Fuel rod support insert for a nuclear fuel assembly spacer grid, spacer grid and nuclear fuel assembly

A spacer grid for a nuclear fuel assembly, the spacer grid comprising:

• interlaced straps defining a lattice of cells for receiving fuel rods;
• and
• support inserts provided at intersections of the straps for supporting the fuel rods which extend through the cells, the support inserts each comprising:
• a first end portion and a second end portion, the first end portion and the second end portion configured for abutting the straps, the fuel rod support insert extending axially along an insert axis between first end portion and the second end portion, the fuel rod support insert being configured such that the insert axis is positioned parallel to a center axis of at least one of the cells when the fuel rod support insert is connected to the straps;
• and
• at least one spring extending axially with respect to the insert axis between the first and second end portions, the at least one spring being defined in part by at least one slot extending axially with respect to the insert axis, the at least one spring being configured for transversely abutting a fuel rod when the fuel rod support insert is connected to the straps, the fuel rod support insert being configured for extending in at least one of the cells when the fuel rod support insert is connected to the straps, the spring extending axially through planes perpendicular to the insert axis and radially away from the first end portion and the second end portion to define an apex configured for contacting the fuel rod when the fuel rod is inserted into one of the cells, the spring having a non-rectilinear cross-section in each of the planes perpendicular to the insert axis,
• wherein the spring comprises a contact wing and a lateral wing adjacent to each other and extending side-by-side along the insert axis, the contact wing and the lateral wing each including an inner surface facing the straps and an outer surface facing away from the straps, the outer surfaces of the contact wing and the lateral wing being inclined relative to each other, the contact wing being configured for contacting the fuel rod and the lateral wing extending laterally from the contact wing towards one of the straps.

A nuclear fuel assembly comprising:

• a bundle of fuel rods;
• and
• an armature for supporting the fuel rods, the armature comprising at least one spacer grid for a nuclear fuel assembly, the spacer grid comprising:
• interlaced straps defining a lattice of cells for receiving fuel rods;
• and
• support inserts provided at intersections of the straps for supporting the fuel rods which extend through the cells, the support inserts each comprising:
• a first end portion and a second end portion, the first end portion and the second end portion configured for abutting the straps, the fuel rod support insert extending axially along an insert axis between first end portion and the second end portion, the fuel rod support insert being configured such that the insert axis is positioned parallel to a center axis of at least one of the cells when the fuel rod support insert is connected to the straps;
• and
• at least one spring extending axially with respect to the insert axis between the first and second end portions, the at least one spring being defined in part by at least one slot extending axially with respect to the insert axis, the at least one spring being configured for transversely abutting a fuel rod when the fuel rod support insert is connected to the straps, the fuel rod support insert being configured for extending in at least one of the cells when the fuel rod support insert is connected to the straps, the spring extending axially through planes perpendicular to the insert axis and radially away from the first end portion and the second end portion to define an apex configured for contacting the fuel rod when the fuel rod is inserted into one of the cells, the spring having a non-rectilinear cross-section in each of the planes perpendicular to the insert axis,
• wherein the spring comprises a contact wing and a lateral wing adjacent to each other and extending side-by-side along the insert axis, the contact wing and the lateral wing each including an inner surface facing the straps and an outer surface facing away from the straps, the outer surfaces of the contact wing and the lateral wing being inclined relative to each other, the contact wing being configured for contacting the fuel rod and the lateral wing extending laterally from the contact wing towards one of the straps.