Download or read book Measured Solubilities and Speciations of Neptunium Plutonium and Americium in a Typical Groundwater J 13 from the Yucca Mountain Region Milestone Report 3010 WBS 1 2 3 4 1 3 1 written by Heino Nitsche and published by . This book was released on 1993 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measured Solubilities and Speciations of Neptunium Plutonium and Americium in a Typical Groundwater J 13 from the Yucca Mountain Region Milestone Report 3010 WBS 1 2 3 4 1 3 1 written by and published by . This book was released on 1993 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solubility and speciation data are important in understanding aqueous radionuclide transport through the geosphere. They define the source term for transport retardation processes such as sorption and colloid formation. Solubility and speciation data are useful in verifying the validity of geochemical codes that are part of predictive transport models. Results are presented from solubility and speciation experiments of 237NpO2, 239Pu{sup 4+}, 241Am{sup 3+}/Nd{sup 3+}, and 243Am{sup 3+} in J-13 groundwater (from the Yucca Mountain region, Nevada, which is being investigated as a potential high-level nuclear waste disposal site) at three different temperatures (25°, 60°, and 90°C) and pH values (5.9, 7.0, and 8.5). The solubility-controlling steady-state solids were identified and the speciation and/or oxidation states present in the supernatant solutions were determined. The neptunium solubility decreased with increasing temperature and pH. Plutonium concentrations decreased with increasing temperature and showed no trend with pH. The americium solutions showed no clear solubility trend with increasing temperature and increasing pH.
Download or read book Measured Solubilities and Speciations from Oversaturation Experiments of Neptunium Plutonium and Americium in UE 25p 1 Well Water from the Yucca Mountain Region Milestone Report 3329 WBS 1 2 3 4 1 3 1 written by Heino Nitsche and published by . This book was released on 1994 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measured Solubilities and Speciations from Oversaturation Experiments of Neptunium Plutonium and Americium in UE 25p No 1 Well Water from the Yucca Mountain Region written by and published by . This book was released on 1994 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solubility and speciation are important in understanding aqueous radionuclide transport through the geosphere. They define the source term for transport retardation processes such as sorption and colloid formation. Solubility and speciation data are useful in verifying the validity of geochemical codes that are a part of predictive transport models. Results are presented from solubility and speciation experiments of 237NpO2, 239Pu{sup 4+}, and 241Am{sup 3+}/Nd{sup 3+} in a modified UE-25p No. 1 groundwater (from the Yucca Mountain region, Nevada, which is being investigated as a potential high-level nuclear waste disposal site) at two different temperatures (25° and 60°C) and three pH values (6.0, 7.0, 8.5). The solubility-controlling steady-state solids were identified and the speciation and/or oxidation states present in the supernatant solutions were determined. The neptunium solubility decreased with increasing temperature and pH. Plutonium concentrations significantly decreased with increasing temperature at pH 6 and 7. The concentration at pH 8.5 hardly decreased at all with increasing temperature. At both temperatures the concentrations were highest at pH 8.5, lowest at pH 7, and in between at pH 6. For the americium/neodymium solutions, the solubility decreased significantly with increasing temperature and increased somewhat with increasing pH.
Download or read book Measured Solubilities and Speculations from Oversaturation Experiments of Neptunium Plutonium and Americium in UE 25p No 1 Well Water from the Yucca Mountain Region written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solubility and Speciation Studies of Waste Radionuclides Pertinent to Geologic Disposal at Yucca Mountain written by and published by . This book was released on 1988 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have studied the solubilities of neptunium, plutonium, and americium in J-13 groundwater from Yucca Mountain (Nevada) at three temperatures and hydrogen ion concentrations. They are 25°, 60°C, and 90°C and pH 5.9, 7.0, and 8.5. The results for 25°C are from a study which we did during FY 1984. We included these previous results in the tables to give more information on the solubility temperature dependence; they were, however, done at only one pH (7.0). The solubilities were studied from oversaturation. The nuclides were added at the beginning of each experiment as NpO2, Pu{sup 4+}, and Am{sup 3+}. The neptunium solubility decreased with increasing temperature and with increasing pH. The soluble neptunium did not change oxidation state at steady state. The pentavalent neptunium was increasingly complexed by carbonate with increasing pH. All solids were crystalline and contained carbonate, except the solid formed at 90°C and pH 5.9. We identified this solid as crystalline Np2P5. The 25°C, pH 7 solid was Na3NpO2(CO3)2 · nH2O. Plutonium concentrations decreased with increasing temperature and showed no trend with pH. Pu(V) and Pu(VI) were the dominant oxidation states in the supernatant solution; as the amount of Pu(V) increased with pH, Pu(VI) decreed. The steady-state solids were mostly amorphous, although some contained a crystalline component. They contained Pu(IV) polymer and unknown carbonates.
