Quantitative analysis of hydrogen gas formed by aqueous corrosion of metallic uranium.

Fonnesbeck, J. E.

doi:10.2172/766357

Cited by 4 publications

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“…Based on the consumption of nitrogen observed in some tests, uranium metal oxidation also is conservatively postulated to occur by Reaction 3. While no explicit mention of the reaction of uranium metal with N 2 in aqueous systems was found in the technical literature, depletion of atmospheric N 2 (and O 2 ) relative to atmospheric argon was observed in this and prior testing with K Basin sludge and also was observed in aqueous corrosion testing of uranium metal in 90°C simulated well water containing ~0.002 M bicarbonate (Fonnesbeck 2000). The postulated Reaction 3 is based on the observed depletion of N 2 from the gas phase in the present tests and the observation of a nonstoichiometric UN 1.75 product from reaction of uranium metal with N 2 at 200°C to 300°C (Cordfunke 1969).…”

Section: Uranium Corrosion and The Roles Of Hydrogen Oxygen And Nitmentioning

confidence: 60%

Gas Generation from K East Basin Sludges - Series II Testing

Bryan¹,

Delegard²,

Schmidt³

et al. 2004

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This report was originally published in March 2001. In January 2004, a transcription error was discovered in the value reported for the uranium metal content of KE North Loadout Pit sample FE-3. This revision of the report corrects the U metal content of FE-3 from 0.0013 wt% to 0.013 wt%. The text also has been revised to more accurately describe the expected uranium metal reactions being measured and evaluated. Experimental Matrix for Series II Gas Generation Tests and Uranium Metal Estimates Sludge Sample Fraction Test Temp., °C Estimated Uranium Metal Content Test Description Sample ID Settled Sludge, g Start ~300 hr Final ~650 hr Wt % U Metal (Settled Sludge Basis) Estimation Technique KE Canister Sludge (Consolidated Sampler Used in Single-Pull Mode) Unmixed KC-1 KC-1 (whole) 23.8 60 95 0.065 Fission Product Gas Mixed KC-1 KC-1 (whole) 25.6 60 95 0.56 Fission Product Gas U Metal in KC-1 Plus 500 µm 14.2 80 95 3.7 Fission Product Gas U Metal in KC-1 Minus 500 µm 22.3 80 95 0.14 Fission Product Gas Single-Pull Core KE Floor and Pit Sludge Samples Main Floor (FE-1) FE-1 (whole) 27.0 90 95 0.022 Fission Product Gas North Loadout Pit (FE-3) FE-3 (whole) 21.2 90 95 0.013 Corrosion Gas Weasel Pit (FE-5) FE-5 (whole) 20.7 90 95 0.027 Fission Product Gas Dummy Elevator and Tech View Pit (FE-4 + FE-6) FE-4 (63%) + FE-6 (37%) 16.1 (10.2/5.9) 90 95 0.0052 Fission Product Gas Other Tests Organic Ion Exchange Resin Sludge KC-6 (whole) 19.1 90 95 0.026 Corrosion Gas 1996 KE Canister Sludge 96-06 19.5 80 95 0.90 Fission Product Gas v gas generation testing. The technique used to estimate uranium metal content (corrosion gas generation or fission product gas release by the corrosion) is also noted in the table. The uranium metal content is estimated based on fission product gas release, where available, because of its higher reliability, especially at low concentrations. Gas Generation Testing Gas production observed in the Series II tests with KE Basin sludge was generally lower than observed in similar Series I studies of KE Basin canister and floor sludges (Delegard et al. 2000). The lower gas generation rates can partially be attributed to the longer storage periods at hot cell temperatures experienced by the Series II sludge samples. All tests in Series II (conducted with sludge from samples KC-1, FE-1, FE-3, FE-5, FE-4/6, KC-6, and 96-06) produced CO 2 as the predominant gas product with lower concentrations of H 2 , except the KC-1 P500 test, which produced predominantly H 2 gas with lower CO 2 concentrations. Other gases released or produced were Xe, Kr, and hydrocarbons (methane, ethane, and higher hydrocarbons). Trace amounts of O 2 and N 2 present from atmospheric contamination also were consumed in each test. Similar gas generation and consumption was observed in the Series I tests and in gas collection tests from KE canister sludge (Makenas et al. 1997). The release of CO 2 in these tests may be due to the reaction of schoepite with calcite to form becquerelite and CO 2 , with some (but not all) of the CO 2 also...

