scholarly journals The importance of thermal loading conditions to waste package performance at Yucca Mountain

10.2172/61006 ◽  
1994 ◽  
Author(s):  
T.A. Buscheck ◽  
J.J. Nitao
Keyword(s):  
Thermal Loading ◽  
Yucca Mountain ◽  
Loading Conditions ◽  
Waste Package

scholarly journals Localized Dryout: an Approach for Managing the Thermal-Hydrological Effects of Decay Heat at Yucca Mountain

1995 ◽  
Vol 412 ◽  
Author(s):  
Thomas A. Buscheck ◽  
John J. Nitao ◽  
Lawrence D. Ramspot
Keyword(s):  
Relative Humidity ◽  
Thermal Load ◽  
Large Scale ◽  
Thermal Loading ◽  
Yucca Mountain ◽  
Large Temperature ◽  
Nuclear Waste Repository ◽  
Waste Package ◽  
Decay Heat ◽  
Hydrological Effects

AbstractFor a nuclear waste repository in the unsaturated zone at Yucca Mountain, there are two thermal loading approaches to using decay heat constructively-that is, to substantially reduce relative humidity and liquid flow near waste packages for a considerable time, and thereby limit waste package degradation and radionuclide dissolution and release. “Extended dryout” achieves these effects with a thermal load high enough to generate large-scale (coalesced) rock dryout. “Localized dryout”(which uses wide drift spacing and a thermal load too low for coalesced dryout) achieves them by maintaining a large temperature difference between the waste package and drift wail; this is done with close waste package spacing (generating a high line-heat load) and/or low-thermal-conductivity backfill in the drift. Backfill can greatly reduce relative humidity on the waste package in both the localized and extended dryout approaches. Besides using decay heat constructively, localized dryout reduces the possibility that far-field temperature rise and condensate buildup above the drifts might adversely affect waste isolation.

scholarly journals The Importance of Thermal Loading Conditions to Waste Package Performance at Yucca Mountain

1994 ◽  
Vol 353 ◽  
Author(s):  
Thomas A. Buscheck ◽  
John J. Nitao
Keyword(s):  
Relative Humidity ◽  
Thermal Load ◽  
Thermal Loading ◽  
Yucca Mountain ◽  
Thermal Loads ◽  
Ambient Conditions ◽  
Factors Affecting ◽  
Waste Package ◽  
Load Distributions ◽  
Wide Range

AbstractTemperature and relative humidity are primary environmental factors affecting waste package corrosion rates for the potential repository in the unsaturated zone at Yucca Mountain, Nevada. Under ambient conditions, the repository environment is quite humid. If relative humidity is low enough (<70%), corrosion will be minimal. Under humid conditions, corrosion is reduced if the temperature is low (<60°C). Using the V-TOUGH code, we model thermo-hydrological flow to investigate the effect of repository heat on temperature and relative humidity in the repository for a wide range of thermal loads. These calculations indicate that repository heat may substantially reduce relative humidity on the waste package, over hundreds of years for low thermal loads and over tens of thousands of years for high thermal loads. Temperatures associated with a given relative humidity decrease with increasing thermal load. Thermal load distributions can be optimized to yield a more uniform reduction in relative humidity during the boiling period.

Impact of Thermal Loading on Waste Package Material Performance

1994 ◽  
Vol 353 ◽  
Author(s):  
D. Stahl ◽  
J. K. McCoy ◽  
R. D. McCright
Keyword(s):  
Thermal Load ◽  
Thermal Loading ◽  
Steel Corrosion ◽  
Yucca Mountain ◽  
Microbiologically Influenced Corrosion ◽  
Corrosion Performance ◽  
Kinetic Relation ◽  
Reference Case ◽  
Time Exponent ◽  
High Thermal Load

AbstractThis report focuses on the prediction of materials performance for the carbon steel corrosion-allowance container as a function of thermal loading for the potential repository at Yucca Mountain. Low, intermediate and high thermal loads were evaluated as to their performance given assumptions regarding the temperature and humidity changes with time and the resultant depth of corrosion penetration. The reference case involved a kinetic relation for corrosion that was utilized in a sensitivity analysis to examine the impacts of time exponent, pitting, and microbiologically-influenced corrosion. As a result of this study, the high thermal load appears to offer the best corrosion performance. However, other factors must be considered in making the final thermal loading decision.

