A passive assembly for operating two cleaning chambers using a single filtration system having a flow diverter assembly is disclosed. The flow diverter assembly is actuated by a fuel assembly when a fuel assembly is inserted into the cleaning chamber. The flow diverter assembly acts so that each cleaning chamber is supplied with suction flow whenever there is a fuel assembly in the cleaning chamber. When a cleaning chamber is empty, the flow diverter acts to block the suction flow from the filtration system, forcing suction flow through the opposite cleaning chamber. The flow diverter only provides suction head to a cleaning chamber when there is a fuel assembly in the cleaning chamber. When both cleaning chambers are empty, suction pressure from the pump increases to the point that the flow diverters in both chambers open sufficiently to maintain flow through the pumps and prevent the pumps from cavitating.