FLOW BALANCING IN LIQUID-METAL BLANKETS

Non-uniform flow distribution between parallel channels is one of the most serious concerns for self-cooled liquid metal blankets with elect rically insulated walls. We show that uncertainties in flow distributi on can be dramatically reduced by relatively simple design modificatio ns. Several design features which impose flow uniformity by electrical ly coupling parallel channels are surveyed. Basic mechanisms for ''flo w balancing'' are described, and a particular self-regulating concept using discrete passive electrodes is proposed for the US ITER advanced blanket concept. Scoping calculations suggest that this simple techni que can be very powerful in equalizing the flow, even with massive ins ulator failures in individual channels. More detailed analyses and exp erimental verification will be required to demonstrate this concept fo r ITER.