Nuclear power plants do not emit as much CO2 as coal-fired power plants and are more environmentally friendly in this respect. They are also very efficient. But they have two other major problems: on the one hand, the final disposal of the radioactive fuel rods, and on the other, the danger of serious accidents with often dramatic consequences. This is why some countries have decided to phase out nuclear energy, while others are planning to build more nuclear power plants despite these problems.
Nuclear fission of uranium and its efficiency
Turbines in nuclear power plants are also driven by heating water. In them, however, this is done by means of uranium, which is a radioactive heavy metal with a very high energy density. Like all other fossil fuels, uranium is finite. The world's uranium reserves will last another 70 years if uranium is used at a constant rate1. 1 kg of uranium is sufficient to generate 24 million kilowatt hours of heat through fission and chain reaction. To generate the same amount of energy, about 3,000 tonnes of hard coal must be burnt in coal-fired power plants2. Uranium is mined mainly in Australia, Canada, Kazakhstan, Russia, Niger, Namibia, Uzbekistan and the USA. Like many other heavy metals, uranium is harmful to the human body. It causes cancer and affects the genetic make-up.
Final storage of fuel rods and accidents
If only CO2 emissions are considered, nuclear power plants are much more environmentally friendly than coal-fired power plants. However, the disposal or storage of the radioactive fuel rods after their use must be viewed critically. This is because after a certain period of operation, a radioactive element can no longer be used to generate energy but must be replaced. However, the spent elements are still radioactive and must be stored temporarily in special containers to be transported to a final repository later. After about 30,000 years, the low- and intermediate-level radioactive waste has the same radiation-related toxicity (radiotoxicity) as natural granite rock3. For highly radioactive waste, repositories are being sought that will shield the nuclear waste from the biosphere for over a million years. Only 30,000 generations after us would the substances no longer be toxic4. It is assumed that the nuclear waste will not radiate more strongly than uranium ores after this period5. Furthermore, accidents and incidents in nuclear power plants have devastating consequences for humans, animals and the environment. For this reason, these power plants are subject to the strictest safety regulations.
Phase-out or expansion?
In Germany, the phase-out of nuclear energy is a done deal. The last nuclear power plant should go off the grid at the end of 20226. However, in response to the gas shortage triggered by the Russian war in Ukraine and the resulting international sanctions against Russia, two nuclear power plants are now to remain in operation until April 2023 for emergencies. Belgium has also decided to phase out nuclear power by 2025. In neighbouring France, 57 reactors were in operation in 2019. Nuclear energy covers 70.5 % of the energy demand. There are no phase-out plans there. Countries like Portugal, Luxembourg, Ireland or Denmark have no NPPs. No nuclear power plants have been operated in Italy since 19907. China, on the other hand, is committed to nuclear energy and plans to build at least 15 nuclear power plants in the next 15 years8. Poland has no NPPs to date and is looking for partners to build six new reactors. Globally, almost all currently operating reactors are located in three countries, namely the USA, France and Japan9.
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