Conducting risk assessments for hydrogen energy systems and facilities is essential for preventing hydrogen accidents and ensuring the safe use of hydrogen energy. With the advancement of commercial applications of hydrogen energy, diversified hydrogen energy application scenarios have put higher demands on risk assessment technologies. This paper summarized the fundamental theories and methods of both qualitative and quantitative risk assessments and reviewed the current development status and main application scenarios of existing risk assessment technologies in the hydrogen energy industry. Emerging risk assessment technologies, such as dynamic Bayesian networks and artificial neural networks, were introduced as well. On this basis, this paper highlighted current challenges in hydrogen safety data, dynamic quantitative risk assessment, risk assessment procedures and acceptable standards, and simulation and assessment tools. Finally, four recommendations were proposed for the future development of hydrogen risk assessment technologies.

The competition among countries in the marine field, whether political, economic or military, is essentially the competition of science and technology. The competition of marine science and technology focuses on deep-sea high-tech. In recent years, more and more countries have raised the development of deep-sea technology to a national strategic level and increased the activities to explore the deep sea. How to ensure the safety of deep-sea activities and improve the deep-sea emergency response capability is a new problem facing China’s deep-sea salvage. This paper comprehensively analyzes the cases and related technologies of deep-sea salvage at home and abroad, summarizes the technical system of deep-sea salvage, and prospects the future development of related fields.