Physical and Chemical Measurements Needed to Support Disposition of Savannah River Site Radioactive High Level Waste Sludge

Abstract Radioactive high level waste (HLW) sludge generated as a result of decades of production and manufacturing of plutonium, tritium and other nuclear materials is being removed from storage tanks and processed into a glass waste-form for permanent disposition at the Federal Repository. Characterization of this HLW sludge is a prerequisite for effective planning and execution of sludge disposition activities. The radioactivity of HLW makes sampling and analysis of the sludge very challenging, as well as making opportunities to perform characterization rare. In order to maximize the benefit obtained from sampling and analysis, a recommended list of physical property and chemical measurements has been developed. This list includes distribution of solids (insoluble and soluble) and water; densities of insoluble solids, interstitial solution, and slurry rheology (yield stress and consistency); mineral forms of solids; and primary elemental and radioactive constituents. Sampling requirements (number, type, volume, etc.), sample preparation techniques, and analytical methods are discussed in the context of pros and cons relative to end use of the data. Generation of useful sample identification codes and entry of results into a centralized database are also discussed

Development of a Crossflow Filter to Remove Solids from Radioactive Liquid Waste: Comparison of Test Data with Operating Experience --9119

ABSTRACT In 2008, the Savannah River Site (SRS) began treatment of liquid radioactive waste from its Tank Farms. To treat waste streams containing Cs-137, Sr-90, and actinides, SRS developed the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The Actinide Removal Process contacts the waste with monosodium titanate (MST) to sorb strontium and select actinides. After MST contact, the process filters the resulting slurry to remove the MST (with sorbed strontium and actinides) and any entrained sludge. The filtrate is transported to the MCU to remove cesium. The solid particles removed by the filter are concentrated to ~ 5 wt %, washed to reduce the concentration of dissolved sodium, and transported to the Defense Waste Processing Facility (DWPF) for vitrification. The authors conducted tests with 0.5 and 0.1 Mott sintered stainless steel crossflow filters at benchscale (0.018 m 2 or 0.19 ft 2 surface area) and pilot-scale (1.04 m 2 or 11.2 ft 2 ). The collected data supported design of the filter for the process and identified preferred operating conditions for the full-scale process (21.4 m 2 or 230 ft 2 ). The testing investigated the influence of operating parameters, such as filter pore size, axial velocity, transmembrane pressure (TMP), and solids loading, on filter flux, and validated the simulant used for pilot-scale testing. The conclusions from this work follow. The 0.1 Mott sintered stainless steel filter produced higher flux than the 0.5 filter. The likely cause of this result is the smaller pore size prevented submicron particles becoming trapped in the pores, which significantly increases filter resistance and decreases filter flux. Filtrate samples showed no visible solids. The filter flux with actual waste is comparable to the filter flux with simulated waste, with the simulated waste being conservative. This result shows the simulated sludge is an acceptable representative of the actual sludge. When the data is adjusted for differences in transmembrane pressure and temperature, the filter flux in the Actinide Removal Process is comparable to the filter flux in the bench-scale and pilotscale testing. Filter flux increased with transmembrane pressure, increased with axial velocity, and decreased with concentration in agreement with classical crossflow filtration theories

Plutonium removal limit for the disposition of plutonium-bearing materials

Recent changes in world politics have resulted in the United States reducing its nuclear weapons and stopping plutonium production. Prior plutonium production, dismantling warheads, and decontamination and decommissioning some facilities have produced plutonium-bearing materials which must continue to be managed. As each lot of material is processed, the processor must decide whether to remove the plutonium before discarding the material or to discard it without plutonium removal. DOE has developed a new method of making this decision, called the Plutonium Removal Limit System (PRLS). The system is based on defining a plutonium concentration above which the cost of disposing of plutonium-bearing materials will be less if plutonium is recovered and below which the cost will be less if plutonium is discarded (following suitable waste treatment). This method minimizes the overall cost to DOE for disposing of the existing inventory of plutonium-bearing materials. The method was used to analyze the plutonium-discard limit for all categories of plutonium-bearing materials currently at each site. This analysis indicated the need to standardize the way sites make the remove-versus-discard decision. For this purpose, a set of departmental plutonium removal limits was developed. DOE expects to approve implementing this new method at all facilities handling plutonium-bearing material in FY 93

