KERNEINBAUTEN EINES WASSERGEKUEHLTEN KERNREAKTORS

摘要

In such core insertions, the upper and lower core structure (3, 4) carries a multiplicity of centring pins (10), which project with their free ends into recesses of a fuel element end section. Particularly in the case of the upper core structure, the nuts for fixing the centring pins have difficult access in the case of later exchange. The aim is therefore to specify core insertions which manage without securing the nuts to the centring pins. For this purpose, a centring pin (10) is provided with a central through bore (22). The central bore (22) is constructed at its end averted from the fuel elements as a conically tapering stepped bore (23). The stepped bore has a plug, which can be displaced in the axial direction relative to the centring pin and whose lateral surface is constructed conically in the same direction and with the same slope as the stepped bore. A centring pin fits the bore (18) without play. The lateral surface of the centring pin is provided at the level of the stepped bore with a set of grooves (25), which fits the wall of the bore (18) positively once the relative movement of the plug has been concluded. ……