Patent Number: 
Section: claims

1. A spacer for a fuel assembly of a nuclear reactor cooled by light cooling water, comprising:a multiplicity of crisscrossing webs forming a grid, each of said webs formed of interconnected first and second sheet-metal strips having corrugations shaped asymmetrically in relation to a vertical middle plane running between said sheet-metal strips such that in each case neighboring corrugations form an enclosed flow sub-channel for receiving the cooling water;said flow sub-channel running oblique to a vertical and having a shape being asymmetric in relation to said vertical middle plane thereby imparting to the cooling water emerging from said flow sub-channel a flow component perpendicular to said vertical middle plane running between said sheet-metal strips; andsaid asymmetric shape of said enclosed flow sub-channel and said asymmetric shape of said corrugations being predefined. 2. The spacer according to claim 1, wherein said flow sub-channel has a first partial channel with a cross section formed by a first corrugation decreasing in a flow direction of the cooling water, and a second partial channel having a cross section formed by a second, neighboring corrugation increasing in the flow direction. 3. The spacer according to claim 1, wherein:said first sheet-metal strips have first corrugations alternately disposed in a longitudinal direction of said first sheet-metal strips;said second sheet-metal strips have second corrugations alternately disposed in a longitudinal direction of said second sheet-metal strips; andsaid first and second sheet-metal strips are assembled to form said webs such that each said flow sub-channel is formed by said first and second corrugations. 4. The spacer according to claim 1, wherein said flow sub-channel has a downstream end and runs oblique to the vertical at least at said downstream end. 5. The spacer according to claim 4, wherein the cooling water respectively emerging from said flow sub-channels which are mutually neighboring and inclined to a crossing point of two of said webs, have mutually opposed flow components perpendicular to the vertical middle plane such that a swirl flow is produced around said crossing point. 6. The spacer according to claim 5, wherein swirl flows around mutually neighboring crossing points are respectively directed in an opposed fashion to each other along said web. 7. A fuel assembly comprising:at least one spacer, containing:a multiplicity of crisscrossing webs forming a grid, each of said webs formed of interconnected first and second sheet-metal strips having corrugations shaped asymmetrically in relation to a vertical middle plane running between said sheet-metal strips such that in each case neighboring corrugations form an enclosed flow sub-channel running oblique to a vertical and having a shape being asymmetric in relation to said vertical middle plane thereby imparting to cooling water emerging from said flow sub-channel a flow component perpendicular to said vertical middle plane running between said sheet-metal strips;said asymmetric shape of said enclosed flow sub-channel and said asymmetric shape of said corrugations being predefined. 8. The fuel assembly according to claim 7, wherein: said asymmetric shape of said corrugations is formed by predefined offset arches. 9. The spacer according to claim 1, wherein: said asymmetric shape of said corrugations is formed by predefined offset arches.