From the Nuclear Regulatory Commission:
The Nuclear Regulatory Commission’s compilation of 2007 nuclear power plant worker doses at U.S. reactors shows the average annual collective dose per plant is 97 person-rem, the lowest ever, and is two-thirds of the dose recorded 10 years ago.To determine a plant's collective dose, hundreds of workers’ individual doses are added up and the result is expressed in person-rem. The average American receives a dose of about 360 millirem every year from all radiation sources; the average nuclear plant worker in recent years received about an additional 160 millirem each year on the job. NRC regulations allow workers at nuclear power plants to safely receive a job-related dose of up to 5,000 millirem each year.
Here is a chart of the data since 1973.
Comments
"Average dose" is perhaps a useful statistic of the valuable work done in progress in radiation awareness and exposure reduction. "Collective dose" is not.
That came from NCRP in 1987. There were 300 mrem from natural background, plus 60 mrem from man-made background, of which 57 mrem was from diagnostic medical sources.
NCRP per capita diagnostic medical radiation is now 320 mrem, according to a report at the April 2008 NCRP Annual meeting by subcommittee chairman Fred Mettler. (This is primarily from a great increase in CT scan number and dose, plus increased use of nuclear medicine.)
So background dose is/will now be 625 mrem?