Laboratory performance testing of an extruded bitumen containing a surrogate, sodium nitrate-based, low-level aqueous waste

International Nuclear Information System (INIS)

Mattus, A.J.; Kaczmarsky, M.M.

1986-01-01

Laboratory results of a comprehensive, regulatory performance test program, utilizing an extruded bitumen and a surrogate, sodium nitrate-based waste, have been compiled at the Oak Ridge National Laboratory (ORNL). Using a 53 millimeter, Werner and Pfleiderer extruder, operated by personnel of WasteChem Corporation of Paramus, New Jersey, laboratory-scale, molded samples of type three, air blown bitumen were prepared for laboratory performance testing. A surrogate, low-level, mixed liquid waste, formulated to represent an actual on-site waste at ORNL, containing about 30 wt % sodium nitrate, in addition to eight heavy metals, cold cesium and strontium was utilized. Samples tested contained three levels of waste loading: that is, forty, fifty and sixty wt % salt. Performance test results include the ninety day ANS 16.1 leach test, with leach indices reported for all cations and anions, in addition to the EP Toxicity test, at all levels of waste loading. Additionally, test results presented also include the unconfined compressive strength and surface morphology utilizing scanning electron microscopy. Data presented include correlations between waste form loading and test results, in addition to their relationship to regulatory performance requirements

Testing waste forms containing high radionuclide loadings

International Nuclear Information System (INIS)

McConnell, J.W. Jr.; Neilson, R.M. Jr.; Rogers, R.D.

1986-01-01

The Low-Level Waste Data Base Development - EPICOR-II Resin/Liner Investigation Program funded by the US Nuclear Regulatory Commission (NRC) is obtaining information on radioactive waste during NRC-prescribed tests and in a disposal environment. This paper describes the resin solidification task of that program, including the present status and results to date. An unusual aspect of this investigation is the use of commercial grade, ion exchange resins that have been loaded with over five times the radioactivity normally seen in a commercial application. That dramatically increases the total radiation dose to the resins. The objective of the resin solidification task is to determine the adequacy of test procedures specified by NRC for ion exchange resins having high radionuclide loadings

DM100 AND DM1200 MELTER TESTING WITH HIGH WASTE LOADING GLASS FORMULATIONS FOR HANFORD HIGH-ALUMINUM HLW STREAMS

Energy Technology Data Exchange (ETDEWEB)

KRUGER AA; MATLACK KS; KOT WK; PEGG IL; JOSEPH I

2009-12-30

This Test Plan describes work to support the development and testing of high waste loading glass formulations that achieve high glass melting rates for Hanford high aluminum high level waste (HLW). In particular, the present testing is designed to evaluate the effect of using low activity waste (LAW) waste streams as a source of sodium in place ofchemical additives, sugar or cellulose as a reductant, boehmite as an aluminum source, and further enhancements to waste processing rate while meeting all processing and product quality requirements. The work will include preparation and characterization of crucible melts in support of subsequent DuraMelter 100 (DM 100) tests designed to examine the effects of enhanced glass formulations, glass processing temperature, incorporation of the LAW waste stream as a sodium source, type of organic reductant, and feed solids content on waste processing rate and product quality. Also included is a confirmatory test on the HLW Pilot Melter (DM1200) with a composition selected from those tested on the DM100. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy's (DOE's) Office of River Protection (ORP) to increase waste loading and processing rates for high-iron HLW waste streams as well as previous tests conducted for ORP on the same waste composition. This Test Plan is prepared in response to an ORP-supplied statement of work. It is currently estimated that the number of HLW canisters to be produced in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) is about 12,500. This estimate is based upon the inventory ofthe tank wastes, the anticipated performance of the sludge treatment processes, and current understanding of the capability of the borosilicate glass waste form. The WTP HLW melter design, unlike earlier DOE melter designs, incorporates an active glass bubbler system. The bubblers create active glass pool convection and thereby improve heat

Waste package performance allocation system study report

International Nuclear Information System (INIS)

Memory, R.D.

1994-01-01

The Waste Package Performance Allocation system study was performed in order to provide a technical basis for the selection of the waste package period of substantially complete containment and its resultant contribution to the overall total system performance. This study began with a reference case based on the current Mined Geologic Disposal System (MGDS) baseline design and added a number of alternative designs. The waste package designs were selected from the designs being considered in detail during Advanced Conceptual Design (ACD). The waste packages considered were multi-barrier packages with a 0.95 cm Alloy 825 inner barrier and a 10, 20, or 45 cm thick carbon steel outer barrier. The waste package capacities varied from 6 to 12 to 21 Pressurized Water Reactor (PWR) fuel assemblies. The vertical borehole and in-drift emplacement modes were also considered, as were thermal loadings of 25, 57, and 114 kW/acre. The repository cost analysis indicated that the 21 PWR in-drift emplacement mode option with the 10 cm and 20 cm outer barrier thicknesses are the least expensive and that the 12 PWR in-drift case has approximately the same cost as the 6 PWR vertical borehole. It was also found that the cost increase from the 10 cm outer barrier waste package to the 20 cm waste package was less per centimeter than the increase from the 20 cm outer barrier waste package to the 45 cm outer barrier waste package. However, the repository cost was nearly linear with the outer barrier thickness for the 21 PWR in-drift case. Finally, corrosion rate estimates are provided and the relationship of repository cost versus waste package lifetime is discussed as is cumulative radionuclide release from the waste package and to the accessible environment for time periods of 10,000 years and 100,000 years

Characterization and testing of a 238Pu loaded ceramic waste form

International Nuclear Information System (INIS)

Johnson, S. G.

1998-01-01

This paper will describe the preparation and progress of the effort at Argonne National Laboratory-West to produce ceramic waste forms loaded with 238 Pu. The purpose of this study is to determine the extent of damage, if any, that alpha decay events will play over time to the ceramic waste form under development at Argonne. The ceramic waste form is glass-bonded sodalite. The sodalite is utilized to encapsulate the fission products and transuranics which are present in a chloride salt matrix which results from a spent fuel conditioning process. 238 Pu possesses approximately 250 times the specific activity of 239 Pu and thus allows for a much shorter time frame to address the issue. In preparation for production of 238 Pu loaded waste forms 239 Pu loaded samples were produced. Data is presented for samples produced with typical reactor grade plutonium. X-ray diffraction, scanning electron micrographs and durability test results will be presented. The ramifications for the production of the 238 Pu loaded samples will be discussed

Waste Load Allocation for Conservative Substances to Protect Aquatic Organisms

Science.gov (United States)

Hutcheson, M. R.

1992-01-01

A waste load allocation process is developed to determine the maximum effluent concentration of a conservative substance that will not harm fish and wildlife propagation. If this concentration is not exceeded in the effluent, the acute toxicity criterion will not be violated in the receiving stream, and the chronic criterion will not be exceeded in the zone of passage, defined in many state water quality standards to allow the movement of aquatic organisms past a discharge. Considerable simplification of the concentration equation, which is the heart of any waste load allocation, is achieved because it is based on the concentration in the receiving stream when the concentration gradient on the zone of passage boundary is zero. Consequently, the expression obtained for effluent concentration is independent of source location or stream morphology. Only five independent variables, which are routinely available to regulatory agencies, are required to perform this allocation. It aids in developing permit limits which are protective without being unduly restrictive or requiring large expenditures of money and manpower on field investigations.

Nuclear heat-load limits for above-grade storage of solid transuranium wastes

International Nuclear Information System (INIS)

Clontz, B.G.

1978-06-01

Nuclear safety and heat load limits were established for above-grade storage of transuranium (TRU) wastes. Nuclear safety limits were obtained from a study by J.L. Forstner and are summarized. Heat load limits are based on temperature calculations for TRU waste drums stored in concrete containers (hats), and results are summarized. Waste already in storage is within these limits. The limiting factors for individual drum heat load limits were (1) avoidance of temperatures in excess of 190 0 F (decomposition temperature of anion resin) when anion resin is present in a concrete hat, and (2) avoidance of temperatures in excess of 450 0 F (ignition temperature of paper) at any point inside a waste drum. The limiting factor for concrete had heat load limits was avoidance of temperatures in excess of 265 0 F (melt point of high density polyethylene) at the drum liners. A temperature profile for drums and hats filled to recommended limits is shown. Equations and assumptions used were conservative

Anaerobic co-digestion of food waste and dairy manure: effects of food waste particle size and organic loading rate.

Science.gov (United States)

Agyeman, Fred O; Tao, Wendong

2014-01-15

This study was to comprehensively evaluate the effects of food waste particle size on co-digestion of food waste and dairy manure at organic loading rates increased stepwise from 0.67 to 3 g/L/d of volatile solids (VS). Three anaerobic digesters were fed semi-continuously with equal VS amounts of food waste and dairy manure. Food waste was ground to 2.5 mm (fine), 4 mm (medium), and 8 mm (coarse) for the three digesters, respectively. Methane production rate and specific methane yield were significantly higher in the digester with fine food waste. Digestate dewaterability was improved significantly by reducing food waste particle size. Specific methane yield was highest at the organic loading rate of 2g VS/L/d, being 0.63, 0.56, and 0.47 L CH4/g VS with fine, medium, and coarse food waste, respectively. Methane production rate was highest (1.40-1.53 L CH4/L/d) at the organic loading rate of 3 g VS/L/d. The energy used to grind food waste was minor compared with the heating value of the methane produced. Copyright © 2013 Elsevier Ltd. All rights reserved.

Waste Load Allocation Based on Total Maximum Daily Load Approach Using the Charged System Search (CSS Algorithm

Directory of Open Access Journals (Sweden)

Elham Faraji

2016-03-01

Full Text Available In this research, the capability of a charged system search algorithm (CSS in handling water management optimization problems is investigated. First, two complex mathematical problems are solved by CSS and the results are compared with those obtained from other metaheuristic algorithms. In the last step, the optimization model developed by the CSS algorithm is applied to the waste load allocation in rivers based on the total maximum daily load (TMDL concept. The results are presented in Tables and Figures for easy comparison. The study indicates the superiority of the CSS algorithm in terms of its speed and performance over the other metaheuristic algorithms while its precision in water management optimization problems is verified.

Performance of asphalt mixture incorporating recycled waste

Science.gov (United States)

Hamid, Nor Baizura; Abdullah, Mohd Ezree; Sanik, Mohd Erwan; Mokhtar, Mardiha; Kaamin, Masiri; Raduan, Rasyidah; Ramli, Mohd Zakwan

2017-12-01

Nowadays, the amount of premix waste was increased every year, especially at the batching plants. Normally, the waste materials will be discarded without doing any innovative and effective research about those materials. This situation has become one of the global concerns due to the increasing number of premix waste produced every year. Therefore, the aim of this study is to evaluate the performance of hot mix asphalt (HMA) using premix waste on improving asphalt mixture fatigue behaviour. The method used in this study was Superpave mix design method. The sample conducted in this study were 0%, 10%, 20%, 30%, and 100% of premix waste respectively. For a binder test, the laboratory test conducted were penetration test, softening test and thin film oven test while for the performance test were resilient modulus test and indirect tensile fatigue test. From the laboratory test, the resilient modulus test was conducted with two different temperature which was 25°C and 40°C. The result from that test was 20% of premix waste had higher resilient modulus at that two different temperatures compared to another samples. From that test also shown that the sample at the lower temperature which was 25°C has higher resilient modulus compared to the temperature of 40°C. Indirect tensile fatigue test showed that the 30% of premix waste sample was suitable for the modified asphalt mixture with referring to the maximum deformation and strain for comparison control, 10%,20%, and 100% of premix waste samples. So, it can be concluded that premix waste inhibits great potential as road construction material and suitable for repeated traffic loading.

