Fusion or thermonuclear power is a promising,literally endless source of energy.Development of fusion power is still in investigation and experimentation phases and the largest fusion experiment device,ITER(International Thermonuclear Experimental Reactor)is under construction in France.And the Tritium Plant system is a first-of-scale,complex and integrated system.In order to meet the requirement of nuclear safety,the tritium plant system should be low inventory,robust confinement and safety controls.The risk analysis was performed on the tritium system to meet the requirement of ITER operation.