check programs couldn't create a nuclear-powered airplane.

Magical Energy Technologies

Fighting entropy is one of the things humans do best. Solar panels turn diffuse sunlight directly into the highest quality carrier of energy - electricity. Wind turbines do the same trick by creating electricity from moving air. Combined cycle natural gas plants use gas turbines to take advantage of high-temperature combustion in a way that traditional steam power plants cannot. Then the outlet temperature from the turbine is still high enough to make steam. The power plants achieve almost double the thermal efficiency of coal and nuclear power plants at a fraction of the capital cost and construction time. Humans can come up with near-magical solutions, but we haven't yet for nuclear.

Paths for Nuclear

A few things have to improve. Construction times need to return to four years but possibly decline to <2 years to compete with gas, solar, and wind. The cost must be <$50/MWh and decline as competing technologies improve. There are a few main options:

  1. Shift Risk Between Interest Groups:

    Regulations seek to protect the general population from any risk or even the slightest exposure to radiation. We can have the general public accept more risk and lower nuclear power's cost with minimal harm to civilians. Jack Devanney has written about this path extensively. I might summarize it as building traditional, large nuclear power plants with fewer safeguards, forgetting the nuclear-specific certifications, putting buffer zones around plants where radiation would be unacceptably high in an accident, coming to terms with the fact that we will melt down some reactors every so often, and using electricity markets as a way to keep costs down.

    Devanney sees nuclear's cost potential as around $30-$40/MWh depending on if it is a traditional power plant or a newer design like the molten salt reactor he is trying to develop through his company ThorCon. Another variation is Last Energy which uses tiny power plants to improve construction time and nearly eliminate the required buffer area. They accept a higher cost, but there is still a market in places like the UK or Poland.

    Ultimately, this is a cultural/social attack vector. It isn't a direct path to nuclear-powered transportation or lower-cost energy for the US (most electricity markets in the US are already in the $30/MWh range). There are a lot of challenges selling this vision even within the industry because of different views on what is politically possible and many in the industry having an allergy to markets.

  2. Make Nuclear Fuel Cheaper:

    Nuclear fuel is considered cheap, but its low quality hurts affordability. In some sense, it needs to be free, and $10/MWh (or much higher for many startup reactors) isn't good enough. Most of the cost is in processing, so there is potential for improvement. Cheaper fuel could allow the use of simpler, less efficient conversion equipment. One of my favorite concepts is heating compressed air to power a gas turbine in an open Brayton Cycle.

    The upshot is nuclear power plants could have rapid construction times even at 500 MW type sizes. It might even be possible to break the $30/MWh barrier. It is not only the fuel that needs to come down in cost but other possible components in the fuel modules like nuclear graphite.

  3. A Magic Energy Concentrator:

    Think of wrapping nuclear fuel in something like a solar panel. A dumb piece of solid material that reflects neutrons then eats heat and radiation to produce electricity. It would start out expensive with initial applications in aerospace or defense. Then get cheaper over time. Regulation is less of a barrier for this path because the material doesn't need licensing. You can test it at existing research reactors or with an alternative neutron, heat, and radiation sources.

    A magic energy concentrator can make our nuclear dreams come true beyond making commodity electricity in a large power plant.

The Bright Nuclear Future

The nuclear industry needs more innovators and entrepreneurs with an internal locus of control. Bret Kugelmass (Last Energy) and Jack Devanney felt they couldn't sell their vision to the US Nuclear Regulatory Commission and are selling power plants abroad instead. You can't stick utilities with all the cost overrun risk and expect them to buy your product. Nuclear fuel manufacturing is a near monopoly with few entrants relative to reactor startups. And very few people are working on magic nuclear materials despite the lower barriers to entry. Blaming everyone else will not bring about a beautiful nuclear future. The government will not either. It has already been the primary benefactor of nuclear power since its inception.