Patent Number: 061756067
Section: claims

1. A fuel assembly for a boiling water nuclear reactor comprising a plurality of vertical fuel rods which are arranged, in spaced relationship, between a bottom tie plate and a top tie plate, wherein the bottom tie plate is provided with through-holes for passage of coolant (F), and a bottom support, wherein the bottom tie plate is arranged at least partly immersed into the bottom support, and wherein the bottom support is substantially formed by a downstream and an upstream flat surface and four side surfaces where the flat surfaces and the side surfaces form a parallelepiped which surrounds a cavity, wherein a filtering member is arranged as an integral part of the upstream flat surface and wherein the filtering member comprises a plurality of through-holes. 2. A fuel assembly according to claim 1, wherein the upstream flat surface comprises a plurality of substantially straight grooves. 3. A fuel assembly according to claim 1, wherein the through-holes are substantially straight. 4. A fuel assembly according to claim 1, wherein the upstream flat surface comprises bypass holes arranged at the respective corners. 5. A fuel assembly according to claim 4, wherein the bottom support in the cavity comprises a flange arranged above the respective bypass hole for the purpose of guiding the coolant which has passed through the bypass hole. 6. A fuel assembly (1) according to claim 4, characterized in that the bottom support (10) in the cavity comprises a second filtering member (19) comprising a plurality of continuous openings (21).