Test plan: Effects of phase separation on waste loading for high level waste glasses

International Nuclear Information System (INIS)

Jantzen, C.M.

2000-01-01

As part of the Tanks Focus Area's (TFA) effort to increase waste loading for high-level waste (HLW) vitrification at various facilities in the Department of Energy (DOE) complex, the occurrence of phase separation in waste glasses spanning the Savannah River Site (SRS) and Idaho National Engineering and Environmental Laboratory (INEEL) composition ranges were studied during FY99. The type, extent, and impact of phase separation on glass durability for a series of HLW glasses, e.g., SRS-type and INEEL-type, were examined

Dry anaerobic digestion of food waste and cardboard at different substrate loads, solid contents and co-digestion proportions.

Science.gov (United States)

Capson-Tojo, Gabriel; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Delgenès, Jean-Philippe; Escudié, Renaud

2017-06-01

The increasing food waste production calls for developing efficient technologies for its treatment. Anaerobic processes provide an effective waste valorization. The influence of the initial substrate load on the performance of batch dry anaerobic co-digestion reactors treating food waste and cardboard was investigated. The load was varied by modifying the substrate to inoculum ratio (S/X), the total solids content and the co-digestion proportions. The results showed that the S/X was a crucial parameter. Within the tested values (0.25, 1 and 4gVS·gVS -1 ), only the reactors working at 0.25 produced methane. Methanosarcina was the main archaea, indicating its importance for efficient methanogenesis. Acidogenic fermentation was predominant at higher S/X, producing hydrogen and other metabolites. Higher substrate conversions (≤48%) and hydrogen yields (≤62mL·gVS -1 ) were achieved at low loads. This study suggests that different value-added compounds can be produced in dry conditions, with the initial substrate load as easy-to-control operational parameter. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial Community in a Biofilter for Removal of Low Load Nitrobenzene Waste Gas.

Directory of Open Access Journals (Sweden)

Jian Zhai

Full Text Available To improve biofilter performance, the microbial community of a biofilter must be clearly defined. In this study, the performance of a lab-scale polyurethane biofilter for treating waste gas with low loads of nitrobenzene (NB (< 20 g m-3 h-1 was investigated when using different empty bed residence times (EBRT (64, 55.4 and 34 s, respectively. In addition, the variations of the bacterial community in the biofilm on the longitudinal distribution of the biofilters were analysed by using Illumina MiSeq high-throughput sequencing. The results showed that NB waste gas was successfully degraded in the biofilter. High-throughput sequencing data suggested that the phylum Actinobacteria and genus Rhodococcus played important roles in the degradation of NB. The variations of the microbial community were attributed to the different intermediate degradation products of NB in each layer. The strains identified in this study were potential candidates for purifying waste gas effluents containing NB.

Part-Load Performance Prediction and Operation Strategy Design of Organic Rankine Cycles with a Medium Cycle Used for Recovering Waste Heat from Gaseous Fuel Engines

Directory of Open Access Journals (Sweden)

Xuan Wang

2016-07-01

Full Text Available The Organic Rankine Cycle (ORC is regarded as a suitable way to recover waste heat from gaseous fuel internal combustion engines. As waste heat recovery systems (WHRS have always been designed based on rated working conditions, while engines often work under part-load conditions, it is quite significant to analyze the part-load performance and corresponding operation strategy of ORC systems. This paper presents a dynamic model of ORC with a medium cycle used for a large gaseous fuel engine and analyzes the effect of adjustable parameters on the system performance, giving effective control directions under various conditions. The results indicate that the intermediary fluid mass flow rate has nearly no effect on the output power and thermal efficiency of the ORC, while the mass flow rate of working fluid has a great effect on them. In order to get a better system performance under different working conditions, the system should be operated with the working fluid mass flow rate as large as possible, but with a slight degree of superheating. Then, with the control of constant superheat degree at the end of the heating process, the performance of the combined system that consists of ORC and the engine at steady state under seven typical working conditions is also analyzed. The results indicate that the energy-saving effect of WHRS becomes worse and worse as the working condition decreases. Especially at 40% working condition the WHRS nearly has no energy-saving effect anymore.

Multi-objective models of waste load allocation toward a sustainable reuse of drainage water in irrigation.

Science.gov (United States)

Allam, Ayman; Tawfik, Ahmed; Yoshimura, Chihiro; Fleifle, Amr

2016-06-01

The present study proposes a waste load allocation (WLA) framework for a sustainable quality management of agricultural drainage water (ADW). Two multi-objective models, namely, abatement-performance and abatement-equity-performance, were developed through the integration of a water quality model (QAUL2Kw) and a genetic algorithm, by considering (1) the total waste load abatement, and (2) the inequity among waste dischargers. For successfully accomplishing modeling tasks, we developed a comprehensive overall performance measure (E wla ) reflecting possible violations of Egyptian standards for ADW reuse in irrigation. This methodology was applied to the Gharbia drain in the Nile Delta, Egypt, during both summer and winter seasons of 2012. Abatement-performance modeling results for a target of E wla = 100 % corresponded to the abatement ratio of the dischargers ranging from 20.7 to 75.6 % and 29.5 to 78.5 % in summer and in winter, respectively, alongside highly shifting inequity values. Abatement-equity-performance modeling results for a target of E wla = 90 % unraveled the necessity of increasing treatment efforts in three out of five dischargers during summer, and four out of five in winter. The trade-off curves obtained from WLA models proved their reliability in selecting appropriate WLA procedures as a function of budget constraints, principles of social equity, and desired overall performance level. Hence, the proposed framework of methodologies is of great importance to decision makers working toward a sustainable reuse of the ADW in irrigation.

DM100 AND DM1200 MELTER TESTING WITH HIGH WASTE LOADING FORMULATIONS FOR HANFORD HIGH-ALUMINUM HLW STREAMS, TEST PLAN 09T1690-1

International Nuclear Information System (INIS)

Kruger, A.A.; Matlack, K.S.; Kot, W.K.; Pegg, I.L.; Joseph, I.

2009-01-01

This Test Plan describes work to support the development and testing of high waste loading glass formulations that achieve high glass melting rates for Hanford high aluminum high level waste (HLW). In particular, the present testing is designed to evaluate the effect of using low activity waste (LAW) waste streams as a source of sodium in place ofchemical additives, sugar or cellulose as a reductant, boehmite as an aluminum source, and further enhancements to waste processing rate while meeting all processing and product quality requirements. The work will include preparation and characterization of crucible melts in support of subsequent DuraMelter 100 (DM 100) tests designed to examine the effects of enhanced glass formulations, glass processing temperature, incorporation of the LAW waste stream as a sodium source, type of organic reductant, and feed solids content on waste processing rate and product quality. Also included is a confirmatory test on the HLW Pilot Melter (DM1200) with a composition selected from those tested on the DM100. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy's (DOE's) Office of River Protection (ORP) to increase waste loading and processing rates for high-iron HLW waste streams as well as previous tests conducted for ORP on the same waste composition. This Test Plan is prepared in response to an ORP-supplied statement of work. It is currently estimated that the number of HLW canisters to be produced in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) is about 12,500. This estimate is based upon the inventory ofthe tank wastes, the anticipated performance of the sludge treatment processes, and current understanding of the capability of the borosilicate glass waste form. The WTP HLW melter design, unlike earlier DOE melter designs, incorporates an active glass bubbler system. The bubblers create active glass pool convection and thereby improve heat transfer and

Pilot-scale anaerobic co-digestion of municipal biomass waste and waste activated sludge in China: Effect of organic loading rate

International Nuclear Information System (INIS)

Liu Xiao; Wang Wei; Shi Yunchun; Zheng Lei; Gao Xingbao; Qiao Wei; Zhou Yingjun

2012-01-01

Highlights: ► Co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) was examined on a pilot-scale reactor. ► System performance and stability under OLR of 1.2, 2.4, 3.6, 4.8, 6.0 and 8.0 kg VS (m 3 d) −1 were analyzed. ► A maximum methane production rate of 2.94 m 3 (m 3 d) −1 was achieved at OLR of 8.0 kg VS (m 3 d) −1 and HRT of 15d. ► With the increasing OLRs, pH values, VS removal rate and methane concentration decreased and VFA increased. ► The changing of biogas production rate can be a practical approach to monitor and control anaerobic digestion system. - Abstract: The effects of organic loading rate on the performance and stability of anaerobic co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) were investigated on a pilot-scale reactor. The results showed that stable operation was achieved with organic loading rates (OLR) of 1.2–8.0 kg volatile solid (VS) (m 3 d) −1 , with VS reduction rates of 61.7–69.9%, and volumetric biogas production of 0.89–5.28 m 3 (m 3 d) −1 . A maximum methane production rate of 2.94 m 3 (m 3 d) −1 was achieved at OLR of 8.0 kg VS (m 3 d) −1 and hydraulic retention time of 15 days. With increasing OLRs, the anaerobic reactor showed a decrease in VS removal rate, average pH value and methane concentration, and a increase of volatile fatty acid concentration. By monitoring the biogas production rate (BPR), the anaerobic digestion system has a higher acidification risk under an OLR of 8.0 kg VS (m 3 d) −1 . This result remarks the possibility of relating bioreactor performance with BPR in order to better understand and monitor anaerobic digestion process.

Large scale centrifuge test of a geomembrane-lined landfill subject to waste settlement and seismic loading.

Science.gov (United States)

Kavazanjian, Edward; Gutierrez, Angel

2017-10-01

A large scale centrifuge test of a geomembrane-lined landfill subject to waste settlement and seismic loading was conducted to help validate a numerical model for performance based design of geomembrane liner systems. The test was conducted using the 240g-ton centrifuge at the University of California at Davis under the U.S. National Science Foundation Network for Earthquake Engineering Simulation Research (NEESR) program. A 0.05mm thin film membrane was used to model the liner. The waste was modeled using a peat-sand mixture. The side slope membrane was underlain by lubricated low density polyethylene to maximize the difference between the interface shear strength on the top and bottom of the geomembrane and the induced tension in it. Instrumentation included thin film strain gages to monitor geomembrane strains and accelerometers to monitor seismic excitation. The model was subjected to an input design motion intended to simulate strong ground motion from the 1994 Hyogo-ken Nanbu earthquake. Results indicate that downdrag waste settlement and seismic loading together, and possibly each phenomenon individually, can induce potentially damaging tensile strains in geomembrane liners. The data collected from this test is publically available and can be used to validate numerical models for the performance of geomembrane liner systems. Published by Elsevier Ltd.

