It’s a matter of power

Over two thousand years ago, on the island of Sicily, the philosopher Empedocles saw the gods at war. He believed that they were not only ruled by the four elements of earth, water, air and fire, but by two additional active forces: Love and Strife. According to him, life on Earth is attributed to the endless cycle of these active forces joining and dividing.

Today, this myth lives on in sterile laboratories, glowing reactors, and within the atom itself. The story of nuclear fission and fusion is in many ways the same story Empedocles told — creation and destruction live side by side in every spark of matter. 

As nations race to secure stable energy supplies in the wake of pollution and overconsumption, recent debates over the climate crisis pose nuclear power as a potential solution. 

However, concerns following the effects of the 1986 Chernobyl fission disaster remain severe, impacting human health, the environment and, consequentially, public trust in nuclear energy. Though currently underdeveloped, fusion technology aims to redeem the trust fission undermined. 

Although both processes garner nuclear energy, fission and fusion are distinctly inverses. Fission energy is harnessed when the nucleus of an atom splits, whereas fusion energy is produced when they are joined together. 

USC alumnus Dr. Greg Sinclair is a research scientist at DIII-D National Fusion Facility who believes the Chernobyl accident has helped guide engineers toward cleaner and safer nuclear practices. He notes that out of this disaster came a revolution in safety: “‘defense in depth.’” These newly standardized fail-safe architectures have made another catastrophic event of the same caliber physically impossible.

With fission, modern advancements include small modular reactors and waste management.

Small modular reactors (SMRs), have taken a short-term role in terms of nuclear energy reducing carbon emissions, producing a power capacity of up to 300 MW(e) per unit. While roughly only one-third of a traditional nuclear reactor’s energy,  they can be placed in locations where large nuclear power plants can’t. 

Microreactors are a subunit of SMRs that are even more suitable for rural and remote areas. They can be used as backup generators for electricity, where they can produce up to 10 MW(e). In comparison to existing reactors, their safety is inherent to their size; lower power and operating pressure create less uncontrollable factors. 

When it comes to waste management, SMRs can be filled once, going on to last nearly 30 years. 

However, the real sustainability win would come from nuclear fusion, a less radioactive and cleaner nuclear source. The National Ignition Facility (NIF) is a California research center at the Lawrence Livermore National Laboratory that uses powerful lasers to model the conditions of stars and study nuclear fusion. 

On Dec. 5, 2022, the NIF reported the first controlled fusion experiment to reach scientific breakeven, i.e. more fusion energy out than laser energy in. They observed and produced 2.05 MJ of laser energy and got about 3.15 MJ of fusion energy out. More experiments were run in 2023 and each improved the overall energy gain. The highest output was recorded around 3.88 MJ of fusion energy. This means that ignition can be achieved repeatedly at multi-MJ levels. 

This milestone confirmed that it’s possible to cross the ignition threshold and demonstrated that inertial confinement fusion is no longer just a theoretical concept, but an experimentally proven process.

Beyond the NIF, the International Thermonuclear Experimental Reactor (ITER), located in Saint-Paul-lez-Durance, France, plans to run the world’s largest tokamak device. This machine will use a powerful magnetic field to confine and burn plasma into the shape of a torus, hopefully demonstrating fusion as a viable energy source. ITER is a collaboration of more than 35 countries that aim to produce around 500 efficient MW of fusion power.  The organization has marked 2035 to begin their first plasma operations, beginning with deuterium-deuterium reactions and then moving on to deuterium-tritium operations. 

In nuclear fission, a heavy nucleus, such as uranium-235, is split into smaller nuclei, releasing stored energy, gamma rays and neutrons. Fission can be achieved by striking the nucleus with another nucleus, which then starts a chain reaction. The newly liberated neutrons then split other nuclei. Currently, nuclear power plants use this process to generate heat to create electricity and steam. 

However, this can be dangerous. 

In the case of Chernobyl, the explosion was caused by errors in the reactor design — that led to an insufficient cooling mechanism and poor containment structure — as well as an inexperienced operating team that incorrectly removed control rods. In total, this explosion killed 30 people directly, but the World Health Organization estimates that up to 4,000 people may eventually die from the radiation that spread over parts of Belarus, Russia, and Ukraine. 

Nuclear fusion is more complex than fission. Its reaction involves the combination of two light nuclei, like hydrogen isotopes, to form a heavier nuclei, such as helium. Through this union, a massive amount of energy is released — almost three to four times more energy per unit than fission reactions — making the new nuclei a bit lighter than expected. This is the same process that stars use for their power, and these extreme conditions are hard to recreate on Earth. Fusion reactions also require temperatures over 100 million ℃ and pressures capable of overcoming the natural repulsions of the positively charged nuclei.

The quest for sustainable energy through fusion technology continues at USC, with alumni, faculty, and student groups working to ignite a clean energy future. 

Sinclair emphasizes that nuclear engineering isn’t just about energy; it's about designing safe and effective systems that outlast us. 

The on-campus Laboratory for Exploration and Astronautical Physics, known as LEAP, focuses on electric propulsion and computational modeling, as well as plasma physics which overlaps with fusion reactor science. 

Additionally,  ASPEN (the Advanced Spacecraft Propulsion and Energy Laboratory) is a student-led research group at USC founded in August 2018. Its focus lies on modeling nuclear-based spacecraft propulsion systems. They too, are more focused on propulsion physics, but contribute to nuclear safety research and advanced reactor modeling. 

The future of nuclear energy is multidisciplinary; it’s not limited to labs or legislation, but is also shaped by public understanding and advocacy. As fusion research moves from experimental to achievable, its objective becomes clearer every day: to deliver cleaner, cheaper, safer, and more abundant power without carbon emissions. This research is building a future for Los Angeles and other cities around the world to be able to power their homes, transportation, and industries through cleaner grids and reduced dependence on fossil fuels.

In the end, progress in nuclear energy isn’t just about physics or policy; it’s about the people.

“The biggest challenge isn’t physics… Its public perception,” Sinclair says. 

The forces Empedocles once named — Love and Strife — still govern the balance between innovation and risk, reminding humanity that the energy to build or to break remains its greatest responsibility.