Fundamental Research Division
Radioactivity has been present on Earth since its formation; natural radionuclides are either cosmic or terrestrial in origin. Thus, man has been exposed to ionizing radiation since always. Artificial radionuclides have appeared with the development of medical, industrial and military radioactivity applications.
The harmful effects of ionizing radiation were demonstrated shortly after the discovery of radioactivity. And even if they are not completely characterized (especially at low doses), it is still necessary to be protected against ionizing radiation, and to establish the health monitoring of persons potentially exposed. These are mainly workers exposed in their normal working conditions, and patients exposed during a medical procedure using ionizing radiation. This monitoring notably includes dose assessments.
Radioactive elements have always been naturally present on Earth. The use of radioactivity for medical, industrial and military applications has generated the production of artificial radionuclides.
Exposure to ionizing radiation can result from external irradiation or internal contamination. In the workforce, the type of exposure determines the protection and monitoring of potentially exposed personnel.
The objective is to estimate as precisely as possible the committed effective dose, i.e. over a lifetime, or the equivalent dose to an organ. Several factors are taken into account and the process differs whether it is a question of irradiation or internal contamination.
Adequate protection for workers concerning ionizing radiation is essential to the safe use of radiation and radioactive materials. Potentially exposed workers in the various sectors concerned are subject to systematic individual monitoring.
Different monitoring programs allow verifying that the required protection level for exposed personnel is well respected.
A criticality accident results from the triggering of an uncontrolled fission chain reaction. This occurs when the amount of nuclear material present (uranium or plutonium) accidentally exceeds a threshold known as “critical mass”, or whenever there is a neutron source that primes the reaction.
The monitoring of patient dosimetry helps to improve practices for the controlled use of radiation in medicine.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.