Fuzzy Simulation-Optimization Model for Waste Load Allocation

Directory of Open Access Journals (Sweden)

Motahhare Saadatpour

2006-01-01

Full Text Available This paper present simulation-optimization models for waste load allocation from multiple point sources which include uncertainty due to vagueness of the parameters and goals. This model employs fuzzy sets with appropriate membership functions to deal with uncertainties due to vagueness. The fuzzy waste load allocation model (FWLAM incorporate QUAL2E as a water quality simulation model and Genetic Algorithm (GA as an optimization tool to find the optimal combination of the fraction removal level to the dischargers and pollution control agency (PCA. Penalty functions are employed to control the violations in the system.  The results demonstrate that the goal of PCA to achieve the best water quality and the goal of the dischargers to use the full assimilative capacity of the river have not been satisfied completely and a compromise solution between these goals is provided. This fuzzy optimization model with genetic algorithm has been used for a hypothetical problem. Results demonstrate a very suitable convergence of proposed optimization algorithm to the global optima.

Utilization of small-angle neutron scattering to decide the maximum loading of nuclear waste in cement matrix

International Nuclear Information System (INIS)

Das, Avik; Mazumder, S.; Sen, D.; Yalmali, V.; Shah, J.G.

2014-01-01

Nuclear power plants generate many kinds of hazardous nuclear waste which are needed to be disposed in an eco-friendly manner. Many different waste incarceration techniques have been adapted for managing the nuclear waste of different category of radioactivity. Immobilisation of low and intermediate level radioactive wastes in cement matrix is one of the widely used and cost-effective techniques in waste management. However, loading of nuclear waste in cement matrix can alter the mesoscopic structure of the hydrated cement and hence, it is very important to set the maximum limit of waste loading in cement for providing proper physical isolation to the nuclear waste

Performance of CASTOR {sup registered} HAW cask cold trials for loading, Transport and storage of HAW canisters

Energy Technology Data Exchange (ETDEWEB)

Wilmsmeier, Marco; Horn, Thomas; Graf, Wilhelm [GNS Gesellschaft fuer Nuklear-Service mbH (Germany)

2009-07-01

With over 30 years of experience in the design, manufacturing, assembly and loading of CASTOR {sup registered} casks, GNS is one of the worldwide leading suppliers of casks for the transport and storage of spent fuel assemblies as well as for canisters with vitrified high active wastes (meanwhile over 1.000 casks loaded and stored and more than 1.500 ordered). GNS's products are used at around 30 sites worldwide for a wide range of inventories from pressurised and boiling water reactor fuels (PWR, VVER and BWR, RBMK), thorium high-temperature reactor fuels (THTR) and research reactor fuels (MTR) to vitrified high active wastes (HAW) from reprocessing plants. GNS is responsible for all nuclear wastes resulting from German Nuclear Power Plants and assists and/or performs in the loading and dispatch of CASTOR {sup registered} casks as well as their transport to and storage at central interim storage facilities and local interim storage areas. (orig.)

Real-Time Monitoring of Low-Level Mixed-Waste Loading during Polyethylene Microencapsulation using Transient Infrared Spectroscopy

International Nuclear Information System (INIS)

Jones, Roger W.; Kalb, Paul D.; McClelland, John F.; Ochiai, Shukichi

1999-01-01

In polyethylene microencapsulation, low-level mixed waste (LLMW) is homogenized with molten polyethylene and extruded into containers, resulting in a lighter, lower-volume waste form than cementation and grout methods produce. Additionally, the polyethylene-based waste form solidifies by cooling, with no risk of the waste interfering with cure, as may occur with cementation and grout processes. We have demonstrated real-time monitoring of the polyethylene encapsulation process stream using a noncontact device based on transient infrared spectroscopy (TIRS). TIRS can acquire mid-infrared spectra from solid or viscous liquid process streams, such as the molten, waste-loaded polyethylene stream that exits the microencapsulation extruder. The waste loading in the stream was determined from the TIRS spectra using partial least squares techniques. The monitor has been demonstrated during the polyethylene microencapsulation of nitrate-salt LLMW and its surrogate, molten salt oxidation LLMW and its surrogate, and flyash. The monitor typically achieved a standard error of prediction for the waste loading of about 1% by weight with an analysis time under 1 minute

Pilot-scale anaerobic co-digestion of municipal biomass waste and waste activated sludge in China: Effect of organic loading rate

Energy Technology Data Exchange (ETDEWEB)

Liu Xiao, E-mail: liuxiao07@mails.tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China); Wang Wei; Shi Yunchun; Zheng Lei [School of Environment, Tsinghua University, Beijing 100084 (China); Gao Xingbao [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Qiao Wei [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhou Yingjun [Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540 (Japan)

2012-11-15

Highlights: Black-Right-Pointing-Pointer Co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) was examined on a pilot-scale reactor. Black-Right-Pointing-Pointer System performance and stability under OLR of 1.2, 2.4, 3.6, 4.8, 6.0 and 8.0 kg VS (m{sup 3} d){sup -1} were analyzed. Black-Right-Pointing-Pointer A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and HRT of 15d. Black-Right-Pointing-Pointer With the increasing OLRs, pH values, VS removal rate and methane concentration decreased and VFA increased. Black-Right-Pointing-Pointer The changing of biogas production rate can be a practical approach to monitor and control anaerobic digestion system. - Abstract: The effects of organic loading rate on the performance and stability of anaerobic co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) were investigated on a pilot-scale reactor. The results showed that stable operation was achieved with organic loading rates (OLR) of 1.2-8.0 kg volatile solid (VS) (m{sup 3} d){sup -1}, with VS reduction rates of 61.7-69.9%, and volumetric biogas production of 0.89-5.28 m{sup 3} (m{sup 3} d){sup -1}. A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and hydraulic retention time of 15 days. With increasing OLRs, the anaerobic reactor showed a decrease in VS removal rate, average pH value and methane concentration, and a increase of volatile fatty acid concentration. By monitoring the biogas production rate (BPR), the anaerobic digestion system has a higher acidification risk under an OLR of 8.0 kg VS (m{sup 3} d){sup -1}. This result remarks the possibility of relating bioreactor performance with BPR in order to better understand and monitor anaerobic digestion process.

Alternative High-Performance Ceramic Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Sundaram, S. K. [Alfred Univ., NY (United States)

2017-02-01

powders were consolidated via SPS. Ce was reduced to the trivalent oxidation state and the zirconolite was converted into undesirable perovskite. The zirconolite polymorphs found in the synthesized powders were recovered after a post-SPS heat treatment in air. These results demonstrated the potential of processing in controlling the phase assemblage in these waste forms. Hollandites with Cr³⁺ trivalent cations were identified as potential hosts for Cs immobilization and are being investigated for Cs retention properties. Series of compositions Ba_1.15-xCs_2xCr_2.3Ti_5.7O₁₆, with increasing Cs loadings, were prepared by sol-gel process and characterized for structural parameters. Structural characterization was performed by a combination of powder XRD and neutron powder diffraction. Phase pure hollandite adapting monoclinic symmetry (I2/m) was observed for 0 ≤ x ≤ 0.55. These results were used to develop a new structural model to interpret Cs immobilization in these hollandites. Performance of these waste forms were evaluated for chemical durability and radiation resistance. Product consistency testing (PCT) and vapor hydration testing (VHT) were used for testing of chemical durability. Radiation resistance was tested using He⁺ ions to simulate $\\alpha$ particles and heavy ions such as Au³⁺ to simulate a recoil. These results showed that these waste forms were chemically durable. The waste forms also amorphized to various degrees on exposure to simulated radiation.

Part-load performance of a high temperature Kalina cycle

International Nuclear Information System (INIS)

Modi, Anish; Andreasen, Jesper Graa; Kærn, Martin Ryhl; Haglind, Fredrik

2015-01-01

Highlights: • Detailed algorithm to solve high temperature Kalina cycle in part load. • A central receiver concentrating solar power plant with direct vapour generation considered as case study. • Part-load performance curves and fitted equations presented. - Abstract: The Kalina cycle has recently seen increased interest as an alternative to the conventional steam Rankine cycle. The cycle has been studied for use with both low and high temperature applications such as geothermal power plants, ocean thermal energy conversion, waste heat recovery, gas turbine bottoming cycle, and solar power plants. The high temperature cycle layouts are inherently more complex than the low temperature layouts due to the presence of a distillation-condensation subsystem, three pressure levels, and several heat exchangers. This paper presents a detailed approach to solve the Kalina cycle in part-load operating conditions for high temperature (a turbine inlet temperature of 500 °C) and high pressure (100 bar) applications. A central receiver concentrating solar power plant with direct vapour generation is considered as a case study where the part-load conditions are simulated by changing the solar heat input to the receiver. Compared with the steam Rankine cycle, the Kalina cycle has an additional degree of freedom in terms of the ammonia mass fraction which can be varied in order to maximize the part-load efficiency of the cycle. The results include the part-load curves for various turbine inlet ammonia mass fractions and the fitted equations for these curves.

Side loading vault system and method for the disposal of radioactive waste

International Nuclear Information System (INIS)

Meess, D.C.; Jones, B.J.; Mello, R.M.; Weiss, T.G. Jr.; Wright, J.B.

1990-01-01

This patent describes a method for the disposal of hazardous radioactive waste. It comprises: constructing a floor slab in the earth; constructing an elongated wall assembly over the floor slab having sidewalls and a front wall and a back wall at either end the side walls being longer than the front and back walls; providing an accessway in the front wall; constructing a ceiling slab over the wall assembly that is supported at least in part by the wall assembly to form a vault cell; inspecting the vault cell for structural defects, introducing hazardous radioactive waste through the accessway in the front wall and loading the cell with the waste from the back wall to the front wall in rows, each of which is substantially parallel to the back wall to minimize radiation exposure to workers loading the cell, and closing the accessway of the vault cell by constructing a removable wall structure within the accessway

Fuel properties and engine performance of biodiesel from waste cooking oil collected in Dhaka city

Science.gov (United States)

Islam, R. B.; Islam, R.; Uddin, M. N.; Ehsan, Md.

2016-07-01

Waste cooking oil can be a potential source of biodiesel that has least effect on the edible oil consumption. Increasing number of hotel-restaurants and more active monitoring by health authorities have increased the generation of waste cooking oil significantly in densely populated cities like Dhaka. If not used or disposed properly, waste cooking oil itself may generate lot of environmental issues. In this work, waste cooking oils from different restaurants within Dhaka City were collected and some relevant properties of these waste oils were measured. Based on the samples studied one with the highest potential as biodiesel feed was identified and processed for engine performance. Standard trans-esterification process was used to produce biodiesel from the selected waste cooking oil. Biodiesel blends of B20 and B40 category were made and tested on a single cylinder direct injection diesel engine. Engine performance parameters included - bhp, bsfc and exhaust emission for rated and part load conditions. Results give a quantitative assessment of the potential of using biodiesel from waste cooking oil as fuel for diesel engines in Bangladesh.

