“Nuclear power has taught us that we must look very closely at the promises and consequences of technologies”

Things had been rather quiet around the topic of the search for a permanent nuclear waste repository in Germany – until the interim report landed in late September. The latter lists the geographical areas that are being considered for the siting of a permanent repository. What reactions did the report provoke?

Jochen Ahlswede: On the one hand, there were some surprised reactions. Perhaps because many people may have thought that nuclear energy was a topic that had gone away – as if the matter had been finally settled with the decision to phase out nuclear power. I also noticed some curiosity about this new search process and a recognition that things are proceeding according to new standards; that this time around, transparency and participation are playing an important role and that independent institutions are involved in the search. Of course, there’s also been some criticism regarding the procedure, the search and the results.

Absolutely. For example, there’s the threat of resistance at the political level: Bavaria’s Minister-President Markus Söder has already rejected the list of potential repositories. How are you dealing with this?

Ahlswede: Like all other German federal states, Bavaria agreed to the search for a permanent repository and was involved in the commission that thought up this procedure. It’s a search taking place across Germany with no preconceived idea of the final result, and no single federal state can dodge participating in this process. But it’s also clear that those sort of statements don’t make the search easier.

According to the report, the interim storage facility for nuclear waste in Gorleben, Lower Saxony, is off the table as a permanent repository. That was a surprising decision, considering there are 113 CASTOR containers with highly radioactive waste currently being stored there. Why is Gorleben suitable as an interim storage facility but not as a permanent repository?

Ahlswede: We need to distinguish between the interim storage facility in Gorleben and the salt dome or the former exploration mine. The interim storage facility is a hall built above ground that has been secured for this purpose and in which CASTOR containers with highly radioactive waste can be stored for a limited period of time. However, the negative assessment of Gorleben’s potential as a permanent repository is related to the salt dome below the interim storage facility. In 1977, policy-makers initially decided to build at Gorleben a national waste management centre – including a permanent repository, an interim storage facility and a reprocessing plant. In later years, only the interim storage facility and an exploration mine remained. Back then, the selection procedure was neither transparent nor science-based. Today, we’ve got the chance to set about the search anew – but this time based on scientific data and with democratic legitimacy.

Since the search for a permanent repository was relaunched in 2017, the players involved have been taking a close look at the whole of Germany. What are they searching for?

Ahlswede: The search is for a repository site that can accommodate around 1,900 CASTORs (casks for storage and transport of radioactive material). This number represents the amount of highly radioactive waste that Germany has produced since starting to generate energy by means of nuclear power plants. We’re on the lookout for so-called host rocks – salt, clay and granite rock – of sufficient thickness to contain the radioactive waste safely in the long term and keep it away from the biosphere. In Germany, all three types of host rock are found in a variety of locations, so there’s a large choice of possible sites that can provide the best possible safety for a million years. Other countries don’t have this range of choice.

What are the criteria that determine the suitability of an area?

Ahlswede: Before the search even started, a large number of geoscientific and spatial-planning criteria were laid down by law for use in the selection and assessment process. After studying the files, Germany’s federal company for radioactive waste disposal (Bundesgesellschaft für Endlagerung – BGE) has now presented its own initial short list based purely on geological criteria and without having carried out any on-site investigations. In the coming years, the number of potential sites will have to be gradually narrowed down and proposals will have to be made as to which specific regions – and later specific sites – are worthy of further exploration.

The Gorleben protests were also protests against nuclear power as such. However, Germany’s nuclear phase-out has now been signed and sealed. Are you hoping to see among the population a greater willingness to compromise – and that people will view the disposal of nuclear waste as a joint task?

Ahlswede: The decision to go for a nuclear phase-out in the wake of the Fukushima disaster created the central precondition for enabling this new search for a permanent repository to be started in the first place. Prior to this, the debate was mainly about whether the search for a final repository might also end up serving the purpose of enabling the continued use of nuclear energy. The decision to phase out nuclear energy has limited the quantities of radioactive waste for which a permanent repository must now be found. I don’t believe that the idea of a repository will be met with enthusiasm by the people living in the area in which it’s going to be located, but the current approach will make the decision-making process more transparent and in this way – one can only hope – make a repository tolerable. There’s no way of getting around finding a solution to this issue if we don’t want to burden future generations with this nuclear waste.

Transparency and participation are welcome measures in this search for a repository. But how do you intend to convince local residents of the merits of having a permanent repository near where they live? What incentives are there?

Ahlswede: The process essentially works with transparency and participation. It’s not a question of buying people’s consent for a repository. Safety will be the decisive factor in the selection of a repository site. In the course of the procedure, however, eligible regions themselves will have the opportunity to develop plans for how they would like to be compensated – a so-called regional development concept.

What might be included under such a compensation scheme?

Ahlswede: As things stand, this is still completely open. And deliberately so, too. We’ve got no desire to confront the regions with a ready-made concept; instead we want them to develop their own concepts in a participatory process.

Will the municipalities have a veto?

