Requirements for the use of radiation appliances

STUK issues in-service acceptability criteria for radiation appliances. The acceptability criteria denote the minimum requirements – acceptability limits – imposed on the performance capacity of the equipment. These requirements are applied as the strictest action limits during the use of the equipment.

Radiation-emitting equipment and radioactive substances are subject to the EEC Treaty and product directives as well as the Euratom Treaty, under which directives on the use of radiation appliances or radioactive substances have been issued.

Of the directives issued under the Euratom Treaty, the most significant are Directive 96/29/Euratom for protecting the health of workers and the general public (the so-called Basic Safety Standards or BSS Directive) and Directive 97/43/Euratom on the medical use of radiation (the so-called Medical Exposure or MED Directive).

The BSS Directive presents an advance approval and regulation procedure for the use of radiation-emitting equipment and radioactive substances. The MED Directive also sets forth requirements concerning the use and regulation of radiological equipment. In Finland, the BSS Directive was enforced through amendments to the Radiation Act (1142/1998) and Radiation Decree (1143/1998) and the MED Directive was enforced with a Decree of the Ministry of Social Affairs and Health (423/2000). Detailed instructions are also presented in STUK’s ST Guides.

According to the Radiation Act (592/1991), the use of radiation is subject to a safety licence issued by STUK, unless the use has been separately exempted from a safety licence. Based on the Radiation Act, STUK issues general radiation safety instructions concerning the use of radiation and other radiation practices (ST Guides). The responsible party is liable for the safety of radiation practices. The responsible party has the obligation to ensure compliance with the Radiation Act and the regulations issued under it and to maintain a sufficient level of safety accordingly.

STUK issues in-service acceptability criteria for radiation appliances. The acceptability criteria denote the minimum requirements – acceptability limits – imposed on the performance capacity of the equipment. These requirements are applied as the strictest action limits during the use of the equipment. The measures for repairing a piece of equipment and restoring its acceptable performance capacity must be taken, at the latest, when an acceptability criterion (performance capacity action limit) is exceeded. If necessary, the piece of equipment must be decommissioned.

The acceptability criteria are not the limit values for the optimal performance of equipment or the tolerance values presented in international equipment standards. When procuring new equipment and conducting acceptance testing and in-service quality control, the responsible parties should apply more stringent requirements, which may be based on equipment specifications or the performance tolerance values recommended in equipment standards, for example.