Loading, moving, and shipping radioactive waste in reusable radioactive material containers

International Nuclear Information System (INIS)

Schillinger, F.J.; Mohr, J.A.

1993-01-01

While the dismantlement of systems and components at the Shoreham Nuclear Power Plant was a monumental task, the loading, movement, temporary storage, and shipping of over 2 1/2 million pounds of contaminated and/or activated material was nearly as difficult. Close coordination and teamwork between such diverse groups as craft labor, health physics, radiation controls, trucking companies and waste volume reducers were crucial elements in performing this work safely, cost effectively, and with particular attention to the station's very aggressive ALARA (As Low As Reasonably Achievable) goals. This paper discusses the actual work that was involved from the time the contaminated component was removed from its location in the plant through actual shipment offsite

40 CFR 62.15265 - How do I monitor the load of my municipal waste combustion unit?

Science.gov (United States)

2010-07-01

... continuously estimate load level (for example, the feed rate of municipal solid waste or refuse-derived fuel... municipal waste combustion unit? 62.15265 Section 62.15265 Protection of Environment ENVIRONMENTAL... DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements for Small Municipal Waste Combustion Units...

Case study of rutting performance of HMA modified with waste rubber powder

Directory of Open Access Journals (Sweden)

G.H. Shafabakhsh

2014-01-01

Full Text Available Low resistance against dynamic loads and short service life of pavement are the most significant problems in the conservation and maintenance of roads, to the extent that, annually enormous costs are spent in order to improve capabilities of road services in the country. Research shows that the use of some wastes such as waste rubber powder in asphalt mixtures not only increase its serves life but also cause to reduce production costs; furthermore, recycling the crumb rubber has also considerably environmental benefits environmental benefits such as reduced need for landfill, less atmospheric pollution from burning. In this paper, the effect of adding waste rubber powder on the rutting performance of asphalt mixtures has been studied. In order to compare the performance of rubberized asphalt mixtures and conventional asphalt, wheel track test has been used. The results of this study show that the use of rubber powder caused a significant decrease in the rate of rutting depth of rubber asphalt mixtures compared to control samples.

Low-risk alternative waste forms for problematic high-level and long-lived nuclear wastes

International Nuclear Information System (INIS)

Stewart, M.W.A.; Begg, B.D.; Moricca, S.; Day, R.A.

2006-01-01

Full text: The highest cost component the nuclear waste clean up challenge centres on high-level waste (HLW) and consequently the greatest opportunity for cost and schedule savings lies with optimising the approach to HLW cleanup. The waste form is the key component of the immobilisation process. To achieve maximum cost savings and optimum performance the selection of the waste form should be driven by the characteristics of the specific nuclear waste to be immobilised, rather than adopting a single baseline approach. This is particularly true for problematic nuclear wastes that are often not amenable to a single baseline approach. The use of tailored, high-performance, alternative waste forms that include ceramics and glass-ceramics, coupled with mature process technologies offer significant performance improvements and efficiency savings for a nuclear waste cleanup program. It is the waste form that determines how well the waste is locked up (chemical durability), and the number of repository disposal canisters required (waste loading efficiency). The use of alternative waste forms for problematic wastes also lowers the overall risk by providing high performance HLW treatment alternatives. The benefits tailored alternative waste forms bring to the HLW cleanup program will be briefly reviewed with reference to work carried out on the following: The HLW calcines at the Idaho National Laboratory; SYNROC ANSTO has developed a process utilising a glass-ceramic combined with mature hot-isostatic pressing (HIP) technology and has demonstrated this at a waste loading of 80 % and at a 30 kg HIP scale. The use of this technology has recently been estimated to result in a 70 % reduction in waste canisters, compared to the baseline borosilicate glass technology; Actinide-rich waste streams, particularly the work being done by SYNROC ANSTO with Nexia Solutions on the Plutonium-residues wastes at Sellafield in the UK, which if implemented is forecast to result in substantial

Performance Assessments of Generic Nuclear Waste Repositories in Shale

Science.gov (United States)

Stein, E. R.; Sevougian, S. D.; Mariner, P. E.; Hammond, G. E.; Frederick, J.

2017-12-01

Simulations of deep geologic disposal of nuclear waste in a generic shale formation showcase Geologic Disposal Safety Assessment (GDSA) Framework, a toolkit for repository performance assessment (PA) whose capabilities include domain discretization (Cubit), multiphysics simulations (PFLOTRAN), uncertainty and sensitivity analysis (Dakota), and visualization (Paraview). GDSA Framework is used to conduct PAs of two generic repositories in shale. The first considers the disposal of 22,000 metric tons heavy metal of commercial spent nuclear fuel. The second considers disposal of defense-related spent nuclear fuel and high level waste. Each PA accounts for the thermal load and radionuclide inventory of applicable waste types, components of the engineered barrier system, and components of the natural barrier system including the host rock shale and underlying and overlying stratigraphic units. Model domains are half-symmetry, gridded with Cubit, and contain between 7 and 22 million grid cells. Grid refinement captures the detail of individual waste packages, emplacement drifts, access drifts, and shafts. Simulations are run in a high performance computing environment on as many as 2048 processes. Equations describing coupled heat and fluid flow and reactive transport are solved with PFLOTRAN, an open-source, massively parallel multiphase flow and reactive transport code. Additional simulated processes include waste package degradation, waste form dissolution, radioactive decay and ingrowth, sorption, solubility, advection, dispersion, and diffusion. Simulations are run to 106 y, and radionuclide concentrations are observed within aquifers at a point approximately 5 km downgradient of the repository. Dakota is used to sample likely ranges of input parameters including waste form and waste package degradation rates and properties of engineered and natural materials to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia National

Polyethylene solidification of low-level wastes

International Nuclear Information System (INIS)

Kalb, P.D.; Colombo, P.

1985-02-01

This topical report describes the results of an investigation on the solidification of low-level radioactive waste in polyethylene. Waste streams selected for this study included those which result from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Four types of commercially available low-density polyethylenes were employed which encompass a range of processing and property characteristics. Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste and polyethylene type. Property evaluation testing was performed on laboratory-scale specimens to assess the potential behavior of actual waste forms in a disposal environment. Waste form property tests included water immersion, deformation under compressive load, thermal cycling and radionuclide leaching. Recommended waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash, and 30 wt % ion exchange resins, which are based on process control and waste form performance considerations are reported. 37 refs., 33 figs., 22 tabs

An Optimization Waste Load Allocation Model in River Systems

Science.gov (United States)

Amirpoor Daylami, A.; jarihani, A. A.; Aminisola, K.

2012-04-01

In many river systems, increasing of the waste discharge leads to increasing pollution of these water bodies. While the capacity of the river flow for pollution acceptance is limited and the ability of river to clean itself is restricted, the dischargers have to release their waste into the river after a primary pollution treatment process. Waste Load Allocation as a well-known water quality control strategy is used to determine the optimal pollutant removal at a number of point sources along the river. This paper aim at developing a new approach for treatment and management of wastewater inputs into the river systems, such that water quality standards in these receiving waters are met. In this study, inspired by the fact that cooperation among some single point source waste dischargers can lead to a more waste acceptance capacity and/or more optimum quality control in a river, an efficient approach was implemented to determine both primary waste water treatment levels and/or the best releasing points of the waste into the river. In this methodology, a genetic algorithm is used as an optimization tool to calculate optimal fraction removal levels of each one of single or shared discharger. Besides, a sub-model embedded to optimization model was used to simulate water quality of the river in each one of discharging scenarios based on the modified Streeter and Phelps quality equations. The practical application of the model is illustrated with a case study of the Gharesoo river system in west of Iran.

Semi-continuous anaerobic digestion of solid poultry slaughterhouse waste: effect of hydraulic retention time and loading.

Science.gov (United States)

Salminen, Esa A; Rintala, Jukka A

2002-07-01

We studied the effect of hydraulic retention time (HRT) and loading on anaerobic digestion of poultry slaughterhouse wastes, using semi-continuously fed, laboratory-scale digesters at 31 degrees C. The effect on process performance was highly significant: Anaerobic digestion appeared feasible with a loading of up to 0.8 kg volatile solids (VS)/m3 d and an HRT of 50-100 days. The specific methane yield was high, from 0.52 to 0.55 m3/kg VS(added). On the other hand, at a higher loading, in the range from 1.0 to 2.1 kg VS/m3 d, and a shorter HRT, in the range from 25 to 13 days, the process appeared inhibited and/or overloaded, as indicated by the accumulation of volatile fatty acids and long-chain fatty acids and the decline in the methane yield. However, the inhibition was reversible. The nitrogen in the feed, ca. 7.8% of total solids (TS), was organic nitrogen with little ammonia present, whereas in the digested material ammonia accounted for 52-67% (up to 3.8 g/l) of total nitrogen. The TS and VS removals amounted to 76% and 64%, respectively. Our results show that on a continuous basis under the studied conditions and with a loading of up to 0.8 kg VS/m3 d metric ton (wet weight) of the studied waste mixture could yield up to 140 m3 of methane.

Waste package performance in unsaturated rock

International Nuclear Information System (INIS)

Pigford, T.H.; Lee, W.W.-L.

1989-03-01

The unsaturated rock and near-atmospheric pressure of the potential nuclear waste repository at Yucca Mountain present new problems of predicting waste package performance. In this paper we present some illustrations of predictions of waste package performance and discuss important data needs. 11 refs., 9 figs., 1 tab

The influence of geological loading on the structural integrity of an underground nuclear waste repository

International Nuclear Information System (INIS)

Jakeman, N.

1985-08-01

Stresses are developed in underground nuclear waste repositories as a result of applied loads from geological movements caused by the encroachment of ice sheets or seismic activity for example. These stresses may induce fracturing of the waste matrix, repository vault and nearfield host geology. This fracturing will enhance the advective flow and allow more-rapid transfer of radionuclides from their encapsulation through the repository barriers and nearfield host rock. Geological loads may be applied either gradually as in crustal folding or encroachment of ice sheets, or rapidly as in the case of seismic movements. The analysis outlined in this report is conducted with a view to including the effects of geological loading in a probabilistic repository site assessment computer code such as SYVAC. (author)

Performance Improvement Of Cross-Flow Filtration For High Level Waste Treatment

International Nuclear Information System (INIS)

Duignan, M.; Nash, C.; Poirier, M.

2011-01-01

In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed

PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT

Energy Technology Data Exchange (ETDEWEB)

Duignan, M.; Nash, C.; Poirier, M.

2011-01-12

In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed

Optimization of waste loading in high-level glass in the presence of uncertainty

International Nuclear Information System (INIS)

Hoza, M.; Fann, G.I.; Hopkins, D.F.