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Section: Uranium Corrosion and The Roles Of Hydrogen Oxygen And Nitmentioning

confidence: 60%

Gas Generation from K East Basin Sludges - Series II Testing

Bryan¹,

Delegard²,

Schmidt³

et al. 2004

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“…Overall, the paired findings for the irradiated and non-irradiated N Reactor fuel at 25°C Einziger 1998 andAbrefah et al 2000, respectively) and irradiated and non-irradiated EBR-II fuel at 90°C (Fonnesbeck et al 1998and Fonnesbeck 2000, 2003 show irradiation to increase rates. However, the effects of irradiated fuel crumbling or increased surface area were not investigated.…”

Section: Correspondence Of Irradiated Uranium Metal Corrosion Rates Imentioning

confidence: 89%

“…The 90°C rate datum for uranium metal blanket fuel irradiated to ~30,000 MWD/MTU (Fonnesbeck et al 1998) also is shown in Figure 3.3 and likewise is consistent with the STP rate. Comparable corrosion-rate measurements of non-irradiated EBR-II fuel metal in anoxic liquid water by hydrogen gas generation were conducted at the same 90°C temperature by the same laboratory (Fonnesbeck 2000(Fonnesbeck , 2003. As seen in Figure 3.3, the corrosion rate for non-irradiated EBR-II fuel metal is about half of the rate for the comparable irradiated EBR-II metal.…”

Section: Correspondence Of Irradiated Uranium Metal Corrosion Rates Imentioning

confidence: 98%

Uranium Metal Reaction Behavior in Water, Sludge, and Grout Matrices

Delegard

Schmidt²

2008

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This report was originally published in September 2008. In May 2009, it was discovered that, in the introductory paragraphs of Section 2.1, the units for the reaction enthalpy of uranium metal with water to form uranium dioxide and hydrogen and the reaction enthalpy of hydrogen with oxygen to form water were incorrectly given as kcal/mole rather than kJ/mole. This version of the report, Revision 1, corrects the units for both enthalpies to kJ/mole. Other small editorial changes also were made.iii SummaryThis report summarizes information and data on the reaction behavior of uranium metal in water, in water-saturated simulated and genuine K Basin sludge, and in grout matrices. This information and data are used to establish the technical basis for metallic uranium reaction behavior for the K Basin Sludge Treatment Project (STP). The specific objective of this report is to consolidate the various sources of information into a concise document to serve as a high-level reference and road map for customers, regulators, and interested parties outside the STP (e.g., external reviewers, other DOE sites) to clearly understand the current basis for the corrosion of uranium metal in water, sludge, and grout.The generation of hydrogen gas through oxidation/corrosion of uranium metal by its reaction with water can potentially create a flammable atmosphere during sludge handling, grouting, or subsequent transport and storage operations. Consequently, a thorough understanding of the uranium metal content and its reaction behavior, both in sludge and in grouted sludge matrices, is essential to the process designs and for management of sludge. Results of studies of this reaction and its characteristics have been reported in the technical literature for over 60 years. More focused studies of the reaction in simulated and genuine K Basin sludge and in grout matrices have been conducted in the past 10 years. The outcomes of these studies, provided in the present review, show that: The reaction of uranium metal with anoxic liquid water is highly exothermic and produces stoichiometric uranium dioxide (UO 2 ) and hydrogen. The reaction apparently proceeds through a uranium hydride intermediate that can sequester part of the hydrogen during the initial reaction. The corrosion reaction occurs isotropically such that the uranium particle size decreases at a constant rate at a given temperature. Based on a survey of 32 studies giving 128 data points, the corrosion rate follows an Arrhenius dependence on temperature (i.e., the logarithm of the rate is proportional to the inverse absolute temperature) from at least 24°C to 350°C. The rate law was adopted for the STP. A 95% confidence level on the predicted rate is plus/minus about a factor of three. The STP rate law is essentially the same as used in the application to license the Yucca Mountain repository. Dissolved oxygen inhibits the reaction of uranium metal with liquid water, but the more rapid anoxic reaction can follow the lower oxic rates at times that are difficult to predict...

