Overview of the experimental studies and numerical simulations on the filtered containment venting systems with wet scrubbers

摘要

A filtered containment venting system (FCVS) is one of the important severe accident mitigation systems designed to prevent containment failure due to potential overpressure during accidents. Especially, many research projects related to FCVS have been initialized after Fukushima Daiichi nuclear accident. To demonstrate the functionality and filtration performance of various types of FCVSs with wet scrubbers, confirmatory experiments were performed on test facilities. To sort out the main outcomes of those experiments, this paper summarizes the major experimental works performed in test facilities from the perspective of filtration efficiency and thermal-hydraulic characteristics. The investigated experimental results showed that there is a variety in retention efficiency among different designs of wet type FCVSs and different tests conditions. The overall decontamination factor (DF) for aerosol is usually higher than 3000, the DF for elemental iodine (100), and for the organic iodine (10) are lower, which are still sufficient for most countries' regulatory requirements, and the DF for CH3I can be improved by efficient zeolite module. Along with the experimental studies, some numerical simulation works based on thermal hydraulic system codes are also summarized. To an extent, thermal-hydraulic codes could predict the long-term operating characteristics of prototypical FCVSs under postulated severe accident conditions, which is complementary to the experiments. This review is expected to provide extensive information to help the optimization and further innovation of FCVSs. (C) 2019 Elsevier Ltd. All rights reserved.