Nuclear fusion has long been considered the holy grail of energy production, harnessing the same process that powers the sun to achieve virtually limitless power generation. Fusion is seen by many as the ultimate target for clean, sustainable energy. Despite recent advancements, nuclear fusion remains an experimental technology with many challenges yet to be overcome.
What Is Nuclear Fusion?
Nuclear fusion is a process where two lighter atoms are combined to form a larger nucleus. This is the same process that powers stars, where hydrogen atoms are combined to form helium and heavier elements in subsequent stages. The extreme pressure and temperature inside stars are what makes fusion possible, conditions that are difficult, if not impossible, to replicate on Earth.
This is a separate process from nuclear fission, which has been used in full-scale power generation for decades. In fission, heavy atoms such as uranium are split into smaller atoms in an ongoing chain reaction. Fusion has proven to be a much more elusive process.
The mechanism of nuclear fusion was first proposed in 1915 by William Draper Harkins. The later development of the mass spectrometer confirmed that four hydrogen atoms are, in fact, heavier than one helium atom. While some criticize nuclear fusion as “always being 50 years away”, there has been substantial progress in the 110 years since this phenomenon was first theorized.
Fusion Reactor Technologies
Sustaining a fusion reaction and extracting energy from it requires the development of a fusion reactor that must overcome a variety of challenges. There are two primary types of fusion reactor technologies currently being explored as options for practical energy production.
Inertial confinement fusion (ICF) relies on high-powered lasers to rapidly heat and compress small fuel pellets, creating the pressure and temperature needed for fusion. These conditions form a plasma envelope, igniting the reaction. The National Ignition Facility (NIF) in the United States is a leader in this area. In 2022, the NIF achieved 3.15 MJ of energy generation from 2.05 MJ of input to the reactor, surpassing the breakeven point in an important milestone.
Magnetic confinement fusion (MCF) uses a torus-shaped chamber called a Tokamak to generate magnetic fields that suspend superheated plasma away from the chamber walls. This technology is the focus of several large-scale projects, including the now-decommissioned Joint European Torus (JET) and the International Thermonuclear Experimental Reactor (ITER) in France.
Nuclear Fusion Fuel
Current nuclear fusion designs use deuterium and tritium as fuel. A standard hydrogen atom contains one proton and no neutrons. Deuterium and tritium are isotopes with one and two neutrons, respectively. Fusion creates tremendous energy, so only a relatively small amount of fuel is needed. Deuterium can be extracted from seawater, while tritium is produced by neutron reactions with lithium.
There are a variety of fusion pathways that can take place within a fusion reactor. The fusion of deuterium with tritium (D-T fusion) is most achievable with current technology. However, it produces high-energy neutrons that can damage reactor materials and create short to medium-term radioactive waste.
There are other pathways, such as deuterium-deuterium (D-D) and deuterium-helium-3 (D-He3), that produce fewer high-energy neutrons. However, they have their own challenges, such as requiring higher temperatures and delivering lower energy yields. D-He3 fusion is also severely limited by fuel scarcity due to the rareness of helium-3 on Earth.
Environmental Benefits of Nuclear Fusion
Nuclear fusion stands as a promising prospect for a future with 100% sustainable energy production. The massive potential energy production from a relatively abundant fuel source makes fusion a contender for achieving global energy security. The uninterrupted availability and affordability of nuclear fusion energy could completely transform energy supply chains.
Fusion is also seen as a highly environmentally friendly technology. Unlike fossil fuels, it does not create any direct greenhouse gas emissions. It also avoids many of the concerns over long-term nuclear waste storage associated with nuclear fission, producing minimal radioactive waste.
Safety is another key focus in fusion reactor development. Fusion only occurs under tightly controlled conditions. If those conditions are not maintained, the fusion reaction will stop, as opposed to the potential runaway reactions or meltdowns possible in some fission reactor designs.
Nuclear Fusion Challenges
While nuclear fusion is a highly promising technology, it brings with it a set of new challenges. Ongoing development by organizations and governments around the world seeks to overcome these hurdles to make nuclear fusion a viable option for full-scale energy production.
Nuclear fusion releases high-energy neutrons that make the inside of the reactor a very hostile environment. The neutrons constantly bombard reactor walls, breaking down materials and causing a variety of additional issues, such as embrittlement. The damaged materials must be removed and replaced to maintain operation. While less hazardous than nuclear waste from fission, these materials will still require dedicated radioactive waste storage for decades.
There is no possibility of achieving the pressure found in the interior of the sun here on Earth. To compensate, fusion reactors must rely on higher temperatures reaching over 100 million degrees Celsius. The hottest part of the sun, the core, reaches just 15 million degrees Celsius. These temperatures pose serious technological challenges, which is why complex magnetic plasma confinement is necessary.
While the fuel used for nuclear fusion is abundant, the construction of reactors can require a variety of rare materials. Superconducting magnets, helium cooling, and various advanced materials increase both the financial and environmental costs of reactor construction.
The Role of Nuclear Fusion in a Sustainable Future
While there are still technological challenges to overcome, the potential benefits of nuclear fusion for a sustainable future continue to drive development forward. Fusion is a clean and sustainable energy source that would be suitable for full-scale baseload generation, fulfilling a role in electrical grids that intermittent sources such as wind and solar struggle to fill without significant energy storage.
Nuclear fusion would also support geopolitical stability and ethical supply chains. Fossil fuels and uranium are often sourced through complex global supply chains, leading to political imbalances and conflict. Fusion fuel could be produced domestically in most countries, reducing tension and dependency.
Fusion research is also pushing a variety of scientific fields further. Superconducting magnets, plasma containment, and the advanced modeling being developed all have other potential applications across fields from materials science to medicine.
The Path Forward for Nuclear Fusion
While recent developments are promising, there is still a long way to go for nuclear fusion. There are hurdles to overcome before a successful proof-of-concept commercial system can be created. From there, massive investment in new infrastructure will be required to build the costly and complex nuclear fusion generators that will, hopefully, one day soon, power the world of the future.
The next generation of electrical generation facilities is sure to be under the same, if not higher, scrutiny as modern facilities with regard to environmental monitoring and reporting, health and safety compliance, and chemical management. The team at ERA Environmental Software Solutions provides EHS software that adapts to changing technology, industry, and regulatory landscapes, no matter what the future may hold.
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