Thermal-hydraulic analysis of the ITER CCWS-1 cooling loop

•Component Cooling Water System 1 serves primary and auxiliary cooling systems.•Fathom model is updated according to the last configuration and layout.•Thermal-hydraulic analyses are conducted to verify clients interface requirements.•Process design updates are proposed to ensure the proper system operation. ITER is designed to produce heat power from the deuterium-tritium fusion reaction burning the confined plasma inside the vacuum vessel. The effective removal of the power generated from fusion reactions and auxiliary systems (e.g. plasma heating systems, cryogenic systems, coils, etc.) represents a key point for the success of ITER. CCWS-1 is a pressurized cooling loop with the main function to guarantee cooling water to TCWS and other served auxiliary systems (e.g. vacuum pumps) maintaining temperature, pressure, flow rates and water chemistry within prescribed values. To support the CCWS-1 design and verify the requirements at the clients’ interface during the different operational modes of the machine, a thermal-hydraulic campaign has been carried out. The work has been conducted using the commercially available thermal-hydraulic software AFT Fathom, performing steady-state and heat transfer analyses of complex systems. The present paper summarizes the computational models, and the hypotheses and critically discusses the obtained outcomes.