scholarly journals YUCCA MOUNTAIN WASTE PACKAGE CLOSURE SYSTEM

2005 ◽  
Author(s):  
G. Housley ◽  
C. Shelton-davis ◽  
K. Skinner
Keyword(s):  
Yucca Mountain ◽  
Closure System ◽  
Waste Package

scholarly journals Evaluation of the Corrosivity of Dust Deposited on Waste Packages at Yucca Mountain, Nevada

2006 ◽  
Vol 932 ◽  
Author(s):  
Charles Bryan ◽  
Russell Jarek ◽  
Thomas Wolery ◽  
David Shields ◽  
Mark Sutton ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Experimental Studies ◽  
Yucca Mountain ◽  
Localized Corrosion ◽  
Small Droplet ◽  
Waste Package ◽  
Physical Isolation ◽  
Salt Minerals ◽  
Dry Out ◽  
Diffusive Gradients

ABSTRACTPotentially corrosive brines can form during post-closure by deliquescence of salt minerals in dust deposited on the surface of waste packages at Yucca Mountain during operations and the pre-closure ventilation period. Although thermodynamic modeling and experimental studies of brine deliquescence indicates that brines are likely to form, they will be nitrate-rich and noncorrosive. Processes that modify the brines following deliquescence are beneficial with respect to inhibition of corrosion. For example, acid degassing (HCl, HNO3) could dry out brines, but kinetic limitations are likely to limit the effect to increasing their passivity by raising the pH and increasing the NO3/Cl ratio.Predicted dust quantities and maximum brine volumes on the waste package surface are small, and physical isolation of salt minerals in the dust may inhibit formation of eutectic brines and decrease brine volumes. If brines do contact the WP surface, small droplet volumes and layer thicknesses do not support development of diffusive gradients necessary for formation on separate anodic-cathodic zones required for localized corrosion. Finally, should localized corrosion initiate, corrosion product buildup will stifle corrosion, by limiting oxygen access to the metal surface, by capillary retention of brine in corrosion product porosity, or by consumption of brine components (Cl−).

Fracture mechanics assessment of divertor vertical target under thermal loading conditions

2019 ◽  
Vol 146 ◽  
pp. 2209-2213 ◽  
Author(s):  
Jae Min Sim ◽  
Sang Yun Je ◽  
Ji-Hoon Kang ◽  
Yoon-Suk Chang
Keyword(s):  
Fracture Mechanics ◽  
Thermal Loading ◽  
Loading Conditions

Design by Analysis of Waste Packages at Yucca Mountain for Impact Loads

2009 ◽  
Author(s):  
Randy J. James ◽  
Kenneth Jaquay ◽  
Michael J. Anderson
Keyword(s):  
Nuclear Waste ◽  
Impact Loading ◽  
Structural Integrity ◽  
Structural Response ◽  
Yucca Mountain ◽  
Impact Loads ◽  
Geologic Repository ◽  
Dynamic Simulations ◽  
Nuclear Waste Storage ◽  
Waste Package

The proposed geologic repository under development at Yucca Mountain, Nevada, will employ multiple shell metallic containers (waste packages) for the disposal of nuclear waste. The waste packages represent a primary engineered barrier for protection and containment of the radioactive waste, and the design of these containers must consider a variety of structural conditions to insure structural integrity. Some of the more challenging conditions for structural integrity involve severe impact loading due to hypothesized event sequences, such as drops or collisions during transport and placement. Due to interactions between the various components leading to complex structural response during an impact sequence, nonlinear explicit dynamic simulations and highly refined models are employed to qualify the design for these severe impact loads. This paper summarizes the Design by Analysis methodologies employed for qualification of waste package design under impact loading and provides several illustrative examples using these methods. Example evaluations include a collision of a waste package by the Transport and Emplacement Vehicle (TEV) and two scenarios due to seismic events, including WP impact within the TEV and impact by falling rock. The examples are intended to illustrate the stringent Design by Analysis methods employed and also highlight the scope of structural conditions included in the design basis for waste packages to be used for proposed nuclear waste storage at Yucca Mountain.

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