This work is a 3D implementation of the model for a shutdown boron injection jet of a Pressurized Heavy Water Reactor [1]. The boron shutdown system injects boron into a moderator tank with an array of cylindrical coolant channels. In order to accurately model the distribution of boron inside the moderator tank, the modeling of the turbulent jet mixing is required. The distribution of boron inside the moderator tank is then used to calculate the multidimensional insertion of negative reactivity into the reactor during a fast shutdown in a PARCS/RELAP5 coupled model. A CFD code is used to calculate the boron distribution in the moderator tank. A porous medium model is used to represent the coolant channels. The porous medium model volume averages the governing equations similar to the two fluid model. Additional source terms that arise, due to the volume averaging, need to be constituted so that the problem can be solved. The additional sources terms for the present model have been related to: 1. drag over a cylinder for the momentum equation and 2. additional mixing effect of the cylinders which results in the form of source terms for both the turbulent kinetic energy and turbulent dissipation transport equations. The CFD analysis is performed on a porous, three dimensional domain. The CFD results are compared with experimental data for the boron concentration distribution obtained in a scaled facility. Though the CFD results over predict the concentration measurements, good agreement is achieved for the curvature of the jet centerline.

This content is only available via PDF.
You do not currently have access to this content.