Evaluation and Recommendation of Waste Form and Packaging for Disposition of the K East Basin North Loadout Pit Sludge

Mellinger, G.B.; Delegard, Calvin H.; Schmidt, Andrew J.; Sevigny, Gary J.

doi:10.2172/15007928

Cited by 10 publications

(18 citation statements)

References 6 publications

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“…All three "KE NLOP" samples have significant sludge volumes in the respective jars and thus were measured with good precision. Therefore their varied settled density values reflect heterogeneity of this sludge material, which is known to be rich in rapidly settling quartz sand and also contain a much slower settling fine fraction that is, overall, low in uranium concentration (Mellinger et al 2004;Delegard et al 2011). In the case of "KC-4-2" sludge the density data scatter for the X-jar and Y-jar replicates is predominantly associated with uneven splitting of the original sample to produce 142 ml and 14 ml of the settled sludge, respectively.…”

Section: Sludge Bulk Propertiesmentioning

confidence: 99%

Characteristics of STP Pre-2004 Archived KE Basin Sludge Samples Before and After Re-Jarring in the RPL - April 2012

Sinkov¹,

Delegard²,

Schmidt³

et al. 2012

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SummaryThe Sludge Treatment Project (STP), managed for the U.S. Department of Energy (DOE) by CH2M Hill Plateau Remediation Company (CHRPC), is responsible for operating the K West (KW) Basin fuel storage pool and managing the sludge (and other materials) that it contains. The STP mission includes characterization, containment, safe removal, treatment, and transportation of all sludge (treated or untreated) from the KW Basin. Since the 1990s, samples of K Basin sludge have been collected during several sampling campaigns. In support of these campaigns, samples have been sent to the Pacific Northwest National Laboratory (PNNL) for characterization and process testing. At the request of the STP, sludge materials from these campaigns are being maintained and archived at PNNL as contingency for future testing requirements. Experience has shown that the archived sample materials have been very useful for the resolution of emerging issues as the sludge disposition path forward has evolved and as project design activities have been implemented. Experience has also shown that obtaining, transporting, and analyzing/testing new sludge sample material from K Basins remains a major investment for the K Basin project in terms of both time (years) and funds (millions of dollars).This report describes results of work performed in the Shielded Analytical Laboratory (SAL) at the Pacific Northwest National Laboratory's (PNNL) Radiochemical Processing Laboratory (RPL) with archive K East (KE) Basin sludge samples obtained before the year 2004, with some of them composited and initially characterized five years ago . The previously performed testing included the physical properties determinations for selected samples (settled and particle densities, water and solids concentrations), the pH, as well as identification of crystalline phases by X-ray diffractometry (XRD) for selected samples. Another objective of the previous characterization and testing campaign was to transfer some sludge composites and individual samples into new storage containers to overcome the embrittlement effect which develops in original glass containers as a result of extended exposure to high radiation fields and which increases probability of sample loss.With more than five years of storage of the abovementioned sludge samples in a hot-cell environment, concerns regarding gradually developing glass embrittlement and degradation of its mechanical strength were raised again and it was decided to transfer all valuable samples into new glass containers of unified geometry (240-ml Qorpak jars). This geometry is ideal for placement of groups of four to six samples inside of stainless steel bins available in the SAL for the long-term storage and regular inspection of archived samples. Some original samples available in amounts exceeding the capacity of a single 240-ml jar were split into two subsamples (denoted as X-jar and Y-jar) to accommodate all the content of the original container. Two subsamples of KC-6 organic ion exchange resin (OIER) beads held in the c...

