Radionuclides in primary coolant of a fluoride salt-cooled high-temperature reactor during normal op

• 作 者: Guo-Qing Zhang Shuai Wang Hai-Qing Zhang Xing-Wang Zhu Chao Peng Jun Cai Zhao-Zhong He Kun Chen
• 机 构: Shanghai Institute of Applied Physics, Chinese Academy of Sciences,University of Chinese Academy of
• 出 处: Nuclear Science and Techniques
• 发表日期: 2017年03期

The release of fission products from coated particle fuel to primary coolant, as well as the activation of coolant and impurities, were analysed for a fluoride saltcooled high-temperature reactor(FHR) system, and the activity of radionuclides accumulated in the coolant during normal operation was calculated. The release rate(release fraction per unit time) of fission products was calculated with STACY code, which is modelled mainly based on the Fick’s law, while the activation of coolant and impurities was calculated with SCALE code. The accumulation of radionuclides in the coolant has been calculated with a simplified model, which is generally a time integration considering the generation and decay of radionuclides. The results show that activation products are the dominant gamma source in the primary coolant system during normal operation of the FHR while fission products become the dominant source after shutdown. In operation condition,health-impacts related nuclides such as ~3H, and ~(14)C originate from the activation of lithium and coolant impurities including carbon, nitrogen, and oxygen. According to the calculated effective cross sections of neutron activation,~6Li and ~(14)N are the dominant ~3H production source and ~(14)C production source, respectively. Considering the high production rate,~3H and ~(14)C should be treated before being released to the environment.

The release of fission products from coated particle fuel to primary coolant, as well as the activation of coolant and impurities, were analysed for a fluoride saltcooled high-temperature reactor (FHR) system, and the activity of radionuclides accumulated in the coolant during normal operation was calculated. The release rate (release fraction per unit time) of fission products was calculated with STACY code, which is modelled primarily based on the Fick’s law, while the activation of coolant and impurities was calculated with SCALE code. The accumulation of radionuclides in the results show that activation products are the dominant gamma source in the primary coolant system during normal operation of the FHR while fission products become the dominant source after shutdown. In operation condition, health-impact related nuclides such as ~ 3H, an According to the calculated effective cross sections of neutron activation, ~ 6Li and ~ (14) N are the dominant ~ 3H production source and ~ (14) C production source, respectively. Considering the high production rate, ~ 3H and ~ (14) C should be treated before being released to the environment.