Chemical Processes in the Reactor Coolant System under Accident Conditions.

摘要

Uncertainty analyses of the potential revaporization of radionuclides in the reactor coolant system are presented. These results indicate deposited Cs, I, Te and to some extent Ru and Ba have significant probabilities of revaporizing from the reactor coolant system once the reactor coolant system has been breached and natural convection causes a flow from the reactor containment building through the coolant system. The magnitude of the revaporization depends critically on the chemical form of the deposited material. Experimental studies of CsI transport behavior in high temperature steam indicate CsI may decompose yielding a volatile form of iodine and leaving cesium bound to structural surfaces in a form substantially less volatile than CsI or CsOH. A factorial design test series considering the variables of flow velocity, surface area, cesium iodide-to-steam concentration ratio, and oxygen potential has been conducted to establish the kinetics of cesium iodide decomposition. A model of the kinetic processes is suggested. 14 refs., 4 figs., 2 tabs. (ERA citation 13:056689)