CATE: A code for activated corrosion products evaluation of water-cooled fusion reactor

Abstract

Activated corrosion products (ACPs) are the dominant source of radiation hazard in water-cooled fusion reactor, and determine the occupational radiation exposure during maintenance. In this paper, a code named CATE (Corrosion, Activation, and Transport Evaluation) was developed to simulate the production and transport process of ACPs in the cooling loops of fusion reactor, especially for CFETR of China in the future. In the first version of CATE, a two-phase homogeneous model was built up, and the main behavior of ACPs, including corrosion, release, dissolution, deposition, purification, activation and decay, were covered in this model. The classical method of Runge–Kutta was adopted to solve the model numerically. Moreover, for getting high calculation efficiency, a special treatment on the short-life nuclides and the adaptive time step algorithm were implemented in CATE. Then the divertor cooling loop and LIM–OBB cooling loop of ITER were adopted for code test. After providing the input parameters, involving material, water chemistry, thermal hydraulics and neutronics, CATE gave the composition and activity of ACPs respectively in coolant and on pipe wall. These results were compared with those of two other codes PACTITER and TRACT, and presented a good consistency of the total ACPs activity with PACTITER (about 30% difference between CATE and PACTITER). The two-phase homogeneous model in CATE is efficient for analyzing the mean ACPs characteristic of the loop, but cannot simulate the space distribution of ACPs, which is also important, so a multi-node model is under developing to improve the analysis ability of CATE.