Nuclear reactor Thermal-Hydraulics Special and prospective topical areas

The purpose of this paper is to summarize the session on Special & Prospective Areas (SPA) as part of the OECD/NEA/CSNI Specialists Meeting on Transient Thermal-hydraulics in Water Cooled Nuclear Reactors (SM-TH). This session dealt with some special and prospective topical areas in current nuclear reactor thermal hydraulics research. These topics are at the intersection of nuclear reactor thermal hydraulics in its traditional sense and multi-scale, multi-physicochemical phenomena associated with a nuclear power plant. The intricacy of nuclear power plants and the variety of possible accident conditions point to the complexity and need for an interdisciplinary approach to assess those phenomena. In addition to the nuclear or power technology itself, a range of unpredictable human actions introduce additional uncertainties in an already complex environment and the events’ initiation and propagation, which may indicate our inability to cover some unexpected or poorly understood phenomena. This should not be construed as conclusive but rather as a starting point and invitation for further discussions and exploration of gaps in our understanding of the phenomena involved.