A Coupled Model for Natural Convection and Condensation in HeatedSubsurface Enclosures Embedded in Fractured Rock

Conference · Fri Apr 14 04:00:00 EDT 2006

OSTI ID:920168

Halecky, N; Birkholzer, J T; Webb, S W; Peterson, P F; Bodvarsson, G S

In heated tunnels such as those designated for emplacementof radioactive waste at Yucca Mountain, axial temperature gradients maycause natural convection processes that can significantly influence themoisture conditions in the tunnels and in the surrounding fractured rock.Large-scale convection cells would provide an effective mechanism foraxial vapor transport, driving moisture out of the formation away fromthe heated tunnel section into cool end sections (where no waste isemplaced). To study such processes, we have developed and applied anenhanced version of TOUGH2 (Pruess et al., 1999) adding a new module thatsolves for natural convection in open cavities. The new TOUGH2 simulatorsimultaneously handles (1) the flow and energy transport processes in thefractured rock; (2) the flow and energy transport processes in thecavity; and (3) the heat and mass exchange at the rock-cavity interface.The new module is applied to simulate the future thermal-hydrological(TH) conditions within and near a representative waste emplacement tunnelat Yucca Mountain. Particular focus is on the potential for condensationalong the emplacement section, a possible result of heat outputdifferences between individual waste packages.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE. Office of Civilian Radioactive Waste Management.Waste Management System
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 920168
• Report Number(s): LBNL--61235; BnR: DF0961000
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CAVITIES
CONVECTION
MOISTURE
NATURAL CONVECTION
POSITIONING
RADIOACTIVE WASTES
SIMULATORS
TEMPERATURE GRADIENTS
TRANSPORT
WASTES
YUCCA MOUNTAIN