Structural behavior of a pool-type LMFBR reactor-vessel deck to beyond-design-basis loads

A study of the structural response of the reactor vessel deck to loads resulting from a hypothetical energetic accident for a conceptual design of a pool-type LMFBR was presented. The size of the reactor was in the 1000 MWe range with a 22m reactor vessel diameter and a vessel depth of 21 m. The vessel contains the entire primary system which includes the primary pumps, intermediate heat exchangers (IHXs), reactor core, core support structure, a cylindrical internal vessel, called a redan, and the sodium pool. The redan serves as a separator between the hot sodium emerging from the top of the reactor and the cooler bulk sodium. The deck structure provides support to the rotatable plug assembly, primary pumps and IHXs. In order to evaluate the structural integrity of this deck during a 1000 MJ excursion, a three-dimensional finite element model was developed for a 45 degree sector of the deck. The model included the main structural elements or the deck and the conical support skirt. The triple rotatable plug (TRP), pumps, and IHXs were represented by concentrated masses