Sealed radioactive sources are used in industrial radiography, gauging applications and mineral analysis. Gamma sterilisation is used for medical supplies, some bulk commodities and food preservation.
Radiotherapy can be used to treat some medical conditions, especially cancer. Tens of millions of nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing rapidly.
Many of the world's nuclear reactors are used for research and training, materials testing, or the production of radioisotopes for medicine and industry. There are about 240 such reactors operating, in 56 countries.
Most smoke detectors which operate alarms contain an artificially produced radioisotope: americium-241. Americium-241 is made in nuclear reactors, and is a decay product of plutonium-241.