Optimisation and larger scale testing of the proposed resin system for the TF coils for ITER

The ITER TF Coils Winding Pack (WP) will be inserted into the TF Coil structural casing to provide mechanical location and support. The design of the coil case includes clearance gaps (∼7–10 mm) to allow for manufacturing tolerances and WP adjustment. The last stage of assembly will be to fill the gaps to complete the geometric location of the WP and provide for a uniform force transfer between the WP and Casing. Properties and specification of the filler material are driven by these requirements, the latter being the most demanding. l selection of the resin system was based on chemical structures to predict radiation stability, with measured low viscosity and adequate working life. This paper includes further optimization of the filler content to improve the mechanical and thermal properties of the system. Larger scale laboratory flow trials have been carried out in vertical tubular and horizontal planar flow configurations to establish flow characteristics in the TF Coil filling operation. This was supplemented by CFD modelling of the filling operation. Filler settling trials are reported, including a 9 m vertical test to determine the uniformity of the resin column. Thermal strain characteristics of the resin system have been explored, together with compression tests at 77 K. Mechanical compressive strength tests on reactor-irradiated samples are reported.