This book introduces readers to basic approaches in and principles of marine nuclear power design, including overall reactor design, in-core design, coolant systems and devices, I&C system design, safety system design, and dynamic analysis assessment. It comprehensively reviews both the fundamentals of and latest trends in nuclear-powered devices, covering their entire lifespan, from design and testing to operation and decommissioning. Further, it explores in detail various real-world conditions in the marine context - such as insufficient space for equipment deployment and frequently changing operating conditions as well as swinging and tilting. Offering extensive information on the design and operation of marine nuclear power systems, the book is a valuable resource for researchers and professionals in the area of marine science and nuclear engineering, and graduate students intending to embark on a career in the field.