Debris filter for a nuclear fuel assembly bottom end part and method of manufacturing such a debris filter

A method of manufacturing a nuclear fuel assembly bottom end part comprising a lower nozzle and a debris filter supported by the lower nozzle, the lower nozzle comprising a first part and a second part, the debris filter having an inlet face and an outlet face opposed to the inlet face, the debris filter comprising at least one filtering section that has a retention capacity that increases gradually or stepwise towards from the inlet face to the outlet face, the method comprising:

• manufacturing the first part;
• manufacturing the second part;
• manufacturing the debris filter at least partly by building up the debris filter by additive manufacturing onto the first part;
• and then
• assembling the second part on the first part.