Operation of a FluorinertTM cooling system for the toroidal field coils on TFTR

An alternate cooling fluid (Fluorinert^TM) was introduced during the D-T experimental runs for cooling the toroidal field (TF) coils on TFTR. This paper addresses how this system performed during the D-T operational period and the special techniques that the alternate cooling system requires for operations and maintenance. Radiation from neutron activation of Fluorinert^TM (fluorine 18 etc) and associated personnel safety issues and safeguards are discussed. Flow reversal in the TF Coils has proven to be a valuable mechanism by which any loose particulates can be cleared from the coolant passages and the development of this operational tool is addressed. Specific draining procedures for the TF Coils have been developed during the D-T run in order to minimize losses of fluid. The toroidal field coil operational characteristics with Fluorinert^TM are compared to those previously observed with water cooling