Carbon capture and storage (CCS) is regarded as one of key technologies to meet global greenhouse gas emission reduction goal. In this manner, South Korea is developing a one-million-ton-scale offshore CCS project to reduce national greenhouse gas emission, entitled the Korea Clean Carbon Storage Project (KCCS) 2025. In this project, the CO2 is captured from power plants on coast, loaded to CO2 carriers, and transported to an intermediate storage terminal, which is located on shoreline nearby offshore storage reservoirs at the Ulleung Basin. Then the CO2 is exported via an offshore pipeline to offshore platform for injection to geological storage site for a permanent containment. Since the concept of the KCCS 2025 includes CO2 carriers as a transportation method, it requires an intermediate storage terminal that receives the CO2 from carrier and send out continuous CO2 flow to the offshore pipeline after the pressurization of CO2 to higher than 100 bar. The intermediate storage terminal will consist of (1) unloading system, (2) CO2 storage tanks, (3) LP pumps, (4) a reliquefaction package, (5) a vent stack and (6) HP pump and injection pump (a booster station). Because there are few actual projects with an intermediate storage terminal worldwide, researches on intermediate storage facilities are insufficient. To support an optimal concept design of the intermediate storage terminal for the KCCS 2025, this study identified the potential hazardous events for the unloading system and the CO2 storage tanks. For the unloading system, an unloading arm and LCO2 recirculating line are found to be major components causing serious damage in case of accident. In the case of the CO2 storage tanks, where large amounts of CO2 are stored, they can cause serious damage due to large amounts of CO2 leakage when the tanks are ruptured, over-pressurized, low-pressurized, overcharged, etc. Because hazardous events may pose significant harm to humans or the environment, these results should be considered in the next phases of the project. The results of this study can be helpful for the development of safe CO2 transportation technology in the future.
CCS, CO2 storage tank, CO2 storage terminal, hazard, PHA, unloading arm
 IEA, Energy technology perspectives 2015, 2015.
 Ministry of Maritime Affairs & Fisheries, Development of Technology for CO2 Offshore Geological Storage, 2016 (in Korean).
 Noh, H., Kang, K., Kang, S.G. & Lee J.G., Strategy for development of HSE management framework for offshore CCS project in Korea. Journal of Korean Society for Marine Environment and Energy, 20(1), pp. 26–36, 2017 (in Korean). https://doi.org/10.7846/jkosmee.2017.20.1.26
 Rausand, M., Risk assessment: theory, methods, and applications, John Wiley & Sons, Inc., Hoboken, NJ, 2011.