Nuclear energy is an extremely polarizing topic, which can make it hard to understand which arguments in the debate are salient and which are distorted or mis-represented. In order to wrap my head around the complex question of whether nuclear energy should have a role in a decarbonized energy future, I explore some of the main considerations of nuclear energy in depth. I found that many of these issues are complex themselves and can’t be easily categorized into “pro” or “anti” nuclear.
Nuclear energy is expensive in comparison to renewable technologies. The unsubsidized “Levelized Cost of Energy” (a.k.a. LCOE, a metric used to compare cost across different power generation technologies) for nuclear power is estimated as $129-$198 per MWh, compared to $26-$54 per MWh for wind or $31-$42 per MWh for utility scale solar. Nuclear energy projects are also slow, taking 5-17 years longer than solar or wind from the time of conception. The confounding factors of time and cost present an opportunity cost: a fixed amount of money can create more energy faster if spent on the renewable trifecta of wind, water, and solar (WWS) technologies instead of nuclear.
It’s important to note that LCOE is an imperfect metric and doesn’t capture everything about the systems. The cost for wind and solar doesn’t account for energy storage, which is necessary if it’s being used as the sole power generation source. The cost for nuclear does not account for meltdown cleanup (the cleanup after the meltdown at Fukushima Dai-ichi cost over $460 billion dollars, so while meltdowns are infrequent, this cost distributed over all active nuclear plants is still $1.2 billion each.) Therefore, cost tells a compelling but incomplete story about nuclear energy. Cost matters, and nuclear is extremely expensive.
Small modular reactors, one of the next generations of nuclear technology, may present a breakthrough in terms of cost given that they can be constructed in factories instead of on-site which would significantly drive down price and construction time. However these technologies are decades away, meaning the cost issue won’t likely be resolved in the short term.
Given the high profile nature of nuclear disasters such as Chernobyl and Fukushima, one common argument against nuclear power is the safety risk from nuclear meltdown. A compiled report of scientific research on the impacts of Chernobyl found that as of 2005, 50 people had died from direct radiation exposure with a possibility of up to 4000 in the future; a further 350,000 people were dislocated from the area near Chernobyl. While these are significant and traumatic impacts, health impacts of fossil fuels are much worse: a modeling study of air pollution found that fossil fuel combustion leads to 1 in every 5 deaths globally. This dwarfs the deaths based on nuclear radiation, and draws into question the salience of arguing against nuclear based on meltdown health risks. Emerging technologies such as molten salt reactors also offer the possibility of increased safety and decreased disaster potential, which could further improve the safety.
One by-product of producing nuclear energy is radioactive waste that emits extremely high levels of radiation for hundreds to thousands of years. This decaying process means that safe, controlled long-term storage is required in order to assure that the nuclear by-products do not cause human or environmental harm. Most nuclear waste is stored on-site in temporary casks, and there are still no long-term storage sites (the first such site is under construction in Finland and set to be operational around 2023.) The issue of long-term storage raises the moral questions of what burden is acceptable to place on future generations to deal with waste they did not create. One partial solution is to decrease the quantity of highly radioactive nuclear waste by reprocessing the spent fuel, however this process adds even further cost on the already-expensive energy source.
Nuclear Weapons Proliferation
The same process (called “enrichment”) that turns uranium and plutonium into usable fuel for nuclear energy can also turn them into usable ammunition for nuclear weapons. Therefore, any countries with the technologies to enrich uranium for energy purposes could theoretically do so for weaponry as well. There is global oversight over the enrichment processes, however the more countries that have active nuclear energy programs, the more countries that have the potential to develop nuclear weapons. These two processes are so tightly connected that it is impossible to separate the knowledge and technologies that create both.
There are ways to mitigate proliferation risks through policy, for example the United Arab Emirates gives spent fuel to other countries which allows for more centralized oversight over potentially dangerous material). A new type of reactor that uses thorium instead of uranium or plutonium produces less weaponizable material which is a step in the right direction, however thorium reactors are not yet commercially viable and still have some proliferation risk.
