Behavior of Antimony Isotopes in the Primary Coolant of WWER-1 000-Type Nuclear Reactors in NPP Kozloduy during Operation and Shutdown

摘要

This paper focuses on the behavior of the antimony isotopes ~(122)Sb and ~(124)Sb in the coolant of the WWER reactors in the nuclear power plant Kozloduy (Bulgaria) during operation and shutdown. It is concluded that the chemical properties of their actual precursor, the isotope ~(121)Sb, determine the behavior of ~(122)Sb and ~(124)Sb during operation, load fluctuations, and shutdown as well as during the reactor coolant purification process. It is supposed that differences between the reactor bulk and the core fuel cladding surface chemistry as well as the presence of sub-cooled nucleate boiling at the fuel cladding may create conditions under which a local oxidizing environment may come into existence.