Thermal considerations in the drift due to the emplacement of a horizontal high level nuclear waste container
Abstract
The Yucca Mountain Site Characterization Project is investigating the feasibility of locating a high level radioactive nuclear waste repository at Yucca Mountain, Nevada. The design of waste containers to be used for the long term storage of the high level nuclear waste has progressed from the borehole model indicated in the original site characterization plan to drift emplaced multi-placed containers. The removal of decay heat is important in the first 1000 years as Zircaloy degradation temperature of 350{dollar}\sp\circ{dollar}C is not to be exceeded; In this study a two dimensional finite element thermal analysis has been completed for two scenarios for the in-drift emplacement scheme i.e. drift without backfill and drift with inverted backfill. Transient and steady state simulations have been carried out for a period of 1000 years and the peak temperatures at the walls of the drift and at the center of the container have been determined. The effects of natural convection and radiation are also discussed.