# Embracing Thorium Molten Salt Reactors for a Sustainable Future

Chapter 1: Rethinking Nuclear Energy

In 2019, I found myself deeply immersed in the world of sustainability. My days were consumed with studying Sustainable Ecology, equipped with a plethora of strong opinions on topics like energy policy, wildlife preservation, and global agriculture. To my surprise, I authored a policy brief advocating for Thorium-fueled nuclear energy as an affordable and clean energy source. After dedicating a month to it, I shamefully discarded my work, believing that no true environmentalist would support nuclear energy.

What follows is that policy brief, revised for clarity. Those familiar with writing such briefs know they can be quite tedious. I never anticipated it would resurface since the subject seemed unappealing. Thorium? Molten Salt Reactors (MSRs)? Who's interested? It seemed far more exciting to discuss solar energy!

However, I’ve come to realize my earlier assumptions were misguided. Nuclear energy remains a polarizing topic, especially among environmentalists. In fact, its controversial nature adds to its intrigue. So, amidst the monotony of recent years, let’s delve into the complexities of this conversation.

Typically, opinions on nuclear energy fall into two categories:

"Absolutely, I support nuclear energy! I'm an environmentalist!"
"How could you possibly think I would back nuclear energy?! I'm an environmentalist!"

It’s time to rejuvenate the dialogue surrounding nuclear energy. You likely identify with one of these two perspectives—either ready to criticize me or commend me for my enlightened view. I welcome the discussion for the sake of scientific advancement.

Chapter 2: Thorium-Fueled Molten Salt Reactors and Their Potential

A significant majority of Americans desire cleaner energy options. Nonetheless, there are doubts about whether solar and wind power can comprehensively meet the demands of the American Energy Grid. Diversifying energy sources can provide consistent power and ensure clean energy availability during peak times and lulls. Nuclear energy serves as a potent, clean power source, often overshadowed by fears stemming from historical disasters. Yet, there exists a safe, cost-effective alternative that is carbon-neutral: thorium.

The Problems with Uranium

Not all elements can undergo nuclear fission. In the case of uranium, only 3%-5% of the ore used in fission reactors consists of U235, the fissile isotope required for energy generation. To attain sufficient U235 for fission, uranium ore must undergo enrichment, which creates plutonium-239—a substance many associate with nuclear weapons.

Let’s briefly address the weapons issue. While producing nuclear weapons from enriched uranium is complex, any nation capable of enriching uranium for reactor fuel is approaching nuclear weapons capability. Enrichment requires transforming uranium from around 5% to 90% for weapon-grade use, a process that is both time-consuming and costly. Once a nation possesses enrichment technology, the timeline to weapons-grade uranium can be mere months.

Historically, the U.S. reached this milestone at Los Alamos in July 1945, leading to the atomic bombing of Hiroshima that August. The bombs used highly enriched uranium, produced during the Manhattan Project in a secretive 27-month endeavor. It’s crucial to recognize that building a bomb requires more than just the warhead; comprehensive technology for testing and construction is necessary.

Another concern regarding weapons is that plutonium, a byproduct of uranium fission, is produced within nuclear reactors. Naturally, plutonium doesn’t exist on Earth; it is generated from the fission process. Each nuclear reactor generates enough plutonium for approximately 45 atomic bombs, necessitating specialized reprocessing due to its high radioactivity.

While it’s not feasible for a layperson to create nuclear weapons using reactor materials, nations with nuclear reactor capabilities can potentially produce weapons-grade materials over time.

Now, let’s shift focus to the inefficiency of traditional uranium use. Conventional nuclear fission generates radioactive waste with half-lives extending up to 10,000 years. To put that into perspective, twelve thousand years ago, humans were just beginning to form villages, and ten thousand years ago, we first domesticated cattle.

Although creating weapons from nuclear waste is unlikely, the potential for misuse exists, along with significant health risks from improperly stored radioactive materials. The issue of half-lives complicates waste management, raising concerns about environmental and societal health.

