Observations Emerged from ISTP-EPICUR on Iodine Behavior During a Severe Accident

Iodine behavior is most important in the evaluation of the early effects of a severe accident on the off-site public health. However, the MELCOR code, which is being used by Korea Institute of Nuclear Safety (KINS) for an integrated severe-accident assessment, does not treat the organic iodine behavior in the containment atmosphere. Therefore, it is needed to develop a standalone model which can be coupled with the current radiological assessment methodology. KINS agreed with other domestic organizations, including Korea Atomic Energy Research Institute (KAERI), Korea Hydro and Nuclear Power Co. Ltd. (KHNP) and KEPCO Engineering and Construction Company, Inc. (KEPCO E and C), to participate in the ISTP (International Source Term Program) operated by IRSN. This Program investigates the behaviour of iodine and ruthenium in the containment of a power plant in case of severe accident. It consists of two sub programs: ISTP-EPICUR and PARIS. This study was carried out to evaluate the experimental results and derive observations that could be used for development of an iodine behavior model and its validation