Effects of long-term exposure of tuffs to high-level nuclear waste repository conditions. Final report

Technical Report · Fri Aug 01 04:00:00 EDT 1986

DOI:https://doi.org/10.2172/59938· OSTI ID:59938

Blacic, J D; Vaniman, D T; Bish, D L; Duffy, C J; Gooley, R C

We have performed exploratory tests to investigate the effects of extended exposure of tuffs from Yucca Mountain, Nevada, to temperatures and pressures similar to those that will be encountered in a high-level nuclear waste repository. In a preliminary report we described statistically significant changes in strength properties and generally minor changes in porosity and grain density. In the present report we describe additional measurements that indicate possible changes in permeability (in one tuff type) after exposure for 2 to 6 months at temperatures from 80 to 180 C, confining pressures of 9.7 and 19.7 MPa, and water pore pressures of 0.5 and 19.7 MPa. Mineralogic examinations have established reactions involving dissolution of silica and feldspar minerals and possible conversion of clinoptilolite to mordenite. We conclude that rock properties important to the operation of a nuclear waste repository in tuff are likely to change over time when exposed to simulated repository conditions, and the details of these time-dependent processes should be investigated further.

• Research Organization: Los Alamos National Lab., NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 59938
• Report Number(s): LA--9330-MS; ON: DE87000791
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
58 GEOSCIENCES
EXPERIMENTAL DATA
GRAIN DENSITY
HIGH-LEVEL RADIOACTIVE WASTES
METAMORPHISM
PERMEABILITY
POROSITY
PRESSURE EFFECTS
TIME DEPENDENCE
TUFF
WASTE-ROCK INTERACTIONS
YUCCA MOUNTAIN
Yucca Mountain Project