Study on Nuclear Material Balance Method of High-temperature Gas-cooled Reactor

High-temperature gas-cooled reactor (HTR) adopts spherical coated particle fuel components and non-stop refueling operation mode. Therefore, the operation mode, the form of fuel element and the refueling method are quite different from those of PWR nuclear power plants. The characteristics of HTR determine that the nuclear material is regulated differently from traditional PWR and bulk nuclear facilities. It is not easy to use the piece material management mode and the bulk material management. In this paper, a suitable method for HTR nuclear material balance and material unaccounted for (MUF) evaluation was proposed for HTR nuclear material management. According to the characteristics of HTR fuel components, operation mode and refueling mode, considering the two modes of piece material management and bulk material management, studying on the rational division of the balance area of HTR nuclear material, the setting of key measurement points and the selection of physical inventory methods, the model of piece material+bulk material is selected for nuclear material accounting management and evaluation, which provides technical basis for HTR nuclear material supervision. At present, this method is applied to the nuclear material management of HTR in China, and the expected results are achieved.