Radiological impact of the atomic centre Centro Atómico Ezeiza on humans and non-human biota.

This work aimed to estimate the radiation doses to humans and non-human biota arising from the operation of the atomic centre Centro Atómico Ezeiza (CAE), Buenos Aires, Argentina. To this end, atmospheric and liquid average discharges for the period 2014-2016, corresponding to all the facilities of the CAE in normal operation were considered. The PC-CREAM 08 and CROM8 codes were applied taking into account local characteristics and reference values. The radiation doses to both humans and non-human biota estimated were considerably lower than the values recommended to protect people and the environment. Thus, it is possible to conclude that both the environment and the human population near the CAE are extremely unlikely to experience any harmful radiological effects caused by the operation of this atomic centre.

Does the use of reference organisms in radiological impact assessments provide adequate protection of all the species within an environment?

Non-human biota in radiological risk assessment is typically evaluated using Reference Organisms (ROs) or Reference Animals and Plants (RAPs), for all exposure situations. However, it still remains open whether the use of an increased number of species would improve the ability to demonstrate protectiveness of the environment. In this paper, the representativeness of a broader list of fauna is tested in terms of the geometrical characteristics and habits for radiological risk assessments in the case of routine discharges from a nuclear installation: the Cadarache centre. A list of terrestrial animal species, compiled from ecological inventories carried out around it was evaluated. A first survey around the centre inventoried >400 terrestrial fauna species, which were then filtered to reduce the number to 28 species for which dose assessments were carried out. Despite the differences between geometries for those site-specific species and the ROs (including RAPs), the absorbed dose rates calculated for both were very close (within a factor of two). Regardless of the studied organism, the absorbed dose rates calculated for the discharge scenario were mainly related to internal exposure, particularly for tritium (3H) and carbon 14 (14C), showing that there would be an acceptable dose rates difference between species from the same organism group. Additionally, sensitivity analyses were conducted to determine if the use of generic, predefined ROs was enough to assure an adequate protection of endangered species. It was observed that for every radionuclide the difference between assessments for site-specific species and ROs are unlikely to exceed a factor of 3. Hence, the result of this evaluation indicates that the use of generic ROs for non-human biota radiological risk assessment covers sufficiently other species, including endangered ones.