사고 대응 작업자 피폭선량 평가

Abstract

To effectively and safely manage the radiation exposure to nuclear power plant (NPP)workers in accidents, major overseas NPP operators such as the United States, Germany, and Francehave developed and applied realistic 3D model radiation dose assessment software for workers. Continuous research and development have recently been conducted, such as performing NPP accidentmanagement using 3D-VR based on As Low As Reasonably Achievable (ALARA) planning tool. In linewith this global trend, it is also required to secure technology to manage radiation exposure of workersin Korea efficiently. Therefore, in this paper, it is described the application method and assessmentresults of radiation exposure scenarios for workers in response to accidents assessment technology,which is one of the fundamental technologies for constructing a realistic platform to be utilized forradiation exposure prediction, diagnosis, management, and training simulations following accidents. First, the post-accident sampling after the Loss of Coolant Accident (LOCA) was selected as the accidentand response scenario, and the assessment area related to this work was established. Subsequently,the structures within the assessment area were modeled using MCNP, and the radiation source of theequipment was inputted. Based on this, the radiation dose distribution in the assessment area wasassessed. Afterward, considering the three principles of external radiation protection (time, distance,and shielding) detailed work scenarios were developed by varying the number of workers, the presenceor absence of a shield, and the location of the shield. The radiation exposure doses received by workerswere compared and analyzed for each scenario, and based on the results, the optimal accident responsescenario was derived. The results of this study plan to be utilized as a fundamental technology to ensurethe safety of workers through simulations targeting various reactor types and accident responsescenarios in the future. Furthermore, it is expected to secure the possibility of developing a data-basedALARA decision support system for predicting radiation exposure dose at NPP sites.