Geology ReportsSearch

USGS · 70012863

Leaching of plutonium from a radioactive waste glass by eight groundwaters from the western United States

Abstract

The leachability of a radioactive waste glass formulated to Battelle Pacific Northwest Laboratory specification 80-270 has been studied using eight actual groundwaters with a range of chemical compositions as leachants. Waters collected from the Grande Ronde Basalt (Washington State) and from alluvial deposits in the Hualapai Valley (Arizona) were the most effective at removing plutonium from this glass. Leaching was shown to be incongruent; plutonium was removed from the glass more slowly than the overall glass matrix. The results of these experiments indicate the need to study the leachability of actual waste forms using the actual projected groundwaters that are most likely to come into contact with the waste should a radioactive waste repository be breached.

Explore related subjects

90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 32.02637914252497° to 48.96938338954959° latitude; -125.22304850505517° to -102.34258038032547° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

T.F. Rees, J.M. Cleveland, K.L. Nash. 2017-05-13. Leaching of plutonium from a radioactive waste glass by eight groundwaters from the western United States. https://doi.org/10.13182/nt85-a33672

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

Plutonium, americium, and neptunium speciation in selected groundwaters

As part of a continuing study, plutonium, americium, and neptunium speciation was determined at 25 and 90°C in four groundwaters from diverse sources: the Sparta aquifer in Louisiana, near the Vacherie salt dome; Mansfield No. 2 well in the Palo Duro Basin, Texas; the Stripa mine in Sweden; and the Waste Isolation Pilot Plant (WIPP) in New Mexico. Plutonium generally was soluble in Sparta and Stripa waters, regardless of temperature or initial oxidation state. Solubility in Mansfield water was high, except in 90 °C experiments using low-oxidation-state plutonium. The WIPP water had the least ability to maintain plutonium in solution; solubility after 30 days exceeded 50% only in experiments at 25 °C using Pu(V) and Pu(VI). Neptunium generally was soluble in all waters and was present exclusively as Np(V) and Np(VI), regardless of initial oxidation state. The solubility of americium was consistently high in Sparta groundwater at both temperatures and in Mansfield and WIPP waters at 25°C, but was < 50% after 30 days in Stripa water at both temperatures and in Mansfield and WIPP waters at 90°C. The results indicated that plutonium and neptunium solubilities were determined by the oxidation-reduction properties of the waters, i.e., their abilities to convert these elements to soluble oxidation states. This was not the case for americium, however; Am(IV) was not detected, and the solubility of this element was determined entirely by the chemical properties of Am(III).

Nuclear Technology

Geohydrologic considerations in the management of radioactive waste

Nongaseous radioactive wastes occur as liquids containing high-level concentrations of radionuclides, liquids containing low concentrations of radionuclides, and solids contaminated by radioactivity. Whether released by accident or design into the earth or onto the earth’s surface, only water is capable of transporting significant quantities of radionuclides away from burial sites. Geohydrologic information that must be determined to predict the velocity and direction of waste movement from a site include climate, hydrology, detailed subsurface geology, permeability, porosity, sorptive potential, seismic potential, and geologic history of the area. Since the late 1960’s mathematical models have been used to make predictions of waste transport in some hydrologic systems. Intensive field investigations at each site are needed before these models can be used.

Nuclear Technology

The effect of composition of selected groundwaters from the Basin and Range Province on plutonium, neptunium, and Americium speciation

The speciation of plutonium, neptunium, and americium was determined in groundwaters from four sources in the Basin and Range Province: the lower carbonate aquifer, Nevada Test Site (NTS) (Crystal Pool); alluvial fill, Frenchman Flat, NTS (well 5C); Hualapai Valley, Arizona (Red Lake south well); and Tularosa Basin, New Mexico (Rentfrow well). The results were interpreted to indicate that plutonium and, to a lesser extent, neptunium are least soluble in reducing groundwaters containing a large concentration of sulfate ion and a small concentration of strongly complexing anions. The results further emphasize the desirability of including studies such as this among the other site-selection criteria for nuclear waste repositories.

Arizoan, Nevada, New Mexico