optimization, by comparing the protection outcome of different technologies. Collective dose must not be used to attribute specific risk of health effects [UNSCEAR 2012 Report] . ICRP Publication 101 [25] describes optimization and the use of collective dose in more detail. ASSESSMENT OF THE DOSE TO THE REPRESENTATIVE PERSON The establishment of an authorization for discharges should take into account the results of an assessment of the radiological environmental impacts commensurate with the radiation risk associated with the facility or activity [3, 7]. To set the discharge limits, prospective estimations of the dose to members of the public should be used to determine acceptable optimized discharge levels that meet the established radiological criteria. The estimation of the effective dose that may be incurred by members of the public depends upon a number of factors, such as the characteristics of the source term, the behaviour of radionuclides in the environment and their transfer to people, the duration of exposure and other relevant factors. These factors cause a wide variation in the effective dose among the exposed population. For the purpose of setting discharge limits, the dose to an individual receiving a dose that is representative of the doses to the more highly exposed individuals in the population (i.e. the representative person) should be assessed. The dose to the representative person “is the equivalent of, and replaces, the mean dose in the ‘critical’ group” [25]. Before starting the estimation of doses to the representative person, a judgement should be made by the applicant regarding the scope and level of detail and the resources that should be allocated to the assessment. These matters should be discussed with and should be subject to the agreement of the regulatory body. The of detail of the assessment model should depend upon the type of facility under consideration, the nature of the discharges and the availability of information and should be consistent with a graded approach. In order to make effective use of assessment resources, a structured iterative approach for assessing doses to the representative person may be useful. Such an approach should start with a simple assessment based on very cautious (conservative) assumptions and should be refined with each iteration, using progressively more complex models with more realistic assumptions and site specific data, as necessary. Consistent with a graded approach, the use of generic assessments should be limited to assessing the impacts from small and simple facilities or activities with standardized practices
period and the regulatory body should consider withdrawing the authorization for discharges or revising the limits and conditions. The limits on effective dose to the representative person should be applied only to future discharges from the facility. They should not take into account the total dose resulting from past unregulated operations of the facility. If appropriate, the contributions to the effective dose from past operations should be addressed within a framework of remedial actions for an existing situation [3]. REFERENCES [1] EUROPEAN ATOMIC ENERGY COMMUNITY, FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, INTERNATIONAL ATOMIC ENERGY AGENCY, INTERNATIONAL LABOUR ORGANIZATION, INTERNATIONAL MARITIME ORGANIZATION, OECD NUCLEAR ENERGY AGENCY, PAN AMERICAN HEALTH ORGANIZATION, UNITED NATIONS ENVIRONMENT PROGRAMME, HEALTH ORGANIZATION, Fundamental Safety Principles, IAEA Safety Standards Series No. SF-1, IAEA, Vienna (2006). [2] INTERNATIONAL ATOMIC ENERGY AGENCY, IAEA Safety Glossary: Terminology Used in Nuclear Safety and Radiation Protection (2007 Edition), IAEA, Vienna (2007). [3] EUROPEAN COMMISSION, FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, INTERNATIONAL ATOMIC ENERGY AGENCY, INTERNATIONAL LABOUR ORGANIZATION, OECD NUCLEAR ENERGY AGENCY, PAN AMERICAN HEALTH ORGANIZATION, UNITED NATIONS ENVIRONMENT PROGRAMME, WORLD HEALTH ORGANIZATION, Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, IAEA Safety Standards Series No. GSR Part 3, IAEA, Vienna (2014). [4] INTERNATIONAL ATOMIC ENERGY AGENCY, Licensing Process for Nuclear Installations, IAEA Safety Standards Series No. SSG-12, IAEA, Vienna (2010). [5] INTERNATIONAL ATOMIC ENERGY AGENCY, Operational Limits and Conditions and Operating Procedures for Nuclear Power Plants, IAEA Safety Standards Series No. NS-G-2.2, IAEA, Vienna (2000).