Nuclear reactor vessel having lower internal hold-down means and hold-down means adjustment method.

摘要

The reactor vessel contains at least 3 support assemblies distributed around the periphery of the lower core support plate to ensure radial and circumferential support and also secondary vertical support in case of accidental drop of the lower reactor internals. Each support assembly has a male part or key welded on the inner surface of the reactor vessel wall. The female part is made of a bedway fixed inside a slot machined in the edge of the core support plate. The top of the slot is closed by the face. The bottom of the slot opens out onto the lower face of the core support plate. Also claimed is the procedure for adjusting the dimensions of the bedway by temporarily inserting a standard sized bedway provided with measuring probes in order to obtain the required gap between the key and the actual bedway.