If you’re receiving this for the first time, welcome to my newsletter Steward. If you’ve received my newsletter before, then you’ll notice the new name. I started this newsletter because I felt compelled to share information about nuclear energy that was important but overlooked. As I make my own journey into this sector I wanted to share my experiences and highlight the news that rarely makes it to the front page.
Over the past couple years I’ve also come to learn about exciting developments across the energy landscape — not just in nuclear. We are living at a pivotal time: both faced with the unprecedented challenge of climate change and equipped with the tools to confront it. But our tools are also what got us here in the first place. The solution to this problem will not be prescriptive. It will require equal parts innovation and humility to fully understand our impact on this planet and how to take better care of it.
Despite the doomsday headlines we are relentlessly bombarded with, there are entire communities of people and projects — local, national, and international — working together to build a more dignified relationship between people and planet. Going forward I plan to highlight more of those initiatives while still discussing nuclear’s role in our energy mix.
I also decided that since I have you all here, I’m going to include my passion for music by sharing completely unrelated music recommendations at the end of each newsletter.
As always, you can find my past emails here, and realtime CO2 emissions here.
Back in August I had an important experience that made me realize I needed to get back to basics. I was at UC Berkeley taking part in the Nuclear Innovation Bootcamp, a 2-week workshop that hosts a diversity of speakers from both the nuclear sphere and outside it in order to familiarize the next generation of engineers with the process of building ventures in nuclear. At the end of a session focused on community and stakeholder engagement in large projects, the sociology professor giving the presentation finished by saying, “Look, I’m a mother and an environmentalist and I’ve had this discussion with enough engineers to understand in my brain that this technology is important for the problems we face today. In my heart though, I still have trouble separating nuclear from the images I grew up with of mushroom clouds and war. Maybe one of you could help explain the difference between a reactor and a bomb so I can feel more comfortable about it.”
The girl next to me didn’t skip a beat. “Yeah, of course, that’s easy. Well you see Pu-239 is highly fissile and is first isolated after being separated from — ”.
The room erupted in laughter: the professor looked like someone who’d been handed a menu in the wrong language. Whether this is a normal exercise she does with rooms full of engineers I could not tell, but it left an impression. When you focus all of your time onto a topic it’s easy to get ahead of yourself when explaining it. This is why I want to dedicate this edition of my newsletter to explaining the basics of nuclear energy. It’s lengthy (I’ll get back to shorter emails again) but I’m going to try my best to explain why it’s an important technology while remaining honest about its shortcomings. I am going to skim lightly across a number of complex subjects, so engineers on the newsletter: please allow me some liberties with the explanations.
Why is nuclear still around and why does River keep writing this newsletter?
The short answer is that nuclear energy provides low-carbon power that is available 24/7/365. The technical and logistical knowhow needed to build and maintain these machines also propels research and education in engineering, medicine, agriculture, and aerospace in both the civilian and military sectors. In short, a nuclear plant not only produces energy with lifecycle emissions comparable to those of renewables, it also encourages research and workforce development within various high-tech sectors. The reason that I care about nuclear is primarily because of its environmental benefits and potential to address growing global energy demand. The majority of emissions from a nuclear power plant are water vapor and/or hot water depending on the plant design — basically the stuff you encounter during your morning shower.
Today we are seeing an unprecedented rate of economic development take place across the planet as entire continents gain access to reliable sources of food, water, shelter, and energy. All of this is happening at a time when we are intensely aware of the impact that our consumption has on the climate. Nuclear energy is currently one of the most widely-used tools for power generation and the world’s second largest source of carbon free energy after hydropower.
E=mc²
So how does it work? Allow me to try and explain fission as well as mass-energy equivalence (represented by the most famous equation of all time) so that you too can impress people at parties.
The process by which a nuclear reactor creates energy is quite simple: water gets heated up to the point where it can create steam, which is in turn used to rotate a turbine that generates electricity. The water is heated through fission, the process more commonly known as atom-splitting and one that requires special “fissile” materials. Under the right conditions, the atoms that make up these materials can break apart. In order to do this, the fissile materials are placed inside a nuclear reactor — essentially a tank of water — where they are bombarded by neutrons, one of the subatomic particles that make up atoms. When this happens, the atoms in that material are impacted and split apart, releasing heat and radiation in the process. A controlled chain reaction ensues in which neutrons continue to bounce around, splitting more atoms in the process. The speed at which this chain reaction occurs is controlled by a number of factors, including the “moderator” which is basically the water in the tank where the materials live.
