The pilot Probabilistic Safety Assessment (PSA) of Thai Research Reactor-1/Modification 1 (TRR-1/M1) was implemented to fulfill the new Thai Ministrial Regulation on Periodic Safety Review (PSR). The paper's objective is to conduct the level 1 PSA of TRR-1/M1 for internal events and human errors. Considering the graded approach, Hazard and Operability (HAZOP) and Human-Hazard and Operability (Human-HAZOP) analyses which require moderate details were selected to assess hazardous events and eventually determine Initiating Events (IEs). Fault Tree Analysis (FTA), Event Tree Analysis (ETA), and Bayesian updating were used to calculate Core Damage Frequencies (CDFs). The assessment showed that HAZOP analysis is suitable for an uncomplicated research reactor like TRR-1/M1 since it does not require lengthy calculation time and detailed failure data. Human-HAZOP analysis revealed inherent-operational errors that were ignored in TRR-1/M1, especially the situation that valves V-3 and V-4 were kept open in order to quicken reactor startup operation. IE1: Loss of Coolant Accident (LOCA), IE2: Insertion of excess reactivity, and IE3: Failure of equipment in fuel handling process were identified as the main IEs. The largest CDF of IE3 (4.36E-02 1/yr) implies that it is the main risk issue of TRR-1/M1 to which operators should pay more attention during the operation.

泰国研究堆 1/修改 1 (TRR-1/M1) 的试点概率安全评估 (PSA) 的实施是为了满足新的泰国部委定期安全审查条例 (PSR)。该论文的目标是针对内部事件和人为错误执行 TRR-1/M1 的 1 级 PSA。考虑到分级方法，选择需要适度细节的危害和可操作性 (HAZOP) 和人体危害和可操作性 (Human-HAZOP) 分析来评估危害事件并最终确定始发事件 (IE)。使用故障树分析 (FTA)、事件树分析 (ETA) 和贝叶斯更新来计算核心损坏频率 (CDF)。评估表明，HAZOP 分析适用于像 TRR-1/M1 这样简单的研究堆，因为它不需要冗长的计算时间和详细的故障数据。Human-HAZOP 分析揭示了 TRR-1/M1 中被忽略的固有操作错误，特别是阀门 V-3 和 V-4 保持打开以加快反应堆启动操作的情况。IE1：冷却剂损失事故 (LOCA)、IE2：插入过量反应性和 IE3：燃料处理过程中的设备故障被确定为主要 IE。IE3最大的CDF（4.36E-02 1/yr）意味着运营商在运营过程中应该更加关注TRR-1/M1的主要风险问题。燃料处理过程中的设备故障被确定为主要 IE。IE3最大的CDF（4.36E-02 1/yr）意味着运营商在运营过程中应该更加关注TRR-1/M1的主要风险问题。燃料处理过程中的设备故障被确定为主要 IE。IE3最大的CDF（4.36E-02 1/yr）意味着运营商在运营过程中应该更加关注TRR-1/M1的主要风险问题。