Article R4451-44 of the French Labour Code
I.-When the installation is commissioned and after any significant change in working methods and conditions likely to affect the health and safety of workers, the employer shall carry out measurements in the delimited areas and in the workplaces adjoining these areas in accordance with Article R. 4451-24, to the initial verification of: 1° The level of external exposure; 2° Where applicable, the concentration of radioactive activity in the air or…