Tech Briefs

Model for Transient Analysis of a Reactor Vessel

Here we show a model built entirely using the ADINA pre-processor. Onsala Ingenjorsbyra (Onsala Engineering AB, Sweden) performed the work under contract from Ringhals AB to analyze the Ringhals nuclear power plant
unit 1.

The purpose of the model is to determine reactor pressure vessel vibrations due to a postulated water line or steam line break. This requires a fully coupled transient fluid structure interaction (FSI) analysis in which, however, inviscid fluid conditions can be assumed.

The model is built from Parasolid parts, imported and modified within the ADINA pre-processor, as well as bottom-up modeling of beams through points and lines. The geometry includes more than 10,000 points, 5,000 lines, and 100 bodies. One of the bodies consists of 1,700 faces which are meshed with shell elements and FSI surfaces coupled to the internal fluid. There are 10 bodies representing the internal fluid. The finite element model consists of more than 10,000 beam elements, 100,000 shell elements, and 200,000 fluid elements. The number of degrees-of-freedom is approximately 800,000, and about 15,000 time steps are used to solve for the transient response.

We are pleased that ADINA is used for this analysis.