Influence of Zircaloy Oxidation and Melting Behavior on Core Behavior During a Severe Accident

摘要

The influence of zircaloy oxidation and melting on core temperatures, hydrogen generation, and fission product release is examined. The uncertainties in phenomena important to the modeling of zircaloy oxidation and melting processes including zircaloy oxidation kinetics, hydrogen blanketing, UO sub 2 -zircaloy interactions, and ZrO sub 2 failure are estimated. These uncertainties are then applied to a sensitivity study of a boiloff-initiated severe accident similar to that which may have occurred in TMI-2. Results indicate that the major uncertainties are in the oxidation kinetics which can contribute a factor of ten to the uncertainties in fission product release and can affect the timing of that release. (ERA citation 10:008619)