National Geographic has a great 2-minute video that outlines this process:
Pretty straightforward. Now let’s get to the physics.
Einstein’s most famous equation (E=mc²) has profound implications for the way we understand our universe. It also applies to what makes nuclear energy so unique. According to this equation, the energy “E” of a physical system is equal to its mass “m” multiplied by the speed of light “c” squared. This is significant when it comes to harnessing energy, which humans have traditionally done by burning stuff like oil, coal, or cow poop. “Stuff” at the molecular level means atoms, and when we light this “stuff” on fire what we are essentially doing is rearranging the electrons within those atoms. This is also known as a chemical reaction and because electrons only make up less than 0.01% of an atom’s mass, that’s roughly the amount of available energy that gets accessed.
When we initiate a nuclear reaction however, we engage the nucleus, where 99.99% of the atom’s mass is located. When we look at Einstein’s equation again, you might get a hint of what this means in terms of potential energy. The speed of light c is equal to 300,000,000 meters per second. When you square that amount, you get a number that looks like 90,000,000,000,000,000. That’s a lot more zeros. This means that based on Einstein’s equation, even a microscopic mass can equate to an enormous amount of energy:
Energy = mass x 90,000,000,000,000,000
It’s for this reason that 1 standard uranium fuel pellet (about the size of a gummy bear) can produce the same amount of energy as 17,000 cubic feet of natural gas: the amount that the average U.S. home uses every three months.
This is also why Darlington Nuclear Generating Station can provide over half of the electricity consumed in nearby Toronto — a city of 2.7 million people — on a piece of land roughly twice the size of the Metropolitan Museum of Art in New York. We refer to the amount of power generated per unit of land as the energy density of a particular source. The higher the density, the smaller the land footprint.
Ok, that’s a lot of energy. So that’s why a nuclear plant can explode like a nuclear bomb.
Not exactly. It’s true that the physics that underlie the mechanics of a nuclear bomb and a nuclear reactor are similar. It’s also true that some of the materials used in both are the same. But they are different in some fundamental ways that mean a nuclear plant cannot explode like a nuclear bomb. The primary difference is the density of fissile materials used and the rate at which they give off energy. The reaction inside a bomb is specifically designed to release all of its energy in less than a second. While the reaction inside a reactor can release energy on a similar scale, it can only do so at a speed that takes years. Even in the case of a meltdown it’s physically impossible for the same type of reaction to occur.
Here’s an analogy. Imagine you have a box of matches with extra-long handles, let’s say each is a kilometer long. Those matches can be ignited in only one of two ways: the first is to arrange the matches in a very long straight line so that when you light the end of one, it burns at a steady rate down its length and onto the next one. This chain reaction continues for years. The second option is to “enrich” the box of matches by removing everything but the combustible tip. You can then take those tips and perfectly arrange them inside a tennis ball so that when thrown at the exact right angle and speed the tips will align perfectly with each other and at the right exact moment to react simultaneously and explode. The second option takes additional years if not decades of intensive research, funding, and geopolitical navigation to whittle down those match handles and design the tennis ball.
Again I’m just skimming the surface here but if you’d like a deeper explanation, MIT has an excellent 6-minute video of the difference between a nuclear reactor and a nuclear bomb. It’s got pretty graphics and a very clear explanation.
Nuclear reactors run on green goo
So what are these “fissile materials” that we bombard with neutrons? Despite the Hollywood imagery associated with nuclear, the fuel that goes into a reactor is neither green nor liquid. It’s actually an utterly uninspiring grey color and comes in the form of small solid pellets, stacked inside rods, and grouped together. This is also how they come out of the reactor.
What happens in between though is pretty cool. While we’ve all learned that nothing can travel faster than the speed of light, this actually depends on the medium in which a particle is moving. In a nuclear reactor for example, which is full of water, light is slowed down as it passes through. This means that certain other particles involved in a nuclear reaction can go faster than the speed of light in this environment. The result is a blue glow known as Cherenkov radiation. It’s like a sonic boom but for your eyes.
