Download or read book Dissolution Studies of Plutonium Oxide in LaBS Glass written by and published by . This book was released on 1997 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of international agreement between the United States and Russia, a significant amount of plutonium requires disposition. One of the disposition paths is to immobilize it and dispose of it in a geological repository. The two favored immobilization forms are glass and ceramic. The plutonium, as an oxide, would be reacted with the glass or ceramic to form a homogeneousmaterial. The resulting solid product would then be encased in High-Level Waste (1-ILW)glass for the can-in-canister option. The HLW glass gives a radiation barrier to increase proliferation resistance. The glass canister would then be disposed of by geological emplacement. This paper discusses how glass meets two criteria: the condition of significant actinide volubility, and That the PuO2 feed should be incorporated into the matrix without significant amount of unreacted material.

Download or read book Plutonium Dioxide Dissolution in Glass written by and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pu Glass Fabrication and Product Consistency Testing written by James Marra and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The DOE/EM plans to conduct the Plutonium Vitrification Project at the Savannah River Site (SRS). An important part of this project is to reduce the attractiveness of the plutonium by fabricating a plutonium glass form and immobilizing the Pu form within the high level waste (HLW) glass prepared in the Defense Waste Processing Facility (DWPF). This requires that a project schedule that is consistent with EM plans for DWPF and cleanup of the SRS be developed. Critical inputs to key decisions in the vitrification project schedule are near-term data that will increase confidence that lanthanide borosilicate (LaBS) glass product is suitable for disposal in the Yucca Mountain Repository. A workshop was held on April 28, 2005 at Bechtel SAIC Company facility in Las Vegas, NV to define the near term data needs. Dissolution rate data and the fate of plutonium oxide and the neutron absorbers during the dissolution process were defined as key data needs. A suite of short-term tests were defined at the workshop to obtain the needed data. The objectives of these short-term tests are to obtain data that can be used to show that the dissolution rate of a LaBS glass is acceptable and to show that the extent of Pu separation from neutron absorbers, as the glass degrades and dissolves, is not likely to lead to criticality concerns. An additional data need was identified regarding the degree of macroscopic cracking that occurs during processing of the Pu glass waste form and subsequent pouring of HLW glass in the DWPF. A final need to evaluate new frit formulations that may increase the durability of the plutonium glass and/or decrease the degree to which neutron absorbers separate from the plutonium during dissolution was identified. This task plan covers testing to support a near term data need regarding glass dissolution performance. Separate task plans will be developed for testing to address the degree of macroscopic cracking and the development of alternative frit formulations. The Product Consistency Test (PCT) was identified as a means to provide some of the near term performance data. The PCT is a static test method in which known masses of crushed glass and demineralized water are reacted for a desired duration [1]. There are two reasons to perform the PCT. The first is that the results are used as a measure of acceptance in the Waste Acceptance Product Specifications Document (WAPS) [2]. The second is the need for long-term static test results that can be used to verify the applicability of the degradation model. Thus, the primary focus will be on the use of the PCT Method B (PCT-B) to study the formation and stability of colloids and to study alteration phases formed on the glass surface. The standard 7-day PCT in demineralized water (PCT-A) will be included to demonstrate compliance with the waste acceptance criterion and determine the value of the k{sub E} rate parameter for comparison with the Defense HLW Glass Degradation Model [3].

