Assessing Dose of the Representative Person for the Purpose of the Radiation Protection of the Public, ICRP Publication 101a, Ann. ICRP 36 (3), 2006: Dose to the public cannot be measured directly, and in some cases, it cannot be measured at all. Therefore, for the purpose of protection of the public, it is necessary to characterise an individual, either hypothetical or specific, whose dose can be used for determining compliance with the stipulated dose constraint/limits on individuals from specified sources.
These dose constraints apply to actual or representative people who receive occupational, medical, and public exposures. This individual is defined as the ‘representative person’ by the ICRP. It is assumed that the Commission’s goal of protection of the public is achieved if the relevant dose constraint for this individual for a single source is met, and radiological protection is optimised.
This report updates the previous guidance and the methods available for estimating annual dose to the public. In selecting characteristics of the representative person, three important concepts used are: reasonableness, sustainability, and homogeneity. Each concept is explained and examples are provided to illustrate their roles. Doses to the public are prospective (may occur in the future) or retrospective (occurred in the past). Prospective doses are for hypothetical individuals who may or may not exist in the future, while retrospective doses are generally calculated for specific individuals.
Unlike in the earlier recommendations, the ICRP now recommends the use of only three age categories for estimating annual dose to the representative person for prospective assessments. These categories are 0–5 years (infant), 6–15 years (child), and 16–70 years (adult). For practical implementation of this recommendation, dose coefficients and habit data for a 1-year-old infant, a 10-year-old child, and an adult should be used to represent the three age categories.
In a probabilistic assessment of dose, whether from a planned facility or an existing situation, the Commission recommends that the representative person should be defined such that the probability is less than about 5% that a person drawn at random from the population will receive a greater dose. If such an assessment indicates that a few tens of people or more could receive doses above the relevant constraint, the characteristics of these people need to be explored and actions to modify the exposure should be considered. The Commission recognises the role of stakeholders in improving the quality, understanding, and acceptability of the characteristics of the representative person and the resulting estimated dose (Extracted from the www.icrp.org).
