Nuclear Energy: Two words radiating powerfully when whispered jointly

Will our nuclear reactors RIP in 2025? After almost twenty years of tormenting Belgian politics, the question of a nuclear exit could finally be resolved by our next federal government. Throughout the long wait for a government to be installed in Brussels, we take some time to recap what makes nuclear energy such a sensitive subject.

Text: Auriane van der Vaeren
Image: Andreas Lorrain

Bad baby bad is what pops up in many heads upon hearing what has become a nowadays delicate word combo: nuclear energy. When investigating nuclear energy whether it is a sustainable source of electricity, one might easily get lost in the plethora of information. Read on to skip the maze.

Mirror, mirror, on the wall, who’s the fairest of them all?

As the world is seeking solutions to cut CO2 emissions, the main component of greenhouse gas (GHG) emissions, and as electricity production accounts for approximately 25% of GHG emissions, some argue in favour of nuclear energy. The graph portrays the GHG emissions per electricity generation system. The data includes the emissions related to the fuel (extraction, conversion, burn-up), to the power plant (construction, operation, decommissioning), and to the waste management (reprocessing of used fuel, waste conditioning, storage, repository construction).

Graph: GHG emissions per electricity generation system in 2010 (IAEA report 2018). The estimates are based on the number of power plants indicated in parentheses (na, not available). CC combined cycle, PV photovoltaic, CCS carbon dioxide capture and storage.

No doubt possible. In 2010, nuclear fission was one of the cleanest electricity production systems in terms of GHG emissions. Still today it seems to maintain that position. The two main reasons are that nuclear energy emits no CO2 during production, and that uranium has a very high energy density (i.e. only little fuel is necessary to generate large amounts of electricity). Nonetheless, the World Nuclear Industry Status Report 2019 argues that expanding the renewables arsenal (hydro, wind, and solar) would cut CO2 emissions comparatively more than expanding the nuclear arsenal.

Fuzzy fuss

Despite the controversy, one must credit the important role of nuclear energy in permitting a stable increase of industrialisation in times of fossil fuel crisis. Electricity harvested through nuclear fission is steady and reliable compared to its current renewable counterparts. This reliability is of utmost importance, especially in the high-tech industry, and thus for a healthy and competitive economy. Which is why nuclear energy will be part of our energy mix for the decades to come. Nonetheless, this statement merely holds if an ever-growing economy, as we know it, will keep being the gold standard.

Also, its reliability may be praised, but some criticise its inflexibility. Monitoring a nuclear power plant is not as simple as switching a computer on and off, and the financial costs associated with such switching are high. This is the reason why nuclear reactors ensure a constant basis level of electricity supply. On top of which the more flexible electricity sources ensure the additional supply to minimise waste (e.g. society’s electricity consumption is not constant throughout the day).

Safe ‘n sound?

Each nuclear electricity production cycle creates little waste and not all of it is as preoccupying. Plus, processes exist to partially recycle spent nuclear fuel, although this is not yet common practice. Nonetheless, the waste and the associated safety do haunt the nuclear world (cf. being exposed to radio-toxic material can for instance cause DNA mutations).

After a cycle of about 5 years, spent nuclear fuel contains: 1% un-split uranium (the initial product), 93% uranium (which is slightly different from the original and no longer splits), 1% plutonium (produced during the cycle), about 4% fission products (remnants of uranium and plutonium splitting), and 1% minor actinides (other radioactive compounds produced during the reaction). This spent fuel is first stored in water at the power plant for a few years to decay radioactively and to remove the heat. Once cooled and safe to handle, it is either going straight into a waste repository, or — if the installation allows it — recycled beforehand.

Without recycling, all the above-mentioned waste is present. With recycling, only the so-called high-level waste subsists, i.e. the fission products and minor actinides. Depending on the radio-toxicity, high-level waste is currently buried either near the Earth’s surface or deep down the crust.

What is the deal? Well, fission products contain short- and long-lived elements: the first are highly radioactive but only shortly radio-toxic (they stabilise after approximately 200 years), the second are less radioactive but need several millennia if not more to stabilise. The minor actinides are mainly long-lived with a high radioactivity. These need millennia to stabilise and form the major share of radio-toxic waste after two hundred years.

Since 2014, nuclear energy has become the costliest electricity production technology

Thus, considering the timeframe of radioactive decay, burying high-level waste does not necessarily imply safe disposal. Even if Chernobyl does not repeat itself, climate and geological events are impossible to predict in those timespans, let alone human conflict. Therefore, experts oscillate between once-and-for-all deep burying (which means difficult access in case of leaking) and surface burying (which means necessary relocation every now and then in renewed safe infrastructure, but would allow easier potential reuse of spent fuels with future developed recycling technologies).

Besides international nuclear safety institutions, in most countries, safety is ensured by the nuclear utilities themselves. They fund the decommissioning and radioactive waste management costs through revenues from the electricity supply. In theory, this sounds like music to the ears. In practice, nuclear utilities do not always possess the necessary financial backup. Another legitimate concern is how to ensure the non-proliferation of nuclear technology and materials; cf. acquisition of the energy technology also promotes that of military technology.

Survival of the fittest

Since 2014, nuclear energy has become the costliest electricity production technology (construction and operating costs included), and renewables now also cost less than coal and gas. Nonetheless, the energy-storage challenge subsists. And building the renewable energy battalion and the large-scale battery-storage systems required to supplant nuclear power plants and fossil fuel plants would generate immense amounts of GHGs, because their production would rely extensively on current non-renewable electricity. Additionally, with the emerging markets and the global population that is expected to rise until 2100, the demand for reliable electricity is equally likely to rise.

Therefore, experts are divided between those claiming that if nuclear phase-out were implemented, it would result in economic decline, public demonstrations, growing international tensions and a global freak show, and those arguing that it omits the additional construction and further technological advances in renewable energy systems.

Moreover, it is to be noted that nuclear energy relies on a finite material. Prospects diverge, but with current consumption rates uranium supply would last for less than a hundred years. This will likely be prolonged with new extraction or fuel recycling methods. Yet, it is not everlasting. Which might be, in addition to climate emergency, another stimulus for the rising international interest in transitioning to sustainable energy systems (cf. global investments in renewables are on the rise and higher compared to nuclear energy).

Looking into the crystal ball

Despite what some may claim, nuclear energy is per definition not sustainable. Sustainability comprehends absence of harmful effects for future generations. Who could seriously maintain that a technology that produces highly hazardous waste for generations ahead is sustainable? Nonetheless, the current climate emergency coupled to the fact that the renewable artillery is still not self-sufficient and outnumbered by heavy CO2 emitters, makes current use of nuclear reactors a necessity. But the benefits linked to the construction of additional reactors should be thoroughly analysed in comparison to building renewables.

The topic can thus not be discussed as if it were a simple binary choice, all or nothing. At some point, nuclear energy was beneficial and helped societal development. Today, we acknowledge its faults (i.e. the lack of true solutions for its waste) and need to address these and shift gradually towards sustainable and non-fossil-fuel based electricity production alternatives.


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