Download or read book Solubility and Speciation Results from Oversaturation Experiments on Neptunium Plutonium and Americium in a Neutral Electrolyte with a Total Carbonate Similar to Water from Yucca Mountain Region Well UE 25p 1 written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1738 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994-05 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Speciation of Plutonium and Americium in Ground Waters from the Radioactive Waste Management Complex Idaho National Engineering Laboratory Idaho written by Jesse M. Cleveland and published by . This book was released on 1993 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solubility and Speciation Results from Over and Undersaturation Experiments on Neptunium Plutonium and Americium in Water from Yuccca Mountain Region Well UE 25p 1 written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluorescence Studies of Plutonium Neptunium and Americium written by George Robert Price and published by . This book was released on 1948 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Batch Sorption Results for Neptunium Transport Through Yucca Mountain Tuffs written by Ines R. Triay and published by . This book was released on 1996 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: We studied the sorption of neptunium onto tuffs characteristic of the proposed nuclear waste repository at Yucca Mountain, Nevada. The neptunium was in the Np(V) oxidation state under oxidizing conditions in groundwaters from two wells located close to the repository site (J-13 and UE-25 p No. 1). We used devitrified, vitric, zeolitic (with emphasis on clinoptilolite-rich samples), and calcite-rich tuffs characteristic of the geology of the site. Neptunium sorbed well onto calcite and calcite-rich tuffs, indicating that a significant amount of neptunium retardation can be expected under fractured-flow scenarios because of calcite coating of the fractures. Neptunium sorption onto clinoptilolite-rich zeolitic tuffs in J-13 well water (pH from 7 to 8.5) was moderate, increased with decreasing pH, and correlated to surface area and amount of clinoptilolite. Neptunium sorbed poorly onto zeolitic tuffs from UE-25 p No. 1 groundwater (pH from 7 to 9) and onto devitrified and vitric tuffs from J-13 and UE-25 p No. 1 waters (pH from 7 to 9). Iron oxides appeared to be passivated in tuffs, not seeming to contribute to the observed neptunium sorption, even though neptunium sorption onto synthetic iron oxide is significant.
Download or read book Transport of Neptunium Through Yucca Mountain Tuffs written by and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neptunium has a high solubility in groundwaters from Yucca Mountain [1]. Uranium in nuclear reactors produces 237Np which has a half-life of 2.1 4 x 106 years. Consequently, the transport of 237Np through tuffs is of major importance in assessing the performance of a high-level nuclear waste repository at Yucca Mountain. The objective of this work is to determine the amount of Np retardation that is provided by the minerals in Yucca Mountain tuffs as a function of groundwater chemistry.
Download or read book Batch Sorption Results for Neptunium Transport Through Yucca Mountain Tuffs Yucca Mountain Site Characterization Program Milestone 3349 written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We studied the sorption of neptunium onto tuffs characteristic of the proposed nuclear waste repository at Yucca Mountain, Nevada. The neptunium was in the Np(V) oxidation state under oxidizing conditions in groundwaters from two wells located close to the repository site (J-13 and UE-25 p No. 1). We used devitrified, vitric, zeolitic (with emphasis on clinoptilolite-rich samples), and calcite-rich tuffs characteristic of the geology of the site. Neptunium sorbed well onto calcite and calcite-rich tuffs, indicating that a significant amount of neptunium retardation can be expected under fractured-flow scenarios because of calcite coating of the fractures. Neptunium sorption onto clinoptilolite-rich zeolitic tuffs in J-13 well water (pH from 7 to 8.5) was moderate, increased with decreasing pH, and correlated to surface area and amount of clinoptilolite. Neptunium sorbed poorly onto zeolitic tuffs from UE-25 p No. 1 groundwater (pH from 7 to 9) and onto devitrified and vitric tuffs from J-13 and UE-25 p No. 1 waters (pH from 7 to 9). Iron oxides appeared to be passivated in tuffs, not seeming to contribute to the observed neptunium sorption, even though neptunium sorption onto synthetic iron oxide is significant.
Download or read book Comparison of Neptunium Sorption Results Using Batch and Column Techniques written by Ines R. Triay and published by . This book was released on 1996 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: We used crushed-rock columns to study the sorption retardation of neptunium by zeolitic, devitrified, and vitric tuffs typical of those at the site of the potential high-level nuclear waste repository at Yucca Mountain, Nevada. We used two sodium bicarbonate waters (groundwater from Well J-13 at the site and water prepared to simulate groundwater from Well UE-25p No. 1) under oxidizing conditions. It was found that values of the sorption distribution coefficient, Kd, obtained from these column experiments under flowing conditions, regardless of the water or the water velocity used, agreed well with those obtained earlier from batch sorption experiments under static conditions. The batch sorption distribution coefficient can be used to predict the arrival time for neptunium eluted through the columns. On the other hand, the elution curves showed dispersivity, which implies that neptunium sorption in these tuffs may be nonlinear, irreversible, or noninstantaneous. As a result, use of a batch sorption distribution coefficient to calculate neptunium transport through Yucca Mountain tuffs would yield conservative values for neptunium release from the site. We also noted that neptunium (present as the anionic neptunyl carbonate complex) never eluted prior to tritiated water, which implies that charge exclusion does not appear to exclude neptunium from the tuff pores. The column experiments corroborated the trends observed in batch sorption experiments: neptunium sorption onto devitrified and vitric tuffs is minimal and sorption onto zeolitic tuffs decreases as the amount of sodium and bicarbonate/carbonate in the water increases.
Download or read book Plutonium Carbonate Speciation Changes as Measured in Dilute Solutions with Photoacoustic Spectroscopy written by and published by . This book was released on 1995 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
