Reference thermal and thermal/mechanical analyses of drifts for vertical and horizontal emplacement of nuclear waste in a repository in tuff

Technical Report · Fri May 01 04:00:00 EDT 1987

OSTI ID:60151

John, C M

Two-dimensional thermal and thermal/mechanical analyses of the designs of drifts for vertical and horizontal emplacement of nuclear waste in a repository in tuff were performed using boundary-element and finite-element computer codes. The fine-element analyses considered the two extreme alternatives of continuous ventilation for 100 yr after waste emplacement and that of no ventilation at any time. The boundary-element code was utilized during scoping studies and it also provided independent verification of the results of the finite-element analyses. The analyses predict the development of increased horizontal stress levels in the rock mass as a result of waste emplacement. These are moderated significantly by ventilation in the case of vertical emplacement, because the drifts are spaced sufficiently close for a substantial amount of the heat generated by the waste to be removed by the ventilating air. Even without such a moderating influence, there is no evidence that the stresses induced by waste emplacement would lead to drift instability. For none of the cases considered was there any indication of a potential for failure of the rock matrix. Regions of overstress of joints were predicted in all cases, but such regions were small and are judged to be of little or no practical significance to the stability of the emplacement drift. 33 refs., 37 figs., 11 tabs.

• Research Organization: Agapito (J.F.T.) and Associates, Inc., Rolling Hills Estates, CA (United States); Sandia National Labs., Albuquerque, NM (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 60151
• Report Number(s): SAND--86-7005; ON: DE87010989
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
CALCULATION METHODS
DESIGN
FINITE ELEMENT METHOD
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MINE ROADWAYS
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE FACILITIES
SHAFT EXCAVATIONS
STABILITY
STRESSES
TEMPERATURE DISTRIBUTION
THERMAL ANALYSIS
THERMODYNAMIC PROPERTIES
TUFF
UNDERGROUND DISPOSAL
VENTILATION
Yucca Mountain Project