Fusion reactors are expected to be more safe and environmentally friendly in the development of nuclear energy systems. It is vital to fully understand the overall radiation risk level of fusion reactors in comparison with existing nuclear energy systems. The objective of this paper is to propose a risk assessment methodology for fusion reactor accidents, which is capable of quantifying the risk level comparable to other advanced nuclear energy systems. In this paper, fusion specific accident characteristics are comprehensively analyzed in comparison with ITER and fission reactors. The postulated initiating events as well as possible environmental release routes are also presented for DEMO, and then deterministic risk assessment is applied to design basis accidents, while the coupling of deterministic risk assessment and probabilistic risk assessment is suggested for design extension conditions. The societal risk of DEMO is proposed to be presented by a Complementary Cumulative Distribution Function (CCDF) risk curve.

在核能系统的发展中，聚变反应堆有望更加安全和环境友好。与现有核能系统相比，充分了解聚变反应堆的总体辐射风险水平至关重要。本文的目的是为聚变反应堆事故提出一种风险评估方法，该方法能够量化与其他先进核能系统相当的风险水平。与国际热核实验堆和裂变反应堆相比，本文对聚变特定事故特征进行了综合分析。还为DEMO提供了假定的启动事件以及可能的环境释放途径，然后将确定性风险评估应用于设计基准事故，对于设计扩展条件，建议将确定性风险评估和概率风险评估结合起来。提议通过补充累积分布函数（CCDF）风险曲线表示DEMO的社会风险。