A pump is fitted to the underside of a large floating platform which has four thrusters to propel it around. The platform is driven remotely from a control cabin to minimise the radiation dose to the workforce. The pump is fitted with a long ‘hoover hose’ and can be remotely raised or lowered to suck up the sludge and mix it with water, resulting in a slurry which can be pumped to the new sludge plant.