Editorial for the special topic

The scientific community is currently paying particular attention on the effects of Na-Tech events to industrial facilities for the important economic and social impact that these events can entail on the society. In fact, effective risk analysis is critical for industrial plants to assure the necessary safety level as clearly demonstrated by very recent events as the 2011 Tohoku Earthquake. Nevertheless, the effort in developing new techniques is being more and more important as clearly proven by the rapid increasing of the contributions on this topic. This special topic, titled "Na-tech risk assessment methodologies and mitigation solutions in the process industries", promoted by the Guest Editors: Oreste S. Bursi, Fabrizio Paolacci and Tomoyo Taniguchi, within the Seismic Engineering Technical Committee of the ASME Pressure Vessel and Piping Division, is aimed to bring together the latest methodologies and techniques for a reliable estimation of Na-Tech risk in process plants that represents one of the most diffused hazards in industrial facilities. Contributions were called from researchers and industry professionals, strongly active in this area. A total of ten papers were accepted that cover many of the key topics related to Na-Tech events and consequences in Industrial Facilities.