ADVANCES IN RADIATION DOSIMETRY Significant improvements and advances have occurred in the methods and technologies available for personnel and environmental radiation monitoring and dosimetry, metabolic modeling and internal dosimetry since the Marshail Islands accident in 1954. This section addresses the use of such technologies in evaluating persons involved in a comparable accident today. 6.1 Radiation Dosimetry: Physical Methods If an accident of similar character and magnitude occurred today, the approach to radiation dosimetry would involve the use of considerably more detailed and precise methods than were available and applied in the 1954 accident. Current radiation accident response would include immediate deploymentof the equipment necessary to conduct a fairly extensive evaluation of the dose from various sources of radioactive material. These surveys would yield information about external radiation fields, environmental radioactive contaminants, and individuals’ radionuclide body burdens and excretion rates. Newer technologies would enable more detailed characterizations of the types of radiation involved and their energies than were possible at that time. Also, various predictive models, often in the form of computer software, are now available that may enable more thorough evaluation of plume behavior, transport of contaminants, and internal doses. These assessments would improve thereliability of the data needed for estimating radiation doses to individuals from these sources. 6.1.1 External Whole-Body Dosimetry The various types of integrating dosimeters with filters of different thicknesses and composition that are now available can distinguish between hard and soft electrons, hard and soft photon doses, and various neutron components. Survey meters also have been refined to provide more accurate measures of the contributions of the different types of | 37