Calculation of Conversion Coefficients for Voxelized Phantoms for Criticality Accident Dosimetry

Abstract

In the event of a criticality accident, not only the maximal doses received by the victims must be determined but it is also crucial to evaluate the doses to the different organs. With a neutron component, morphology is a key parameter in the organ dose calculation. As the simulation tools can be time consuming to proceed, especially if morphology is taken into account, for all the victims, it may be very useful to have a database of conversion coefficients that allow to obtain the organ doses from the dose measured in the dosemeter for different kinds of morphology. In this paper, we present a study performed to evaluate such conversion coefficients using voxelized anthropomorphic phantoms. These coefficients take into account two crucial parameters having an impact on the dose at the organs: the orientation of the victim in the radiation field and the morphology, that is to say the body mass index of the different victims.

Reflections on the future developments of research in retrospective physical dosimetry

“…Because in many practical circumstances the precise details of exposure are likely partially or completely unknown, ICRU [1] suggested that conversion of dose in the dosimeter to dose to the body might be appropriate only in specific small-scale scenarios. These could be those in which relatively few individuals are exposed and conditions could be reconstructed in greater detail than in large-scale events, although this may not always be true in all contexts, or in those cases where scenario complexity hinders timely simulation, as in the case of neutron irradiation in criticality accidents [129]. Instead, the ICRU [1] report recommended that the dose to be used for early-stage dose assessment after a large-scale radiological event should be the absorbed dose in the fortuitous dosimeter material, without any conversion factor applied.…”