Ahlswede: No municipality will have the power of veto over the site for the permanent repository. This has already been discussed, and at the end of the day policy-makers stipulated that Germany’s democratically elected parliament alone would be making the final decisions at the various milestones of the process – although only after the search has passed through all of the procedures laid down for citizens’ participation.

Would you personally agree to a repository being built in your own neighbourhood?

Ahlswede: I could hardly work at the Federal Office for the Safety of Nuclear Waste Management (BASE) if I’d object to such an eventuality. As a citizen, I would certainly take a close look at the decision-making process, but ultimately we need to solve this problem. And if a permanent repository were to be built near where I live, and I was convinced that the search for this site had followed a science-based process, then I think I could accept it.

Nuclear waste radiates for hundreds of thousands of years. However, today we don’t even know what the conditions on, and under, the earth surface will be like in 500 years from now. So how seriously can we take predictions about the perfect repository?

Ahlswede: In the history of nuclear energy, the consequences of this form of energy generation have been underestimated time and time again. The current interim storage facilities are only temporary solutions for a few decades. No one can guarantee that in 50 or 100 years from now we as a society will still have the resources to safeguard these facilities. According to the current state of international scientific knowledge, storing the waste in deep geological repositories (that is, in a stable geological environment) is the only permanent solution that doesn’t require the radioactive waste to be actively monitored. Geologists are trusting themselves to explore and model a site so thoroughly that they’re able to make a very well-founded prediction that extends a million years into the future. However, there‘s no such thing as absolute certainty – in the sense of definitive proof – with this sort of question.

A permanent repository needs to have been found by 2031. Sounds like a lot of time. But is it enough?

Ahlswede: 2031 is a very ambitious target. But a deadline like this is also necessary. The interim storage facilities cannot be regarded as a permanent solution. We as a society must make sure rather quickly that this waste is transferred to a place where we no longer have to monitor it ourselves and where we’re allowed to forget about it. The longer it takes, the greater the burden for our current generation, and especially for those living near the interim storage facilities. They’re pressing for a solution too.

What does a permanent repository actually cost? And who will pay for it?

Ahlswede: We can only estimate the final costs. The former nuclear power plant operators have transferred 24 billion euros to a state fund for this purpose. The costs include the search across Germany, the exploration of a repository – also on site – its construction and operation over decades, as well as the costs for the interim storage of the nuclear waste, of course. This is a major infrastructure project. No one today can in all seriousness give an exact final sum.

Why doesn’t Germany simply sell its radioactive waste to other countries?

Ahlswede: We as a society have produced this waste ourselves. Independent of our personal opinions with regard to nuclear energy: we’re the ones who have to take care of it and we can’t simply push it somewhere else – possibly with the acceptance of the less stringent safety standards that exist in other countries. Personally, I would find the export of nuclear waste unethical.

The search for a permanent repository is a mammoth project that harbours within itself a lot of conflicts. Let’s take a look back: was the generation of nuclear power worth all this?

Ahlswede: In my opinion, this form of energy generation, like few others, makes clear what far-reaching burdens can be entailed by technologies that seem so promising at the time. Either because those burdens were underestimated or because they ended up being dismissed as a result of the interests in play. Now, we’ve got to deal with this waste. It's futile wondering if it was worth it. It shows what serious consequences such technological applications can have. We see this in other areas too. I only have to think of the consequences of CO₂emissions through fossil energy production. Nuclear energy has taught us that we must look very closely at the promises and consequences of technologies before we use them on a large scale. This mustn’t be something that happens only in retrospect because, if we do so, path dependencies are created from which we cannot escape. This has been the case with nuclear power: for decades, we’ve been using a form of energy for the disposal of which we don’t yet have an option. What’s more, in this case we’re talking about substances that are capable of fundamentally endangering the existence of the environment and of human life. It’s important to bear this in mind. Many succeeding generations will still have to deal with this issue and will be burdened by it – not only financially, but also in terms of having as a society to manage a major conflict.

In parallel to the search for a permanent repository, researchers in Germany and abroad are working on developing a new generation of nuclear power plants, so-called Generation IV reactors. They’re supposed to meet high standards with regard to sustainability, safety and efficiency – however, they won’t be ready for launch until 2030. What role could these power plants still play in our energy generation, despite Germany’s phase-out?

Ahlswede: With the German government’s decision to phase out nuclear energy, it’s been made clear that these Generation IV reactors will not be playing any role in Germany’s future energy production. However, these concepts are being pursued in other countries. The manufacturers are making major promises with regards to safety and waste prevention. However, based on the current state of knowledge, it can be stated with certainty that even these concepts cannot avoid the problems associated with radioactive waste. Even these reactors will produce large quantities of highly hazardous waste that need to be disposed of.

In connection with these new types of reactors, one reads about so-called artificial transmutation as an option for reducing nuclear waste.

Ahlswede: The idea is to use so-called transmutation plants to reduce some of the particularly long-lived isotopes in the radioactive waste. So far, these plants only exist on paper; whether and when a large-scale application might be possible is completely open. And these plants too would be bound up with the risk of accidents and radiation exposure, and would only be able to treat part of the waste they cause. There’s no getting around the issue of finding permanent repositories.