Nuclear reactor fuel rod assembly - with split collar retainers for upper space plate

摘要

The upper spacer plate is fixed to an upper mounting and stop plate by a number of spring shouldered pins passing through mating holes drilled in the stop plate. The pin has a reduced cross section above the shoulder with a square edged annular groove near its chamfered top. The split retainer collar has a tapered upper section and cylindrical lower section. The bore in the stop plate has a chamfered entry followed by a relatively wide cylindrical bore, in which the retainer slides easily with a conical transition to a short length to tight bore in the top of the stop plate, above which the clip springs outwards. Device is simple, robust and gives positive action.