Lee UkJae, Choi Woo Nyun, Kim Hee Reyoung
Department of Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan 44919, Republic of Korea.
J Radiol Prot. 2019 Jun;39(2):422-442. doi: 10.1088/1361-6498/ab039d. Epub 2019 Jan 31.
In heavy water reactors, radionuclides are generated, then removed and treated by ion exchange resin. The disposal cost of spent resin is expected to increase because of the saturation of the existing storage capacity. In this study, a spent resin treatment process using microwaves is proposed, and a radiological safety assessment and cost evaluation of the spent resin treatment process are performed. A dose assessment was conducted by using the established exposure scenarios and the RESRAD-Build software. A sensitivity analysis was conducted to identify the main contributory radionuclide of the dose according to each exposure pathway because a spent resin consists of various radionuclides. The main exposure pathway was identified, and sensitivity analysis was applied to the working time and radioactivity concentrations of C, Co and Cs to confirm their effect on the dose. Finally, an optimal shielding system for a safe work environment was proposed. The disposal cost of the spent resin is reduced by lowering its radioactivity level via a treatment process using microwaves. The treatment process can reduce the radioactivity level through the desorption of C and can also recycle the C nuclide. These characteristics have great economic advantages from the viewpoint of the entire nuclear energy cycle. Thus, this study evaluates the radiological safety of the spent resin treatment process for actual application in a heavy water reactor power plant.
在重水反应堆中，会产生放射性核素，然后通过离子交换树脂将其去除并处理。由于现有储存容量饱和，预计废树脂的处置成本将会增加。在本研究中，提出了一种使用微波的废树脂处理工艺，并对该废树脂处理工艺进行了辐射安全评估和成本评估。利用既定的照射情景和RESRAD-Build软件进行了剂量评估。由于废树脂由各种放射性核素组成，因此进行了敏感性分析，以确定根据每种照射途径对剂量起主要作用的放射性核素。确定了主要照射途径，并对工作时间以及碳、钴和铯的放射性浓度进行了敏感性分析，以确认它们对剂量的影响。最后，提出了一种用于安全工作环境的最佳屏蔽系统。通过使用微波的处理工艺降低废树脂的放射性水平，从而降低了废树脂的处置成本。该处理工艺可以通过碳的解吸降低放射性水平，还可以回收碳核素。从整个核能循环的角度来看，这些特性具有很大的经济优势。因此，本研究评估了废树脂处理工艺在重水反应堆核电站实际应用中的辐射安全性。