1995-02-01

Hanford high-level liquid waste will be converted into a glass form for long-term storage. The glass must meet certain constraints on its composition and properties in order to have desired properties for processing (e.g., electrical conductivity, viscosity, and liquidus temperature) and acceptable durability for long-term storage. The Optimal Waste Loading (OWL) models, based on rigorous mathematical optimization techniques, have been developed to minimize the number of glass logs required and determine glass-former compositions that will produce a glass meeting all relevant constraints. There is considerable uncertainty in many of the models and data relevant to the formulation of high-level glass. In this paper, we discuss how we handle uncertainty in the glass property models and in the high-level waste composition to the vitrification process. Glass property constraints used in optimization are inequalities that relate glass property models obtained by regression analysis of experimental data to numerical limits on property values. Therefore, these constraints are subject to uncertainty. The sampling distributions of the regression models are used to describe the uncertainties associated with the constraints. The optimization then accounts for these uncertainties by requiring the constraints to be satisfied within specified confidence limits. The uncertainty in waste composition is handled using stochastic optimization. Given means and standard deviations of component masses in the high-level waste stream, distributions of possible values for each component are generated. A series of optimization runs is performed; the distribution of each waste component is sampled for each run. The resultant distribution of solutions is then statistically summarized. The ability of OWL models to handle these forms of uncertainty make them very useful tools in designing and evaluating high-level waste glasses formulations

The effects of load drop, uniform load and concentrated loads on waste tanks

International Nuclear Information System (INIS)

Marusich, R.M. Westinghouse Hanford

1996-01-01

This document provides the supporting calculations performed by others specifically for the TWRS FSAR and more detailed summaries of the important references issued in the past regarding the effects of various loads

Performance of continuous stirred tank reactor (CSTR) on fermentative biohydrogen production from melon waste

Science.gov (United States)

Cahyari, K.; Sarto; Syamsiah, S.; Prasetya, A.

2016-11-01

This research was meant to investigate performance of continuous stirred tank reactor (CSTR) as bioreactor for producing biohydrogen from melon waste through dark fermentation method. Melon waste are commonly generated from agricultural processing stages i.e. cultivation, post-harvesting, industrial processing, and transportation. It accounted for more than 50% of total harvested fruit. Feedstock of melon waste was fed regularly to CSTR according to organic loading rate at value 1.2 - 3.6 g VS/ (l.d). Optimum condition was achieved at OLR 2.4 g VS/ (l.d) with the highest total gas volume 196 ml STP. Implication of higher OLR value is reduction of total gas volume due to accumulation of acids (pH 4.0), and lower substrate volatile solid removal. In summary, application of this method might valorize melon waste and generates renewable energy sources.

Glass Ceramic Waste Forms for Combined CS+LN+TM Fission Products Waste Streams

International Nuclear Information System (INIS)

Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.; Tang, Ming; Kossoy, Anna; Sickafus, Kurt E.

2010-01-01

In this study, glass ceramics were explored as an alternative waste form for glass, the current baseline, to be used for immobilizing alkaline/alkaline earth + lanthanide (CS+LN) or CS+LN+transition metal (TM) fission-product waste streams generated by a uranium extraction (UREX+) aqueous separations type process. Results from past work on a glass waste form for the combined CS+LN waste streams showed that as waste loading increased, large fractions of crystalline phases precipitated upon slow cooling.(1) The crystalline phases had no noticeable impact on the waste form performance by the 7-day product consistency test (PCT). These results point towards the development of a glass ceramic waste form for treating CS+LN or CS+LN+TM combined waste streams. Three main benefits for exploring glass ceramics are: (1) Glass ceramics offer increased solubility of troublesome components in crystalline phases as compared to glass, leading to increased waste loading; (2) The crystalline network formed in the glass ceramic results in higher heat tolerance than glass; and (3) These glass ceramics are designed to be processed by the same melter technology as the current baseline glass waste form. It will only require adding controlled canister cooling for crystallization into a glass ceramic waste form. Highly annealed waste form (essentially crack free) with up to 50X lower surface area than a typical High-Level Waste (HLW) glass canister. Lower surface area translates directly into increased durability. This was the first full year of exploring glass ceramics for the Option 1 and 2 combined waste stream options. This work has shown that dramatic increases in waste loading are achievable by designing a glass ceramic waste form as an alternative to glass. Table S1 shows the upper limits for heat, waste loading (based on solubility), and the decay time needed before treatment can occur for glass and glass ceramic waste forms. The improvements are significant for both combined waste

Glass Ceramic Waste Forms for Combined CS+LN+TM Fission Products Waste Streams

Energy Technology Data Exchange (ETDEWEB)

Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.; Tang, Ming; Kossoy, Anna; Sickafus, Kurt E.

2010-09-23

In this study, glass ceramics were explored as an alternative waste form for glass, the current baseline, to be used for immobilizing alkaline/alkaline earth + lanthanide (CS+LN) or CS+LN+transition metal (TM) fission-product waste streams generated by a uranium extraction (UREX+) aqueous separations type process. Results from past work on a glass waste form for the combined CS+LN waste streams showed that as waste loading increased, large fractions of crystalline phases precipitated upon slow cooling.[1] The crystalline phases had no noticeable impact on the waste form performance by the 7-day product consistency test (PCT). These results point towards the development of a glass ceramic waste form for treating CS+LN or CS+LN+TM combined waste streams. Three main benefits for exploring glass ceramics are: (1) Glass ceramics offer increased solubility of troublesome components in crystalline phases as compared to glass, leading to increased waste loading; (2) The crystalline network formed in the glass ceramic results in higher heat tolerance than glass; and (3) These glass ceramics are designed to be processed by the same melter technology as the current baseline glass waste form. It will only require adding controlled canister cooling for crystallization into a glass ceramic waste form. Highly annealed waste form (essentially crack free) with up to 50X lower surface area than a typical High-Level Waste (HLW) glass canister. Lower surface area translates directly into increased durability. This was the first full year of exploring glass ceramics for the Option 1 and 2 combined waste stream options. This work has shown that dramatic increases in waste loading are achievable by designing a glass ceramic waste form as an alternative to glass. Table S1 shows the upper limits for heat, waste loading (based on solubility), and the decay time needed before treatment can occur for glass and glass ceramic waste forms. The improvements are significant for both combined waste

Polyethylene encapsulation of mixed wastes: Scale-up feasibility

International Nuclear Information System (INIS)

Kalb, P.D.; Heiser, J.H.; Colombo, P.

1991-01-01

A polyethylene process for the improved encapsulation of radioactive, hazardous, and mixed wastes have been developed at Brookhaven National Laboratory (BNL). Improvements in waste loading and waste form performance have been demonstrated through bench-scale development and testing. Maximum waste loadings of up to 70 dry wt % mixed waste nitrate salt were achieved, compared with 13--20 dry wt % using conventional cement processes. Stability under anticipated storage and disposal conditions and compliance with applicable hazardous waste regulations were demonstrated through a series of lab-scale waste form performance tests. Full-scale demonstration of this process using actual or surrogate waste is currently planned. A scale-up feasibility test was successfully conducted, demonstrating the ability to process nitrate salts at production rates (up to 450 kg/hr) and the close agreement between bench- and full-scale process parameters. Cored samples from the resulting pilot-scale (114 liter) waste form were used to verify homogeneity and to provide additional specimens for confirmatory performance testing

Environmental performance of household waste management in Europe - An example of 7 countries.

Science.gov (United States)

Andreasi Bassi, Susanna; Christensen, Thomas H; Damgaard, Anders

2017-11-01

An attributional life cycle assessment (LCA) of the management of 1ton of household waste was conducted in accordance with ISO 14044:2006 and the ILCD Handbook for seven European countries, namely Germany, Denmark, France, UK, Italy, Poland and Greece, representing different household waste compositions, waste management practices, technologies, and energy systems. National data were collected from a range of sources regarding household waste composition, household sorting efficiency, collection, waste treatments, recycling, electricity and heat composition, and technological efficiencies. The objective was to quantify the environmental performance in the different countries, in order to analyze the sources of the main environmental impacts and national differences which affect the results. In most of the seven countries, household waste management provides environmental benefits when considering the benefits of recycling of materials and recovering and utilization of energy. Environmental benefits come from paper recycling and, to a lesser extent, the recycling of metals and glass. Waste-to-energy plants can lead to an environmental load (as in France) or a saving (Germany and Denmark), depending mainly on the composition of the energy being substituted. Sensitivity analysis and a data quality assessment identified a range of critical parameters, suggesting from where better data should be obtained. The study concluded that household waste management is environmentally the best in European countries with a minimum reliance on landfilling, also induced by the implementation of the Waste Hierarchy, though environmental performance does not correlate clearly with the rate of material recycling. From an environmental point of view, this calls for a change in the waste management paradigm, with less focus on where the waste is routed and more of a focus on the quality and utilization of recovered materials and energy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimal Waste Load Allocation Using Multi-Objective Optimization and Multi-Criteria Decision Analysis

Directory of Open Access Journals (Sweden)

L. Saberi

2016-10-01

, five alternatives and their performances under criteria are found. Values that are calculated by MOPSO are applied to form the cardinal Multi-Criteria Decision Making (MCDM matrix. Afterwards, the cardinal MCDM matrix is transformed into the ordinal form. For studying competitive behaviors in such situations, a mathematical tool called game theory is used. Hence the transition matrix is formed for solving the problem by game theory and qualitative data. Finally the best non-dominated solution is defined using the Nash conflict resolution theory. Results and Discussion: The interaction point of the Sefidrood River and Caspian Sea is considered as a checkpoint and the standard amount of BOD considering the Iranian Protection Agency’s standards is equivalent to 5 mg/l. In the studied area, none of waste load dischargers perform current wastewater treatment. Under this circumstance, the BOD has the value of 26.59 mg/l which violated its standard amount. By MOPSO algorithm and Nash theory five alternatives, which each of them includes both the amount of BOD in checkpoint and treatment and penalty total cost, are obtained for two decision makers. The best and final alternative, that is preferred by both of decision-makers, reduces the BOD amount and the total payable cost to 6.16 mg/l and 296,293 $/year respectively. Conclusion: The practical utility of the proposed model in decision-making is illustrated through a realistic example of the Sefidrood River in the northern part of Iran. As a final alternative, that suggests the most economical measurement by minimizing of treatment and penalty total cost, there are acceptable percentage of treatment per discharge and the violation of standard for BOD parameter is negligible.

Performance objectives for the Hanford Immobilized Low-Activity Waste (ILAW) performance assessment

International Nuclear Information System (INIS)

MANN, F.M.

