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The Nuclear Waste Problem

You only have to look as far back as six years ago to see the last time nuclear power had a devastating effect on the planet. The Fukushima Daiichi nuclear disaster of 2011 has been called the biggest environmental disaster in history, and the reactor continues to pump 300 tonnes of nuclear waste into the Pacific Ocean every day. Most recent estimates suggest that nuclear power accounts for around 11% of the world’s total electricity production. So why then, is the first waste management solution for nuclear waste still three years away from completion?

How is nuclear waste created?

Before understanding the reasons why a nuclear waste management solution is still so far away, you first have to understand how nuclear waste is created.

Creating electricity using nuclear power is, as you can imagine, pretty complicated. But in the simplest terms possible,during nuclear fission, atoms are split apart, releasing energy in the form of heat and radiation. If you want to get more technical, the nucleus of an unstable, radioactive atom loses energy, becoming stable and non-radioactive as a result. In boiling water reactors, (the most common form of reactor)this energy is used to heat water, producing steam that is used to turn a turbine which generates electricity.The amount of electricity produced, and the power of the reactor, is controlled by the flow of water through the reactor core by a circulation pump.

Because it is the only naturally occurring fissile isotope (which basically means that it is easily split)Uranium is the most commonly used element. When it is split apart however, it gives birth to a range of radioactive products with half-lives of up to 15 million years. Not only is this spent nuclear fuel long-lasting, exposure to it will kill 50% of those who are exposed to it in three or four hours. So which proposals to combat this growing problem of radioactive waste seem most promising?

Reprocessing

Reprocessing, essentially the re-cycling of nuclear waste, has been shown to recover up to 97% of the useful uranium and plutonium that makes up spent nuclear fuel. While this sounds promising, there is still the problem of the 3% of highly radioactive material that is left behind. It is for this reason that nuclear energy has only been able to flirt with the possibility of being categorized as a legitimate source of renewable energy. And why another more conclusive solution is needed to dispose of nuclear waste. Whether reprocessing is used or not, there will still be nuclear waste left over that has to be disposed of.

Geological repositories

Nuclear waste has to be stored somewhere, and it is looking increasingly likely that burying it thousands of feet below ground is the best available option. Finland is the first nation to commit to this, and their Onkalu geological repository is set to be the first one on the globe - it is due to beopen for business in 2022.

Storing spent nuclear fuel securely for 100,000 years (longer than any man-made structure has ever stood) is a technical challenge to say the least. After being cooled for several decades in an interim facility, spent fuel rods are placed inside a 1m-wide casing of cast iron, which is then placed inside a 5cm-thick casing of copper, ready to be plunged thousands of feet down a cylindrical hole padded with bentonite clay. The clay will expand and solidify in the presence of water, eradicating the threat of radioactive material tainting water supplies. Sounds promising, right? So why has there been so little global progress in regards to nuclear waste?

The obstacles

Even in the face of these undeniably extensive precautions, there remains a degree of scepticism. The Asse salt mine, located in the Lower Saxony region in Germany, where 130,000 drums of radioactive waste are stored, is now in serious danger of collapsing and becoming flooded - releasing radioactivity into the biosphere in the process. Understandably then, it has been a struggle for national bodies to get the acquiescence from locals that is needed to establish a geological repository.After all, who really wants nuclear waste on their doorstep?

The progress of Finland’s geological repository can be credited to the Olkiluoto residents’ familiarity with nuclear power - most of Finland’s spent fuel is already located on the island and many of the residents either work or know someone who works in nuclear power. Finland certainly benefited from this unique set of circumstances, but their approach is worthy of praise too. The openness and transparency with which they operated during the proposal stage only served to speed up the process where the presumption of others (Yucca Mountain in the US and Cumbria in the UK) led them to derailment.

The world’s high-level nuclear waste grows by 12,000 tonnes every year and everyone will have to learn from Finland’s example if real progress is to be made in solving this truly global crisis.

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