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Near-drift thermal analysis including combined modes of conduction, convection, and radiation

Description: The performance of waste packages containing high-level nuclear wastes at underground repositories such as the potential repository at Yucca Mountain, Nevada, depends, in part, on the thermodynamic environment immediately surrounding the buried waste packages. For example, degradation of the waste packages can be caused by corrosive and microbial processes, which are influenced by both the relative humidity and temperature within the emplacement drifts. In this paper, the effects of conduction,… more
Date: December 31, 1995
Creator: Ho, C.K. & Francis, N.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effects of conduction, convection, and radiation on the thermodynamic environment surrounding a heat-generating waste package

Description: The thermodynamic environment surrounding a heat-generating waste package can play an important role in the performance of a high-level radioactive waste repository. However, rigorous models of heat transfer are often compromised in near-drift simulations. Convection and radiation are usually ignored or approximated so that simpler conduction models can be used. This paper presents numerical simulations that explicitly model conduction, convection, and radiation in an empty drift following empl… more
Date: January 1, 1996
Creator: Ho, Clifford K. & Francis, N.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effects of infiltration on the thermo-hydrologic behavior of the potential repository at Yucca Mountain

Description: The thermo-hydrologic behavior of the potential repository at Yucca Mountain, Nevada, has been simulated to investigate the effects of infiltration. Transient temperatures, liquid saturations, and liquid mass flow rates through the fractures and matrix were simulated using several different steady infiltration rates ranging from 0.3 to 30 min./year. The lower infiltration rates resulted in higher temperatures near the repository element, but the overall transient temperature profiles were simil… more
Date: March 1, 1997
Creator: Ho, C. K.; Arnold, B. W.; Francis, N. D. & McKenna, S. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Results of the Single Heater Test at Yucca Mountain, Nevada

Description: The Yucca Mountain Project conducted a Single Heater Test (SHT) in the Exploratory Studies Facility at Yucca Mountain. During the nine month-long heating phase, approximately 4 m{sup 3} of in situ, fractured, 92% saturated, welded tuff was heated to temperatures above 100 C by a 5 m long, 3.8 kW, horizontal, line heater. In this paper, the thermal data collected during the test (Sandia National Laboratories, 1997) are compared to three numerical simulations (Sobolik et al., 1996) in order to ga… more
Date: December 1, 1997
Creator: Ballard, S.; Francis, N.D. & Sobolik, S.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Post-test comparison of thermal-hydrologic measurements and numerical predictions for the in situ single heater test, Yucca Mountain, Nevada

Description: The Single Heater Test (SHT) is a sixteen-month-long heating and cooling experiment begun in August, 1996, located underground within the unsaturated zone near the potential geologic repository at Yucca Mountain, Nevada. During the 9 month heating phase of the test, roughly 15 m{sup 3} of rock were raised to temperatures exceeding 100 C. In this paper, temperatures measured in sealed boreholes surrounding the heater are compared to temperatures predicted by 3D thermal-hydrologic calculations pe… more
Date: June 1, 1998
Creator: Ballard, S.; Francis, N.D.; Sobolik, S.R. & Finley, R.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Abstraction of Drift-Scale Coupled Processes

Description: This Analysis/Model Report (AMR) describes an abstraction, for the performance assessment total system model, of the near-field host rock water chemistry and gas-phase composition. It also provides an abstracted process model analysis of potentially important differences in the thermal hydrologic (TH) variables used to describe the performance of a geologic repository obtained from models that include fully coupled reactive transport with thermal hydrology and those that include thermal hydrolo… more
Date: March 31, 2000
Creator: Francis, N. D. & Sassani, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

HEat Decay Data Repository Footprint for Thermal-Hydrologic and Conduction-Only Models for TSPA-SR

Description: The repository heat decay data contained within this calculation is specified for both mountain-scale and drift-scale thermal-hydrologic (TH), thermal-hydrologic-mechanical (THM), and thermal-hydrologic-chemical (THC) simulations used in total systems performance assessments (TSPA). Repository thermal output data, and how it decays in time, is required by the models that compute changes to the geologic system as a result of a heat addition. The mountain-scale problem requires a repository-wide … more
Date: April 24, 2000
Creator: Francis, N.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Tabulated In-Drift Geometric and Thermal Properties Used In Drift-Scale Models for TSPA-SR

Description: The objective of this calculation is to provide in-drift physical properties required by the drift-scale models (both two- and three-dimensional) used in total system performance assessments (TSPA). The physical properties include waste package geometry, waste package thermal properties, emplacement drift geometry including backfill and invert geometry and properties (both thermal and hydrologic), drip shield geometry and thermal properties, all tabulated in a single source.
Date: June 16, 2000
Creator: Francis, N.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Uncertainty: a discriminator for above and below boiling repository design decisions

Description: The US nuclear waste disposal program is evaluating the Yucca Mountain (YM) site for possible disposal of nuclear waste. Radioactive decay of the waste, particularly spent fuel, generates sufficient heat to significantly raise repository temperatures. Environmental conditions in the repository system evolve in response to this heat. The amount of temperature increase, and thus environmental changes, depends on repository design and operations. Because the evolving environment cannot be directly… more
Date: November 14, 2000
Creator: Wilder, D G; Lin, W; Buscheck, T A; Wolery, T J & Francis, N D
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Effective Thermal Conductivity For Drift-Scale Models Used In TSPA-SR

Description: The objective of this calculation is to develop a time dependent in-drift effective thermal conductivity parameter that will approximate heat conduction, thermal radiation, and natural convection heat transfer using a single mode of heat transfer (heat conduction). In order to reduce the physical and numerical complexity of the heat transfer processes that occur (and must be modeled) as a result of the emplacement of heat generating wastes, a single parameter will be developed that approximates… more
Date: January 25, 2001
Creator: Francis, N.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

CFD Calculation of Internal Natural Convection in the Annulus between Horizontal Concentric Cylinders

Description: The objective of this heat transfer and fluid flow study is to assess the ability of a computational fluid dynamics (CFD) code to reproduce the experimental results, numerical simulation results, and heat transfer correlation equations developed in the literature for natural convection heat transfer within the annulus of horizontal concentric cylinders. In the literature, a variety of heat transfer expressions have been developed to compute average equivalent thermal conductivities. However, th… more
Date: October 1, 2002
Creator: Francis, N. D., Jr; Itamura, M. T.; Webb, S. W. & James, D. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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