Conventional Reactors: A Closer Look

Let’s examine light water reactors (LWRs), which use water to control and moderate the fission process. In these reactors, graphite fuel rods heat water to produce steam, which spins a turbine to generate power. The water serves both as an energy source and a safety mechanism. As water levels drop, steam production increases, which slows the fission reaction.

However, solid nuclear fuel requires continuous cooling to prevent meltdowns, a risk evidenced by incidents like Fukushima, Chernobyl, and Three Mile Island. User errors or unforeseen natural events can compromise the safety feedback loop, leading to catastrophic outcomes—even with extensive safety measures in place. It’s understandable why many people fear these scenarios.

Innovative Solutions: Thorium

One significant advantage of thorium is that most of it found in nature is TH232, which is the most useful form for reactors. Unlike Uranium-235, thorium is not fissile on its own and requires the addition of neutrons for fission. This characteristic provides a built-in safety mechanism; if the neutron source is removed, the reaction ceases.

Thorium eventually decays into U233, which can be utilized in additional reactors to generate more energy. The best part? This method produces 1,000 to 10,000 times fewer waste products compared to traditional uranium reactors. Importantly, thorium does not create plutonium, significantly reducing the risk of weapons proliferation. Furthermore, its radioactivity lasts only 500 years, far less than uranium's 10,000-year lifespan.

Molten Salt Reactors (MSRs)

Another critical aspect is the development of Molten Salt Reactors (MSRs), which began during the Manhattan Project in the 1960s. Interest waned when funding diminished, but the technology remains promising.

MSRs utilize liquid fuel—molten salts like fluoride—rather than solid fuel rods. When an MSR reaches 700 degrees Celsius, it stabilizes naturally, expanding into a cooling circulation loop. Since fission cannot occur in this loop, the salts cool further. This feature ensures that MSRs cannot exceed 700 degrees Celsius, making them inherently safe and stable.

In 1960s experiments, MSRs demonstrated their ability to operate continuously without human intervention, even during peak performance, without the need for control rods. The design of MSRs inherently prevents meltdowns and allows for recycling used nuclear fuel.

Perhaps most importantly, MSRs require fewer components, resulting in smaller and cheaper reactors compared to conventional models. Imagine a compact nuclear reactor, slightly larger than a human, and the possibilities become exciting.

Conclusion: The Path Forward

Despite the challenges associated with radioactive waste, nuclear energy is considered "clean" due to its low CO2 emissions compared to fossil fuels like coal and natural gas. While the risks surrounding radioactivity cannot be ignored, the key concern for many remains safety.

The combination of thorium as fuel and molten salt reactor technology presents a nuclear energy option that is significantly safer than traditional reactors. MSRs are gaining renewed interest globally in countries like China, Russia, and Japan, with several prototypes already in development, including a Molten Salt Fast Neutron Reactor utilizing thorium fuel.

To ensure the U.S. remains competitive in this vital energy sector, policymakers should prioritize MSRs over other nuclear technologies, promote public education on their safety, and invest in research and development for thorium and molten salt reactors.

Final Thoughts:

Nuclear energy often divides environmentalists into two camps—those who embrace it and those who oppose it. Perhaps you’re apprehensive about it, as I once was. Consider these points regarding the future of energy in the U.S.:

Molten Salt Reactors (MSRs) are safe, cost-effective alternatives to traditional nuclear reactors.
Thorium is more abundant than uranium and doesn’t require enrichment for fission.
Thorium produces less waste, and its byproducts are less radioactive and shorter-lived than uranium; it does not generate plutonium.
Emergency shutdowns are more straightforward with thorium than with uranium.
The combination of MSRs and thorium yields safe, clean, and affordable nuclear energy without CO2 emissions.

Which side of the nuclear debate do you align with? Are you skeptical or supportive of this technology? Thorium MSRs have significantly shifted my perspective on the future of nuclear energy, and for that, I owe a debt of gratitude to my Sustainable Energy Policies professor.