Laboratory studies of fluid flow through borehole seals

Thesis/Dissertation · Sat Dec 31 00:00:00 EST 1983

OSTI ID:60541

South, D L

Boreholes in the vicinity of a nuclear waste repository must be reliably sealed to prevent rapid migration of radionuclide contaminated water from the vicinity of the repository to the accessible environment. Few data currently exist regarding the effectiveness of borehole sealing. The objective of this research was to assess the performance of borehole seals under laboratory conditions, particularly with regard to varying stress fields. The approach used to evaluate borehole seals was to compare flow through a sealed borehole with flow through intact rock. Granite, basalt, and tuff were tested, using either cement or bentonite as the seal material. The main conclusions reached as a result of the experiments is that currently existing materials are capable of forming high quality seals when placed under laboratory conditions. Variation of triaxial stress state about a borehole does not significantly affect seal performance if the rock is stiffer than the seal material. Temperature/moisture variations (drying) degraded the quality of cement seals significantly. Performance partially recovered upon resaturation. Significant remaining questions include field emplacement techniques; field vertification of plug quality; plug performance over long time periods, particularly with respect to temperature/moisture variations and chemical stability; and radionuclide sorption capabilities. Scale effects are also important, as shafts and drifts must be sealed as well as larger diameter boreholes.

• Research Organization: Arizona Univ., Tucson, AZ (United States)
• OSTI ID: 60541
• Resource Relation: Other Information: TH: Thesis (Ph. D.); PBD: 1983
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
54 ENVIRONMENTAL SCIENCES
BOREHOLES
SEALS
SEALING MATERIALS
PERFORMANCE TESTING
GROUND WATER
RADIONUCLIDE MIGRATION
RADIOACTIVE WASTE DISPOSAL
SAFETY ENGINEERING
GRANITES
BASALT
TUFF
STEMMING MATERIALS
RADIOACTIVE WASTE FACILITIES
RADIOISOTOPES
ROCKS
CONTAMINATION
FLUID FLOW
CEMENTS
BENTONITE
BENCH-SCALE EXPERIMENTS
Yucca Mountain Project