1999-01-01

Performance objectives for the disposal of low activity waste from Hanford Waste Tanks have been developed. These objectives have been based on DOE requirements, programmatic requirements, and public involvement. The DOE requirements include regulations that direct the performance assessment and are cited within the Radioactive Waste Management Order (DOE Order 435.1). Performance objectives for other DOE complex performance assessments have been included

Structure and short time degradation studies of sodium zirconium phosphate ceramics loaded with simulated fast breeder (FBR) waste

Energy Technology Data Exchange (ETDEWEB)

Ananthanarayanan, A., E-mail: arvinda@barc.gov.in [Process Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Ambashta, R.D., E-mail: aritu@barc.gov.in [Process Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sudarsan, V. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Ajithkumar, T. [Applied Catalysis Unit, National Chemical Laboratory, Pune 411008 (India); Sen, D.; Mazumder, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Wattal, P.K. [Process Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2017-04-15

Sodium zirconium phosphate (NZP) ceramics have been prepared using conventional sintering and hot isostatic pressing (HIP) routes. The structure of NZP ceramics, prepared using the HIP route, has been compared with conventionally sintered NZP using a combination of X-ray diffraction (XRD) and ({sup 31}P and {sup 23}Na) nuclear magnetic resonance (NMR) spectroscopy techniques. It is observed that NZP with no waste loading is aggressive toward the steel HIP-can during hot isostatic compaction and significant fraction of cations from the steel enter the ceramic material. Waste loaded NZP samples (10 wt% simulated FBR waste) show significantly low can-interaction and primary NZP phase is evident in this material. Upon exposure of can-interacted and waste loaded NZP to boiling water and steam, {sup 31}P NMR does not detect any major modifications in the network structure. However, the {sup 23}Na NMR spectra indicate migration of Na{sup +} ions from the surface and possible re-crystallization. This is corroborated by Small-Angle Neutron Scattering (SANS) data and Scanning Electron Microscopy (SEM) measurements carried out on these samples.

Analysis of waste-load assimilative capacity of the Yampa River, Steamboat Springs to Hayden, Routt County, Colorado

Science.gov (United States)

Bauer, Daniel P.; Steele, Timothy Doak; Anderson, Richard D.

1978-01-01

An analysis of the waste-load assimilative capacity of the Yampa River from Steamboat Springs to Hayden, Colo., a distance of 38 miles, was made during September 1975 to obtain information on the effects of projected waste loadings on this stream reach. Simulations of effects of waste loadings on streamflow quality were made using a steady-state water-quality model. The simulations were based on 7-day low-flow values with a 10-year recurrence interval and population projections for 2010. Model results for December and September streamflow conditions indicated that the recommended 1978 Colorado and 1976 U.S. Environmental Protection Agency water-quality standard of 0.02 milligram per liter for nonionized ammonia concentration would be exceeded. Model simulations also included the effect of a flow augmentation of 20 cubic feet per second from a proposed upstream reservoir. The permissible ammonia loading in the study reach could be increased approximately 25 percent with this amount of flow augmentation. Simulations of concentrations of dissolved oxygen, fecal-coliform bacteria, and nitrate nitrogen indicated that the State 's water-quality goals proposed for 1978, 1983, or 1985 would not be exceeded. (Woodard-USGS)

Evaluation of the performance of different anaerobic digestion technologies for solid waste treatment

Energy Technology Data Exchange (ETDEWEB)

Chavez-Vazquez, M.; Bagley, D.M. [Univ. of Toronto, Dept. of Civil Engineering, Toronto, Ontario (Canada)

2002-06-15

The anaerobic digestion of solid wastes is now a widely-used technology in Europe with more than 50 full-scale plants operating. However, anaerobic solid waste digestion is still used to only a limited extent in North America with only three facilities in Canada. Because of the expected importance of anaerobic digestion in the future for energy recovery, reliable tools are required to evaluate the different available technologies, as well as the feed stocks that are suitable for treatment. Therefore, this paper presents a framework that has been developed for evaluating anaerobic solid waste digestion. To develop the framework, a review of the performance of digestion processes was first conducted. Because the data presented were for very different operational parameters (retention time, temperature, configuration set up, mixing, etc.) as well as substrates used for digestion, a standard method of comparison was developed. Gas production per Mg input, organic loading rate and percent volatile solids removal were identified as useful standard parameters for evaluating the performance of different technologies. This framework was constructed as a spread sheet and can be used for different set ups (configuration, organic loading rate, etc.) and with different substrates. It can predict, based on the input and using mass balances, the mass of products of the digester including biogas, treated solids and water. This framework provides a useful tool for evaluating the technical capabilities of different technologies, predicting the quantity of the products, and ultimately, making decisions as to which technologies best meet local needs. (author)

Evaluation of the performance of different anaerobic digestion technologies for solid waste treatment

International Nuclear Information System (INIS)

Chavez-Vazquez, M.; Bagley, D.M.

2002-01-01

The anaerobic digestion of solid wastes is now a widely-used technology in Europe with more than 50 full-scale plants operating. However, anaerobic solid waste digestion is still used to only a limited extent in North America with only three facilities in Canada. Because of the expected importance of anaerobic digestion in the future for energy recovery, reliable tools are required to evaluate the different available technologies, as well as the feed stocks that are suitable for treatment. Therefore, this paper presents a framework that has been developed for evaluating anaerobic solid waste digestion. To develop the framework, a review of the performance of digestion processes was first conducted. Because the data presented were for very different operational parameters (retention time, temperature, configuration set up, mixing, etc.) as well as substrates used for digestion, a standard method of comparison was developed. Gas production per Mg input, organic loading rate and percent volatile solids removal were identified as useful standard parameters for evaluating the performance of different technologies. This framework was constructed as a spread sheet and can be used for different set ups (configuration, organic loading rate, etc.) and with different substrates. It can predict, based on the input and using mass balances, the mass of products of the digester including biogas, treated solids and water. This framework provides a useful tool for evaluating the technical capabilities of different technologies, predicting the quantity of the products, and ultimately, making decisions as to which technologies best meet local needs. (author)

Optimised anaerobic treatment of house-sorted biodegradable waste and slaughterhouse waste in a high loaded half technical scale digester.

Science.gov (United States)

Resch, C; Grasmug, M; Smeets, W; Braun, R; Kirchmayr, R

2006-01-01

Anaerobic co-digestion of organic wastes from households, slaughterhouses and meat processing industries was optimised in a half technical scale plant. The plant was operated for 130 days using two different substrates under organic loading rates of 10 and 12 kgCOD.m(-3).d(-1). Since the substrates were rich in fat and protein components (TKN: 12 g.kg(-1) the treatment was challenging. The process was monitored on-line and in the laboratory. It was demonstrated that an intensive and stable co-digestion of partly hydrolysed organic waste and protein rich slaughterhouse waste can be achieved in the balance of inconsistent pH and buffering NH4-N. In the first experimental period the reduction of the substrate COD was almost complete in an overall stable process (COD reduction >82%). In the second period methane productivity increased, but certain intermediate products accumulated constantly. Process design options for a second digestion phase for advanced degradation were investigated. Potential causes for slow and reduced propionic and valeric acid degradation were assessed. Recommendations for full-scale process implementation can be made from the experimental results reported. The highly loaded and stable codigestion of these substrates may be a good technical and economic treatment alternative.

Chassis loading investigation of two-shaft shredder for construction waste management

Directory of Open Access Journals (Sweden)

Vatskicheva Malina

2017-01-01

Full Text Available Recycling industry development need cracked materials with different composition and characteristics. New constructions shredders creation, their engineering design, development through adequate mechanical-mathematical models and practical realization determines the actuality of this paper. The materials crushing for recycling solves important environmental tasks related to environmental protection. The two-shaft hydraulic shredder realized the first and the second stage from the crushing (disintegration process. Disintegration as part of the recycling process can be successfully applied to the domestic and industrial waste processing, singleand multi-component materials crushing, and to secondary raw materials grinding. The paper is dedicated to the emerging loading of the two-shaft shredder chassis and the resulting calculations and verifications. In the present work has been performed a modeling study of the chassis for such type of shredder for concrete, rubber, plastic and wood crushing. The studies of the mechanical load and behaviour of the chassis have been conducted. The equations characterizing the mechanical processes in the working conditions by the finite element method are solved. For this purpose has been generated a chassis three-dimensional geometrical model, which has been discretized to a planned network of finite elements in the ANSYS MECHANICAL APDL programming environment.

Equitable fund allocation, an economical approach for sustainable waste load allocation.

Science.gov (United States)

Ashtiani, Elham Feizi; Niksokhan, Mohammad Hossein; Jamshidi, Shervin

2015-08-01

This research aims to study a novel approach for waste load allocation (WLA) to meet environmental, economical, and equity objectives, simultaneously. For this purpose, based on a simulation-optimization model developed for Haraz River in north of Iran, the waste loads are allocated according to discharge permit market. The non-dominated solutions are initially achieved through multiobjective particle swarm optimization (MOPSO). Here, the violation of environmental standards based on dissolved oxygen (DO) versus biochemical oxidation demand (BOD) removal costs is minimized to find economical total maximum daily loads (TMDLs). This can save 41% in total abatement costs in comparison with the conventional command and control policy. The BOD discharge permit market then increases the revenues to 45%. This framework ensures that the environmental limits are fulfilled but the inequity index is rather high (about 4.65). For instance, the discharge permit buyer may not be satisfied about the equity of WLA. Consequently, it is recommended that a third party or institution should be in charge of reallocating the funds. It means that the polluters which gain benefits by unfair discharges should pay taxes (or funds) to compensate the losses of other polluters. This intends to reduce the costs below the required values of the lowest inequity index condition. These compensations of equitable fund allocation (EFA) may help to reduce the dissatisfactions and develop WLA policies. It is concluded that EFA in integration with water quality trading (WQT) is a promising approach to meet the objectives.

Load responsive multilayer insulation performance testing

Energy Technology Data Exchange (ETDEWEB)

Dye, S.; Kopelove, A. [Quest Thermal Group, 6452 Fig Street Suite A, Arvada, CO 80004 (United States); Mills, G. L. [Ball Aerospace and Technologies Corp, 1600 Commerce Street, Boulder, CO 80301 (United States)

2014-01-29

Cryogenic insulation designed to operate at various pressures from one atmosphere to vacuum, with high thermal performance and light weight, is needed for cryogenically fueled space launch vehicles and aircraft. Multilayer insulation (MLI) performs well in a high vacuum, but the required vacuum shell for use in the atmosphere is heavy. Spray-on foam insulation (SOFI) is often used in these systems because of its light weight, but can have a higher heat flux than desired. We report on the continued development of Load Responsive Multilayer Insulation (LRMLI), an advanced thermal insulation system that uses dynamic beam discrete spacers that provide high thermal performance both in atmosphere and vacuum. LRMLI consists of layers of thermal radiation barriers separated and supported by micromolded polymer spacers. The spacers have low thermal conductance, and self-support a thin, lightweight vacuum shell that provides internal high vacuum in the insulation. The dynamic load responsive spacers compress to support the external load of a vacuum shell in one atmosphere, and decompress under reduced atmospheric pressure for lower heat leak. Structural load testing was performed on the spacers with various configurations. LRMLI was installed on a 400 liter tank and boil off testing with liquid nitrogen performed at various chamber pressures from one atmosphere to high vacuum. Testing was also performed with an MLI blanket on the outside of the LRMLI.

Load responsive multilayer insulation performance testing

International Nuclear Information System (INIS)

Dye, S.; Kopelove, A.; Mills, G. L.

