This book presents a compilation of selected papers from the Fourth International Symposium on Software Reliability, Industrial Safety, Cyber Security and Physical Protection of Nuclear Power Plant, held in August 2019 in Guiyang, China. The purpose of the symposium was to discuss inspection, testing, certification and research concerning the software and hardware of instrument and control (I&C) systems used at nuclear power plants (NPP), such as sensors, actuators and control systems. The...