The valley system of the Jihlava river and Mohelno reservoir with enhanced tritium activities.

Abstract The Dukovany nuclear power plant (NPP Dukovany) releases liquid effluents, including HTO, to the Mohelno reservoir, located in a deep valley. Significantly enhanced tritium activities were observed in the form of non-exchangeable organically bound tritium in the surrounding biota which lacks direct contact with the water body. This indicates a tritium uptake by plants from air moisture and haze, which is, besides the uptake by roots from soil, one of the most important mechanisms of tritium transfer from environment to plants. Results of a pilot study based on four sampling campaigns in 2011–2015 are presented and discussed, with the aim to provide new information on tritium transport in the Mohelno reservoir - Jihlava River – plants ecosystems.