As nuclear engineer and close friend Emma Redfoot puts it “nuclear energy is basically just glowing rocks that create energy.”
There are liquid forms of nuclear waste as well that come from various processes within the nuclear fuel cycle, medical uses, mining, and the historic production of nuclear weapons. The ongoing cleanup from 20th century nuclear weapons production is an important environmental problem that is still being addressed. The Manhattan Project and subsequent Nuclear Arms Race that took place in the second half of the 20th century left in their wake a dismal legacy for the places where radioactive materials were mined and used. For some communities in the U.S. and central Asia, the situation is still not rectified today. While today’s commercial nuclear waste management practices have improved by leaps and bounds, the legacy waste created by nuclear weapons and nuclear power during their origins in the middle of the 20th century are an ongoing environmental justice issue.
Lacy M. Johnson is one of my favorite environmental writers who I first started following after she wrote in 2017 about the ongoing impact of Manhattan Project waste on a small town in Missouri. The Fallout, Guernica Mag.
There’s only one destination for nuclear waste: deep in the ground
This is arguably the most contentious topic related to nuclear energy. I’ll try and outline what nuclear power waste is and what we do with it. As mentioned above, nuclear waste comes from many sources, many of which have problematic legacies attached to them. For the purposes of focusing on modern nuclear power, I’ll explain what gets produced by nuclear power plants today.
The stuff that comes out of a nuclear reactor when it’s done being used has different nicknames depending on who you are talking to. Most of us know it as “nuclear waste.” Others refer to it as “spent fuel” or “unspent fuel”, which comes from the fact that existing nuclear reactors generally extract less than 5% of the useable energy from each unit of fuel. This means there’s a lot of potential energy still trapped in there that for various reasons we do not access. To explain what we do with the waste/unspent fuel, I’ll refer to it as “the assemblies”, which are the structures in which the fuel pellets are stacked.
Refueling a nuclear reactor is kind of like swapping the batteries in your tv remote, but much more involved. When an assembly comes out of the reactor it’s very radioactive and not something you want to hang out around. This is why reactor refueling is continuously and meticulously planned throughout the plant’s lifetime. The actual process takes place every few years over the span of several weeks and is executed like clockwork by a workforce with an average size of 500 full-time plant workers and over 1000 temporary workers. When the assembly comes out of the reactor, it is moved to “wet” storage, which is basically a big swimming pool. Similar to how the density of water inside the nuclear reactor can moderate the heat during a reaction, the water in this swimming pool can moderate the release of radiation. It’s actually safe enough to swim in as long as you don’t go too deep.
The radioactivity of these assemblies, while initially deadly, is also what makes them ideal waste products. Over time as radiation levels decrease the assemblies become less dangerous. What’s eventually left over is a mixture of elements that are still radioactive and will stick around for thousands of years, but which are also far less harmful — the type of stuff you can actually touch. This is because of “radioactive half-life”: the measurement of time that it takes for one-half of the atoms in a radioactive material to decay. By nature, the elements that are the most radioactive are also the ones that give off the most energy initially and disappear the quickest. The elements that stick around for millennia do so because they’re less radioactive.
After about 5–15 years in wet storage, the assembly is moved to “dry” storage, which means it’s placed inside a reinforced cask made of steel and concrete and parked outside next to the nuclear plant. The integrity of these casks are tested to withstand being hit by trains, trucks, rockets, rocket-propelled trucks, airplanes, and most other projectiles we can come up with. The casks are pretty harmless at this point. Forbes columnist Dr. James Conca has some excellent short videos about this process — all shot next to some of these casks.
What happens next is probably the largest source of debate surrounding nuclear. The reality is there isn’t that much of it — all of the civilian nuclear waste in the U.S. could fit inside a Walmart — but it’s still a contentious topic that often frames the nuclear energy discussion. While it’s referred to as a problem, it’s more a reflection of how each country chooses to deal with it. Some places like France recycle the waste and use it again in existing reactors. Other countries like the U.S. keep it parked by the plants awaiting to be stored deep underground. Many people think this is unnecessary and that it doesn’t need to go anywhere. A number of new reactor designs are being developed that are designed to consume unspent fuel, so that introduces another option.
