Radiation weighting factor

Use of old factors

The International Committee for Weights and Measures (CIPM) and the U.S. Nuclear Regulatory Commission (NRC) continue to use the old terminology of quality factors and dose equivalent. The NRC quality factors are independent of linear energy transfer, though not always equal to the ICRP radiation weighting factors. The NRC's definition of dose equivalent is "the product of the absorbed dose in tissue, quality factor, and all other necessary modifying factors at the location of interest." However, it is apparent from their definition of effective dose equivalent that "all other necessary modifying factors" excludes the tissue weighting factor. As shown in accompanying figure, the radiation weighting factors for neutrons are also different between the U. S. NRC and the ICRP.