Calculation and analysis of activation products source term in water-cooled fusion reactor primary circuit

Abstract Background: Activated corrosion products (ACPs) from structure materials and coolant activation products are the dominant radiation hazard in water-cooled fusion reactor under normal operation conditions, and directly determine the occupational radiation exposure (ORE) during operation and maintenance. Purpose: The aim is to quantitatively analysis source term of activation products in International Thermonuclear Experimental Reactor (ITER). Methods: CATE V2.1 is used to simulate the ACPs from structure materials and coolant activation products in the ITER blanket circuit, and then the dose rate of the LIM-OBB (Limiter-Out-Bboard Baffle) cooling loop operating for 1.2 a, and 15 d after shutdown is calculated by point kernel code ARShield. Results & Conclusion: Under operation conditions, the specific activity and dose rate of the coolant activation products are much higher than those of ACPs from structure material, while after shutdown, the coolant activation products decay out rapidly, and the ACPs from structure material become the main contributor to specific activity and dose rate. (authors)