Implications of manufacturing deviations on fuel performance

Prototype Fast Breeder Reactor (PFBR) core consists of 181 Fuel subassembly (FSA), 120 blanket SA and shielding SA of steel and B₄C besides 9 Control Safety Rod SA and 3 Diverse Safety Rod SA. All the subassemblies (SA) stand vertically on the grid plate. PFBR FSA consists of 217 fuel pins of 2540 mm length arranged in a triangular pitch standing vertically on the rails inside a hexagonal duct. The bottom of the hexagon is screwed and welded to a cylindrical foot of length 600 mm. The SA foot has radial slots that provide an entry to the coolant sodium and also houses flow control devices. While the foot of the A handling head is welded to the top of hexagon, provides an aid for fuel handling machine to insert and withdraw the FSA from the grid plate. The length of the FSA is 4500 mm.