Transuranium elements and fission products in technological channels of unit No. 2 of Chernobyl Nuclear Power Plant

A gamma-spectrometric and radiochemical analysis was carried out of a material (Zr-2.5% Nb alloy) of technological channels (TC) of Chernobyl Nuclear Power Plant (NPP) power unit No. 2 RBMK-1000 reactor, being under the beginning stage of decommissioning. Activities of 90 Sr, 137 Cs, 238 Pu, 239+240 Pu, 241 Am and 244 Cm were determined. It was established that the main source of the revealed actinides and fission products was an impurity of natural thorium and uranium in TC source material on the level of several tenths of ppm. Impurity analysis of TC source material was performed by neutron activation analysis (NAA) and inductively coupled plasma mass spectrometry (ICP-MS). Fission product and transuranium element activities measured were compared with the results of prognostic calculations performed with the help of the NAAPRO code.