2014-01-01

Cryogenic insulation designed to operate at various pressures from one atmosphere to vacuum, with high thermal performance and light weight, is needed for cryogenically fueled space launch vehicles and aircraft. Multilayer insulation (MLI) performs well in a high vacuum, but the required vacuum shell for use in the atmosphere is heavy. Spray-on foam insulation (SOFI) is often used in these systems because of its light weight, but can have a higher heat flux than desired. We report on the continued development of Load Responsive Multilayer Insulation (LRMLI), an advanced thermal insulation system that uses dynamic beam discrete spacers that provide high thermal performance both in atmosphere and vacuum. LRMLI consists of layers of thermal radiation barriers separated and supported by micromolded polymer spacers. The spacers have low thermal conductance, and self-support a thin, lightweight vacuum shell that provides internal high vacuum in the insulation. The dynamic load responsive spacers compress to support the external load of a vacuum shell in one atmosphere, and decompress under reduced atmospheric pressure for lower heat leak. Structural load testing was performed on the spacers with various configurations. LRMLI was installed on a 400 liter tank and boil off testing with liquid nitrogen performed at various chamber pressures from one atmosphere to high vacuum. Testing was also performed with an MLI blanket on the outside of the LRMLI

Performance Evaluation of Asphalt Modified with Municipal Wastes for Sustainable Pavement Construction

Directory of Open Access Journals (Sweden)

Muhammad Nasir Amin

2016-09-01

Full Text Available The severe hot temperature and high traffic loadings in the Kingdom of Saudi Arabia (KSA are causing distress in flexible pavements within a few years of service. Secondly, the conventional bitumen extracted from Saudi oil refineries have a performance grade of 64-10 (PG 64-10, which does not meet the SuperPave performance grade requirement for most of the KSA’s regions. In order to improve the performance grade of bitumen, different percentages of municipal wastes (plastic and crumb rubber were used as bitumen additives. The performance of bitumen at low, intermediate, and high temperatures was evaluated. This is important as the waste production is rising significantly due to the fast urbanization and high population growth in the KSA. Particularly, when there are very few ways of recycling these wastes (municipal, as well as industrial, which in fact have great impact on the environment. High-density polyethylene (HDP, low-density polyethylene (LDP, and crumb rubber (CR with 5%, 10%, and 15% by weight of bitumen, were mixed with the base bitumen (PG 64-10. Rotational viscometer (RV, dynamic shear rheometer (DSR, and bending beam rheometer (BBR were used to evaluate the viscosity, rutting, fatigue, and low-temperature behavior of base and modified binders. The test results indicated that the rutting (permanent deformation and fatigue resistance were significantly improved in modified binders due to the improvement in the visco-elastic properties.

Effects of waste content of glass waste forms on Savannah River high-level waste disposal costs

International Nuclear Information System (INIS)

McDonell, W.R.; Jantzen, C.M.

1985-01-01

Effects of the waste content of glass waste forms of Savannah River high-level waste disposal costs are evaluated by their impact on the number of waste canisters produced. Changes in waste content affect onsite Defense Waste Processing Facility (DWPF) costs as well as offsite shipping and repository emplacement charges. A nominal 1% increase over the 28 wt % waste loading of DWPF glass would reduce disposal costs by about $50 million for Savannah River wastes generated to the year 2000. Waste form modifications under current study include adjustments of glass frit content to compensate for added salt decontamination residues and increased sludge loadings in the DWPF glass. Projected cost reductions demonstrate significant incentives for continued optimization of the glass waste loadings. 13 refs., 3 figs., 3 tabs

Developing a methodology for real-time trading of water withdrawal and waste load discharge permits in rivers.

Science.gov (United States)

Soltani, Maryam; Kerachian, Reza

2018-04-15

In this paper, a new methodology is proposed for the real-time trading of water withdrawal and waste load discharge permits in agricultural areas along the rivers. Total Dissolved Solids (TDS) is chosen as an indicator of river water quality and the TDS load that agricultural water users discharge to the river are controlled by storing a part of return flows in some evaporation ponds. Available surface water withdrawal and waste load discharge permits are determined using a non-linear multi-objective optimization model. Total available permits are then fairly reallocated among agricultural water users, proportional to their arable lands. Water users can trade their water withdrawal and waste load discharge permits simultaneously, in a bilateral, step by step framework, which takes advantage of differences in their water use efficiencies and agricultural return flow rates. A trade that would take place at each time step results in either more benefit or less diverted return flow. The Nucleolus cooperative game is used to redistribute the benefits generated through trades in different time steps. The proposed methodology is applied to PayePol region in the Karkheh River catchment, southwest Iran. Predicting that 1922.7 Million Cubic Meters (MCM) of annual flow is available to agricultural lands at the beginning of the cultivation year, the real-time optimization model estimates the total annual benefit to reach 46.07 million US Dollars (USD), which requires 6.31 MCM of return flow to be diverted to the evaporation ponds. Fair reallocation of the permits, changes these values to 35.38 million USD and 13.69 MCM, respectively. Results illustrate the effectiveness of the proposed methodology in the real-time water and waste load allocation and simultaneous trading of permits. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effect of vitrification technology on waste loading

International Nuclear Information System (INIS)

Hrma, P.R.; Smith, P.A.

1994-08-01

Radioactive wastes on the Hanford Site are going to be permanently disposed of by incorporation into a durable glass. These wastes will be separated into low and high-level portions, and then vitrified. The low-level waste (LLW) is water soluble. Its vitrifiable part (other than off-gas) contains approximately 80 wt% Na 2 O, the rest being Al 2 O 3 , P 2 O 5 , K 2 O, and minor components. The challenge is to formulate durable LLW glasses with as high Na 2 O content as possible by optimizing the additions of SiO 2 , Al 2 O 3 , B 2 O 3 , CaO, and ZrO 2 . This task will not be simple, considering the non-linear and interactive nature of glass properties as a function of composition. Once developed, the LLW glass, being similar in composition to commercial glasses, is unlikely to cause major processing problems, such as crystallization or molten salt segregation. For example, inexpensive LLW glass can be produced in a high-capacity Joule-heated melter with a cold cap to minimize volatilization. The high-level waste (HLW) consists of water-insoluble sludge (Fe 2 O 3 , Al 2 O 3 , ZrO 2 , Cr 2 O 3 , NiO, and others) and a substantial water-soluble residue (Na 2 O). Most of the water-insoluble components are refractory; i.e., their melting points are above the glass melting temperature. With regard to product acceptability, the maximum loading of Hanford HLW in the glass is limited by product durability, not by radiolytic heat generation. However, this maximum may not be achievable because of technological constraints imposed by melter feed rheology, frit properties, and glass melter limits. These restrictions are discussed in this paper. 38 refs

Effect of feeding mode and dilution on the performance and microbial community population in anaerobic digestion of food waste.

Science.gov (United States)

Park, Jong-Hun; Kumar, Gopalakrishnan; Yun, Yeo-Myeong; Kwon, Joong-Chun; Kim, Sang-Hyoun

2018-01-01

The effect of feeding mode and dilution was studied in anaerobic digestion of food waste. An upflow anaerobic digester with a settler was fed at six different organic loading rates (OLRs) from 4.6 to 8.6kgCOD/m 3 /d for 200days. The highest methane productivity of 2.78LCH 4 /L/d was achieved at 8.6kgCOD/m 3 /d during continuous feeding of diluted FW. Continuous feeding of diluted food waste showed more stable and efficient performance than stepwise feeding of undiluted food waste. Sharp increase in propionate concentration attributed towards deterioration of the digester performances in stepwise feeding of undiluted food waste. Microbial communities at various OLRs divulged that the microbial distribution in the continuous feeding of diluted food waste was not significantly perturbed despite the increase of OLR up to 8.6kgCOD/m 3 /d, which was contrast to the unstable distribution in stepwise feeding of undiluted food waste at 6.1kgCOD/m 3 /d. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of Waste Load Allocation Strategiesin Rivers Using Social Choice Approach

Directory of Open Access Journals (Sweden)

mohammad amin zolfagharipour

2015-01-01

Full Text Available In this paper, river water quality management was implemented to minimize the costs of environmental protection and to meet the environmental water quality requirements. For this purpose, the social choice approach was adopted to consider the role of wastewater dischargers in the decision-making process and to increase the applicability of the proposed waste load allocation programs. Firstly, different wastewater treatment scenarios were identified for each water pollutant and treatment alternatives which are combinations of treatment scenarios were defined. For each treatment alternative, penalties due to violations of river water quality standards were then calculated using the qualitative simulation model (Qual2kw and each discharger was assumed to prioritize the treatment alternatives based on the treatment costs and the fines defined for water quality standard violations. Finally, using different social choice methods, the most preferred treatment alternative was identified. In order to reduce costs and to encourage dischargers to participate in river water quality protection programs, the most preferred treatment alternative was exchanged among the dischargers as an initial discharge permit using the extended trading-ratio system (ETRS. The results of applying the proposed model to a case study, the Zarjub River located in north Iran, showed the model’s efficiency in developing river waste load allocation strategies.

Modified sulfur cement solidification of low-level wastes

Energy Technology Data Exchange (ETDEWEB)

1985-10-01

This topical report describes the results of an investigation on the solidification of low-level radioactive wastes in modified sulfur cement. The work was performed as part of the Waste Form Evaluation Program, sponsored by the US Department of Energy's Low-Level Waste Management Program. Modified sulfur cement is a thermoplastic material developed by the US Bureau of Mines. Processing of waste and binder was accomplished by means of both a single-screw extruder and a dual-action mixing vessel. Waste types selected for this study included those resulting from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste type and method of processing. Property evaluation testing was carried out on laboratory scale specimens in order to compare with waste form performance for other potential matrix materials. Waste form property testing included compressive strength, water immersion, thermal cycling and radionuclide leachability. Recommended waste loadings of 40 wt. % sodium sulfate and boric acid salts and 43 wt. % incinerator ash, which are based on processing and performance considerations, are reported. Solidification efficiencies for these waste types represent significant improvements over those of hydraulic cements. Due to poor waste form performance, incorporation of ion exchange resin waste in modified sulfur cement is not recommended.

Modified sulfur cement solidification of low-level wastes

International Nuclear Information System (INIS)

1985-10-01

This topical report describes the results of an investigation on the solidification of low-level radioactive wastes in modified sulfur cement. The work was performed as part of the Waste Form Evaluation Program, sponsored by the US Department of Energy's Low-Level Waste Management Program. Modified sulfur cement is a thermoplastic material developed by the US Bureau of Mines. Processing of waste and binder was accomplished by means of both a single-screw extruder and a dual-action mixing vessel. Waste types selected for this study included those resulting from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste type and method of processing. Property evaluation testing was carried out on laboratory scale specimens in order to compare with waste form performance for other potential matrix materials. Waste form property testing included compressive strength, water immersion, thermal cycling and radionuclide leachability. Recommended waste loadings of 40 wt. % sodium sulfate and boric acid salts and 43 wt. % incinerator ash, which are based on processing and performance considerations, are reported. Solidification efficiencies for these waste types represent significant improvements over those of hydraulic cements. Due to poor waste form performance, incorporation of ion exchange resin waste in modified sulfur cement is not recommended

The role of performance assessment in radioactive waste disposal

International Nuclear Information System (INIS)

Stenhouse, M.J.

