This paper presents the evaluation of the economic and social effect from revised nuclear power plant (NPP) planning in Thailand according to the accident of NPP at Fukushima in Japan. From the latest of Thailand Power Development Plans, 5 NPPs with totally 5,000 MW will be installed in year 2020, 2021, 2024, 2025 and 2028, respectively. After the unfortunate disaster, the NPP planning is postponed to unexpected period due to the social and safety concerns. However, the NPP is still need to be reconsidering as soon as possible which depends on many factors such as the rapid growth of power demand and energy crisis. The simulation of three feasible scenarios will be presented to guide the appropriate planning of NPP in next PDP. In addition, the economic value, performance and environmental aspect will be discussed from utilities and customer point of view, especially the industrial customer. Finally, the worst case scenario of NPP in Thailand will be evaluated in term of economic loss, performance crisis, loss of power supply and environmental aspect comparing with the electricity generation from the fossil based power plants. © 2011 IEEE.