Download or read book Conversion of Plutonium containing Materials Into Borosilicate Glass Using the Glass Material Oxidation and Dissolution System written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book VARIABILITY STUDY TO DETERMINE THE SOLUBILITY OF IMPURITIES IN PLUTONIUM BEARING LANTHANIDE BOROSILICATE GLASS written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focuses on the development of a compositional envelope that describes the retention of various impurities in lanthanide borosilicate (LaBS) glass for vitrification and immobilization of excess, defense-related plutonium. A limited amount of impurity data for the various plutonium sources is available and projections were made through analysis of the available information. These projections were used to define types and concentrations of impurities in the LaBS glass compositions to be fabricated and tested. Sixty surrogate glass compositions were developed through a statistically designed approach to cover the anticipated ranges of concentrations for several impurity species expected in the plutonium feeds. An additional four glass compositions containing actual plutonium oxide were selected based on their targeted concentrations of metals and anions. The glasses were fabricated and characterized in the laboratory and shielded cells facility to determine the degree of retention of the impurity components, the impact of the impurities on the durability of each glass, and the degree of crystallization that occurred, both upon quenching and slow cooling. Overall, the LaBS glass system appears to be very tolerant of most of the impurity types and concentrations projected in the plutonium waste stream. For the surrogate glasses, the measured CuO, Ga2O3, Na2O, NiO, and Ta2O5 concentrations fell very close to their target values across the ranges of concentrations targeted in this study for each of these components. The measured CaO and PbO concentrations were consistently higher than the targeted values. The measured Cr2O3 and Fe2O3 concentrations were very close to the targets except for the one highest targeted value for each of these components. A solubility limit may have been approached in this glass system for K2O and MgO. The measured Cl−, F−, SeO2 and SO42− concentrations were well below their target values for all of the study glasses. This is likely due to volatilization of these species during melting of the glass batch. Note that the degree of volatilization that occurred in this crucible-scale study may differ from the full-scale melter. The measured HfO2 concentrations were below their target values for all of the surrogate glasses. It is likely that for HfO2, the solubility limit in the glass was exceeded and some of the HfO2 batch material remained in the bottom of the crucibles after pouring the glasses. X-ray diffraction and scanning electron microscopy (SEM) results indicated that some crystalline HfO2 remained in some of the surrogate glasses with the lowest concentration of impurities. No other crystalline phases were identified. The Product Consistency Test (PCT) results showed that all 60 of the surrogate glass compositions tested were very durable, regardless of thermal history, with the highest normalized release for boron being 0.041 g/L. The pH of the leachate solutions was generally lower than that of conventional waste glasses due to the lack of alkali in the LaBS glass, which likely impacted the PCT results. The normalized release rates for the elements measured were generally too small to attempt to correlate the results with the compositions of the test glasses. The Toxicity Characteristic Leaching Procedure results showed that no hazardous metals were leached from the surrogate glasses in any measurable concentration. A plutonium-containing crystalline phase with a cross-shaped morphology was identified via SEM in the glasses fabricated with plutonium oxide. This phase was identified in a previous study of plutonium-bearing LaBS glasses and may provide an opportunity to intentionally crystallize some of the plutonium oxide into a highly insoluble form with an intrinsic neutron absorber. Additional work is necessary to better characterize the influence that this phase has on durability of the glass. The PCT results for the plutonium-containing LaBS glasses with impurities were similar to previous tests conducted on PuO2-containing glasses without impurities added. The highest normalized release for boron was 0.02 g/L, which bounded the highest normalized release for plutonium of 0.01 g/L.

Download or read book Waste Immobilization in Glass and Ceramic Based Hosts written by Ian W. Donald and published by John Wiley & Sons. This book was released on 2010-04-01 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: The safe storage in glass-based materials of both radioactiveand non-radioactive hazardous wastes is covered in a single book,making it unique Provides a comprehensive and timely reference source at thiscritical time in waste management, including an extensive andup-to-date bibliography in all areas outlined to waste conversionand related technologies, both radioactive and non-radioactive Brings together all aspects of waste vitrification, drawscomparisons between the different types of wastes and treatments,and outlines where lessons learnt in the radioactive waste fieldcan be of benefit in the treatment of non-radioactive wastes