I personally think that other industries could take a few cues from the nuclear industry when it comes to waste. As we learned from Hurricane Florence, it’s probably not a great idea to keep toxic coal ash in open-air pits.
Again, MIT has a great 5-minute explanation of what nuclear waste is if you’d like to learn more.
OK, whatever, but nuclear is still inherently unsafe
When it comes to popularity rankings for energy sources, nuclear energy consistently ranks toward the bottom alongside coal and fracked gas. It’s not difficult to understand why when you remember the industry’s unofficial mascot is Homer Simpson.
As the result of nuclear accidents (Three Mile Island in 1979, Chernobyl in 1986, and Fukushima in 2011) and general familiarity with the technology since its invention, safety has become a tenet of the design, training, protocols, and procedures of every single nuclear plant and its workforce. This is why nuclear has a safety record that beats every other utility-scale energy source when accounting for deaths per terawatt hours of energy produced. This is even including the accidents that have taken place.
The U.S. Environmental Protection Agency concluded early on that the release of radioactive materials from the Three Mile Island incident did not raise radioactivity enough past natural levels to cause even one additional cancer death in the surrounding area. These findings have since been confirmed by a list of other organizations including the U.S. Department of Health and Human Services, The Commonwealth of Pennsylvania, and Columbia University.
In contrast to Three Mile Island, the Chernobyl disaster that took place in April of 1986 is the worst man-made civilian nuclear accident in history. While conducting an electrical system experiment that included a disabling of the plant’s automatic shutdown equipment, an overheating of the reactor led to explosions and the release of radioactive material into the immediate area and surrounding regions. An amount of radioactive fallout larger than that of the bomb detonated over Hiroshima ultimately spread across more than 77,000 square miles throughout Ukraine, Russia, and Belarus. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and World Health Organization (WHO) routinely publish information related to their monitoring of public health impacts of the Chernobyl and Fukushima nuclear disasters. The Chernobyl disaster has to date claimed 31 lives and WHO models predict up to 4,000 additional deaths could ultimately be attributed to radiation exposure from the accident. The majority of these are thyroid cancer cases among residents exposed to concentrated radiation levels in local cow milk and other dairy products. An article published in The Lancet in 2006 highlighted research done by experts in Kiev, Moscow, and Minsk who have claimed the death toll could reach into the tens of thousands. As the article points out, “The main point of contention among scientists is the long-term effect of low doses of radiation that were suffered by most of the liquidators (the clean up crew) and people living near Chernobyl.” This is because studying the effects of isolated events of radiation exposure is notoriously difficult against the backdrop of daily exposure we get from our surroundings and the environment.
The aftermath of the Chernobyl accident is tragic, but as the HBO mini-series Chernobyl made abundantly clear, the conditions that led up to it were defined by negligence and incompetence. The reactor operator in charge of the plant was a Soviet political appointee with limited experience who had been responsible for a previous reactor incident. The reactor itself was a relatively primitive design that lacked the most important safety feature of any nuclear power plant today: a containment structure. One quote I’ve read referred to the design as “basically a pile of graphite blocks in a quonset hut”. This would be the equivalent of ditching your home’s central heating system to make a campfire on your living room floor and hoping it didn’t burn the neighborhood down. A reactor like this would not be built today, let alone financed or insured by anyone in their right mind. Shortly after the disaster, other reactors of the same model underwent a suite of modifications recommended by the International Atomic Energy Agency and the UN to assure that a similar accident could not happen again.
