Repository thermal response: A preliminary evaluation of the effects of modeled waste stream resolution

Abstract

Prepared by Yucca Mountain Site Characterization Project (YMSCP) participants as part of the Civilian Radioactive Waste Management Program (CRWM). The YMSCP is managed by the Yucca Mountain Project Oflice of the US. Department of Energy, DOE Field Office, Nevada (DOE/NV). YMSCP work is sponsored by the office of Geologic Repositories (OGR) of the DOE office of Civilian Radioactive Waste Management (OCRWM)." Issued by Sandia National Laboratories, operated for the United States Department of Energy by Sandia Corporation. NOTICEI This report was prepared as an account of work sponsored by a n agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe pnvately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government, any agency thereof or any of their contractors or subcontractors. The views and opinions expressed herein do not necessarily state or reflect those of the United States Government, any agency thereof or any of their contractors.

Thermal loading study for FY 1995

“…As a result of this, the local area power densities (LAPD) for this base case vary between 9.8 to 30.9 W/m2 (40 to 125 kW/acre) as discussed in Ryder and Dunn (1995).…”

“…This base case was done in support of North Ramp design activities (YMP, 1994). The yearly average characteristics of each waste package type (PWR or BWR) were then assigned an order for emplacement for a given year using a nonunique, randomized selection process which minimized bias (Ryder and Dunn, 1995). Canister-to-canister spacings in a drift were assigned based on yearly average values of MTUs per canister defined for each type of waste which would provide a uniform AML of 19.3 kgU/m2.…”

“…Figure 4.5-1 shows the predicted base case temperature contours (Ryder and Dunn, 1995) at 5 m above the potential repository horizon (a plane connecting the waste package centerlines) for 50 years after the initial start of waste emplacement (assumed to be in 2010). The effects of stepped emplacement (emplacement started on the left side and progresses to the right) can clearly be seen in the figure as a growth in temperature perturbations.…”

“…In this effort, the predicted temperatures at 5 meters above the potential repository obtained for a base case that was done using yearly averages in support of subsurface design (YMP, 1993) were compared with predictions made for a case in which three years of emplaced waste were replaced by actual package-to-package heat characteristics. Further details of the effort, beyond the summary of information below, can be found in a Sandia report by Ryder and Dunn (1995 …”

“…For this investigation, packageby-package information for fuel projected to arrive at the repository for emplacement in years 2028, 2029, and 2030 were considered. The package-by-package details can be found in the more detailed Ryder and Dunn (1995) report. Additionally there was no limit placed on the heat output of the packages.…”