Patent Number: 
Section: claims

1. A fuel assembly for a boiling water reactor, the fuel assembly comprising:a filter plate having an upper side;a fuel assembly base having an upper side with a top and closed at said top by said filter plate disposed above said fuel assembly base;a separate holding part fastened to said filter plate on said upper side of said filter plate and thereby connected to said upper side of said fuel assembly base, said separate holding part including a plurality of latch assemblies projecting away from said filter plate;a fuel assembly head;a bundle of fuel rods, including long fuel rods and medium-length fuel rods, extending away from said fuel assembly base and disposed between said fuel assembly base and said fuel assembly head, a plurality of said medium-length fuel rods each being fixed axially on a respective one of said latch assemblies, each of said plurality of said medium-length fuel rods being held entirely above said filter plate by said respective latching assembly; anda water channel disposed inside of said bundle of fuel rods. 2. The fuel assembly according to claim 1, wherein said separate holding part also supports thereon said long fuel rods. 3. The fuel assembly according to claim 1, wherein at least some of said long fuel rods are fixed at least radially on said separate holding part. 4. The fuel assembly according to in claim 3, wherein at least some of said medium-length fuel rods are fixed radially on said separate holding part. 5. The fuel assembly according to claim 1, wherein said fuel rods are fixed on said separate holding part with an aid of a snap connection with an axial assembly direction. 6. The fuel assembly according to claim 5,wherein said medium length fuel rods have a lower end with a waist behind which said latch assembly disposed on said separate holding part engages in an axially effective fashion. 7. The fuel assembly according to claim 6, wherein each of said latch assemblies has two clip assemblies, molded onto said separate holding part, with flat sides facing one another and each having a precurved region, each of said flat sides of said clip assemblies engages resiliently into said waist with said precurved region. 8. The fuel assembly according to claim 7, wherein:said clip assemblies have recesses formed therein; andsaid lower end of said medium length fuel rods have two projections protruding laterally at diametrically opposing positions, each of said two projections engaging in said recesses of said clip assemblies. 9. The fuel assembly according to claim 1, wherein:said filter plate has filter openings formed therein; andsaid separate holding part is one of a plurality of holding parts, said holding parts are disposed on said filter plate such that said filter openings remain substantially unblocked. 10. A fuel assembly for a boiling water reactor, the fuel assembly comprising:a filter plate having bars extending mutually parallel;a fuel assembly base having an upper side with a top and closed at said top by said filter plate disposed above said fuel assembly basea separate holding part connected to said upper side of said fuel assembly base, said holding part being rails disposed mutually parallel and with a grid period of said bars of said filter plate, said separate holding part including a plurality of latch assemblies projecting away from said filter plate;a fuel assembly head;a bundle of fuel rods, including long fuel rods and medium-length fuel rods, extending away from said fuel assembly base and disposed between said fuel assembly base and said fuel assembly head, a plurality of said medium-length fuel rods each being fixed axially on a respective one of said latch assemblies, each of said plurality of said medium-length fuel rods being held entirely above said filter plate by said respective latching assembly; anda water channel disposed inside of said bundle of fuel rods. 11. The fuel assembly according to claim 10, further comprising a grid plate having connecting bars, said rails are components of said grid plate, and said rails having ends molded onto said connecting bars aligned transversely to said rails. 12. The fuel assembly according to claim 11, wherein said grid plate has a grid opening formed therein defined by an opening edge, through said grid opening said water channel passes, and behind said opening edge said water channel engages in an axially effective fashion. 13. The fuel assembly according to claim 12, wherein said grid plate is rotationally fixed on said water channel. 14. The fuel assembly according to claim 13, wherein said water channel passes through said grid opening with a form fit that is effective in a rotational direction. 15. The fuel assembly according to claim 1, wherein said holding part is a sheet metal grid plate. 16. The fuel assembly according to claim 10, wherein said holding part is a sheet metal grid plate.