The Fukushima Daiichi nuclear disaster is the only other event since Chernobyl to receive a “7” rating on the International Atomic Energy Agency’s (IAEA) International Nuclear and Radiological Event Scale (INES) — the highest possible rating. Unlike Chernobyl, it has to date claimed no more than 1 life from radiation exposure. While most official tallies recognize 0 deaths, compensation paid in 2018 to the family of a deceased plant worker has been interpreted differently depending on who you talk to. In 2013 the WHO reported that area residents were exposed to so little radiation that any related health effects were likely to be below detectable levels. In August of 2019 The Fukushima prefectural government decided to end its health survey of expectant and nursing mothers, as survey results since the accident have shown percentages of birth defects, babies with low birth weights and other abnormal conditions to be almost the same as the nationwide average. While the cleanup is ongoing and expected to take at least 30 years, it is mostly contained to the immediate area surrounding the plant. Regardless, the 2011 Tōhoku earthquake, tsunami, and ensuing nuclear disaster were traumatic events for the Japanese people and with respect to nuclear specifically they have complicated an already complex relationship with the technology. The majority of the country’s nuclear power plants remain closed today and it is difficult to know what their fate would be.
It would be wrong to say that another nuclear plant disaster will never happen. For as long as the technology exists, so does the risk. The possibility of an event happening identical to Chernobyl or Fukushima however is very close to zero. This is because mistakes and best practices are continuously shared across the industry and each incorrectly flipped switch is heavily scrutinized to a point that assures the lesson learned is embedded in protocol going forward. This is arguably why the worst possible type of nuclear accident (level 7) has had entirely different public health consequences after Chernobyl and after Fukushima.
Many advocates for nuclear actually look at Fukushima as the point when they became supportive of the technology. The fact that an earthquake and tsunami that killed nearly 16,000 people and shifted Earth 6 inches on its rotational axis would result in a maximum of 1 death from a nuclear plant failure speaks to the maturity of this technology and the amount of innovation in safety that’s taken place. There is still much for us to learn however and unfortunately in 2011 the story that was most reported on focused on doomsday headlines.
The risk calculations for using nuclear power are complex and different for each person. It’s important to keep things in perspective however. While nuclear plants have associated risks that I’ve been discussing here, fossil fuel plants risk obvious harm to our air, water, land, and climate. The WHO reports that over 20,000 people die every day from air pollution related to fossil fuel combustion. That’s a full Boeing 747 crashing every 30 minutes. Even renewables carry risk with them through their land use, material use, and need for backup generation (when there’s no sun or wind) that today comes mostly from burning more fossil fuels. The YouTube channel Kurzgesagt recently produced an engaging video about putting these issues into perspective.
Nuclear technology is an old technology and obsolete.
While it’s true that nuclear technologies have been around since the middle of the 20th century, they’re by no means outdated. The reality is that nuclear is an evolving technology where improvements to its efficiency, cost, and safety are constantly being made. Current reactors have capacity factors above 90%, which means they pump out energy for more than 90% of the time they’re in operation and makes them more efficient than nearly all other energy sources. A 90% capacity factor is like working without any breaks for almost 22 hours every single day of your life. Existing nuclear technologies are being used beyond the power sector as well for things like medicine and agriculture. NASA’s Mars rover Perseverance currently uses a miniature radioactive source for power.
There is also an ongoing expansion in the number of nuclear energy companies building next-generation designs. Fueled by the largest influx of nuclear engineering graduates in three decades and funded by investors like Bill Gates and Jeff Bezos, these startups are pursuing reactors that are designed to be more suitable for today’s energy landscape. This means reactors that integrate better with intermittent sources like wind and solar, come in various sizes to better suit developing economies, and use safety systems that can prevent accidents like the one in Fukushima.
To give one example, the U.S. military spends an immense amount of resources on moving supplies like fuel and water between its bases. They are currently looking into smaller nuclear reactors that could nearly eliminate these trips. Just like duct tape and the internet, those technologies will have huge implications for civilians in situations like natural disaster relief and generating energy for remote communities.
It’s either renewables or nuclear
This is one of the most pointless arguments between environmentalists today. The fact of the matter is that communities of all shapes and sizes have their own unique energy demands and constraints. It should come as no surprise then that a growing body of research from institutions like the Intergovernmental Panel on Climate Change, Massachusetts Institute of Technology, and World Resources Institute conclude that hybrid systems of nuclear+renewables+carbon capture represent the most cost effective way to get to a low-carbon grid. This is mostly because we need a diversity of energy sources to supply different types of energy demands. The electricity that you charge your phone with only represents about a third of our overall energy consumption. The rest of the energy pie includes transportation, manufacturing, buildings, and agriculture, which also require energy in other forms like liquid fuels and high temperature heat. To steal an analogy from Jesse Jenkins at MIT, assembling an “energy team” to decarbonize our grid and deal with climate change is like assembling an all-star basketball team. You can’t win if all the players are point guards. If this topic interests you and you like podcasts you can hear more about Jesse’s research here.
