ASN issues its first conclusions on exposure to ionising radiation in professional activities implementing raw materials containing naturally occurring radionuclides not used because of their radioactive properties

Some industrial processes concentrate natural radionuclides contained in raw materials, manufactured products or production waste. ASN worked in collaboration with IRSN, the French National Institute for Radiation Protection and Nuclear Safety, to assess the exposure of workers and the population at large to this “technologically enhanced natural radioactivity” [1].

List of categories of professional activities concerned:

1.  Coal combustion in thermal power stations;
2. Treatment of tin, aluminium, copper, titanium, niobium, bismuth and thorium ores;
3. Production of refractory ceramics and glassmaking, foundry, steel industry and metallurgical activities using refractory ceramics;
4. Production or use of compounds containing thorium;
5. Production of zircon and baddeleyite, and foundry and metallurgical activities using zircon and baddeleyite;
6. Production of phosphate fertiliser and the manufacture of phosphoric acid;
7. Titanium dioxide treatment;
8. Rare earth treatment and production of pigments containing rare earths;
9. Treatment of underground water by filtration for the production of:
   • water for human consumption;
   • mineral waters;
10. Spas

The assessment is based on the examination of more than 80 reports filed by the companies concerned.

Regarding worker exposure, it shows that estimated doses exceed 1 mSv/year for 16% of workplaces. More specifically, these doses concern categories 2, 3, 4 and 5 listed in the regulations (see box).

Available data regarding general population exposure does not differ significantly from that found in the existing scientific literature, although it is true that little data was received.

ASN monitors these industrial sectors from the radiation protection point of view and has been conducting site inspections since 2008 to optimise radiation protection. It also ensures compliance with the radiation protection rules laid down in the French Labour Code.

The assessment includes proposals for updating the national regulations currently in force. In particular, it suggests updating the list of categories of professional activities concerned by the regulations and defining a qualitative population dose assessment method.

An English version of the document can also be consulted on the ASN website at www.french-nuclear-safety.fr.

[1] Further to the Order of 25 May 2005 on professional activities implementing raw materials containing naturally occurring radionuclides not used because of their radioactive properties, published in the Official Journal of the French Republic on 1 June 2005.