STUK supervises STUK supervises
STUK supervises


The Radiation and Nuclear Safety Authority conducts inspections of places where radiation is used. Inspections help ensure that the use of radiation meets the safety requirements presented in the statutes and meets the licence conditions and regulations.

Targets to be inspected include all places of use of radiation that require a safety licence. The operations or an associated piece of equipment can also exempted from on-site inspection on certain grounds. Information about the possibility of release is specified in the safety licence or a separate decision issued by STUK.

When are inspections conducted?

An example of a typical inspection is the periodical inspection, which is conducted regularly. The periodical inspection is conducted to ensure that the operations comply with the safety licence conditions, legislation and the regulations and instructions issued thereunder. The periodical inspection also verifies that the licensee has met the obligations placed on it, such as implementing the orders issued during the previous inspection. Periodical inspections are conducted every 2–8 years depending on the difficulty and scope of the operations. In ordinary dental X-ray operations (conducted using intraoral X-ray units) and veterinary radiology, some of the on-site inspections may be implemented through the use of a separate regulatory questionnaire.

In some cases, the inspection is carried out before commissioning. This is done when new radiotherapy equipment or a new radiographic imaging room is commissioned, for example. When new types of radiation appliances are commissioned, it may also be necessary to verify their radiation safety before their commissioning.

As regards health care X-ray equipment, computed tomography (CT) equipment, fixed fluoroscopy equipment (typically used in interventional radiology or cardiological operations), mobile fluoroscopy equipment used in operating theatre activities and cone beam computed tomography (CBCT) equipment must undergo a commissioning inspection. The inspection is conducted once the equipment has been used for patient imaging for some time and the imaging protocols and practices have been optimised. In addition, a commissioning inspection is also conducted if the place of use of radiation is new or has undergone significant changes.

A re-inspection is conducted if, in matters with serious safety significance, for example, it is necessary to ensure that the completed corrections are sufficient. The re-inspection is a special procedure that is rarely needed.

If necessary, when the radiation practices are discontinued, a final inspection can be conducted at the place of use of radiation to verify that all sources containing radioactive substances and all radioactive waste have been dispatched and that the place of use and its surroundings are clean of radioactive substances. The final inspection is usually necessary in case of the use of unsealed sources that involved a significant risk of contamination.

The Radiation and Nuclear Safety Authority primarily arranges the inspection times in advance with the responsible party. If necessary, however, inspections may also be conducted without prior notice. The practices or the use of the equipment may also be inspected at the separate request of the responsible party.


Use of radiation in health care
Telephone 09 759 88 246
Industrial use of radiation
Telephone 09 759 88 246
Dental X-ray examinations
Telephone 09 759 88 520 or 09 759 88 300
Veterinary X-ray examinations
Telephone 09 759 88 246