Activation analysis of coolant in a water-cooled loop of China fusion engineering test reactor

作者：Guo, Qingyang; Zhang, Jingyu^*; Fang, Sheng; Chen, Yixue

来源：Fusion Engineering and Design, 2018, 136: 694-698.

DOI：10.1016/j.fusengdes.2018.03.059

• Activation analysis
• Coolant
• Water-cooled loop
• CFETR
• Dose rate

In the design scheme of China Fusion Engineering Test Reactor (CFETR), water will be adopted as the coolant in some cooling loops. The water itself and the impurities in it will be activated by neutrons, and the activation products N-16, N-17, H-3 and C-14 are important to the occupational radiation exposure (ORE) during operation and maintenance. In this paper, two analysis models (homogeneous model and two-node model) are developed to calculate the radioactivity of activation products in the water-cooled loop. Then, the impact of water chemistry parameters (pH and Li-7 abundance) on tritium production is analyzed. At last, the dose rate of one typical blanket water-cooled loop is calculated using the point kernel code ARShield. The results show that: (1) the radioactivity of short-lived nuclides N-16 and N-17 is obviously affected by coolant flow and the results from the two-node model considering coolant flow are more conservative; (2) the radioactivity of long-lived nuclides H-3 and C-14 is obviously affected by purification; (3) N-16 and N-17 are the main contributors to radioactivity, whose radioactivity are several orders of magnitude higher than that of H-3 and C-14; (4) tritium is susceptible to water chemistry environment, and at pH of 7.1 tritium radioactivity is about two orders of magnitude higher than that at pH of 5.7; (5) at pH of 7.1, the contribution of lithium to tritium production increases linearly with increase of Li-7 abundance in LiOH in the water.

• 出版日期2018-11
• 单位华北电力大学（保定）; 清华大学; 华北电力大学