Industry and research have been using ionising radiation sources for a long time in a variety of applications.
One of the non destructive testing techniques uses radioactive sources: gammagraphy, which assesses the lack of homogeneity in metal, in particular in weld beads. This technique uses sources of highly active iridium 192 and cobalt 60 (usually around 3 TBq).
2Monitoring of industrial processes2
The most commonly used radioactive elements are krypton 85, caesium 137, americium 241, cobalt 60 and promethium 147. Source activities range from a few kBq to several GBq.
Sources are used to:
Short-lived radioactive elements (less than one hundred days half-life) can be collected and stored for a duration of approximately ten times the half-life of the radioactive element, sufficient to allow the radioactivity to practically disappear. Subsequently, this waste can be disposed of after inspection in traditional waste disposal channels and liquid wastewater is discharged after verifying that its activity is lower than regulatory thresholds.
Radioactive elements with a half-life higher than 100 days are collected and treated by the National Agency for the Management of Radioactive Waste (ANDRA).
Disposal of sealed sources is ensured by the source supplier or by ANDRA.
Measurement units and limit exposure values:
To quantify radioactive emissions, scientists have established three units designating different phenomena:
Annual exposure limits
|Organ||Public (public health code)|
Maximum permissible levels for the marketing of food products (in Bq/kg)
|Radioactive elements||Baby food||Dairy products||Other food||Liquids|
|Iodine including 131I||150||500||2,000||500|
|Long-life isotopes (excluding Sr and Pu) including 134Cs and 137Cs||400||1,000||1,250||1,000|
|Strontiums including 90Sr||75||125||750||125|
|Plutonium and emitters including 139Pu||1||20||80||20|