The methods of radioactive labelling the sea water and the conditions for reaching the equivalence of physico-chemical states
of radiotracers and corresponding stable nuclides in sea water are analyzed. The process of bioassimilation, the uptake and
release of radionuclides by plankton organisms, is considered as the way of fast stabilization of physicochemical forms of
radiotracers in sea water. The data are presented on the sorption of iron, cobalt, nickel and manganese by typical ocean bottom
sediments (deep-water red clay, diatomic coze, carbonate deposit).
Ionizing radiation is shown not to create any additional lattice defects in yttriumaluminium garnet (YAG) due to their high
radiation stability. However, it generates different kinds of electron-hole centres that are stabilized on structural imperfections.
In the temperature range 77–300 K three kinds of trapping centres in YAG irradiated by γ-rays have been identified by means
of ESR and thermoluminescence technique, namely an electron centre of the first type with g=1.996, stable within the temperature
range 77–150 K, a hole centre of the second type (g=2.018) existing up to 250 K and a hole centre of the third type (g=2.016)
stable at 300 K. Localisation of these centres in the garnet lattice is discussed and their participation in the luminescence
processes considered. The influence of the crystallochemical nature of doped ions (Nd, Ce, Cr) on the stabilization of each
of these electron-hole centres has also been studied.