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“…Increases in solution pH and depletion of atmospheric N 2 (and O 2 ) relative to atmospheric argon were observed in aqueous corrosion testing of uranium metal in 90°C simulated well water containing ~0.002 M bicarbonate (Fonnesbeck 2000). Unintentional atmospheric contamination occurred in the tests, introducing O 2 and N 2 .…”

Section: Nitrogen and The Possible Formation Of Ammoniamentioning

confidence: 94%

“…The possible formation of NH 3 in the aqueous reaction of uranium with atmospheric N 2 and H 2 generated by uranium metal corrosion or reaction of trace nitrogen from the fuel may explain the pH increases observed in a number of the Series I, II, and III tests and in the tests of Fonnesbeck (2000). The product NH 3 , dissolved in water, produces a mildly alkaline solution (for example, the pH of a 0.01 M NH 3 solution is 10.6):…”

Section: Nitrogen and The Possible Formation Of Ammoniamentioning

confidence: 99%

Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

Schmidt¹,

Delegard²,

Bryan³

et al. 2003

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The path forward for managing Hanford K Basin sludge calls for it to be packaged, shipped, and stored at T Plant until final processing at a future date. An important consideration for the design and cost of retrieval, transportation, and storage systems is the potential for heat and gas generation through oxidation reactions between uranium metal and water. This report, the third in a series (Series III), describes work performed at the Pacific Northwest National Laboratory (PNNL) to assess corrosion and gas generation from irradiated metallic uranium particles (fuel particles) with and without sludge addition. The first test series (Series I; Delegard et al. 2000) focused on gas generation from K East (KE) Basin floor and canister sludge (size-fractionated and unfractionated samples collected using a consolidated sampling technique (Baker et al. 2000). The second series (Series II; Bryan et al. 2001) examined the gas generation behavior of KE Basin floor, pit, and canister sludge. Mixed and unmixed and fractionated KE canister sludge materials were tested, along with floor and pit sludge from areas in the KE Basin not previously sampled. The sludge material used in all three test series was saturated with water, consistent with sludge management plans. The work for all three test series was conducted under the direction of the Spent Nuclear Fuel (SNF) Sludge Handling Project managed by Fluor Hanford, and in accordance with the corresponding data quality objectives (Makenas 2000) and the sampling and analysis plan (Baker et al. 2000). The overall goal for the Series III testing was to evaluate the behavior and reactivity of the fuel particles, with and without K Basin sludge, under known conditions, through the evaluation of gas generation rate and composition data. Specific objectives for Series III included: The test matrix shown below displays the mass and size distribution of the fuel particles (and any associated cladding), the type and quantity of the added K Basin sludge, the test vessel size, test temperatures, and total test duration. The last column lists the fraction of the sample that was corroded at

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Quantitative analysis of hydrogen gas formed by aqueous corrosion of metallic uranium.

Cited by 4 publications

References 1 publication

Gas Generation from K East Basin Sludges - Series II Testing

Gas Generation from K East Basin Sludges - Series II Testing

Uranium Metal Reaction Behavior in Water, Sludge, and Grout Matrices

Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

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