Analysis of Corrosion Products Behavior in Reactor Coolant Circuit of SMART-P

摘要

SMART-P is a soluble boron free reactor, and the ammonia is used as a pH-reagent.The titanium alloy, which has a high corrosion resistance, is chosen as a steam generator tube material. Despite these design features to achieve the corrosion reduction, it is expected that SMART-P exhibits a relatively high specific activity in the coolant due to the lack of purification during the power operation. The main reason for the high specific activity is the activation and transportation of the corrosion products that released from the primary circuit surfaces. Over the last few decades, many studies have been carried out to understand the behavior of the primary circuit corrosion products of PWR. The most effective way to reduce the radiation exposure to the operational and maintenance personnel is to reduce the source of radiation, which is mainly from the activated corrosion products in operating nuclear power plants. The analysis of corrosion product activity in the primary circuit of SMART-P is performed by an engineering computational tool, KORA. Specific activities of separate radionuclides in the primary coolant as well as on the surfaces of equipments that are washed by the coolant throughout one fuel cycle are analyzed under the ammonia water chemistry. As a result, SMART-P shows very low specific activities of corrosion products. It can be concluded that this low activities are achieved by the introduction of the titanium alloy to the SG tube material and the avoidance of boric acid, which induces high corrosion.