FUEL ASSEMBLY FOR A LIGHT-WATER NUCLEAR REACTOR(EMBODIMENTS), LIGHT-WATER NUCLEAR REACTOR AND FUEL ELEMENT OF THE FUEL ASSEMBLY

摘要

The invention falls into the category of light-water reactor's designs, in which thorium is used as the fuel, especially the designs of 17×17 jacketless fuel assembly, from which the cores of water-cooled, water-moderated power reactors are formed, such as reactors of the PWR type (for example, the AP-1000, the EPR, etc.). The light-water reactor fuel assembly has a square shape in the plan view and contains a seed region, a blanket region that encircles it, a upper nozzle, a lower nozzle of seed region, and a lower nozzle of blanket region. The fuel elements' bundle of seed region is arranged in the rows and columns of a square coordinate grid and has a four-lobed profile that forms spiral spacer ribs along the length of a fuel element. The blanket region contains a frame structure within which a bundle of fuel elements made from thorium with the addition of enriched uranium is positioned. The blanket region fuel elements are arranged in the two rows and columns of a square coordinate grid. In the other embodiment of the invention, the light-water reactor fuel assembly has a similar design; here, the blanket region fuel elements are arranged in the three rows and columns of a square coordinate grid. The invention also falls into the category of the fuel elements employed in fuel assemblies and light-water reactors of the PWR type (for example, the AP-1000, EPR, etc.) that use fuel assemblies.