TYPE AF CERTIFICATE FOR TRANSPORTATION OF LOW ENRICHED URANIUM OXIDE (LEUO) FOR DISPOSAL

ABSTRACT SED-ESV-2007-0005 Washington Savannah River Company (WSRC) operates the Savannah River Site (SRS) in Aiken, SC under contract with the U.S. Department of Energy (DOE). SRS had the need to ship 227 drums of low enriched uranium oxide (LEUO) to a disposal site. The LEUO had been packaged nearly 25 years ago in U.S. Department of Transportation (DOT) 17C 55-gallon drums and stored in a warehouse. Since the 235 U enrichment was just above 1 percent by weight (wt%) the material did not qualify for the fissile material exceptions in 49 CFR 173.453, and therefore was categorized as "fissile material" for shipping purposes. WSRC evaluated all existing Type AF packages and did not identify any feasible packaging. Applying for a new Type AF certificate of compliance was considered too costly for a one-time/one-way shipment for disposal. Down-blending the material with depleted uranium (to reduce enrichment below 1 wt% and enable shipment as low specific activity (LSA) radioactive material) was considered, but appropriate blending facilities do not exist at SRS. After reviewing all options, WSRC concluded that seeking a DOT Special Permit was the best option to enable shipment of the material for permanent disposal. WSRC submitted the Special Permit application to the DOT, and after one request-for-additional-information (RAI) the permit was considered acceptable. However, in an interesting development that resulted from the DOT Special Permit application process, it was determined that it was more appropriate for the DOE to issue a Type AF certificate [Ref. 1] for this shipping campaign. This paper will outline the DOT Special Permit application and Type AF considerations, and will discuss the issuance of the new DOE Type AF certificate of compliance.

Proceedings of PVP2007 2007 ASME Pressure Vessels and Piping Division Conference PVP2007-26722 Derivations for Hoop Stresses Due to Shock Waves in a Tube

ABSTRACT Equations describing the hoop stresses in a pipe due to water hammer have been presented in the literature in a series of papers, and this paper discusses the complete derivation of the pertinent equations. The derivation considers the pipe wall response to a water hammer induced shock wave moving along the inner wall of the pipe. Factors such as fluid properties, pipe wall materials, pipe dimensions, and damping are considered. These factors are combined to present a single, albeit rather complicated, equation to describe the pipe wall vibrations and hoop stresses as a function of time. This equation is also compared to another theoretical prediction for hoop stresses, which is also derived herein. Specifically, the two theories predict different maximum stresses, and the differences between these predictions are graphically displayed

ABSTRACT: WASTE MANAGEMENT – 00

ABSTRACT Thirty-one years have passed since the United States Congress passed the Toxic Substances Control Act (TSCA) PCBs were manufactured in the United States between 1929 and 1977. They were highly valued for their fire and heat-resistance properties and for their chemical stability. As a result, PCBs were used in a variety of thermally and/or chemically stressful applications. They did not conduct electricity and therefore were particularly well-suited for use as insulating fluids in high-voltage electric equipment. PCBs were also used in various other applications, such as in hydraulic and heat transfer fluids. Strict controls on the use and disposal of PCBs were imposed by the TSCA implementing regulations at 40 CFR 761 [2]. As a result, most heavy users of PCB products worked hard to curtail their PCB use. Many organizations that once used substantial amounts of PCBs, subsequently declared themselves "PCB free". Unfortunately, in many cases, these "PCB-free" declarations were premature, as PCBs were used in many more applications than insulating fluids. From the 1990s and to the present day, PCBs increasingly have been discovered in non-liquid forms. These materials were used or installed in facilities constructed before the 1979 "PCB ban". Examples include applied paints and coatings, caulking, pre-formed joint filler, and plastic or rubber wire and cable insulation. Proper identification of these materials is necessary for appropriate and compliant waste management during deactivation and decommissioning (D&D) activities. PCBs can pose other significant waste management issues for D&D projects, particularly for nuclear facilities. Depending upon the waste form and the intended disposal path, PCBs can be regulated at thresholds in the low parts-per-billion (ppb). These low regulatory thresholds often are overlooked due to the erroneous belief by many waste management professionals that materials containing PCBs are regulated by TSCA only if their PCB concentration is at least 50 parts-per-million (ppm). Failure to recognize when and how the lower thresholds apply can lead to rejection of the waste materials by treatment, storage and disposal (TSD) facilities as well as potential regulatory non-compliance. Furthermore, re-use of "excess" materials with PCBs is also regulated by TSCA. In the event of a characterization error, the costs required to make necessary corrections can be very high. This paper will focus on PCB characterization and waste management issues associated with D&D of DOE nuclear facilities. It will identify PCB materials that are likely to be present in such facilities, with emphasis on the nonliquid PCB forms. The paper will discuss characterization pitfalls associated with Non-Liquid PCBs (NLPCBs), including circumstances in which NLPCBs can migrate into other materials. The paper also will identify TSCA requirements for materials with very low concentrations of PCBs; certain materials are regulated at concentrations as low as 0.5 µg/L PCBs (approximately 0.5 ppb). The paper will then examine the potentially extensive impacts to a facility if the materials are not managed in a TSCA-compliant manner. Examples from a recent D&D project at the DOE Savannah River Site will be used to illustrate key points and lessons learned. It is expected that this information would be useful to other DOE sites, DoD installations and commercial nuclear facilities constructed prior to 1979

Savannah River Site Public and Regulatory Involvement in the Cercla Low-Level Waste (LLW) Program and Their Effect on Decisions to Dispose of LLW Generated by Cercla

