Fast-neutron reactor fuel rod

A fast-neutron lead-cooled nuclear reactor fuel assembly, comprising:

• a plurality of fuel rods, each fuel rod comprising nuclear fuel arranged in a sealed housing in the form of a tubular steel shell and end parts, and
• a spacer element wound in a coil with a specific pitch on an outside surface of the tubular steel shell and fastened to ends of the fuel rod on the end parts, wherein the spacer element is in the form of a band twisted around a longitudinal axis of the band, the width of the band transverse to the longitudinal axis being equal to the minimum distance between adjacent tubular steel shells in the fuel assembly of the nuclear reactor, a transverse cross-sectional area of the band being within a range from 0.1 to 0.5 times the area of a circle described around the width of the band,
• wherein a band twist pitch is calculated by the formula
• S
• 2
• =
• S
• 1
• 2
• +
• (
• π
• ·
• (
• d
• +
• δ
• )
• )
• 2
• N
• ,
• where S2 is the band twist pitch of the band twisted around the longitudinal axis;
• S1 is the winding pitch of the spacer element on the tubular steel shell;
• d is the outer diameter of the tubular steel shell;
• δ is the transverse width of the twisted band;
• N is the number of full turns of the twisted band per pitch S1.