Higher exposures of nuclear workers
As all personnel exposed to radiation and because of their professional activity, nuclear industry workers receive doses higher than those allowed for the public. The average doses (excluding natural radioactivity) are some millisieverts (mSv) per year. The operations of the uranium cycle which exposes the more to radiation are ore extraction and purification of uranium from ore ( "yellow cake"), by exposure to radon. The legislation requires that the dose does not exceed 50 mSv in a period of 5 years and 20 mSv in a year for exposed workers. (Report of the United Nations Scientific Committee on the Effects of Atomic Radiation.)