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Post Waterflood C02 Miscible Flood in Light Oil Fluvial-Dominated Deltaic Reservoirs
No full textThe only remaining active well, Kuhn #14, in the Port Neches CO2 project went off production in October 1997. Production from this project is reached economic limit and the project termination began in the last quarter of 1997
Task 1.16 - Enhanced Mobility of Dense Nonaqueous-Phase Liquids (DNAPLs) Using Dissolved Humic Acids
No full textChlorinated solvent contamination is widespread across the U.S. Department of Energy (DOE) complex and other industrial facilities. Because of the physical properties of dense nonaqueous-phase liquids (DNAPLs), current treatment technologies are generally incapable of completely removing contamination from the source area. Incomplete removal means that the residual DNAPL WN persist as a long-term source of groundwater contamination. When DNALPs occur in the subsurface, they resist remediation, owing to low water volubility, high viscosity and interracial tension, and microbial recalcitrance. Because of their high density and polarity, they are usually found sorbed to aquifer solids or in pools on impermeable materials. Surfactants have been used with some success to reduce interracial tension between the aqueous and organic phases and improve volubility of DNAPLs. However, surfactants are expensive and toxic and exhibit an oxygen demand. An alternative is the use of dissolved humic acids in improving DNAPL mobilization and solubilization. Humic acids, a natural form of organic carbon, are abundant, inexpensive, and nontoxic; biodegrade slowly (low oxygen demand); and have excellent mobilization properties. The present work is to establish the feasibility of using hurnates for enhancing DNAPL remediation
Iodine Volatility and pH Control in the AP-600 Reactor
No full textTwo design-basis accidents for the AP-600 reactor are formulated and evaluate~ in which significant bypass of the principal pH control system occurs. Some iodine released from the reactor primary system is retained in the Incontainment Refaeling Water Storage Tank (IRWST) water, never entering the containment where trisodium phosphate produces a high pH. Some of this iodine is volatilized and is transported into the reactor containment airspace. in the worst case, a small fraction is released to the environment at design-basis leak rate, yielding a total cumulative iodine release at 30 days of 0.0352 mol (0.023% of core iodine inventory) due to the iodine volatilization bypassing the pH control system. No fission product removal in the containment atmosphere (i.e., natural deposition sprays) is considered
What is "Normative" at Cooling Water Intakes? Defining Normalcy Before Judging Adverse
No full textJudgments of adverse environmental impact from cooling water intake structures need to be preceded by an appreciation of what is normal. In its repo~ Return to the River, the Independent Scientd5c Group (now called the Independent Scientfilc Advisory Board) --the scientific peer review arm of the Northwest Power Planning Council-- advanced the notion of a "normative river ecosystem" as a new conceptual foundation for salrnonid recovery in the Columbia River basin. With this perspective, the sum of the best scientific understanding of how organisms and aquatic ecosystems function should be the norm or standard of measure for how we judge the effects of human activities on aquatic systems. ,For the best likelihood of recovery, key aspects of altered systems should be brought back toward nonnative (although not necessarily fully back to the historical or pristine state); new alterations should be judged for adversity by how much they move key attributes away from normative or what might be considered normal. In this presentation, I ask what "normative" is for the setting of cooling water intake structures and how this concept could help resolve long-standing disputes between groups interested in avoiding darnage to all organisms that might be entrained or impinged and those who take a more population or community perspective for judging adverse environmental impact. In essence, I suggest that if a water intake does not move the aquatic ecosystem outside the "normative" range, based on expressions of norrrdcy such as those discussed, then no adverse impact has occurred. Having an explicit baseline in normal or normative would place 316(b) analyses on the same conceptual foundation as 316(a) analyses, which strive to demonstrate the continuation of a balanced, indigenous community of aquatic organisms at the power station Iocation
Corrosion Testing of Low-Activity Waste Glasses Fiscal Year 1998 Summary Report
No full textAnalytical results are presented on the chemical composition and other physical properties of a glass, given the identification BNFL-A-S98, made at Pacific Northwest National Laboratory' that is representative of the low-activity waste glass composition proposed by BNFL, Inc.* for immobilization of envelope A double-shell tank wastes at the Hanford Site. This glass was prepared for use in a testing program to be conducted at Pacific Northwest National Laboratory and at Argonne National Laboratory for the purpose of characterizing its long-term corrosion behavior. Detailed examination of the glass microstructure using transmission electron microscopy showed structural features indicative of amorphous phase separation. A remelt was performed on a smaller batch (100 g) to ensure rapid cooling. The glass microstructure was reexamined and showed no evidence of phase separation. Selected long-term (some to 860 d) product consistency tests were terminated, and the leachates were analyzed on tests with three other representative low-activity waste glass formulations (L8- 1, L8-3, and L8-7). The results showed no evidence of corrosion rate acceleration at three times the duration of tests where another well-studied glass, LD6-5412, had been completely altered under identical test conditions. These tests (and others not discussed in this report) provide clear evidence that low-activity waste glasses with at least 20 mass% Na20 can be made that have excellent long-term corrosion resistance. However, glass composition has a large impact on long-term behavior and so careful experiments with several different techniques are essential to ensuring that a particular glass will have good long-term corrosion resistance
Evaluation of Reservoir Wettability and its Effect on Oil Recovery
