Experimental study of colloid filtration by compacted bentonite

Book · Wed Dec 31 04:00:00 EST 1997

OSTI ID:572217

Kurosawa, Susumu ^[1]; Yui, Mikazu; Yoshikawa, Hideki ^[2]

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1. Mitsubishi Materials Corp., Naka, Ibaraki (Japan). Naka Energy Research Center
2. Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan)

In this study, the transport behavior of colloids through compacted bentonite and sand-bentonite mixtures was investigated. Colloidal gold was used to simulate mobile colloids because it was well characterized and its dispersivity was controlled. The bentonite used was a sodium bentonite. The sand-bentonite mixtures were prepared by mixing up to 50 wt.% silica sand with the bentonite. The bentonite and the sand-bentonite mixtures were compacted to dry densities of 1,000 and 1,800 kg/m{sup 3} and then saturated with distilled water. The sand-bentonite mixture was also saturated with synthetic sea-water. Column experiments were performed to investigate colloidal transport. Further, colloidal particles stabilities in high ionic strength water such as bentonite porewater or saline groundwater were interpreted based on the repulsion potential from the double layer force and the attraction potential from the van der Waals force. The results indicated that the colloidal particles were effectively filtered by both the compacted bentonite and the sand-bentonite mixtures. This study indicated that the effect of colloids on radionuclide transport in compacted bentonite is negligible for the safety assessment of high level radioactive waste (HLW) disposal.

• OSTI ID: 572217
• Report Number(s): CONF-961202--
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
54 ENVIRONMENTAL SCIENCES
BENTONITE
COLLOIDS
DIFFUSION
EXPERIMENTAL DATA
FILTRATION
HIGH-LEVEL RADIOACTIVE WASTES
RADIOACTIVE WASTE DISPOSAL
RADIONUCLIDE MIGRATION
SAND