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SIMPLE TRANSIENT CALCULATIONS OF CELL FLAMMABLE GAS CONCENTRATIONS

Description: The Saltstone Facility at Savannah River Site (SRS) mixes low-level radiological liquid waste with grout for permanent disposal as cement in vault cells. The grout mixture is poured into each cell in approximately 17 batches (8 to 10 hours duration). The grout mixture contains ten flammable gases of concern that are released from the mixture into the cell. Prior to operations, simple parametric transient calculations were performed to develop batch parameters (including schedule of batch pours) to support operational efficiency while ensuring that a flammable gas mixture does not develop in the cell vapor space. The analysis demonstrated that a nonflammable vapor space environment can be achieved, with workable operational constraints, without crediting the ventilation flow as a safety system control. Isopar L was identified as the primary flammable gas of concern. The transient calculations balanced inflows of the flammable gases into the vapor space with credited outflows of diurnal breathing through vent holes and displacement from new grout pours and gases generated. Other important features of the analyses included identifying conditions that inhibited a well-mixed vapor space, the expected frequency and duration of such conditions, and the estimated level of stratification that could develop.
Date: May 6, 2009
Creator: Allison, David K.; McAllister, John E.; Thoman, David C.; McCord, J. Brent & Campbell, Corey
Partner: UNT Libraries Government Documents Department

Effects of Temperature and CSSX Organics on Saltstone Processing Properties

Description: This task was performed to determine whether the two variables, ''mix temperature'' and ''quantity of organics'' introduced into the decontaminated salt solution by the caustic side solvent extraction (CSSX) process, need to be included in the upcoming Saltstone Variability Study. Because the amount and types of organics introduced through the CSSX process do not significantly impact the fresh properties of Saltstone, the ''quantity of organics'' variable will not be included in the Saltstone Variability Study. The Saltstone Variability Study should include the variable of ''mix temperature'' in the experimental design. Examples are presented in this report that clearly demonstrate a pronounced dependence of the fresh grout properties on ''mix temperature''. One example, using mixes made with the Deliquification, Dissolution and Adjustment (DDA) simulant, shows that the properties of gel time and bleed water are highly mix temperature dependent. The gel time increased from 15 minutes at 10 C to 90 minutes at 35 C with most of the change occurring between 20 and 30 C. That is, gel time is highly sensitive to mix temperature, especially in the temperature range over which processing is most likely. The volume percent bleed water for these mixes increased from {approx}1 % at 10 C to 13 % at 35 C. The gel times and volume percent bleed water are correlated such that the longer the gel time, the greater the amount of bleed water. In another example, and in contrast to the DDA results, gel times decreased with increasing temperatures for mixes made using the Modular CSSX Unit (MCU) simulants. In this case the gel time decreased from 150 minutes at 10 C to 20 minutes at 38 C. The rheological properties of these mixes were shown to be dependent on temperature over the range of 10 to 40 C. The plastic viscosity ...
Date: February 6, 2006
Creator: Harbour, J
Partner: UNT Libraries Government Documents Department

ISOPAR L Release Rates from Saltstone Using Simulated Salt Solutions

Description: The Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) and the Salt Waste Processing Facility (SWPF) will produce a Deactivated Salt Solution (DSS) that will go to the Saltstone Production Facility (SPF). Recent information indicates that solvent entrainment in the DSS is larger than expected. The main concern is with Isopar{reg_sign} L, the diluent in the solvent mixture, and its flammability in the saltstone vault. If it is assumed that all the Isopar{reg_sign} L is released instantaneously into the vault from the curing grout before each subsequent pour; the Isopar{reg_sign} L in the vault headspace is well mixed; and each pour displaces an equivalent volume of headspace, the allowable concentration of Isopar{reg_sign} L in the DSS sent to SPF has been calculated at approximately 4 ppm. The amount allowed would be higher, if the release from grout were significantly less. The Savannah River National Laboratory was tasked with determining the release of Isopar{reg_sign} L from saltstone prepared with a simulated DSS with Isopar{reg_sign} L concentrations ranging from 50 mg/L to 200 mg/L in the salt fraction and with test temperatures ranging from ambient to 95 C. The results from the curing of the saltstone showed that the Isopar{reg_sign} L release data can be treated as a percentage of initial concentration in the concentration range studied. The majority of the Isopar{reg_sign} L that was released over the test duration was released in the first few days. The release of Isopar{reg_sign} L begins immediately and the rate of release decreases over time. At higher temperatures the immediate release is larger than at lower temperatures. In one test at 95 C essentially all of the Isopar{reg_sign} L was released in three months. Initial curing temperature was found to be very important as slight variations during the first few days affected the final Isopar{reg_sign} L ...
Date: February 6, 2006
Creator: Bronikowski, M
Partner: UNT Libraries Government Documents Department

