Attachable debris filter for BWR nuclear fuel assemblies

A debris filter for filtering out debris from reactor coolant water for being installed within a modified irradiated nuclear fuel assembly and disposed through the inlet orifice and supported by the inlet nozzle, the debris filter comprising:

• a cap ring adapted to form a coolant entrance orifice, said cap ring having a first side from which extends a multi-pronged guide, said cap ring having a second side from which extends a support ring for aligning the debris filter within the fuel assembly, the debris filter further including a filter media comprising an assembly of louver blade discs for filtering out debris from reactor coolant water, the filter media being secured to the support ring;
• guide rods extending from the support ring, wherein the assembly of louver blade discs are stacked on the guide rods;
• and
• at least one spring connected at one end to the support ring for securing the debris filter in place within the inlet nozzle.