Download or read book MacroscoMacroscopic Cracking Determination in LaBS Glasspic Cracking Determination in LaBS Glass written by James Marra and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The DOE/EM plans to conduct the Plutonium Vitrification Project at the Savannah River Site (SRS). An important part of this project is to reduce the attractiveness of the plutonium by fabricating a plutonium glass form and immobilizing the Pu form within the high level waste (HLW) glass prepared in the Defense Waste Processing Facility (DWPF). This requires that a project schedule that is consistent with EM plans for DWPF and cleanup of the SRS be developed. Critical inputs to key decisions in the vitrification project schedule are near-term data that will increase confidence that the lanthanide borosilicate (LaBS) glass product is suitable for disposal in the Yucca Mountain Repository. A workshop was held on April 28, 2005 at Bechtel SAIC Company (BSC) facility in Las Vegas, NV to define the near term data needs. Dissolution rate data and the fate of plutonium oxide and the neutron absorbers during the dissolution process were defined as key data needs. A suite of short-term tests were defined at the workshop to obtain the needed data. The objectives of these short-term tests are to obtain data that can be used to show that the dissolution rate of a LaBS glass is acceptable and to show that the extent of Pu separation from neutron absorbers, as the glass degrades and dissolves, is not likely to lead to criticality concerns. An additional data need was identified regarding the degree of macroscopic cracking and/or voiding that occurs during processing of the Pu glass waste form and subsequent pouring of HLW glass in the DWPF. A final need to evaluate new frit formulations that may increase the durability of the plutonium glass and/or decrease the degree to which neutron absorbers separate from the plutonium during dissolution was identified. This task plan covers the need to evaluate the degree of macroscopic cracking and/or voiding that occurs during processing of the Vitrified Plutonium Waste Form (i.e. the can-in-canister configuration containing the vitrified Pu product). Separate task plans were developed for Pu glass performance testing of the current baseline LaBS glass composition and development of alternative frit formulations. Recent results from Pressurized Unsaturated Flow (PUF) testing showed the potential separation of Pu from Gd during the glass dissolution process [3]. Post-test analysis of the LaBS glass from a 6-year PUF test showed a region where Pu had apparently accumulated in a Pu-bearing disk-like phase that had become separated from neutron absorber (Gd). It should be noted that this testing was conducted on the early LaBS Frit A glass composition that was devoid of HfO{sub 2} as a neutron absorber. PUF testing is currently being initiated using the LaBS Frit B composition that contains HfO{sub 2}. The potential for fissile material and neutron absorber separation is a criticality risk for the repository. The surface area that is available for leaching (i.e. due to the degree of cracking or voiding within the Pu glass cylinder) is a factor in modeling the amount of fissile material and neutron absorber released during the dissolution process. A mathematical expression for surface area is used in the Total Systems Performance Assessment (TSPA) performed by BSC personnel. Specifically, the surface area available for leaching is being used in current external criticality assessments. The planned processing steps for producing a VPWF assembly involves processing Pu feed and LaBS frit to produce a can of Pu LaBS glass, packaging this can into a second can (i.e. bagless transfer) for removal from the glovebox processing environment, placing a series of bagless transfer cans into a DWPF canister, and pouring HLW glass into the DWPF canister to encapsulate bagless transfer cans. The objective of this task is to quantify the degree of cracking and/or voiding that will occur during the processing of the VPWF.