Grout Analysis for EC and CC Calorimeters

Description: The EC and CC calorimeters roll on Two parallel hardened steel ways which reside on the top of the D0 platform's center beam. The ways will be grouted to the center beam once their correct elevation has been established. The purpose of this report is to evaluate and compare three different epoxy grouts and their properties for this application.
Date: January 6, 1987
Creator: Engstrom, L.L.
Partner: UNT Libraries Government Documents Department

REFERENCE CASES FOR USE IN THE CEMENTITIOUS BARRIERS PARTNERSHIP

Description: The Cementitious Barriers Project (CBP) is a multidisciplinary cross cutting project initiated by the US Department of Energy (DOE) to develop a reasonable and credible set of tools to improve understanding and prediction of the structural, hydraulic and chemical performance of cementitious barriers used in nuclear applications. The period of performance is >100 years for operating facilities and > 1000 years for waste management. The CBP has defined a set of reference cases to provide the following functions: (1) a common set of system configurations to illustrate the methods and tools developed by the CBP, (2) a common basis for evaluating methodology for uncertainty characterization, (3) a common set of cases to develop a complete set of parameter and changes in parameters as a function of time and changing conditions, and (4) a basis for experiments and model validation, and (5) a basis for improving conceptual models and reducing model uncertainties. These reference cases include the following two reference disposal units and a reference storage unit: (1) a cementitious low activity waste form in a reinforced concrete disposal vault, (2) a concrete vault containing a steel high-level waste tank filled with grout (closed high-level waste tank), and (3) a spent nuclear fuel basin during operation. Each case provides a different set of desired performance characteristics and interfaces between materials and with the environment. Examples of concretes, grout fills and a cementitious waste form are identified for the relevant reference case configurations.
Date: January 6, 2009
Creator: Langton, C
Partner: UNT Libraries Government Documents Department

STATUS OF MECHANICAL SLUDGE REMOVAL AND COOLING COILS CLOSURE AT THE SAVANNAH RIVER SITE - F TANK FARM CLOSURE PROJECT - 9225

Description: The Savannah River Site F-Tank Farm Closure project has successfully performed Mechanical Sludge Removal using the Waste on Wheels (WOW) system within two of its storage tanks. The Waste on Wheels (WOW) system is designed to be relatively mobile with the ability for many components to be redeployed to multiple tanks. It is primarily comprised of Submersible Mixer Pumps (SMPs), Submersible Transfer Pumps (STPs), and a mobile control room with a control panel and variable speed drives. These tanks, designated as Tank 6 and Tank 5 respectively, are Type I waste tanks located in F-Tank Farm (FTF) with a capacity of 2839 cubic meters (750,000 gallons) each. In addition, Type I tanks have 34 vertically oriented cooling coils and two horizontal cooling coil circuits along the tank floor. DOE intends to remove from service and operationally close Tank 5 and Tank 6 and other HLW tanks that do not meet current containment standards. After obtaining regulatory approval, the tanks and cooling coils will be isolated and filled with grout for long term stabilization. Mechanical Sludge Removal of the remaining sludge waste within Tank 6 removed {approx} 75% of the original 25,000 gallons in August 2007. Utilizing lessons learned from Tank 6, Tank 5 Mechanical Sludge Removal completed removal of {approx} 90% of the original 125 cubic meters (33,000 gallons) of sludge material in May 2008. The successful removal of sludge material meets the requirement of approximately 19 to 28 cubic meters (5,000 to 7,500 gallons) remaining prior to the Chemical Cleaning process. The Chemical Cleaning Process will utilize 8 wt% oxalic acid to dissolve the remaining sludge heel. The flow sheet for Chemical Cleaning planned a 20:1 volume ratio of acid to sludge for the first strike with mixing provided by the submersible mixer pumps. The subsequent strikes will utilize ...
Date: January 6, 2009
Creator: Jolly, R
Partner: UNT Libraries Government Documents Department