Model to Estimate Volume Change Due to Radiolytic Gas Bubbles and ThermalExpansion in Solution Reactors

摘要

Aqueous homogeneous solution reactors have been proposed for the production ofmedical isotopes, such as 99 Mo. Commercial production of 99 Mo in solution reactors requires steady-state operation at about 200 kW during a five-day week period to meet the 16500 Ci per week demand in the United States. This amount is about 50% of the world's demand of 99 Mo. However, previous experiments with solution reactors suggest that radiolytic gas bubble formation may impede steady-state operation above a certain power threshold and, therefore, commercial production of 99 Mo may not be accomplished in solution reactors without mitigation of the effects of radiolytic gas bubbles. The main coefficients of reactivity observed in transient experiments in aqueous homogeneous solution reactors are due to temperature (thermal expansion) and radiolytic gas bubble formation. Both effects result in volumetric expansion of the fuel solution, which decreases the reactor core surface-to-volume ratio (geometrical effect) and decreases the fuel density.