There is a growing number of decommissioned nuclear facilities, and the trend of planned nuclear-decommissioning projects does not show any decline. To ensure safe and economical nuclear decommissioning, a robust risk assessment model capable of evaluating all the risk factors associated with a nuclear decommissioning project is critical. This study identifies and evaluates novel nuclear decommissioning project risk factors. A comprehensive literature search is done to identify all the relevant risk factors. Then, an expert judgement approach is used in evaluating the identified risk factors and developing novel risk factors. The expert judgement technique is implemented using a web-based questionnaire containing all 81 identified risk factors from the literature search as a prompt. The respondents are sixty recognized nuclear-decommissioning experts. Forty-eight responses were received, while 9 responses were discarded based on predefined criteria. Resulting from the unique experience of the experts in managing nuclear-decommissioning projects, twenty-four additional novel risk factors are proposed. Moreover, a scoring metric is used to evaluate the proposed novel risk factors. The result shows that the facility pre-decommissioning radiological characteristics are a major risk factor with a median score of 5, while 50 other risk factors (61.7%) have a median score of 4, and 30 risk factors (37%) has a median score of 3 or 3.5. Calculating the risk factors with the percentage scores between 4 and 5 in each risk family, it is observed that legal and regulatory framework (85.7%), stakeholders (83.3%), and initial condition of the facility (77.8%) are the highest-ranking risk family. The result serves as a pilot study that presents critical information towards the design and implementation of robust risk assessment models for nuclear decommissioning.

退役的核设施越来越多，计划中的核退役项目的趋势并未显示任何下降。为了确保安全和经济地进行核退役，建立能够评估与核退役项目相关的所有风险因素的强大风险评估模型至关重要。这项研究确定并评估了新型核退役项目的风险因素。进行了全面的文献搜索，以确定所有相关的风险因素。然后，专家判断方法用于评估已识别的风险因素并开发新的风险因素。专家判断技术是使用基于网络的调查表来实施的，该调查表包含从文献搜索中提示的所有81种已识别的危险因素。受访者是60名公认的核退役专家。根据预定义的标准，收到了48个响应，而9个响应被丢弃。基于专家们在管理核退役项目方面的独特经验，提出了二十四种新的新型危险因素。此外，使用评分标准来评估提出的新颖风险因素。结果表明，设施退役放射线特征是主要危险因素，中位数为5，而其他50个危险因素（61.7％）的中位数为4，而30个危险因素（37％）的中位数为4得分为3或3.5。通过计算每个风险家族中得分在4到5之间的百分比的风险因素，可以发现法律和法规框架（85.7％），利益相关者（83.3％），设施的初始状况（77.8％）是风险最高的家庭。该结果是一项试点研究，为设计和实施可靠的核退役风险评估模型提供了重要信息。