A broad field – An interview with the radiation protection officer of GRS

16.03.2020

© istockphoto.com/ Demina Ekaterina

Thorsten Stahl holds a doctorate in physics and is radiation protection officer at GRS. In this interview he talks about his tasks, why GRS has a radiation protection officer at all, and how he helps employees to minimise their occupational radiation exposure.

Mr Stahl, you are the radiation protection officer at GRS. First of all, can you explain to us what exactly is meant by radiation protection?

Radiation protection officer of GRS Dr. Thorsten StahlRadiation protection is concerned with the protection of man and the environment from the harmful effects of ionising radiation. This is of course a broad field. It includes protection against natural radioactivity, such as the radioactive noble gas radon. On the other hand, it also includes protection against artificially generated radiation, such as the radiation that occurs in nuclear power plants or in medical applications.

To give you an example: In medicine, ionising radiation is used for various examinations, for example in X-rays. There are protective measures for the patient, such as wearing a lead apron to protect those parts of the body that should not be exposed to radiation. There are also protective measures for the staff. Among other things, they must stay outside the room during an X-ray.

But there are also other measures of radiation protection in place in many other areas that you might not necessarily think of. In air traffic or in waterworks, for example. In air traffic, flight personnel are exposed to cosmic radiation. In waterworks, the naturally occurring radioactive noble gas radon, which is dissolved in water, can concentrate in the ambient air. Here too, the personnel must be protected from the effects of ionising radiation.

Besides occupational health and safety, radiation protection also includes emergency response - when an accident occurs in a nuclear power plant, as was the case at Fukushima. With our own emergency centre at GRS, we are integrated into the Federal Radiological Situation Centre for such cases. We would then analyse, for example, whether the radiation exposure values at the site submitted by the operator of the affected plant appear plausible and whether this could affect on-site measures.

Why does GRS even need a radiation protection officer - after all, we do not operate any nuclear installations?

GRS conducts research and carries out expert assessments in the fields of nuclear safety, radioactive waste disposal, and radiation protection. It may therefore happen that our colleagues sometimes work in the controlled area of a nuclear power plant. Put simply, this is the area in which radioactive substances are handled. The people who work in these areas have to comply with special rules. In order to be allowed to work there at all, GRS needs a permit. One of the conditions for this permit is that the company has a radiation protection officer. This person is commissioned by the radiation protection executive - the technical and scientific director of our company - who is also required by law to take care of the radiation protection of the employees. Incidentally, GRS has not only one radiation protection officer, but several. One for each company location. I myself am the radiation protection officer for the whole of GRS.

And what are your duties as radiation protection officer?

Basically, the job of the radiation protection officer is to ensure that the radiation protection regulations are adhered to. The basis for all regulations is the Radiation Protection Act with the Radiation Protection Ordinance and other subordinate regulations.

In concrete terms, this includes compliance with all limit values and keeping the radiation exposure for the individual(s) as low as possible, even below the limit values. For people who are classified as occupationally exposed, for example, a limit value of 20 millisieverts per year, effective dose, applies. This is laid down in the Radiation Protection Act. These employees are obliged to wear dosimeters in the controlled areas, to have themselves examined annually, and to take part in regular instructions.

I am responsible for ensuring that all colleagues who work more frequently in a controlled area and are therefore classified as occupationally exposed are provided with radiation passbooks and dosimeters and that the dosimeters are also worn and evaluated. In addition, I am also the one who does the regular instructions. In doing so, I inform my colleagues about the organisational measures of radiation protection within GRS, point out possible hazards, and explain how they can best protect themselves.

You have just mentioned that there are organisational measures for radiation protection in a company. What exactly should one imagine those to be?

The organisational measures include, for example, that all employees are obliged to report every visit to a controlled area to the responsible radiation protection officer on site in advance, so that the latter can then arrange everything necessary for this. This also applies, by the way, to those colleagues who do not have a radiation passbook because they only visit a controlled area once or very rarely. It also applies to personnel organisation, which means that a radiation protection officer is appointed at each company location. All these measures are listed in our radiation protection instructions, which all employees must comply with. These instructions also state that the radiation protection regulations applicable at the site of deployment and any orders on site must be followed.

In the end, radiation protection starts with each individual. Classically, as an employee I have to think about how to keep my own personal exposure as low as possible, even below the limit values. In concrete terms, this means always staying as far away from a radiation source as possible, with short exposure times.

What happens if these measures are not observed?

If I noticed that someone was not following the rules or that there was a risk that limits might be exceeded, then I would have to say "No, this person will not enter any controlled areas" or "This person will not be allowed to go on that particular business trip". In other words, the radiation protection officer has a certain authority to give instructions to the employees in the context of radiation protection.

Has it ever happened that an employee has come to you who has exceeded the limit value for whatever reason?

No, I've never experienced that. Basically, that's not supposed to happen either. I check the dose measured on site by our employees after each visit. They are always far below these limits. I would also not allow anyone to be sent into a controlled area if I were concerned that a limit value would be exceeded. In that case, they would not be allowed to do that particular job.

Is this also checked by a body outside GRS?

I'll have to go a bit further afield to answer this question. As I said, our colleagues who are considered to be occupationally exposed have radiation passbooks. In these radiation passbooks, the radiation dose received is recorded for each visit to a controlled area. The dose is measured with an electronic dosimeter that the person wears during the visit. In addition, people wear a second dosimeter, a so-called film dosimeter. The film dosimeter is evaluated once a month by an officially designated measurement office. If this evaluation reveals values above a certain threshold, the measurement office will inform the local supervisory authority, and the authority will contact us.  However, this has never happened before.

You must have held radiation passbooks or dosimeters in your hands of people who had been to Fukushima or Chernobyl. Did these people receive a significantly higher dose?

For visits to Fukushima and Chernobyl, we have once again listed special regulations in our radiation protection instructions. For this purpose, we work out a forecast in advance. Before the visit, for example, as radiation protection officers we gather more detailed information: Which area is to be visited? How long will the stay be? What dose values are to be expected? With all this, we want to rule out in advance that limit values will be exceeded. But the Japanese at Fukushima also have their own limit values and make sure on their part that visitors will not receive doses above the local limits. So far, none of our colleagues who have been there have actually received a significantly higher dose.

What do you particularly like about your role as radiation protection officer?

That's a good question. During my studies, radiation protection was already one of the things I dealt with, and I have been working for GRS in the field of radiation protection for a long time. So the role of radiation protection officer is an additional facet. You think outside the box. You have to deal with many different people from different areas and get to know radiation protection from its pragmatic side.

Have you got have any ideas or wishes on how the role of the radiation protection officer might develop in the future?

In fact, it was only last year that the new Radiation Protection Act brought about quite a few changes. For example, airlines are now also required to have radiation protection officers. In this respect, radiation protection has been further strengthened, especially in the area of natural radioactivity. The regulations on radiation protection are always based on new findings from science and technology. Hence, any experience that is gained is again used to adapt the regulations.