It’s prohibitively expensive to build new nuclear
This is in fact true. And at the same time it isn’t. The cost of different energy sources varies greatly depending on where they’re built, how they’re used, and how long they continue generating power for. These costs are often compared using LCOE, which stands for the levelized cost of energy (LCOE) — a calculation that takes into account how much a power-generating asset costs during its lifetime and how much energy it sells during that time. This is why you can compare the costs of a multi-billion dollar nuclear plant with a 60-year lifespan to a solar farm that costs far less but has a 25-year lifespan.
The majority of a nuclear plant’s cost comes from its construction. The fuel itself is relatively cheap. This means that it takes longer to pay off the initial investment and as a result benefits by producing lots of energy all the time. Until recently, this was a great arrangement for utilities that sold electricity in one direction: to the consumer. In the past decade however, the plummeting costs of technologies like solar photovoltaics have made it possible for individual homes to purchase the means to generate their own electricity and sell it back into the grid. More people generating more energy in more places has led to a more distributed energy network.
Cheaper wind and solar technologies also means more of them are being installed, and fast. A solar installation for example can be as small as your rooftop or as large as to have comparable generation capacity to a conventional nuclear, natural gas, or coal plant. These technologies didn’t get cheap on their own however. A concerted effort on the part of government, industry, and activists has created a suite of incentives by which renewables have been able to flourish. This is good news for renewables, whose costs have dropped by orders of magnitude. In the U.S., this has also been good news for natural gas plants, which are flexible enough to pair with renewables and cleaner than plants that burn coal. Natural gas and renewables have been largely responsible for the ongoing closures of coal plants, which is excellent for reducing carbon emissions. But there have been unintended consequences as electricity demand in the U.S. has currently plateaued and more electricity coming from gas and renewables means less coming from other plants, including nuclear. This has led to massive losses for nuclear plants and in the worst cases their early closure, which has consistently resulted in higher carbon emissions when they stop generating energy on the grid. This is a serious problem and one that is beginning to be addressed through a number of state and federal programs designed to compensate nuclear for it’s low-carbon energy. The situation sounds more like life support than a flashing green traffic light telling investors that nuclear is the place to be right now.
The U.S. nuclear industry hasn’t done itself many favors in the past decade either. Two new-builds in South Carolina and Georgia have encountered eye-watering cost and schedule overruns that have led to a mess of lawsuits. The overruns themselves are the result of poor project management, open-ended contracts that have disincentivized strict timelines, and an inexperienced construction workforce, among other things. Building a nuclear plant in the U.S. today is like building custom furniture: there’s no standardized design or the economies of scale that come with one.
Standardization is exactly what places like France and South Korea have done to build out large networks of nuclear plants in a timely fashion. The results have been predictable: low-carbon electricity grids that supply cheap power. Countries like South Korea with strong nuclear exports have used these lessons to continue building and operating plants in other countries as well.
The reality in the U.S. is that the demand for electricity has been mostly flat for the past decade and the places where that electricity is coming from is increasingly distributed. This doesn’t leave much room for any new massive nuclear plants, which is why the future of nuclear isn’t massive, it’s small. Many of the new designs that I frequently reference are a fraction of the size of those being built today.
The energy market is fundamentally like any other market: prices are ultimately a reflection of the things we do and don’t value. While there’s an unprecedented amount of work ahead of us to clean up our energy system, I think we as a society are beginning to truly understand what we want out of it: energy that is clean, affordable, and resilient. Between now and then there will be many interesting ups and downs but you can be sure of one thing: there’ll be plenty more newsletters from me trying to make sense of it all.
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For your ears:
30/70, Elevate
Label: Rhythm Section International
Deeply-pocketed jazzy neosoul hailing from Melbourne. This should come as little surprise to anyone familiar with the group Hiatus Kaiyote. Top review from the Discogs comment section: “the proverbial dogs bollocks. Proper mustard.” Couldn’t have said it better myself.