No full textThis project has three main goals. The first is to achieve improved understanding of the surface and interfacial properties of crude oils and their interactions with mineral surfaces. The second goal is to apply the results of surface studies to improved predictions of oil production in laboratory experiments. Finally, we aim to use the results of this research to recommend ways to improve oil recovery by waterflooding. In order to achieve these goals, the mechanisms of wetting alteration must be explained. We propose a methodology for studying those mechanisms on mineral surfaces, then applying the results to prediction and observation of wetting alteration in porous media. Improved understanding of the underlying mechanisms will show when and how wettability in the reservoir can be altered and under what circumstances that alteration would be beneficial in terms of increased production of oil. In the work reported this quarter, crude oil interactions with Berea sandstone have been used to prepare cores with mixed wettability
A Strategy to Conduct an Analysis of the Long-Term Performance of Low-Activity Waste Glass in a Shallow Subsurface Disposal System at Hanford
No full textPrivatized services are being procured to vitrify low-activity tank wastes for eventual disposal in a shallow subsurface facility at the Hanford Site. Over 500,000 metric tons of low-activity waste glass will be generated, which is among the largest volumes of waste within the U.S. Department of Energy (DOE) complex and is one of the largest inventories of long-lived radionuclides planned for disposal in a low-level waste facility. Before immobilized waste can be disposed, DOE must approve a "performance assessment," which is a document that describes the impacts of the disposal facility on public health and environmental resources. Because the release rate of radionuclides from the glass waste form is a key factor determining these impacts, a sound scientific basis for determining their long-term release rates must be developed if this disposal action is to be accepted by regulatory agencies, stakeholders, and the public. In part, the scientific basis is determined from a sound testing strategy. The foundation of the proposed testing strategy is a well accepted mechanistic model that is being used to calculate the glass corrosion behavior over the geologic time scales required for performance assessment. This model requires that six parameters be determined, and the testing program is defined by an appropriate set of laboratory experiments to determine these parameters, and is combined with a set of field experiments to validate the model as a whole. Three general classes of laboratory tests are proposed in this strategy: 1) characterization, 2) accelerated, and 3) service condition. Characterization tests isolate and provide specific information about processes or parameters in theoretical models. Accelerated tests investigate corrosion behavior that will be important over the regulated service life of a disposal system within a laboratory time frame of a few years or less. Service condition tests verify that the techniques used in accelerated tests do not change the alteration mechanisms. The recommended characterization tests are single-pass flow-through tests using a batch reactor design, Accelerated and service conditions tests include product consistency and pressurized unsaturated flow (PUF) tests. Nonradioactive glasses will be used for the majority of the laboratory testing (-80%), with the remainder performed with glasses containing a selected set of key radionuclides. Additionally, a series of PUF experiments with a natural analog of basaltic glass is recommended to confirm that the alteration products observed under accelerated conditions in the PUF tests are similar to those found associated with the natural analog. This will provide additional confidence in using the PUF test results to infer long-term corrosion behavior. Field tests are proposed as a unique way to validate the glass corrosion and contaminant transport models being used in the performance assessment. To better control the test conditions, the field tests are to be performed in lysimeters (corrugated steel containers buried flush with the ground surface). Lysimeters provide a way to combine a glass, Hanford soil, and perhaps other engineered materials in a well-controlled test, but on a scale that is not practicable in the laboratory. The recommended field tests include some experiments where a steady flow rate of water is artificially applied. These tests use a glass designed to have a high corrosion rate so that it is easier to monitor contaminant release and transport. Existing lysimeters at the Hanford Site can be used for these experiments or new lysimeters that have been equipped with the latest in monitoring equipment and located near the proposed disposal site
Micro-Fluidic Diffusion Coefficient Measurement
No full textA new method for diffusion coefficient measurement applicable to micro-fluidics is pre- sented. The method Iltilizes an analytical model describing laminar dispersion in rect- anglllar ~llicro_channe]s. The Illethod ~vas verified throllgh measllremen~ of fllloresceill diffusivity in water and aqueolls polymer solutions of differing concentration. The diffll- sivity of flllorescein was measlmed as 0.64 x 10-gm2/s in water, 0.49 x 10-gm2/s in the 4 gm/dl dextran solution and 0.38 x 10-9n12/s in the 8 gnl/dl dextran solution
Scalable Parallel Utopia
No full textThis contribution proposes a 128 bit wide interface structure clocked at approximately 80 MHz that will operate at 10 Gbps as a strawman for a 0C192C Utopia Specification. In addition, the concept of scalable width of data transfers in order to maintain manageably low clock rates is proposed
Evaluation of the ISUS Power Management and Distribution System Under Operational Conditions
No full textAn operational evaluation of the Integrated Solar Upper Stage (ISUS) power management and distribution (PMAD) system was conducted as part of the Engine Ground Demonstration thermionic power system test program-- START-3. START-3 testing took place at the Baikal Test Stand, located in the University of New Mexico's Energy Conversion Research Laboratory at the New Mexico Engineering Research Institute in Albuquerque, NM. One objective of this test was to evaluate the operational performance of the lSUS PMAD system developed by the National Aeronautics and Space Administration (NASA) Lewis Research Center. Tests of the PMAD with the ISUS diode string demonstrated that the PMAD could regulate the output of an array of thermionic converters within the design requirements and couId be modified to optimize performance for diode strings of fewer than 16 diodes