Saltstone: cement-based waste form for disposal of Savannah River Plant low-level radioactive salt waste

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6418145

Langton, C A

Defense waste processing at the Savannah River Plant will include decontamination and disposal of approximately 400 million liters of waste containing NaNO/sub 3/, NaOH, Na/sub 2/SO/sub 4/, and NaNO/sub 2/. After decontamination, the salt solution is classified as low-level waste. A cement-based waste form, saltstone, has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy of leached and unleached specimens were characterized by SEM and x-ray diffraction analyses. The disposal system for the DWPF salt waste includes reconstitution of the crystallized salt as a solution containing 32 wt % solids. This solution will be decontaminated to remove /sup 137/Cs and /sup 90/Sr and then stabilized in a cement-based waste form. Laboratory and field tests indicate that this stabilization process greatly reduces the mobility of all of the waste constitutents in the surface and near-surface environment. Engineered trenches for subsurface burial of the saltstone have been designed to ensure compatibility between the waste form and the environment. The total disposal sytem, saltstone-trench-surrounding soil, has been designed to contain radionuclides, Cr, and Hg by both physical encapsulation and chemical fixation mechanisms. Physical encapsulation of the salts is the mechanism employed for controlling N and OH releases. In this way, final disposal of the SRP low-level waste can be achieved and the quality of the groundwater at the perimeter of the disposal site meets EPA drinking water standards.

• Research Organization: Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Lab.
• DOE Contract Number: AC09-76SR00001
• OSTI ID: 6418145
• Report Number(s): DP-MS-84-110; CONF-841187-4; ON: DE85002831
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BUILDING MATERIALS
CEMENTS
LIQUID WASTES
LOW-LEVEL RADIOACTIVE WASTES
MANAGEMENT
MATERIALS
PERFORMANCE TESTING
PHASE TRANSFORMATIONS
PROCESSING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTES
SOLIDIFICATION
TESTING
WASTE FORMS
WASTE MANAGEMENT
WASTE PROCESSING
WASTES