The Future of Energy is Here — and It’s Not Renewable
If we are serious about halting carbon emissions, there is another option to go along with wind and solar
Somewhere along the line, “renewable” became synonymous with carbon-free. But solar and wind are not the only means to produce energy without CO2 emissions. Renewables are important, and they should definitely be a part of every country’s energy mix. However, they should not be the entire focus of our shared energy future. Renewables are intermittent, requiring mega battery storage and massive tracts of land or consumer responsibility to install on their own properties. The exception to this is hydro power, which may be the best overall form of energy due to its carbon-free, reliable power. Yet even hydro has its downsides, such as harmful impacts on local ecosystems and geographical limitations. The bottom line is that all energy systems should have a mix of generation — from wind, solar, hydro, and, despite much contention, nuclear.
Nuclear energy has saved millions of tonnes of CO2 from being emitted into the atmosphere for nearly three-quarters of a century. But that has come with many serious drawbacks, such as radioactive waste and the potential for meltdowns or other serious incidents. Clearly, this is not an ideal form of energy for the future, even if it can help dramatically reduce our carbon output. Scaling up nuclear production would mean scaling up the amount of waste and increase the chances for more Fukushima or Chernobyl-like accidents. But what if there was a way to harness the carbon-free electricity that is created from splitting atoms without the waste, meltdowns, high costs, and ominous-looking cooling towers?
Such an option is possible, though it is not operative anywhere in the world. This is because it hasn’t proved commercially viable on any scale — which, combined with a fear of the word ‘nuclear’ and the almost dogmatic belief that the only form of carbon-free energy is renewable energy, has prevented its implementation.
We should really explore if this form of energy can help us with our growing atmospheric carbon problem.
Why SMR Nuclear is Ideal
Forget about the daunting, expensive, and contested power plants featured in typical portrayals of nuclear power. These older, outdated models are not the way forward. The future of clean energy can be much smaller and less menacing. And it could include a lot of small modular reactors (SMRs), specifically liquid fluoride thorium reactors (LFTRs).
Thorium is number 90 on the periodic table of elements, two behind uranium. It is a weakly radioactive substance that is much more abundant than naturally-occurring uranium — and there are numerous advantages to using it as a fuel over the latter. No, it is not renewable, but a golf ball of thorium could, in theory, power a small city for decades. And the fact that it isn’t renewable shouldn’t be a negative trait. Renewables are, with the exception of hydro, intermittent; LFTRs would provide baseload power to the grid to backup increased solar and wind power. It becomes even more essential to have a new, scalable form of carbon-free energy if we follow the route of electrifying everything to cut fossil fuel usage. This is because electricity grids will have to expand to triple or quadruple their current capacity (or more) to accommodate the influx in electricity-dependent practices, such as driving and manufacturing. LFTRs are carbon-free, nearly waste-free, reliable, efficient, and theoretically safe. Sameer Surampalli from Power Engineering does a great job of describing some of the more technical details of thorium power:
A typical arrangement for a modern thorium-based reactor resembles a conventional reactor, albeit with notable differences. First, thorium-232 and uranium-233 are added to fluoride salts in the reactor core. As fission occurs, heat and neutrons are released from the core and absorbed by the surrounding salt. This creates a uranium-233 isotope, as the thorium-232 takes on an additional neutron. The salt melts into a molten state, which runs a heat exchanger, heating an inert gas such as helium, which drives a turbine to generate electricity. The radiated salt flows into a post-processing plant, which separates the uranium from the salt. The uranium is then sent back to the core to start the fission process again.
There are also cost benefits that would come into play if thorium reactors were commissioned, with LFTRs needing less money to operate than solid-fuel reactors (once operational, the salts would cost roughly $150/kg and the thorium would cost about $30/kg). Surampalli also states:
If thorium becomes popular, this cost will only decrease as thorium is widely available anywhere in the earth’s crust. Thorium is found in a concentration over 500 times greater than fissile uranium-235. Historically, thorium was tossed aside as a byproduct of rare-earth metal mining. With extraction, enough thorium could be obtained to power LFTRs for thousands of years. For a 1 GW facility, material cost for fuel would be around $5 million. Since LFTRs use thorium in its natural state, no expensive fuel enrichment processes or fabrication for solid fuel rods are required, meaning the fuel costs are significantly lower than a comparable solid-fuel reactor. In an ideally working reactor, the post chemical reprocessing would allow a LFTR to efficiently consume nearly all of its fuel, leaving little waste or byproduct unlike a conventional reactor.
These benefits should not be taken lightly. If we are serious about halting CO2 emissions — which we all should be — then this technology should be given a fair chance to see if it can provide baseload power to electricity grids worldwide.
Why SMR Nuclear is Safer than Traditional
Small, modular LFTR nuclear energy addresses nearly all the issues that are associated with traditional nuclear energy. There is less waste, it operates at atmospheric pressure, and uses liquid salt instead of high-pressure water coolants. It also has a reliable passive shutdown system.
LFTRs generate significantly less radioactive waste than generation III reactors and can re-use separated uranium, making the SMR reactor nearly self-sufficient once started. Unlike traditional high-pressure nuclear systems, LFTRs are designed to operate as low-pressure systems, which are much more stable, and the fluoride salts have very high boiling points, making them resistant to large or sudden increases in pressure.
The combination of a low-pressure system and a high boiling point greatly limits the chance of a containment explosion. LFTRs don’t require massive cooling — they can be placed anywhere and can be air-cooled, which is why they are considered small modular reactors. These particular SMRs also have the best safety feature of all: if the core were to overheat, a gravity-enabled passive shutdown system would send the heated, radiated salt into an underground containment chamber and turn off the reactor. And if there is one thing that can be relied upon in this universe, it’s gravity.
The Downsides
Thorium-based energy is not without its flaws. The main complaints from anti-nuclear activists and scientists skeptical of its merit are that its untested, non-viable, and merely a distraction to the status quo of the current nuclear industry. These claims are not baseless — it is untested, which makes its viability a question, and it is deflecting attention from the current nuclear state, whether intentional or not. And the safety claims, while solid in theory, have yet to be tested in any real-world scenarios. Even Surampalli, a proponent or thorium SMRs, writes:
LFTRs do present a few challenges. There are significant gaps in the research and necessary materials for LFTRs. The post-processing chemical facilities, which would separate uranium from the molten salts for re-use, haven’t been viably constructed yet. Each reactor would require some highly enriched uranium (such as uranium-235) to start the reactor, which is very expensive.
He also states that “Any leftover radioactive waste cannot be used to create weaponry,” but this is a debated assertion. Some scientists claim that the U-233 created in thorium reactors could be used to create atomic weapons if done the right way. Others claim this is not possible. Either way, it would be a good idea to secure LFTRs from outside interference, regardless of their proliferation capabilities. A Guardian article from nearly a decade ago outlines why thorium isn’t as “green” as it seems to be, and some of the points made in it are fair.
What’s Next?
Thorium power is not a silver bullet. There isn’t a fix-all cure that can be put in place and solve the climate issue overnight. Even if the all-hallowed fusion power were to become a reality (which is anywhere from six months to sixty-years away), it would come with its own set of issues to overcome. However, if we are serious about halting carbon emissions with the available technology oh hand, we need to consider LFTRs. We can label any non-renewable technology as blasphemous while continuing to emit carbon in the meantime. But we can also move forward with untested, high-reward technologies that might be a huge part of the solution to the most serious global problem that human beings have ever created.
Do we care more about sticking to ideology than implementing the best available options to cut carbon emissions?
I worry it’s the former. ‘
I hope I’m wrong.
