Now is really the end of nuclear energy in Germany. After the politicians had given the last three active reactors Neckarwestheim 2, Isar 2 and Emsland a few months’ delay because of the Russian war of aggression in the Ukraine and the resulting energy crisis, they are now going off the grid. How does it work?
How does a nuclear power plant work?
A nuclear power plant produces electricity from heat. When the atomic nuclei split, energy is released. The heat that is generated is used to convert water into steam. This then drives a turbine, which in turn drives a generator that produces electricity.
What happens when a reactor is shut down?
According to the power plant operator Energie Baden-Württemberg (EnBW), the output of the reactor is being reduced continuously. This is done by gradually retracting so-called control rods in the reactor cores – these are used to regulate and shut down a nuclear reactor. After that, the generator is disconnected from the power grid and the reactor is completely shut down.
The shutdown process works like regular checks, explains the power plant manager of the Bavarian Isar 2 reactor, Carsten Müller. After the network disconnection, the reactor will be shut down. “It takes about a quarter of an hour.”
Then the actual work begins: The highly radioactive fuel elements are removed and placed in a spent fuel pool for a few years. They are then stored in so-called castor containers in interim storage facilities. There are currently 16 interim storage facilities for high-level radioactive waste in Germany.
Isn’t there a repository in Germany?
No. A repository for high-level radioactive waste is still being sought. In the 1970s, the political decision-makers had determined the Gorleben mine in Lower Saxony as the repository site without the participation of the population – and thus triggered large-scale protests. In 2017, a new process was launched to involve the public. But it remains a mammoth task – who would want to live next door to a nuclear waste storage facility?
“Nor is this the aim of the procedure,” says the President of the Federal Office for the Safety of Nuclear Waste Management (BASE), Wolfram König. The decision should at least be tolerated by those affected. And it doesn’t matter how one “stands or has stood for nuclear power: the waste is there. Now it’s our job not to leave this problem behind for future generations,” says König.
After all, a repository seems to have been found for low-level and intermediate-level radioactive waste: According to BASE, the former iron ore mine in Salzgitter, Konrad shaft, is the first repository licensed under nuclear law for this purpose. It is scheduled to go into operation in 2027.
How much radioactive waste is there in Germany?
A distinction is made between high, medium and low level radioactive waste. Highly radioactive waste is mostly spent fuel from nuclear power plants or research reactors. According to the BASE, these make up only 5 percent of the total volume of radioactive waste, but they are responsible for 99 percent of the activity.
However, the disposal of low- and medium-level radioactive waste – for example contaminated parts from the dismantling of nuclear power plants such as parts of the generator – also poses challenges for those responsible. According to BASE estimates, there are around 620,000 cubic meters of them in Germany.
According to Environment Minister Steffi Lemke, around 300,000 cubic meters of this is to be stored in the Konrad repository. “This volume corresponds approximately to the content of 100 Olympic swimming pools,” said the Green politician recently. It would therefore need a large, secure storage room. The waste for the Konrad pit was distributed over 30 interim storage facilities throughout the country. For the remaining cubic meters of low-level and intermediate-level radioactive waste, disposal options still have to be found.
Can’t the waste simply remain in the interim storage facilities?
Only repositories in deep geological layers are considered to be a permanently safe solution. “Concrete, barbed wire and security guards” couldn’t replace this, says BASE President König. Low-lying rocks provide a natural barrier that protects against radiation.
What happens to the site of a nuclear power plant after the shutdown?
Opponents of nuclear power keep calling for “blossoming meadows” that should return the country to its natural state after a nuclear power plant has been dismantled. But that’s not so easy. Because the building cannot simply be demolished as long as there are radioactive elements in it. However, once the fuel elements have been removed, the activity levels are only small – for example, if the reactor pressure vessel itself has become radioactive.
BASE estimates that it will take around 15 years for a nuclear reactor to be dismantled before it can be released from nuclear monitoring. In addition, there are still about two years for the demolition of the buildings. According to the planning of the operator RWE, the Emsland plant will be demonstrably free of any radioactivity in 2037, for example.
Are there international role models for the decommissioning of reactors?
The International Atomic Energy Agency (IAEA) in Vienna counted 198 nuclear power plants that were shut down or in the process of being decommissioned in 2021, but only 20 of them have been completely decommissioned. In some countries, the resources and structures for this are still lacking. Underground repositories are being sought in several countries. According to the Ministry of the Environment, there is still no operational repository for high-level radioactive waste from the peaceful use of nuclear energy in Europe or anywhere in the world.
Who pays for the nuclear phase-out?
The nuclear phase-out will be expensive – that much is certain. A commission has estimated the total costs for the decommissioning and dismantling of the reactors as well as the transport and storage of the waste at 48.8 billion euros. As a result, a fund was set up into which the nuclear power plant operators had to pay. The interim and final storage is to be paid from this amount.
The energy suppliers are also responsible for the costs of decommissioning and dismantling the reactors. According to RWE, the costs for the post-operation and dismantling of a nuclear power plant vary between 500 million and 1 billion euros depending on the size, age and operating hours of the plants.