It’s impossible to know for sure what the implications of increased global nuclear energy on nuclear weapons proliferation would be, however there is no doubt that the more nuclear energy programs, the higher chance of proliferation. Without transparent, secure, and universal oversight of nuclear energy programs across the globe, nuclear proliferation will remain a threat of increased nuclear energy. This connects nuclear deeply to other geopolitical issues and contributes an extremely complicated “wrinkle” to stories of universalized nuclear energy.
Human & Environmental Health
Uranium mining is dangerous for human health because of both the chemical toxicity of the metal and radioactivity. The health impacts are of concern for uranium miners in particular, but uranium can also impact air, soil, and water quality in localities near uranium mines. In the United States pre-1990 many of the miners were Navajo people and were exploited for their labor. This calls into question the disproportionate negative impacts of uranium mining on marginalized populations; if certain communities overwhelmingly bear the burdens of externalities from nuclear energy, it is not an equitable manner in which to decarbonize the energy system. However, it is also important to acknowledge that nuclear is not the only energy source which produces toxic waste. Solar panels contribute to e-waste streams which are often shipped to Africa where they pollute the environment and human health at e-waste disposal sites. Projected increases in demand for solar and wind technologies will quadruple demand for certain minerals which will have drastic impacts on the mining communities. As demand for specific minerals increases, whether related to nuclear energy or other technologies, it will be critical to pay attention to protecting the miners and communities.
One of the main draws of nuclear energy is that it offers consistent base-load power. Solar and wind are cheap, but they are intermittent, meaning that they only general energy during some parts of the day. There are many different ideas about how to account for this among energy experts. One possibility is creating energy storage to complement wind and solar generation, capturing the excess energy generated during sunny or windy parts of the day and saving it for the dark or calmer parts. However energy storage in the form of batteries is expensive and unproven at scale. Nuclear energy provides reliable baseload power that could alleviate these concerns, and help lessen infrastructural changes necessary when decarbonizing energy grids build on coal and gas.
Stanford professor Mark Jacobson performed a feasibility study to see if it would be possible to match power demand in 2050 using just wind, water, and solar technologies. They perform multiple model runs with different storage options including varying grid and energy storage technologies. They found that a fully renewable, decarbonized grid is possible. Across the simulation, the globally-averaged cost of electricity using just renewables was about equal to business as usual projections for energy cost, and the social cost (including health and climate considerations) was 1/4th of the business as usual. This is a promising result given how important cost is toward dictating energy systems, especially if the externalities are added into market price in the future. There are critiques of Jacobson’s studies, and feasibility of a completely WWS grid doesn’t make it the easiest or most likely path. Therefore, one of the most salient and consequential arguments for nuclear remains the issue of baseload power.
So, what’s the takeaway?
There’s no straightforward answer to what the role of nuclear should be in a clean, healthy energy system. To come to my personal conclusion, I found it useful to consider the historical example of Germany.
Over the past decades Germany has pursued parallel energy goals of phasing out nuclear as well as aggressively increasing the share of renewable energy on its grid. Between 2000 and 2019, the share of renewable energy in Germany rose from 6.6% to an impressive 41.1%. However, phasing out nuclear power at the same time left a need for baseload energy. Energy historian Vaclav Smil found that the extreme growth in renewables did not result in as significant a drop in fossil fuels, and that in fact the share of fossil fuels on the grid in the US declined by a similar amount to Germany during the time period without any concerted renewable policy. Thus, it is highly possible that phasing out or banning nuclear energy would be detrimental in the short-term toward decarbonization goals.
While the consequences of nuclear should prevent it from any drastic increases in the near future, a phase-out like in Germany is counter-productive to the goal of decarbonization. Nuclear energy should be used to enhance increased production of renewables; it should be subsidized in quantities that allow it to replace fossil fuels for minimum necessary baseload power to assure continuity of the grids; and emerging technologies should receive investment in order to minimize the issues and possibly increase the role of nuclear energy in the future. Decarbonization is important, however keeping the goal of decarbonization in mind is important too: an energy grid that is equitable, minimizes environmental and health consequences, and offers sustainability going forward. The role of nuclear power is a balancing act between generating enough power to allow for decarbonization, but not so much that it jeopardizes the fundamental value of decarbonization by creating new causes of environmental degradation and human harm.