Shin Kori unit 3 of Korea Hydro and Nuclear Power Co. is the pressurized water reactor of advanced power reactor 1400 (APR1400) in the Republic of Korea. A hypothetical accident was assumed for Shin Kori unit 3 to perform the time-dependent dose calculations along with the release rates of radionuclides to the environment. In order to assess the accident scenarios, Radiological Assessment System for Consequence Analysis code was used, which is a set of tools for emergency response applications developed by US Nuclear Regulatory Commission. A straight-line Gaussian model was used for the near-field atmospheric calculations and a Lagrangian Gaussian puff model was used for the far-field simulations where released radioactive materials to the environment were transported, dispersed and deposited. In this study, long-term station blackout in spring, summer, autumn and winter season was considered in 2016–2018 based on reactor condition and seasonal effects. It was found that the worst season is the spring and the worst scenario found during the evening time of spring in 2017. The calculated maximum values of total effective dose equivalent (TEDE) and thyroid committed dose equivalent (CDE) are 22 mSv and 390 mSv, respectively, around 5 km of precautionary action zone (PAZ) in 2 days after the accident. According to Korean regulations on urgent public protective actions, for indoor sheltering, the criteria are 10 mSv in 2 days. For public evacuation 50 mSv in 1 week and iodine prophylaxis should be introduced if thyroid protection level is 100 mSv. Calculated values of TEDE are more than double and thyroid CDE is almost four times in the PAZ compared with Korean regulations; hence, it was found that indoor sheltering and supply of iodine prophylaxis should be executed for short/mid-term protective measures. In this situation, indoor sheltering should be decided by off-site emergency management center, which was accountable for emergency decision-making process in nuclear accident under nuclear safety and security commission in Korea.

中文翻译：

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4月严重核事故中的场外放射剂量评估。

韩国水电和核电公司的新光里3号机组是大韩民国先进功率反应堆1400（APR1400）的压水堆。假设Shin Kori单元3发生了一次假设事故，以进行随时间变化的剂量计算以及放射性核素向环境的释放速率。为了评估事故情况，使用了后果分析放射学评估系统代码，这是美国核监管委员会开发的一套用于应急应用的工具。直线高斯模型用于近场大气计算，拉格朗日高斯吹气模型用于远场模拟，在该模拟中，释放到环境中的放射性物质被运输，分散和沉积。在这项研究中，春季长期停电，根据反应堆条件和季节影响，在2016–2018年考虑了夏季，秋季和冬季。发现最坏的季节是春季，2017年的春季傍晚是最坏的情况。计算的总有效剂量当量（TEDE）和甲状腺定剂量当量（CDE）的最大值为22 mSv和390 mSv事故发生2天后，分别在约5 km的预防行动区（PAZ）上。根据韩国关于紧急公共防护措施的规定，对于室内庇护，标准为2天10 mSv。对于公共疏散，一周内50 mSv，如果甲状腺保护水平为100 mSv，则应采取碘预防措施。与韩国法规相比，在PAZ中TEDE的计算值是其两倍多，甲状腺CDE几乎是其四倍。因此，发现应采取室内庇护和碘预防措施，以采取短期/中期保护措施。在这种情况下，室内避难所应由现场应急管理中心决定，该中心由韩国核安全与安保委员会负责核事故的应急决策过程。