New tech could make nuclear a safer, cleaner option.
Nuclear power plants produce zero emissions, but are still controversial due to safety concerns from leakage and meltdowns, as well containment issues of the radioactive waste. Is there a place for this carbon-free technology as the world moves towards 100% clean energy economies?
Nuclear energy’s four challenges
In a report sponsored by the US Department of Energy, the authors claim that nuclear power, the only carbon-free source of electricity that is already adopted world-wide on a large scale, could be expanded to even greater capacity if four key challenges are solved:
- Safety: For many, this is the biggest issue to nuclear energy. When something goes wrong at a nuclear plant, it can turn into life-threatening situations. We watched this unfold just a few years ago, when 2011’s Fukushima meltdown contaminated 11,580 square miles of land, with the 300 square miles directly around the power plant now a permanently-evacuated ‘exclusion’ zone. If a solar panel or wind turbine stops working, it just stops producing power. If a nuclear plant stops working, there can be truly catastrophic results.
- Waste management: Nuclear energy produces radioactive waste that remains dangerous for thousands of year. Spent fuel goes through a multi-step storage process as it becomes less radioactive, but we’re never able to completely destroy it.
- Proliferation: If nuclear energy became more commonplace, how do we keep the technology from being turned into nuclear weapons? While there’s only a few hundred large nuclear plants active in the world today, new SMRs have the potential to expand its use into more remote locations, with less
- Cost-effectiveness: Building nuclear plants is expensive, prohibitively expensive in many cases, though after the plant is built, nuclear produces some of the cheapest electricity available. If nuclear is going to play a part in our future emissions-free world, we’ll need to find ways to drop these construction costs.
From a clean energy perspective, safety and waste management are most importance. Is there room in a clean energy world for a technology that can and has ruined thousands of square miles of land and threatened human life?
New nuclear tech looks to combat these issues
Nuclear developers are looking to combat these challenges with a handful of new and not-yet-ready nuclear technologies, as reported by the MIT Technology Review in February.
Specifically, experts are looking at three nuclear technologies to answer these challenges: small modular reactors, advanced fission reactors, and fusion reactors.
First up, small modular reactors (or SMRs) are based on the same principles as conventional fission nuclear reactors, but on a much smaller scale. While a typical nuclear reactor produces around 1,000 MW of electricity, an SMR produces around 60 MW. This makes SMRs much cheaper to manufacture, as they can be mass-produced at a factory and shipped to the site for assembly. Along with lower construction costs, designers hope SMRs are safer than conventional plants. Some employ cooling systems that can continue to run even after the reactors shut down, see greater reactor efficiency that reduces waste, and boast better containment thanks to their smaller size.
Beyond SMRs, new ‘advanced fission’ nuclear reactors (also known as Generation IV reactors) use one of a variety of new cooling techniques, like sodium, helium, and molten-salt, the latter of which can continue to cool reactors even after losing power. Advanced fission reactors also increase safety by increasing energy production from the same amount of fuel, and some can even reuse spent fuel to produce more electricity. On top of that, waste from advanced fission systems remains radioactive for only a few hundred years, compared to thousands for conventional systems.
Lastly, fusion reactors create electricity by replicating the sun’s own process. Unlike nuclear fission in conventional plants, fusion needs extremely precise temperatures and regular, active refueling. Take away either of these and the fusion reactions abruptly end, so meltdowns aren’t an issue. On top of that, waste from fusion reactors is only radioactive for a hundred years or so, making safe storage and containment much easier.
The MIT Technology Review notes that none of these technologies is commercially available yet. Helium-cooled advanced fission should be available this year, but the rest won’t be ready for another 8 to 15 years.
Does nuclear energy have a place in 100% renewable economies?
Unlike coal, natural gas, and oil-fueled power plants, nuclear energy produces no emissions while generating electricity. No matter how much electricity is generated, nuclear plants create the same amount of emissions: zero.
Nuclear is the 2nd most common emissions-free electricity source on the planet – accounting for about 10% of the total – behind only hydro.
If you adhere to the notion that sustainability simply entails no adverse effects to the environment, nuclear energy then is a sustainable energy source as well as carbon-free.
But while nuclear is sustainable, it’s certainly not a renewable energy source. Unlike wind or solar energy, nuclear energy’s fuel – uranium – is finite. If we continue our current uranium usage, experts believe we could get another 200 to 400 years’ worth. That’s quite a long time, but nowhere close to the longevity of solar and wind power’s energy source – ie forever.
Upon cursory glance, nuclear energy seems to be on the way out, as plants in the US – like the San Onofre plant in southern California – and abroad close due to safety concerns and public/political outcry.
However, nuclear usage is continuing to rise every year and the MIT Technology Review notes that governments and policy makers, including researchers at the United Nations, are increasingly seeing nuclear energy as a key component to combat global warming. They note that the Union of Concerned Scientist argues that, when nuclear power plants shut down, the electricity generation could very well fall to a natural gas plant and if all nuclear plants shut down, carbon emissions could increase 6%.
Renewable energy mandates alleviate this fear, as new energy production would instead fall to solar, wind, and storage. However, there could be a place for nuclear in a world of clean energy, providing researchers could make headway on the challenges we looked at above, especially around safety and waste management and storage.
California’s 100% clean energy goal could include nuclear
In late 2018, former California governor Jerry Brown signed into law a goal of 100% clean energy by 2045. Considering that California is the world’s fifth largest economy, this is a major piece of legislation, though not surprising considering California’s previous renewable energy goals over the last 15 years.
Specifically, the goal states that utilities must source 60% of all electricity from renewable sources by 2030 – a moderate increase of their pre-existing goal, known as a renewable portfolio standard, of 50% renewable by 2030. Utilities can use solar, wind, and other renewable sources to meet this goal.
The remaining 40% can be met by any clean energy technology and is therefore much more flexible. While California hasn’t yet ironed out the details of exactly what technologies are allowed, non-renewable, low or zero-emission energy sources like fossil-fuel power plants with CCS (carbon capture and storage) and nuclear energy could potentially make the cut.
In comparison to California’s 100% clean energy goal, Hawaii’s 100% renewable goal is much more stringent, allowing only completely renewable sources. Of course, Hawaii’s own electricity needs are unique to the island state, which must import the oil and coal needed to generate the majority of the islands’ electricity, leading to the highest electricity rates in the US. Moving to 100% home-grown renewable energy – not just finite clean energy sources they’d still have to import – could create greater energy independence, leading to lower electricity prices.
Whether or not nuclear energy will fit into our future clean-energy world is yet to be seen. While government and utilities continue to shut nuclear plants, worldwide nuclear energy production is still on the rise. If researchers can create an unequivocally safe method of producing nuclear energy and dealing with the waste, nuclear could continue to grow, especially if policies trend towards clean energy – not renewable energy – goals.