몬테칼로 방법을 이용한 초소형 이동형 원자로용기의 방사화에 의한 수송 시 운전원 선량 평가

Abstract

Transportable micro reactors, one of the latest reactor concepts under development, offer a flexibleoption by allowing deployment and operation in areas with immediate power demand. Reactors are usually run atfull capacity before being moved, but recent researches investigate the idea of adjusting power output as necessaryand then moving the reactor system to a different place for later operation. For this concept, it is essential toevaluate the radiation dose received by both the operator during reactor operation and the transport operator duringreactor relocation. This study conducted a radiological impact assessment using the Monte Carlo simulation codesOpenMC and MCNP. Activation analysis was performed on the reactor vessel using OpenMC, and gamma raydose assessments at the operator's location were carried out using the generated data as a source term in MCNP. Calculations revealed that the operator’s dose rate is 4.14 mSv/hr, whereas the transport operator’s dose rate is 0.129mSv h-1. Although both values fall within the annual dose limit, they may not be suitable for prolonged exposure. For the transport operator, adding an extra tungsten shielding wall between the container and the operator lowered thedose rate to 0.02 mSv/hr. Thus, installing additional shielding should be considered to mitigate exposure during longtermtransport operations.