French Public Health Code
In forceI.-For the application of article L. 1333-22, when at least one radon volumetric activity measurement result exceeds the reference level set in article R. 1333-28 , the owner or, where applicable, the operator must implement corrective measures to improve the airtightness of the building with regard to radon entry points or the air renewal of the premises. He shall have the effectiveness of these measures checked by measuring the radon activity concentration.
II - When the radon activity level is still greater than or equal to the reference level after corrective action has been taken, or in situations where this is justified, as defined by the order referred to in III, the owner or, where applicable, the operator, shall arrange for any expert assessment required to identify the causes of the presence of radon to be carried out, if necessary on the basis of additional measurements, and shall carry out work to ensure that people's exposure to radon remains below the reference level.
The effectiveness of this work will be verified by measuring radon activity by volume.
III - The measurements mentioned in I and II are carried out no later than 36 months following receipt of the results of the initial measurement carried out in accordance with the provisions of article R. 1333-33.
An order by the ministers responsible for radiation protection and construction specifies the nature of the actions mentioned in I and II to be implemented if the reference level is exceeded.
