Legacy waste – weakly radioactive but long-lived

Radium-bearing waste
Radium-bearing waste is a low-level long-lived waste. The production of this waste containg radium  has now ceased. According to the 2012 inventory, it consists of 7326 m3 of standard radium-bearing residue (RSB), the conditioning of which is the subject of ongoing research, and radium-bearing waste (RRA), which is more radioactive and is conditioned in drums. This waste is either being stored or is in the process of being conditioned, awaiting a final management solution from Andra. Andra has recommended disposal in a clay layer fifteen meters below ground level (subsurface disposal). No decision has been made on the siting of this facility to date

Recent and less recent industrial activities have generated radium-bearing waste. It is only slightly radioactive but there are much larger quantities of it than the other types of waste. As its name suggests, this waste contains traces of radium and its descendants from the decay chain of uranium, traces of which are found in the Earth’s crust. Alongside uranium, which is long-lived (it has a half-life of 1600 years), there is also radon, a natural radioactive gas with a half-life of four days.

Some radium-bearing waste comes from the cleanup of former radium industry sites, which were contaminated when this industry was flourishing before 1940. Other more recent waste comes from the processing of weakly radioactive ores such as monazite, which contains rare earths and their oxides in varying proportions. About fifteen chemical elements with similar structures and properties are known as the rare earths or lanthanides.

Until July 1994, Rhône-Poulenc and then Rhodia Electronics and Catalysis processed monazite to extract the rare earths, at their factory in La Rochelle. Since August 1994 this factory has imported pre-processed ores with lower levels of radioactivity. The rare earths are used in electronics, magnetism (tape heads), the automobile industry (catalytic converters), television screens, etc.

The radioactivity level of radium-bearing waste is usually somewhere between a few dozen Bq and a few thousand becquerels per gram. The radioelements are mainly long lived aalpha emitters.

Radium-bearing waste is classed as low-level long-lived waste (LLW-LL). It has its own special conditioning and disposal process, on which research is being done by ANDRA.