STUDY OF RADIATION SHIELDING MATERIALS FOR NUCLEAR FUEL WASTE

• Main Author: Putro Amadeo, Matthew
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68558
• Institution: Institut Teknologi Bandung

Any activities related to radioactive materials will inevitably produce radioactive waste. The radioactive waste mentioned can be in the form of residual fuel, worker equipments, clothings, and so on which have been exposed to radiation. The radioactive waste can be categorized into three types, known as Low-Level Waste (LLW), Intermediate-Level Waste (ILW), and High-Level Waste (HLW). During processing, especially final storage, this waste must not be processed carelessly, especially the nuclear fuel which is included in the HLW. To avoid radioactive hazards, shielding must be used in the process to cover the source. This paper focused more on shielding for final storage facility. Initially, the performance of lead (Pb) in absorbing the radiations from the source will be studied, and then additional shielding in the form of concretes will be used to reduce radioactive hazards. As a start, a study was conducted on the performance of lead against radiation sources in the form of Cesium-137. Furthermore, an analysis was conducted regarding various kinds of concretes. In the calculation results, it is found that the thickness of the material greatly affects the intensity of the outgoing radiation. In addition, the density of the material also affects the intensity of the emitted radiation because density affects the attenuation coefficient of a material. After some calculations, to reach the safe limit based on Annual Limit Intake for Cs-137, it requires a lead plate with a thickness of 21,62 cm. Then, 5 cm thicnkess of lead plate was combined based on the assumption of limited amout of lead, so additional shielding was required in the form of normal concrete. The next process is a case where several types of nuclides produced from LWR-type reactor will be shielded after being discharched for 180 days and about to undergo final disposal process. Assuming the unavailability of lead plates as shielding, an analysis will be taken for three types of concrete, which are normal concrete, basalt-magnetite concrete, and steel-magnetite concrete, where these types of concrete have different compositions and density.