Fuel Bundle Impact Velocities due to Reverse Flow

Abstract

If a break should occur in the inlet feeder or inlet header of a CANDU reactor, the rapid depressurizarion will cause the channel flow(s) to reverse. Depending on the gap between the upstream bundle and shield plug. the string of bundles will accelerate in the reverse direction and impact with the upstream shield plug. The reverse flow impact velocities have been calculated for various operating states for the Bruce NGS A reactors. The sensitivity to several analysis assumptions has been determined.