Decay chain equilibrium is achieved, each successive daughter isotope is present in direct proportion to its half-life; but since its activity is inversely proportional to its half-life, each nuclide in the decay chain finally contributes as many individual transformations as the head of the chain, though not the same energy. For example, uranium-238 is weakly radioactive, but pitchblende, a uranium ore, is 13 times more radioactive than the pure uranium metal because of the radium and other daughter isotopes it contains. Not only are unstable radium isotopes significant radioactivity emitters, but as the next stage in the decay chain they also generate
Naturally occurring radioactive material UK regulation is via the Environmental Permitting (England and Wales)Regulations 2010. This defines two types of NORM activity: (a)the production and use of thorium, or thorium compounds, and the production of products where thorium is deliberately added; or (b)the production and use of uranium or uranium compounds, and the production of products where uranium is deliberately added (a)the extraction, production and use of rare earth elements and rare earth element alloys; (b)the mining and processing of ores other than uranium ore; (c)the production of oil and gas; (d)the removal and management of radioactive scales and precipitates from equipment associated with