STUK monitors around the clock

The Radiation and Nuclear Safety Authority (STUK) maintains continuous preparedness. The system is spearheaded by the expert on call, who generally receives and handles radiation and nuclear safety-related notifications and alarms at all times of the day and, if necessary, initiates measures to the extent required by the situation.  

In 2023, STUK’s expert on call was contacted approximately 150 times. The task of the expert on call is to initiate investigations into the safety significance of the incident. During the past year, there were no situations that would have posed a danger to the population or the environment or required protective measures. The majority of contacts were related to radiation observations from border stations, transport of radioactive substances and various sources of radiation. In addition, the expert on call received notifications from other authorities, requests for information and connection tests.

We detect even the smallest changes in the radiation situation 

There are approximately 250 measurement stations around Finland that form an automatic radiation monitoring network. The radiation monitoring network has two main functions: to produce a real-time radiation situation overview and to alert when the radiation level increases. The sensors of the measurement stations are highly sensitive, so even the smallest changes in the radiation levels can be reliably detected.

The measurement data of the external radiation monitoring network is updated automatically once an hour on the website of the Radiation and Nuclear Safety Authority and the European Radiological Data Exchange Platform EURDEP. You can also find radiation information about the measurement stations on Yle's Teksti-TV radiation safety page 867.

STUK’s expert on call receives all alarms for abnormal measurement results. Last year, alarms were caused, for example, by X-rays of the weld seam at the new district heating plant which was located approximately 30 metres away from the measurement station and a failure of the radiation meter. 

STUK publishes information about abnormal events in its annual reports, which are published in the Julkari electronic publication archive. 

Preparedness develops through practice 

Emergency preparedness exercises are key to preparing for unforeseen situations and crises. They provide individuals and communities with the knowledge and skills to act effectively together in a real radiological emergency situation.

In 2023, STUK participated in approximately 30 domestic and international emergency preparedness exercises in different roles, such as trainee, trainer, organizer or assessor. The exercises focused, among other things, on creating a situation overview, cooperation between authorities and other operators, decision-making and communication. A wide range of representatives from the government, municipalities, regional operators, the private sector and organizations took part. In addition, the radiation measurement team arranged their own exercises during which they practised how to take measurements and how to work together. A trained and appropriately equipped team of volunteers strengthens Finland’s national radiation monitoring capability.     

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Super weekend of preparedness

​​"Everyone knows from their own experience that things tend to accumulate from time to time. The "Super weekend of preparedness" occurred last November, when completely independent events started to happen in different parts of Finland. During the period between Friday and Sunday, STUK’s expert on call received notifications from several collaborating authorities which required STUK’s preparedness regulation. The so-called normal cases included notifications relating supervision at the borders and material transport, but others required a more extensive investigation.

At midday on Friday, the expert on call was contacted by the police. They had been notified that a Russian tank destroyed by the Ukrainians, which, according to information received, contains radioactive substance, will be arriving at the Citizens’ Square in Helsinki on public display. STUK’s internal readiness was increased quickly, and the first situation assessment meeting was held without delay. The case was found to be complex. It was primarily about the safety of the members of public, in other words, whether the tank in question could be brought into the centre of Helsinki. It was also a question of competence. It is not clear which authority can stop the import of this type of material. The third point of view was international cooperation. The tank had been on display at the Freedom Square in Tallinn for a long time, so it was deemed that it was necessary to exchange information on the matter with the Estonian radiation authority. And perhaps the most extensive issue was the communications perspective. Possible influencing through information had to be taken into account in communications, in addition to all of the above. 

The next contact came from Customs, where they had made a radiation observation concerning a cargo ship arriving at the port. What made the situation interesting was that, in addition to the "normally radiating" cargo, other radioactivity was detected on board the ship, which had to be checked. This led to a multi-authority operation under the leadership of our expert on call and remote support. The unloading permit for the cargo had to be delayed for several hours in order to obtain certainty about the sources and levels of radiation. The collaboration between the different parties was once again seamless. Development of measurement capacity and ability became the most important lesson learned from this. 

I was talking on the phone with our expert on call on Sunday evening before seven o'clock and said that it had been a busy weekend and I hope that this would be a peaceful evening. Well, it was not. Immediately after seven o'clock, the expert on call received a call from Olkiluoto reporting that an incident had occurred at OL3 and the plant was being shut down. These types of incidents and related measures are deep in STUK’s DNA. People responsible for the situation management know exactly what to do. Together with the plant representatives, they clarified the safety significance of the incident in a couple of minutes and decided on the next steps without any hassle. 

Competent and motivated employees as well as a shared and up-to-date overview of the situation are good starting points for maintaining continuous preparedness. We are constantly working hard on both of these matters at STUK." 

Text: Jyrki Heinonen (in the photo). The writer works as Head of Emergency Preparedness at the Radiation and Nuclear Safety Authority.