Hydrothermal interactions of cesium and strontium phases from spent unreprocessed fuel with basalt phases and basalts
This investigation is a segment of an extensive research program aimed at investigating the feasibility of long-term, subsurface storage of commercial nuclear waste. Specifically, it is anticipated that the waste will be housed in a repository mined from the basalt formations which lie beneath the Hanford Site. The elements monitored during the present experiments were Cs and Sr. These two elements represent significant biohazards if released from a repository and are the major heat producing radionuclides present in commercial radioactive waste. Several Cs phases and/or solutions were reacted with either isolated basalt phases or bulk-rock basalt, and the resulting solids and solutions were analyzed. The hydrothermal reactivity of SrZrO/sub 3/, which is believed to be a probable host for Sr in SFE was investigated. While so far no evidence exists which indicates that Sr is present in a water soluble phase in spent fuel elements (SFE), detailed investigation of a potential hazard is warranted. This investigation has determined that some Cs compounds likely to be stable components of spent fuel (i.e., CsOH, Cs/sub 2/MoO/sub 4/, Cs/sub 2/U/sub 2/O/sub 7/) have significant hydrothermal solubilities. These solubilities are greatly decreased in the presence of basalt and/or basalt minerals. The decrease in the amount of Cs in solution results from reactions which form pollucite and/or CsAlSiO/sub 4/, with the production of pollucite exceeding that of CsAlSiO/sub 4/. Dissolution of ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ implies solubilizing a uranium species to an undetermined extent. The production of schoepite (UO/sub 3/.3H/sub 2/O) during some experiments containing basalt phases, indicates a tendency to oxidize U/sup 4 +/ to U/sup 6 +/. When diopside (nominally CaMgSi/sub 2/O/sub 6/) and ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ were hydrothermally reacted, at 300/sup 0/C both UO/sub 2/ and UO/sub 3/.3H/sub 2/O were produced. Results of experiments on SrZrO/sub 3/ show it to be an unreactive phase.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (United States); Atomics International Div., Richland, WA (USA). Rockwell Hanford Operations
- DOE Contract Number:
- AC06-77RL01030
- OSTI ID:
- 5306867
- Report Number(s):
- RHO-BWI-C-70; TRN: 80-010440
- Country of Publication:
- United States
- Language:
- English
Similar Records
Hydrothermal reactions of shales and clay minerals with cesium phases representative of spent reactor fuel
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Related Subjects
54 ENVIRONMENTAL SCIENCES
BASALT
CHEMICAL REACTIONS
CESIUM
CESIUM OXIDES
SOLUBILITY
MOLYBDENUM OXIDES
STRONTIUM
STRONTIUM OXIDES
ZIRCONIUM OXIDES
ALUMINIUM OXIDES
DIOPSIDE
EXPERIMENTAL DATA
GRAPHS
HANFORD RESERVATION
RADIOACTIVE WASTE DISPOSAL
SCHOEPITE
SILICON OXIDES
SPENT FUEL STORAGE
TABLES
UNDERGROUND DISPOSAL
URANIUM OXIDES
X-RAY DIFFRACTION
ACTINIDE COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
ALUMINIUM COMPOUNDS
CESIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
DATA
DATA FORMS
DIFFRACTION
ELEMENTS
IGNEOUS ROCKS
INFORMATION
MANAGEMENT
METALS
MINERALS
MOLYBDENUM COMPOUNDS
NATIONAL ORGANIZATIONS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PYROXENES
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
ROCKS
SCATTERING
SILICATES
SILICON COMPOUNDS
STRONTIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
URANIUM COMPOUNDS
URANIUM MINERALS
US DOE
US ERDA
US ORGANIZATIONS
WASTE DISPOSAL
WASTE MANAGEMENT
ZIRCONIUM COMPOUNDS
052002* - Nuclear Fuels- Waste Disposal & Storage
510301 - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- Soil- (-1987)