중저준위 폐기물 처분용기의 차폐 성능 분석 및 설계 최적화

Abstract

The increasing number of disused sealed radioactive sources (DSRSs) in Korea necessitates thedevelopment of effective disposal methods. This study aims to enhance the safety and efficiency of DSRS disposalthrough improved design of disposal containers. This study focuses on enhancing the safety and efficiency of DSRSdisposal by analyzing the impact of external coating materials, inner container thickness variations, and innercontainer size changes on radiation shielding performance and loading capacity. Using 200 L and 320 L steel drums,radiation shielding was assessed through MicroShield with various coatings, including tungsten carbide (WC) andboron carbide (BC). The analysis explored inner container thicknesses (0 to 4 mm). Results indicate that WC coatingprovides superior shielding due to its high density and larger atomic number. Also, an inner container thickness of3 mm offers the best balance between cost and shielding performance. The study shows that increasing the innercontainer size in both drum types decreases the volume-based loading capacity. This reduction occurs because largercontainers result in thinner shielding material and increased self-shielding effects. However, when considering theweight of the shielding material, larger inner containers may reduce total shielding weight, which can positively affectloading capacity if the weight reduction outweighs the decrease in shielding efficiency. Thus, both the size and totalweight of the shielding material must be considered when determining inner container dimensions. In conclusion,when designing disposal containers and determining inner container sizes, it is essential to balance shieldingefficiency with loading capacity. The study emphasizes optimal design based on radiation exposure and shieldingweight, providing a conceptual design that meets current standards and enhances the management of DSRSs duringlong-term storage.