PWR Integral tie plate and locking mechanism

In the nuclear power reactor fuel bundle having a plurality of the fuel rods and tie rods, an upper tie plate locking mechanism, comprising:

• (a) a tubular locking sleeve fixed to an end of a plurality of said tie rods, said locking sleeves including sleeve lugs projecting radially outward and spaced in increments about the periphery of said locking sleeve at an end away from said fuel bundle;
• (b) an upper tie plate having a plurality of openings, one of said openings receiving each of said locking sleeves, such that said sleeve lugs on said locking sleeves extend beyond the tie plate on the side away from said fuel rods;
• (c) locking nuts corresponding to each of said locking sleeves, said locking nuts including a hollow tubular cap capable of receiving said locking sleeves with lugs projecting radially inward from the interior walls of said cap, said cap lugs spaced about the periphery of said cap and corresponding to said sleeve lugs for mating engagement, said locking nuts movable between a locked and unlocked position;
• (d) a retaining sleeve including a hollow tubular member capable of receiving said locking sleeve and extending through said openings on both sides of said tie plate, said tubular member having an enlarged end toward said fuel bundle so that said enlarged end may not pass through said openings of said tie plate, said retaining sleeve fixed at the end away from said fuel bundle to said nut, thereby operably connecting said locking nut to said tie plate;
• and
• (e) means for restraining said locking nuts in said locked position, said restraining means operably connected to one of said retaining sleeve and said locking nuts such that said upper tie plate, said locking, nuts said retaining sleeve and said restraining means form an integral unit when said locking nuts is in said locked and said unlocked position and are removable from said fuel bundle as as integral assembly.