MONITORING AND CONTROL OF IMPURITIES IN THE PRIMARY CIRCUIT OF THE IBR-2 REACTOR

The periodically pulsed IBR-2 reactor of the Joint Institute for Nucle ar Research in Dubna (Russian Federation) uses liquid sodium as the co olant for the fuel elements. The installation of sodium circuits in th e reactor system poses numerous tasks in regard of control and safety. Electrochemical cells with solid electrolytes were installed for the measurement of the oxygen activity in the sodium of the primary circui t. The carbon contained in the sodium was determined by sampling using the vacuum distillation method. Metallic impurities were ascertained by atomic emission spectrometry while radiochemical impurities were an alysed on whole samples or from the distillation residues. The results of the investigations are presented and discussed.