“We are learning from the case of the Asse repository how it shouldn’t be done”

The ailing radioactive waste repository Asse II is to be closed. But what is to happen to the radioactive waste: remove it, put it in new mine shafts or fill the repository with special concrete? Oeko-Institut is providing expert and organisational advice in this race against time. An interview with Beate Kallenbach-Herbert, Head of the Nuclear Engineering and Facility Safety Division.

Ms Kallenbach-Herbert, is radioactivity currently getting into our groundwater?
No. No radioactive salt solution is currently getting into the groundwater. The solutions entering the mine are pumped out and the contamination is far below the threshold values.

What steps were initially taken?
In 2007 the district of Wolfenbüttel disagreed with the plans of the former operator to close Asse. We then developed an action plan to bring all stakeholders together constructively. In January 2008 an advisory group was set up for Asse II, which includes representatives of, for example, regional initiatives. We are also participating as observers. The German Federal Ministry for the Environment and the current operator, the Federal Office for Radiation Protection (Bundesamt für Strahlenschutz, BfS), are discussing technical and organisational issues relating to closure of the site with the group.

Is the retrieval of 126,000 barrels by 2020 – as planned by the BfS – realistic?
Even under very favourable conditions – all barrels are intact and can be easily transported with machines – this time plan is too optimistic, I think. We know too little right now about the condition of the barrels, the level of contamination, etc. As a result it’s practically impossible to provide a projected timetable at the moment. The current plans for preliminary examination of one of the chambers alone will take almost a year.

So what’s the best way forward?
The participants generally have too little knowledge about all three options. In parallel to the retrieval examination, the plans to close Asse without retrieving the radioactive waste beforehand have to be optimised so that BfS can react quickly in the danger of collapse. To aid this, we’re for example assessing expert reports on the closure options for the German Federal Ministry for the Environment.

Hindsight is always 20/20: What have you learnt from Asse that is important in terms of handling nuclear waste in the future?
Asse shows how important reasonable regulation of the competences and responsibilities of those involved is. Independent bodies have to accompany and check all steps with the operator on an equal footing. For this they need the relevant competences, knowledge and resources. This wasn’t the case with Asse, which initially fell under German mining law and then the German Atomic Energy Act in 2008. Also it’s important to have a broad specialist scene where different opinions are discussed. In the case of Asse there was an expert report that indicated what the situation would be today. But those involved at the time did not adequately pursue it. Had a comprehensive process been initiated back then, the current situation could probably have been prevented. We are now using our findings to develop recommendations for possible procedures that could be used in other regions in the future.

Thank you.