The removal and disposal of spent fuel rods from a nuclear reactor is an extremely precise and controlled process. Used fuel rods are placed at the bottom of a spent fuel pond to begin a process of cooling that will last for years. The highly specialised overhead gantry crane used to transport and position the fuel rods must offer complete reliability. For a recently commissioned crane in the Czech Republic, the OEM chose to specify the NFF series of compact electromagnetic brakes from Stromag. Every 12 to 24 months, up to one third of the total fuel load of a nuclear reactor is removed from the core. The spent fuel rods, fresh from the core, will be generating immense amounts of heat and radiation that must be controlled and contained locally, prior to being moved into dry casks for final disposal. The spent fuel pond is typically at least 12m deep, with temperatures carefully managed to remain below 50°C. The pools contain boric acid for its neutron-absorbing capability, which reduces the ionising radiation emanating from the rods and helps to ensure subcriticality.
Engineer Live 1st June 2020 read more »