Hans Wanner: "Cultural differences mean that you analyse problems differently."

When you were a kid, what did you want to be?

I didn't aspire to be anything. As a teenager, I liked to experiment with everything. I also enjoyed taking old devices apart to see how they worked. Initially, I was mainly interested in electrical engineering. Just before my school-leaving examinations, I started to work through a kit of chemical experiments. Understanding these reactions threw up so many questions, which I put to my chemistry teacher at school. All too often he said that I wouldn’t be able to understand because I didn’t know the basic principles. I found it very frustrating and that’s why I decided to study chemistry.

You studied and gained a doctorate in chemistry at ETH Zurich. What inspired you to study at ETH?

I discussed which uni to attend with the aforementioned chemistry teacher. And he recommended ETH. I decided to get my doctorate because I wanted to keep all my options open, including an academic career. After leaving ETH, I opted for a post doc, I had already secured a position in the USA with a grant. Then a postgraduate who I’d been studying with rang me up and told me about a job at the Swiss Federal Institute for Reactor Research, now the Paul-Scherrer-Institute (PSI). Despite the position I had in the USA, I was open to suggestions and looked at it in more detail.

I had specialised in how heavy metals behave in aqueous solutions; a topic of significance in environmental chemistry too. The job involved the disposal of radioactive waste, more specifically the modelling of how waste behaves in water deep underground. I thought it sounded fascinating because it was applied chemistry. I didn’t want to let this opportunity pass me by and decided not to go for the post doc, which would have meant more fundamental research. And that’s how I got into the nuclear sector.

About a year after you had become Director of ENSI (Swiss Federal Nuclear Safety Inspectorate), the accident at the Fukushima reactor occurred. What were your experiences of the disaster?

I was surprised at how much panic and alarm the accident in Fukushima caused in Switzerland. It had occurred way off in Japan with no measurable consequences for Switzerland. It was all people were talking about throughout the German-speaking world for a long time, while interest waned much faster in other language areas. At the time, we made ourselves available to the media to assist them in reporting on what was happening in Fukushima because we were the responsible Swiss authority and through our knowledge, we were able to analyse the events in Japan. While our specialists had contacts in Japan, we hardly got a response at the time.

A few days after the accident in Fukushima, the media shifted its focus to Switzerland. What about our nuclear plants? Are they safe? They were convinced that what had happened in Japan could also occur in Switzerland. The same type of reactor as that in Fukushima is used at Mühleberg. The ENSI had to explain why we were allowing such plants to run in Switzerland.

But there were some key differences to Japan: We have always had a high level of safety awareness in Switzerland. The plants were equipped with safety technology and were being improved continually. For example, after around twenty years of operation, the nuclear power plants at Beznau and Mühleberg had to be upgraded on a huge scale in line with new developments in safety technology. This meant that we were able to minimise the risk of a serious accident and radioactive contamination of the environment. This wasn't done in Japan.

At the start of 2011, we were still planning to build more nuclear power plants in Switzerland but in mid-2011 we decided to abandon nuclear all together. What did you think of this turnaround?

From a political standpoint, I could understand the logic. It was also what the majority of the population wanted. Several years later when we had the referendum on the new Energy Act, the majority were still in favour of the new energy strategy. While our nuclear power plants have very high levels of protection, we don't want to live with the residual risk. But the decision was taken just after Fukushima without anyone knowing how to fill the huge gap this left in our energy generation system. But it wasn't of great importance to my work. It was simply a political decision and nothing to do with safety technology, and the existing plants were able to remain online provided that the safety requirements were met.

Between 2011 and 2019 you were also the Chair of WENRA (Western European Nuclear Regulators Association). How important is dialogue with other countries to you?

Dialogue with other countries is crucial. Cultural differences mean that you analyse problems differently. So we can learn a lot from one another. After Fukushima, I asked myself why despite intense international dialogue we didn’t know that the plant in Japan didn't have adequate protection against the natural disasters that occur in that region.

So we at ENSI decided to ramp up our international work. The way in which we worked meant that we had achieved a lot and we wanted to share this knowledge. In November 2011, I was elected Chair of WENRA. The heads of all the European nuclear safety authorities are members of this association, which makes for a very interesting group. We know one another and share our opinions. Friendships also result from this regular contact. I found it hugely life-enriching.

You have now retired and can look back over a long and interesting career. What advice would you give today’s students?

I always chose my own destiny. So if you are interested in something, if you want to do something, then follow your nose. You know what you are most interested in and what motivates you. If you really want something then don't shy away from the work you will need to put in to achieve it. There will always be elements of your course that are tiresome. That’s life. Don't be tricked into believing that the grass is always greener on the other side. In both your work and private life, there are always things that you don’t want to do. So it’s a good life skill to be able to grit your teeth and get on with it.

You can try to pursue specific goals by following as straight a course as possible. But I followed a different approach: I always seized opportunities that on reflection seemed right for me. For example, I spent just one year at PSI before taking a job at the OECD in Paris. This was a short stay, which was unusual, but it seemed right so I did it.