An investigation of enhanced thermosolutal axial dispersion in a horizontal concentric annular enclosure

Date

2004-08

Journal Title

Journal ISSN

Volume Title

Publisher

Texas Tech University

Abstract

For the post-closure phase of waste package cooling in the proposed Yucca Mountain Repository. it is important to be able to predict possible regions in the drift enclosure where condensation may occur. During this post-closure phase, natural convection and radiation are the mechanisms by which heat is transported from the heated waste packages to the host rock. Material failure due to corrosion is a significant issue due to the hazardous materials being stored and the extensive project design life of 10.000 years.

The objective of the experimental investigation is to quantify the axial dispersion of a secondary gas in a horizontal enclosure including heat sources similar to the YMP drift configuration. Test results showed that the aided mixing due to unheated concentration buoyancy effects enhanced the dispersion coefficient by 8 times. The heated tests in which a turbulent plume from the simulated heater packages aided in mixing, yielded an axial dispersion coefficient of 20 times molecular diffusion.

The objective of the numerical investigation is to develop a 3-D computational fluid dynamics (CFD) model using Fluent based on the experimental mockup of a YMP configuration and to compare the steady-state mass-transport results of the simulations to the experimental data. In this study, interest is focused solely on quantifying the increased axial mass dispersion of a secondary gas due to buoyancy.

Description

Keywords

Gas flow -- Experiments -- Observations, Heat -- Radiation and absorption, Heat -- Transmission -- Mathematical models, Heat -- Convection -- Mathematical models, Cooling, Radioactive waste disposal in the ground

Citation