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Section: Sludge Bulk Propertiesmentioning

confidence: 99%

Characteristics of STP Pre-2004 Archived KE Basin Sludge Samples Before and After Re-Jarring in the RPL - April 2012

Sinkov¹,

Delegard²,

Schmidt³

et al. 2012

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“…Size-fractionated and agitated versus non-agitated KE canister sludge also were tested as well as floor and pit sludge from areas in the KE Basin that had not previously been sampled (Bryan et al 2004). The objective of the third test series was to determine uranium metal concentration in K East Basin North Loadout Pit sludge and gas generation from sludge waste forms (Mellinger et al 2004). …”

Section: Uranium Metal Concentration By Gas Generation and Releasementioning

confidence: 99%

“…The quantities of uranium metal present in sludge samples have been estimated based on these individual reactions and their summations in the characterization testing for sludge gas generation , Bryan et al 2004, and Mellinger et al 2004). …”

Section: Uranium Metal Concentration By Gas Generation and Releasementioning

confidence: 99%

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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“…In another example of sludge hardening under water-saturated conditions, significant physical resistance was encountered at 13 inches and 10 inches from the floor while driving an isolation tube (a pipe) into the ~36-inch thick sludge layer of uranium-poor K East Basin North Loadout Pit in December 2003 during a sampling operation. The resistance may have indicated that the sludge hardened at this level (Mellinger et al 2004), though this resistance could have been inpart caused by buried debris in the sludge as well in some instances. Other instances of sludge selfcementation (hardpans) have been encountered during K Basin sludge retrieval operations.…”

Section: Cerclamentioning

confidence: 99%

Test Plan: Sludge Treatment Project Corrosion Process Chemistry Follow-on Testing

Delegard¹,

Schmidt²,

Poloski³

2007

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ForwardThis test plan was prepared by the Pacific Northwest National Laboratory (PNNL) under contract with Fluor Hanford (FH). The test plan describes the scope and conditions to be used to perform laboratoryscale testing of the Sludge Treatment Project (STP) hydrothermal treatment of K Basin sludge.On July 3, 2007, the U. S. Department of Energy (DOE) provided direction (a) to FH regarding significant changes to the scope of the overall Sludge Treatment Project. As a result of the changes, FH directed PNNL to stop work on most of the planned activities covered in this test plan. Therefore, it is unlikely the testing described here will be performed. However, to preserve the test strategy and details developed to date, the test plan has been published.Prior to the changes in project direction, a final version of the test plan was issued for review. Consistent with the request of the DOE, Dr. J. Abrefah (PNNL) provided an independent technical review (Appendix C), and most of his comments have been incorporated into this document (Appendix E). FH also provided technical review (Appendix D) and these comments have been addressed (Appendix E). As a result of the project redirection, comments from other stakeholders (DOE, US Environmental Protection Agency, and BNG America) were not prepared. Much of the testing in this plan will be conducted in a sequential manner that allows the knowledge obtained in one series to refine the next series of tests. Thus, the initial tests will be static tests designed to duplicate the previous experiments and to benchmark the behavior of sludge at the current lower design processing temperature for the STP. Testing with a broader set of sludge compositions will follow to improve the understanding of the chemistry producing high shear strength values. Testing will also be performed using a scaled (1-L) reactor to evaluate the effects of mixing, with the agitation level set to match that anticipated in the STP corrosion vessel.The planned testing is designed to yield further understanding of the nature of the chemical reactions, the effects of compositional and process variations and the effectiveness of various strategies to mitigate the observed high shear strength phenomenon observed by Delegard et al. (2007). These tests are being conducted to provide process validation and refinement vs. process development and design input. The expected outcome is to establish a level of understanding of the chemistry such that successful operating strategies and parameters can be implemented within the confines of the existing STP corrosion vessel design. K Basin Sludge OverviewThe sludge currently found in the water-filled Hanford K Basins is a mixture of particulate materials including irradiated metallic uranium reactor fuel, fuel corrosion products, wind borne soil, filter sand, corrosion products from racks (iron and aluminum), canisters (aluminum), and walls (concrete), spilled organic and inorganic Ion Exchange Module (IXM) media (mixed bed cation/anion resin and mordenite), and other ...

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Evaluation and Recommendation of Waste Form and Packaging for Disposition of the K East Basin North Loadout Pit Sludge

Cited by 10 publications

References 6 publications

Characteristics of STP Pre-2004 Archived KE Basin Sludge Samples Before and After Re-Jarring in the RPL - April 2012

Characteristics of STP Pre-2004 Archived KE Basin Sludge Samples Before and After Re-Jarring in the RPL - April 2012

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

Test Plan: Sludge Treatment Project Corrosion Process Chemistry Follow-on Testing

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