ABSTRACT The key to successful public involvement at the Savannah River Site (SRS) has been and continues to be vigorous, up-front involvement of the public, federal and state regulators with technical experts. The SRS Waste Management Program includes all forms of radioactive waste. All of the decisions associated with the management of these wastes are of interest to the public and successful program implementation would be impossible without including the public upfront in the program formulation. Serious problems can result if program decisions are made without public involvement, and if the public is informed after key decisions are made. This paper will describe the regulatory and public involvement program and their effects on the decisions concerning the disposal at the Savannah River Site (SRS) of LLW generated from CERCLA Removal and Remedial Actions. At SRS the Deactivation and Decommissioning (D&D) project has generated large amounts of LLW from the removal of buildings and processing facilities. The D&D project is expected to generate even larger amounts of LLW in the future. The most cost effective disposal alternated is to use the onsite LLW disposal facility in E-Area. The E-Area LLW Facility is owned and operated by the Department of Energy (DOE) under its authority granted by the Atomic Energy Act of 1954, as amended. Since the disposal of CERCLA generated waste is also governed by the Environmental Protection Agency (EPA) CERCLA regulations, it is important that EPA, DOE, and the South Carolina Department of Health and Environmental Control (SCDHEC) work together to resolve any conflicts in implementation of the D&D project so that all regulations are followed and the project can be continued successfully. An issue of particular significance will be described in this paper that, were it not resolved successfully, would have jeopardized the completion of one project and resulted in higher overall project costs. The EPA determined in review of the E-Area LLW Facility groundwater monitoring that a "release" under CERCLA had occurred. As a result, EPA determined that it was necessary to issue a "Notice of Unacceptability" to SRS revoking the CERCLA Off-Site Rule approval for the E-Area LLW Facility, thus, no longer allowing the E-Area LLW Facility Slit trenches to receive CERCLA waste for disposal. It became critical to the success of the D&D project to reestablish CERCLA Off-Site Rule approval. The discussions and negotiations Comment [HB1]: 2 with the South Carolina regulators and EPA were conducted in full view of the public and as such, an informed decision as to resolution included the public interactions. This paper will describe the successful results of this technical, regulatory, and public involvement program, explore the challenges, how the accomplishments occurred, and describe the future challenges along with the road map for the future. In doing this, the SRS D&D project must be described to give the readers an understanding of the technical complexities that must be communicated successfully to achieve constructive stakeholder participation and regulatory approval.

ABSTRACT: WASTE MANAGEMENT – 00

ABSTRACT Thirty-one years have passed since the United States Congress passed the Toxic Substances Control Act (TSCA) PCBs were manufactured in the United States between 1929 and 1977. They were highly valued for their fire and heat-resistance properties and for their chemical stability. As a result, PCBs were used in a variety of thermally and/or chemically stressful applications. They did not conduct electricity and therefore were particularly well-suited for use as insulating fluids in high-voltage electric equipment. PCBs were also used in various other applications, such as in hydraulic and heat transfer fluids. Strict controls on the use and disposal of PCBs were imposed by the TSCA implementing regulations at 40 CFR 761 [2]. As a result, most heavy users of PCB products worked hard to curtail their PCB use. Many organizations that once used substantial amounts of PCBs, subsequently declared themselves "PCB free". Unfortunately, in many cases, these "PCB-free" declarations were premature, as PCBs were used in many more applications than insulating fluids. From the 1990s and to the present day, PCBs increasingly have been discovered in non-liquid forms. These materials were used or installed in facilities constructed before the 1979 "PCB ban". Examples include applied paints and coatings, caulking, pre-formed joint filler, and plastic or rubber wire and cable insulation. Proper identification of these materials is necessary for appropriate and compliant waste management during decommissioning and deactivation (D&D) activities. PCBs can pose other significant waste management issues for D&D projects, particularly for nuclear facilities. Depending upon the waste form and the intended disposal path, PCBs can be regulated at thresholds in the low parts-per-billion (ppb). These low regulatory thresholds often are overlooked due to the erroneous belief by many waste management professionals that materials containing PCBs are regulated by TSCA only if their PCB concentration is at least 50 parts-per-million (ppm). Failure to recognize when and how the lower thresholds apply can lead to rejection of the waste materials by treatment, storage and disposal (TSD) facilities as well as potential regulatory non-compliance. Furthermore, re-use of "excess" materials with PCBs is also regulated by TSCA. In the event of a characterization error, the costs required to make necessary corrections can be very high. This paper will focus on PCB characterization and waste management issues associated with D&D of DOE nuclear facilities. It will identify PCB materials that are likely to be present in such facilities, with emphasis on the nonliquid PCB forms. The paper will discuss characterization pitfalls associated with Non-Liquid PCBs (NLPCBs), including circumstances in which NLPCBs can migrate into other materials. The paper also will identify TSCA requirements for materials with very low concentrations of PCBs; certain materials are regulated at concentrations as low as 0.5 µg/L PCBs (approximately 0.5 ppb). The paper will then examine the potentially extensive impacts to a facility if the materials are not managed in a TSCA-compliant manner. Examples from a recent D&D project at the DOE Savannah River Site will be used to illustrate key points and lessons learned. It is expected that this information would be useful to other DOE sites, DoD installations and commercial nuclear facilities constructed prior to 1979