Abstract: A fuel assembly for a nuclear water reactor having an upstream end, a downstream end, and a flow interspace between the upstream and downstream ends. Fuel rods are provided in the flow interspace between the upstream and downstream ends. The flow interspace permits a flow of coolant through the fuel assembly along a flow direction from the upstream end to the downstream end. A filter device is provided to catch debris particles in the flow of coolant. The filter device has a first filter zone for a major part of the flow of coolant, and a second filter zone for a minor part of the flow of coolant. The first filter zone has a first filtering efficiency and the second filter zone has a second filtering efficiency. The second filtering efficiency is higher than the first filtering efficiency.

Abstract: A fuel assembly for a nuclear water reactor having an upstream end, a downstream end, and a flow interspace between the upstream and downstream ends. Fuel rods are provided in the flow interspace between the upstream and downstream ends. The flow interspace permits a flow of coolant through the fuel assembly along a flow direction from the upstream end to the downstream end. A filter device is provided to catch debris particles in the flow of coolant. The filter device has a first filter zone for a major part of the flow of coolant, and a second filter zone for a minor part of the flow of coolant. The first filter zone has a first filtering efficiency and the second filter zone has a second filtering efficiency. The second filtering efficiency is higher than the first filtering efficiency.

Abstract: A method for production of spacers to hold at least a number of elongated fuel rods (5) in a fuel unit (20) for placement in a re-actor (1) is described. The method comprises the steps of providing at least two spacers (30), to provide a set of mandrels (40) comprising a number of mandrels (42), to arrange at least two spacers (30) with one on top of the other on the set of mandrels (40), and to heat treat the spacers (30) when they are arranged on the set of mandrels (40) so that the cells (31) in the spacers (30) adapts to the mandrels (42).

Abstract: A method for production of spacers to hold at least a number of elongated fuel rods (5) in a fuel unit (20) for placement in a re-actor (1) is described. The method comprises the steps of providing at least two spacers (30), to provide a set of mandrels (40) comprising a number of mandrels (42), to arrange at least two spacers (30) with one on top of the other on the set of mandrels (40), and to heat treat the spacers (30) when they are arranged on the set of mandrels (40) so that the cells (31) in the spacers (30) adapts to the mandrels (42).

Abstract: The invention refers to a filter (1) for separating particle from cooling water in a nuclear plant, and a fuel assembly with such a filter. The filter has an inlet end (2) and an outlet end (3) and permits through-flow of the cooling water in a main flow direction (x). The filter includes a number of sheets (4) extending in the flow direction from the inlet end to the outlet end. The sheets are arranged beside each other and form passages for the cooling water. The sheets include a first portion (4?) extending from the inlet end (2), a second portion (4?) extending from the outlet end (3), and a third portion (4??) extending between the first portion (4?) and the second portion (4?). The sheets (4) have along the first portion continuous wave-shape extending in a direction (y) transversally to the flow direction (x) and along the third portion a continuous wave-shape extending in the flow direction (x).

Abstract: A fuel assembly (1) for a boiling water nuclear reactor comprising a plurality of vertical fuel rods (3) which are arranged in spaced relationship between a bottom tie plate (6) and a top tie plate (5). The bottom tie plate (6) is provided with through-holes (6a) for the passage of a coolant (F). Further, the fuel assembly (1) comprises a bottom support (10) which is formed substantially from a downstream and an upstream flat surface (12, 13) and four side surfaces (14). The flat surfaces (12, 13) and the side surfaces (14) form a parallelepiped which surrounds a cavity. A filtering member is arranged in the upstream flat surface (13) and comprises a plurality of through-holes (11).