Nuclear security arrangements 

Nuclear security arrangements are measures to secure the use of nuclear energy from activities that endanger nuclear and radiation safety. Safety arrangements are implemented in the nuclear facility and its area as well as in other places or means of transport where nuclear energy is used. In addition, security arrangements protect radiation sources.

Security arrangements provide protection not only against intentional acts but also against damage caused by carelessness or thoughtlessness. Security arrangements include both administrative, technical and operational arrangements. Information security is also part of security arrangements, and the development of its monitoring is a current issue.

The primary responsibility for security arrangements rests with operators of nuclear energy and radiation use. Other parties involved in the security arrangements are various competent authorities, such as STUK, the police, the rescue service, Customs, the Border Guard, the Defense Forces and the traffic safety authorities. STUK's task is to set official requirements for security arrangements for the use of nuclear energy and radiation and supervise their implementation.

Aspects of security arrangements

The aspects of security arrangements are the prevention, detection and delay of illegal activity and the response to illegal activity. The areas of security arrangements together with the sharing of information between authorities form a risk-aware, classifying approach. The security arrangements are measured based on how likely it is that illegal activity could be directed at nuclear material or other radioactive material and what kind of consequences it could have.

Prevention includes the requirements and monitoring of nuclear facilities and radiation sources. The general obligations of security arrangements regarding the use of nuclear energy come from the nuclear energy and radiation legislation. More detailed requirements for security arrangements are presented in STUK's regulations, YVL instructions and the design basis threat document. Obligations are also included in international agreements concluded by Finland, other contractual arrangements between governments and commitments given by Finland.

Illegal activity is detected through notifications, intelligence, radiation measurements and monitoring. The authorities have created a common architecture for the detection of nuclear and other radioactive substances, which improves the authorities' ability to work together. For example, notifications and intelligence information come to STUK from other authorities, operators or international information exchange systems. Radiation measurement observations come primarily from the operator or other authorities, such as Customs, the police, rescue services, the Border Guard and the Finnish Defense Forces. If necessary, STUK also conducts radiation measurements in the field.

In security arrangements, the response includes 24/7 on-call and readiness to initiate response activities and providing expert assistance to the authority in charge of the situation. At STUK, preparedness means the assessment of a threatening situation, the assessment of the consequences of a damage or intentional act that has already occurred, and the making of recommendations related to radiation protection measures. In an unusual situation related to a nuclear facility or radiation source, STUK is an expert authority that supports the authority leading the situation as part of the joint situation organization of the authorities. STUK assesses the nuclear and radiation safety significance of the situation for both the population and the first responders, analyzes and interprets the radiation observations made by the first responders in the field, makes supplementary measurements on site as necessary and gives recommendations on radiation protection issues.


STUK maintains and develops its regulatory oversight and detection and response readiness with the information it receives from other authorities. STUK also monitors the situational picture related to information security of information networks, telecommunications networks and industrial automation systems maintained by the CERT-FI unit of the Finnish Communications Regulatory Authority.

If necessary, STUK provides expert assistance to other authorities in the prevention of illegal activities related to nuclear facilities or radiation sources, in the development of operational readiness and in operational activities. Cooperation includes coordinated operating models, instructions, training and joint exercises. National security arrangements also provide for the possibility that nuclear materials or other radioactive materials will be attempted to be transported across the borders of countries, either intentionally or accidentally. With regard to border control, STUK and the Customs have systematic and continuous cooperation, which is used to maintain and develop the operational cooperation model, the control equipment of border stations and the expertise of customs officers.

The National Security Police and STUK together regularly update the threat picture of illegal activities related to nuclear facilities and radiation sources. Based on the threat picture, STUK maintains a basic planning threat for the use of nuclear energy and radiation as part of the official requirements.

STUK also participates in the preparation of safety arrangements guidelines under the leadership of the International Atomic Energy Agency (IAEA) and in international peer reviews of safety arrangements, as well as in the preparation and development of guidelines for nuclear safety arrangements. The last international peer review of security arrangements coordinated by the IAEA, IPPAS, organized in Finland was held in 2022. STUK is Finland's point of contact in the information exchange systems of the IAEA and the European Commission, which are used to report abnormal events related to radioactive substances (e.g. ITDB). In addition, STUK is Finland's point of contact in international systems that monitor the export, import and transfers of radiation sources, especially high-activity sealed sources, between different countries