Section Three
SITE REMEDIATION
7    REDUCTION OF RADIONUCLIDE AND OTHER
RADIOACTIVE SUBSTANCE LEACHABILITY FROM
OHIO AND NEW JERSEY SOILS USING AN
INNOVATIVE CHEMICAL TREATMENT PROCESS
Karl W. Yost, Director of Treatment Services
Sevenson Environmental Services, Inc.
Munster, Indiana 46321
Steven A. Chisick, Certified Professional Geologist
Durham, North Carolina 27703
James J. Mueller, President
Controls for Environmental Pollution, Inc.
Santa Fe, New Mexico 87502
INTRODUCTION
The disposal of soil and solid waste containing radionuclides and other radioactive substances
has historically relied on various artificial and natural barriers, and physical binding stabilization
and containment systems. Dynamic material with such activity must be separated from the environment for geological periods of time in order to prevent the migration of long-lived radionuclides and their decay-daughters.
During the last 40 years, efforts to retain leachable radionuclides within host-matrices
were usually overlooked, with researchers focusing on leaching and extraction nuclide recovery
methods that originated from ore processing procedures. Those proponents that did emphasize
matrix retainage concepts prescribed cements, pozzolans, and other physical agglomeration or
encapsulation agents to control matrix stability and strength properties, and hence, it was believed, nuclide leachability reduction. Another retainage concept near or at full-scale commercial
availability is vitrification where material containing radionuclides is directly converted to a
borosilicate-glass matrix by intense heat and molten-mass cooling. While vitrification may create
an end product with exceptional geologic stability and longevity, it is highly energy dependent
and has limited treatment production capabilities. On the other hand, physical stabilization methods have improved treatment productivity capacities, but create long-term stability concerns, and
contribute excess bulk and mass to the matrix.
To ensure long-term security, it appears desirable to chemically alter radionuclides in a host-
matrix by forming stoichiometrically defined crystalline compounds with low solubilities. The
treatability studies presented in this chapter were the initial and subsequent attempts to examine
the behavior of leachable radionuclides before and after chemical treatment of host soil by the
MAECTITE® chemical treatment technology.
MAECTITE® TREATMENT TECHNOLOGY TREATABILITY
STUDY OBJECTIVES
A series of experiments were conducted on soils containing radionuclides and other radioactive substances to examine the ability of the MAECTITE® chemical treatment process to reduce
radionuclide leachability from the host-matrix. USEPA SW-846 extraction methods were selected to leach nuclides from soils instead of column-leach tests traditionally utilized in radioac-
51st Purdue Industrial Waste Conference Proceedings, 1996, Ann Arbor Press, Inc., Chelsea, Michigun 481 IK.
Printed in U.S.A.
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