Lips-type multi-purposed nuclear fuel assembly spacer grid

A multi-purposed spacer grid fabricated by a plurality of two types of inner strips intersecting each other to form a plurality of unit cells, and used for supporting a plurality of fuel rods in a nuclear fuel assembly such that one fuel rod is supported within one unit cell, each of said two types of inner strips being fabricated by integrating a plurality of unit-strip parts into a linear strip, and having a plurality of notches at junctions of the unit strip parts such that each notch vertically extends downward or upward, wherein each of said unit strip parts comprises:

• a frame used as a support frame of the unit strip part, said frame comprising:
• two support columns vertically disposed in parallel while being spaced apart from each other at a predetermined interval;
• and
• two support beams horizontally extending between the two support columns at upper and lower positions to connect the two support columns to each other and define a middle opening between the support beams and the support columns;
• at least one spring provided in the middle opening of the frame while being projected in a direction from a vertical surface formed by the frame, said spring comprising:
• a curved part axially formed along the spring and having a predetermined width while being curved within a direction of the width;
• two side extensions extending outward in opposite directions from both sides of the curved part to a predetermined width while being bent at a predetermined angle;
• and
• four spring legs diagonally extending from upper and lower corners of the two side extensions, said four spring legs being connected to inside edges of the frame at four corners of the middle opening of the frame and being bent in a direction opposed to the bent direction of the two side extensions;
• and
• upper and lower dimples provided at positions above and under the spring while being projected from the vertical surface formed by the frame in a direction opposed to the projecting direction of the spring, said upper dimple being curved along a lower edge thereof to form an arc-shaped lower edge, and the lower dimple being curved along an upper edge thereof to form an arc-shaped upper edge, each of said upper and lower dimples comprising:
• a curved dimple part axially formed along each dimple, and having a predetermined width while being curved within a direction of the width at a radius of curvature corresponding to that of an external surface of each fuel rod;
• and
• two side dimple extensions extending outward in opposite directions from both sides of the curved dimple part to a predetermined width while being curved at a predetermined angle.