The IAEA fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. Therefore, in order to prove the applicability of 100 TBq Cs-137 release into environment as a safety criterion at reactor design approval stage, the limitedness of the consequences of the release to both people and the environment must be demonstrated. As it was shown by preceding study that the release generates limited health effects, this study is dedicated to demonstration of limitedness of the consequences of the release to the environment. We formed the environmental impact index based on insights from our previous studies. It is composed of decontamination index and relocation index. It is used to assess consequences to the environment under several conditions. The estimated environmental impact indices under all conditions were small enough to confirm the limitedness of the environmental impacts of the 100 TBq Cs-137 release, which ensure its applicability as a safety criterion for consequence assessment at reactor design approval stage.
