ITER is a joint international fusion facility to demonstrate the scientific and technological feasibility of fusion power for future commercial electric power facilities. ITER is designed to reject all the heat generated in the plasma and transmitted to the in-vessel components through the Tokamak Cooling Water System (TCWS) to the intermediate closed loop Component Cooling Water System (CCWS) and then to the environment via the open Heat Rejection System (HRS) and Cooling Towers. At the present the main in-vessel components as First Wall-Blanket (FW-BLK) and the Divertor (DIV) are cooled via four separated Primary Heat Transfer Systems (PHTSs). This paper describes the proposal to integrate the PHTS for the FW-BLK and DIV in a common loop to improve the availability and reliability of the cooling system. Furthermore, the paper presents the new thermal hydraulic design parameters, the relevant Process Flow Diagram (PFD) and a study for the new arrangements of the piping in the TCWS vault. Some associated issues for safety accidental scenarios are planned to be solved before the final acceptance of the proposal in the baseline design.