Determining the Effective Dose Equivalent for External Photon Radiation: Calculational Results for Beam and Point Source Geometries

Abstract

In 1994, US nuclear plants must implement a new Code of Federal Regulations which adopts the methodology of ICRP 26 for effective dose equivalent (H E ) from internally deposited radionuclides. For exposure to photons from sources outside the body, the new regulations propose an ad hoc extension of the ICRP 26 methodology by defining a new tissue ― «the whole body» ― and assigning it a weighting factor of 1. This study provides basic data to build a methodology for assessing H E based on the original ICRP 26 organ dose methods. Specifically, Monte Carlo photon transport calculations were done with anthropomorphic male and female phantoms and a hermaphroditic phantom to calculate organ doses, and thereby H E , for each gender, for selected photon energies, for photon beams at any three-dimensional angle, and for point sources anywhere external to the torso