Rating of nuclear events: interview with the German INES officer



For about 10 years, our GRS colleague Dr. Michael Maqua has been performing the duties of the Ines officer for Germany on behalf of the Federal Environment Ministry. INES stands for "International Nuclear and Radiological Event Scale", a scale for the classification of nuclear incidents and accidents. More than 70 countries are currently using INES. The graduate engineer is engaged in international project management and answers all our questions about his work as an INES officer.

Dr. Michael Maqua, you have been tasked with the role of the German INES officer. How would you explain to an unknown person what the benefits of INES are?

The special thing about INES is that this tool can be used to show the significance of a nuclear event for the public – without having to have in-depth knowledge in this area. This is similar to temperature or earthquake scales. We live with scales, all over the world. With earthquake level 7 or wind level 8, nobody knows exactly what that means, but you have some idea of how strong the event and its effects are. It's the same with INES. For example, when I see an event with INES 3, I know that the impact on people and the environment is not serious. In the case of INES level 7, as we had in Chernobyl or Fukushima, I know, however, that there have been very large releases of radioactive material.

If we did not have INES, it would be very complicated to present the significance of an event in a consistent manner. INES makes it possible to compare apples to oranges. I can compare a transport accident involving radioactive substances with an event in a nuclear power plant. Otherwise, that would be almost impossible.

What are your tasks as an INES officer?

As INES officer, I have two main tasks: The first task is to make an INES rating for all German nuclear facilities for an event, also based on technical discussions with the respective operators and authorities involved. If the INES rating is 2 or higher, I must report it to the International Atomic Energy Agency IAEA in Vienna.

The other task is to look at INES events from other countries that are reported to the IAEA. If it is a significant event in the border area, I rate what this event means for Germany or the German population.

How is such an INES rating usually carried out?

The work of the INES officer starts as soon as the information about an event is received. For events in German facilities I receive the information from the operator, for international events via the mail service of the IAEA. There is a fixed workflow for the events in German facilities, which has been agreed upon with the Federation and the Länder and which is a multi-stage process. In the case of nuclear power plants, an initial rating is carried out by the operator of the nuclear power plant itself. The authorities, the TÜV and me on behalf of the Federal Government assess the adequacy of this rating. If it is incorrect, we intervene.

In the case of a dissent, the INES officer determines the final rating in consultation with the Federal Environment Ministry, but in 99.9 percent of all cases, everyone can agree on a common rating.

What are the consequences of your rating?

From Level 2 onwards, the IAEA will be informed. For releases from Level 4 and higher, the actions must, for example, be discussed with the disaster control authorities.
Since INES is an information system for the population, there are no consequences for the operator as a result of the rating. INES is not a penalty catalogue and clearly differs from the reporting criteria for events that may have consequences, such as the shutdown of a facility.

You just mentioned the reactor accident in Fukushima, which was rated Level 7 on the INES scale. Do you remember how this came about?

Oh yes, I remember it very well. The accident in Fukushima has revealed a shortcoming in the INES User’s Manual. There were two things that had not been foreseen in this manual. Firstly that it could affect several units of one facility at the same time. This is especially difficult when allocating the releases to the individual units. The second problem was that an INES rating had already to be carried out during the event.

The first INES assessment by the Japanese authorities took place within 24 hours as scheduled. With INES 3, it was relatively low in retrospect, but more did the operators not know at this early stage and they had no scientifically-based knowledge about a meltdown. We at GRS, however, already assumed that a meltdown had taken place, even though no release was measurable at that time.

When had the final INES rating for Fukushima been made?

That was almost half a year later. The INES officers have had to convince the Japanese authorities that you cannot assign an INES rating of 6 three times – that is for each reactor – but to increase the rating for the entire plant to INES 7. The Japanese have been very reluctant to do so. They did not want Fukushima to be as disastrous as Chernobyl – and actually, it isn’t. In fact, far less has been released than in Chernobyl, but for the INES rating it is the same level.

How did the idea come up to introduce the international event scale?

INES is a result of the accident in Chernobyl. In the aftermath of Chernobyl, the fear of a nuclear accident was very present. In the media, virtually every incident and every event was called a "near-worst-case". One has therefore been looking for an idea for rating the events and accidents in nuclear power plants or other nuclear facilities, this means to classify them according to their safety significance, and in a way that everyone can understand at first glance. And, as a result, the International Atomic Energy Agency IAEA introduced the INES system in the early 1990s.

How to become an INES officer?

INES officer is not an apprenticeship occupation. My former boss was the one who helped developing this system for Germany and wrote the first German INES User’s Manual. When he retired, I became his successor. It's grown that way and not a planned career. I simply continued the tasks that I had done before for years as an INES officer deputy. Apart from the scientific and technical knowledge, you have to be able to communicate well - also in English. Ultimately, rating an event is also a communication process.

You have been working with the INES tool for many years now. Do you have any visions or ideas on how INES could evolve?

Yes, I have. Apart from issues that we have just addressed in the context of Fukushima, there are of course completely different areas that can be integrated into INES. One area, for example, is the application of INES to medical events. This means, in particular, faulty radiation treatment of patients.
Another topic would be the discharge of radioactive substances into water. This topic also came up with Fukushima. Before Fukushima, the contamination of the environment without direct releases from a nuclear power plant had already been an issue dealt with. In these cases, no human being is directly affected, but the environment. How do I rate such a thing? For example, if you think of Fukushima or Chernobyl, how do I rate it if areas need to be closed?

There are still many other interesting aspects that could be rated. We will definitely be adding something in the coming years. This means that the INES User’s Manual is a living document and so there will probably never be a final version.

Thank you very much for the interview!

Find out more

INES – International Nuclear Event Scale
Information of the IAEA on INES
German INES User’s Manual