About ASN

The Nuclear Safety Authority (ASN), an independent administrative authority set up by law 2006-686 of 13 June 2006 concerning nuclear transparency and safety (known as the “TSN law”) is tasked, on behalf of the State, with regulating nuclear safety and radiation protection in order to protect workers, patients, the public and the environment from the risks involved in nuclear activities. It also contributes to informing the citizens.

Medical uses

For more than a century, medicine has used, both for diagnosis and therapy, varied sources of ionising radiation produced either by electric generators or radionuclides. The field is large and diversified, as France has approximately 50,000 facilities for medical and dental diagnostic radiology, around 300 nuclear medicine departments and nearly 400 radiotherapy devices. Overall, these facilities perform nearly 70 million radiological procedures each year.

Major medical techniques that rely on ionising radiation are radiology, radiotherapy and nuclear medicine:

  • Radiology, and radiological diagnosis in particular, includes all techniques for morphological exploration of the human body using X-rays produced by electric generators. Holding a dominant position in the field of medical imaging, it covers diverse fields (medical radiology, dental radiology, etc.) and a wide variety of examinations (chest and abdominal radiography, etc.).
  • Radiotherapy is, along with surgery and chemotherapy, one of the major techniques used in the treatment of malignant tumours. In France, some 200,000 patients receive treatment each year. Radiotherapy uses ionising radiation to destroy malignant cells. Ionising radiation necessary for treatment is produced either by an electric generator or emitted by sealed radionuclides.
  • Nuclear medicine includes all uses of radionuclides in unsealed sources for diagnosis or therapy. Diagnostic uses cover in vivo techniques that involve administering radionuclides to the patient and applications that are exclusively in vitro. They are used to study organ morphology (research in cerebral or bone metastases) and their function (metabolism of a gland, research into myocardial function, etc.).

Safety issues

After exposure to natural radiation, exposure for medical reasons constitutes the second source of exposure for the population and the primary source of exposure from artificial sources.

For workers and the public, the nature and significance of risks from the use of such sources vary according to whether radioactive sources are sealed or unsealed, devices for electrical generation of X-rays used for medical and dental diagnosis or particle accelerators for external radiotherapy. The sources must be used in compliance with safety rules set by the labour code to protect workers and rules in the public health code to protect the public and patients.

ASN’s role

In the area of medical applications, ASN performs or has certified organisations perform inspections of radiation protection at facilities for radiology, radiotherapy, brachytherapy, nuclear medicine and irradiators of blood products. These inspections regularly evaluate the safety of the facilities to verify the radiation level with regard to current regulations, and to strengthen it as needed.

Inspections performed by ASN directly in facilities for radiotherapy, brachytherapy and nuclear medicine are part of delivery procedures (inspections prior to operation) or renewal (periodic inspections) for authorisation to store and use radiation sources.

Date of last update : 25/09/2017