The American company X-energy has developed a new type of nuclear fuel with built-in protection from one of the most dangerous phenomena during NPP operation – meltdown of a nuclear reactor. Officially, the new product is called TRISO-X FUEL, but the developers called them “balls uranium” or “uranium candy” because of the characteristic shape. Most of this fuel is reminiscent of the many candy-dragee in the glaze.
The idea was to surround a nuclear source of energy released in the form of heat, so heat-resistant sheath, so it is not destroyed in critical situations. The ideal material is ceramic, which retains enormous amounts of heat and can give it out, but does not deform even after prolonged heating. And in order to reduce dangerous radiation, between the core and the shell adds a layer of graphite. The fuel element is made in the form of a sphere, which further enhances the similarity of candy.
For the production of such fuel, the uranium is mixed with a chemical reagent, which divides the whole mass into a multitude of tiny balls with a diameter of about 1 mm. Balls are fed into the furnace with the gaseous graphite, which is deposited on the uranium, forming the first protective layer. Further, thousands of beads were Packed in separate granules and sealed in a shell of ceramic.
Such fuel is considered as the main raw material for low-power mobile nuclear reactors of the future. In modern stationary nuclear power plants, the lion’s share of all equipment refers to the systems of security and protection. If we can reduce risks, eliminate a number of dangers, it will open the way to minimize the construction of nuclear power plants and the emergence of a new generation of powerful and efficient reactors.
Source — Wired