Download or read book Conversion of Plutonium Containing Materials Into Borosilicate Glass Using the Glass Material Oxidation and Dissolution System written by C. W. Forsberg and published by . This book was released on 1996 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Vitrification of Plutonium containing Materials PCM s with the Glass Material Oxidation and Dissolution System GMODS 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 Dissolution of Plutonium Oxide written by G.F. Molen and published by . This book was released on 1967 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Glass as a Waste Form and Vitrification Technology written by National Research Council and published by National Academies Press. This book was released on 1997-03-02 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acid Dissolution Method for the Analysis of Plutonium in Soil written by E. L. Whittaker and published by . This book was released on 1979 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSILICATE FRIT B COMPOSITION FOR PLUTONIUM DISPOSITION written by J. Marra and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is a leading candidate for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (LaBS) Frit B) was developed during the Plutonium Immobilization Program (PIP) to immobilize plutonium. A limited amount of performance testing was performed on this baseline composition before efforts to further pursue Pu disposition via a glass waste form ceased. Therefore, the objectives of this present task were to fabricate plutonium loaded LaBS Frit B glass and perform additional testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the Yucca Mountain Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit B composition with a 9.5 wt% PuO{sub 2} loading was prepared for testing. Glass was prepared to support Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL) and for additional performance testing at Argonne National Laboratory (ANL) and Pacific Northwest National Laboratory (PNNL). The glass was characterized using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. A series of PCTs were conducted at SRNL with varying exposed surface area and test durations. The leachates from these tests were analyzed to determine the dissolved concentrations of key elements. Acid stripping of leach vessels was performed to determine the concentration of the glass constituents that may have sorbed on the vessels during leach testing. Additionally, the leachate solutions were ultrafiltered to quantify colloid formation. The leached solids from select PCTs were examined in an attempt to evaluate the Pu and neutron absorber release behavior from the glass and to identify the formation of alteration phases on the glass surface. Characterization of the glass prior to testing revealed that some undissolved plutonium oxide was present in the glass. The undissolved particles had a disk-like morphology and likely formed via coarsening of particles in areas compositionally enriched in plutonium. Similar disk-like PuO{sub 2} phases were observed in previous LaBS glass testing at PNNL. In that work, researchers concluded that plutonium formed with this morphology as a result of the leaching process. It was more likely that the presence of the plutonium oxide crystals in the PNNL testing was a result of glass fabrication. A series of PCTs were conducted at 90 C in ASTM Type 1 water. The PCT-Method A (PCT-A) was conducted to compare the Pu LaBS Frit B glass durability to current requirements for High Level Waste (HLW) glass in a geologic repository. The PCT-A test has a strict protocol and is designed to specifically be used to evaluate whether the chemical durability and elemental release characteristics of a nuclear waste glass have been consistently controlled during production and, thus, meet the repository acceptance requirements. The PCT-A results on the Pu containing LaBS Frit B glass showed that the glass was very durable with a normalized elemental release value for boron of approximately 0.02 g/L. This boron release value was better than two orders of magnitude better from a boron release standpoint than the current Environmental Assessment (EA) glass used for repository acceptance. The boron release value for EA glass is 16.7 g/L.

Download or read book Plutonium Oxide Dissolution written by and published by . This book was released on 1992 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several processing options for dissolving plutonium oxide (PuO2) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO2 typically generated by burning plutonium metal and PuO2 produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuO2 in canyon dissolvers. The options involve solid solution formation of PuO2 With uranium oxide (UO2) and alloying incinerator ash with aluminum. An oxidative dissolution process involving nitric acid solutions containing a strong oxidizing agent, such as cerium (IV), was neither proven nor rejected. This uncertainty was due to difficulty in regenerating cerium (IV) ions during dissolution. However, recent work on silver-catalyzed dissolution of PuO2 with persulfate has demonstrated that persulfate ions regenerate silver (II). Use of persulfate to regenerate cerium (IV) or bismuth (V) ions during dissolution of PuO2 materials may warrant further study.

Download or read book Methods for the Accountability of Plutonium Dioxide written by R. G. Gutmacher and published by . This book was released on 1974 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Review of the Dissolution of Plutonium Dioxide written by W. S. Gilman and published by . This book was released on 1968 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conversion of Plutonium Scrap and Residue to Boroilicate Glass Using the GMODS Process written by and published by . This book was released on 1995 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plutonium scrap and residue represent major national and international concerns because (1) significant environmental, safety, and health (ES & H) problems have been identified with their storage; (2) all plutonium recovered from the black market in Europe has been from this category; (3) storage costs are high; and (4) safeguards are difficult. It is proposed to address these problems by conversion of plutonium scrap and residue to a CRACHIP (CRiticality, Aerosol, and CHemically Inert Plutonium) glass using the Glass Material Oxidation and Dissolution System (GMODS). CRACHIP refers to a set of requirements for plutonium storage forms that minimize ES & H concerns. The concept is several decades old. Conversion of plutonium from complex chemical mixtures and variable geometries into a certified, qualified, homogeneous CRACHIP glass creates a stable chemical form that minimizes ES & H risks, simplifies safeguards and security, provides an easy-to-store form, decreases storage costs, and allows for future disposition options. GMODS is a new process to directly convert metals, ceramics, and amorphous solids to glass; oxidize organics with the residue converted to glass; and convert chlorides to borosilicate glass and a secondary sodium chloride stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium (a plutonium surrogate), Zircaloy, stainless steel, and other materials to glass. GMODS is an enabling technology that creates new options. Conventional glassmaking processes require conversion of feeds to oxide-like forms before final conversion to glass. Such chemical conversion and separation processes are often complex and expensive.