1998-01-01

Performance assessment has many applications in the field of radioactive waste management, none more important than demonstrating the suitability of a particular repository system for waste disposal. The role of performance assessment in radioactive waste disposal is discussed with reference to assessments performed in civilian waste management programmes. The process is, however, relevant, and may be applied directly to the disposal of defence-related wastes. When used in an open and transparent manner, performance assessment is a powerful methodology not only for convincing the authorities of the safety of a disposal concept, but also for gaining the wider acceptance of the general public for repository siting. 26 refs

Effects of loading rate and temperature on anaerobic co-digestion of food waste and waste activated sludge in a high frequency feeding system, looking in particular at stability and efficiency.

Science.gov (United States)

Li, Qian; Li, Hao; Wang, Gaojun; Wang, Xiaochang

2017-08-01

A continuously stirred tank reactor (CSTR) with a high feeding frequency (HFF) of once every 15min was employed in order to ease the loading shock frequently occurred in digester with a low feeding frequency. The effects of the organic loading rate (OLR) and temperature on the co-digestion of food waste and waste activated sludge was evaluated in a 302-day long-term experiment. Due to the high hydrolysis rate, the maximum CH 4 yield in a thermophilic reactor was 407mL CH 4 /gVS added , a value that was significantly higher than the 350mL CH 4 /gVS added that occurred in a mesophilic reactor. Although the alkalinity declined when HRT was shorted than 10d, caused by the decrease of conversion ratio from protein to ammonium, the increase of specific methanogenic activity helped HFF system to achieve stable performance at an OLR of 11.2 (HRT 7.5d) and 30.2gVS/L/d (HRT 3d) under mesophilic and thermophilic conditions, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cognitive load predicts point-of-care ultrasound simulator performance.

Science.gov (United States)

Aldekhyl, Sara; Cavalcanti, Rodrigo B; Naismith, Laura M

2018-02-01

The ability to maintain good performance with low cognitive load is an important marker of expertise. Incorporating cognitive load measurements in the context of simulation training may help to inform judgements of competence. This exploratory study investigated relationships between demographic markers of expertise, cognitive load measures, and simulator performance in the context of point-of-care ultrasonography. Twenty-nine medical trainees and clinicians at the University of Toronto with a range of clinical ultrasound experience were recruited. Participants answered a demographic questionnaire then used an ultrasound simulator to perform targeted scanning tasks based on clinical vignettes. Participants were scored on their ability to both acquire and interpret ultrasound images. Cognitive load measures included participant self-report, eye-based physiological indices, and behavioural measures. Data were analyzed using a multilevel linear modelling approach, wherein observations were clustered by participants. Experienced participants outperformed novice participants on ultrasound image acquisition. Ultrasound image interpretation was comparable between the two groups. Ultrasound image acquisition performance was predicted by level of training, prior ultrasound training, and cognitive load. There was significant convergence between cognitive load measurement techniques. A marginal model of ultrasound image acquisition performance including prior ultrasound training and cognitive load as fixed effects provided the best overall fit for the observed data. In this proof-of-principle study, the combination of demographic and cognitive load measures provided more sensitive metrics to predict ultrasound simulator performance. Performance assessments which include cognitive load can help differentiate between levels of expertise in simulation environments, and may serve as better predictors of skill transfer to clinical practice.

Methodology for assessing performance of waste management systems

International Nuclear Information System (INIS)

Meshkov, N.K.; Herzenberg, C.L.; Camasta, S.F.

1988-01-01

The newly revised draft DOE Order 5820.2, Chapter 3, requires that DOE low-level waste shall be managed on a systematic basis using the most appropriate combination of waste generation reduction, segregation, treatment, and disposal practices so that the radioactive components are contained and the overall cost effectiveness is minimized. This order expects each site to prepare and maintain an overall waste management systems performance assessment supporting the combination of waste management practices used in generation reduction segregation, treatment, packaging, storage, and disposal. A document prepared by EG and G Idaho, Inc. for the Department of Energy called Guidance for Conduct of Waste Management Systems Performance Assessment is specifically intended to provide the approach necessary to meet the systems performance assessment requirement of DOE Order 5820.2, Chapter 3, and other applicable state regulations dealing with LLW (low-level radioactive wastes). Methods and procedures are needed for assessing the performance of a waste management system. This report addresses this need. The purpose of the methodology provided in this report is to select the optimal way to manage particular sets of waste streams from generation to disposal in a safe and cost-effective manner, and thereby assist the DOE LLW mangers in complying with the DOE Order 5820.2, Chapter 3, and the associated guidance document

Performance of a 2-megawatt high voltage test load

International Nuclear Information System (INIS)

Horan, D.; Kustom, R.; Ferguson, M.

1995-01-01

A high-power, water-cooled resistive load which simulates the electrical load characteristics of a high-power klystron, capable of 2 megawatts dissipation at 95 kV DC, was built and installed at the Advanced Photon Source for use in load-testing high voltage power supplies. During this testing, the test load has logged approximately 35 hours of operation at power levels in excess of one mezawatt. Slight variations in the resistance of the load during operation indicate that leakage currents in the cooling water may be a significant factor affecting the performance of the load. Sufficient performance data have been collected to indicate that leakage current through the deionized (DI) water coolant shunts roughly 15 percent of the full-load current around the load resistor elements. The leakage current could cause deterioration of internal components of the load. The load pressure vessel was disassembled and inspected internally for any signs of significant wear and distress. Results of this inspection and possible modifications for improved performance will be discussed

Admissible thermal loading in geological formations. Consequences on radioactive waste disposal methods

International Nuclear Information System (INIS)

1982-01-01

The study of the ''Admissible thermal loading in geological formations and its consequence on radioactive waste disposal methods'' comprises four volumes: Volume 1. ''Synthesis report'' (English/French text). Volume 2. Granite formations (French text). Volume 3. Salt formations (German text). Volume 4. Clay formations (French text). The present ''synthesis report'' brings together the formation produced by the three specific studies dealing with granite, salt and clay

Demonstration of GTS Duratek Process for Stabilizing Mercury Contaminated (<260 ppm) Mixed Wastes. Mixed Waste Focus Area. OST Reference No. 2409

International Nuclear Information System (INIS)

1999-01-01

Mercury-contaminated wastes in many forms are present at various U. S. Department of Energy (DOE) sites. At least 26 different DOE sites have this type of mixed low-level waste in their storage facilities, totaling approximately 6,000 m 3 . Mercury contamination in the wastes at DOE sites presents a challenge because it exists in various forms, such as soil, sludges, and debris, as well as in different chemical species of mercury. Stabilization is of interest for radioactively contaminated mercury waste (<260 ppm Hg) because of its success with particular wastes, such as soils, and its promise of applicability to a broad range of wastes. However, stabilization methods must be proven to be adequate to meet treatment standards. They must also be proven feasible in terms of economics, operability, and safety. This report summarizes the findings from a stabilization technology demonstration conducted by GTS Duratek, Inc. Phase I of the study involved receipt and repackaging of the material, followed by preparations for waste tracking. Phase II examined the bench-scale performance of grouting at two different loadings of waste to grouted mass. Phase III demonstrated in-drum mixing and solidification using repackaged drums of sludge. Phase IV initially intended to ship final residues to Envirocare for disposal. The key results of the demonstration are as follows: (1) Solidification tests were performed at low and high waste loading, resulting in stabilization of mercury to meet the Universal Treatment Standard of 0.025 mg/L at the low loading and for two of the three runs at the high loading. The third high-loading run had a Toxicity Characteristic Leaching Procedure (TCLP) of 0.0314 mg/L. (2) Full-drum stabilization using the low loading formula was demonstrated. (3) Organic compound levels were discovered to be higher than originally reported, including the presence of some pesticides. Levels of some radionuclides were much higher than initially reported. (4

Mixed Waste Salt Encapsulation Using Polysiloxane - Final Report

International Nuclear Information System (INIS)

Miller, C.M.; Loomis, G.G.; Prewett, S.W.

1997-01-01

A proof-of-concept experimental study was performed to investigate the use of Orbit Technologies polysiloxane grouting material for encapsulation of U.S. Department of Energy mixed waste salts leading to a final waste form for disposal. Evaporator pond salt residues and other salt-like material contaminated with both radioactive isotopes and hazardous components are ubiquitous in the DOE complex and may exceed 250,000,000 kg of material. Current treatment involves mixing low waste percentages (less than 10% by mass salt) with cement or costly thermal treatment followed by cementation to the ash residue. The proposed technology involves simple mixing of the granular salt material (with relatively high waste loadings-greater than 50%) in a polysiloxane-based system that polymerizes to form a silicon-based polymer material. This study involved a mixing study to determine optimum waste loadings and compressive strengths of the resultant monoliths. Following the mixing study, durability testing was performed on promising waste forms. Leaching studies including the accelerated leach test and the toxicity characteristic leaching procedure were also performed on a high nitrate salt waste form. In addition to this testing, the waste form was examined by scanning electron microscope. Preliminary cost estimates for applying this technology to the DOE complex mixed waste salt problem is also given

Above and below boiling thermal loading strategies for large waste packages

International Nuclear Information System (INIS)

Smith, M.L.

1994-01-01

A simplified repository thermal model was developed with the Mathcad computer code which indicates that large waste packages may be compatible with both above and below boiling repository thermal loading strategies. Minimum spent fuel decay time of at least 20 to 30 years was shown to be important for both thermal loading strategies. Constant isothermal boundary conditions are assumed at the ground surface (296 K) and 305 meters below the water table (309.7 K) with a uniform temperature change of 1.55 10 -2 K/meter. Homogeneous tuff properties are assumed: conductivity (2.1 watt/m-k); density (2.22 gm/cm 3 ); and thermal capacitance (2.17 joule/cm 3 K). Based on these properties, the tuff thermal diffusion coefficient is 9.68 x 10 -7 m 2 /sec

Testing of variables which affect stablity of cement solidified low-level waste

International Nuclear Information System (INIS)

Boris, G.F.

1989-01-01

This paper describes the test program undertaken to investigate variables which could affect the stability of cement solidified low-level waste and to evaluate the effect of these variables on certain tests prescribed in the Technical Position on Waste Form. The majority of the testing was performed on solidified undepleted bead resin, however, six additional waste types, suggested by the NRC, were tested. The tested variables included waste loading, immersion duration, depletion level, ambient cure duration, curing environment, immersion medium and waste type. Of these, lower waste loadings, longer ambient cures prior to testing and immersion in demineralized water versus simulated sea water and potable water resulted in higher compressive strengths for bead resin samples. Immersion times longer than 90 days did not affect the resin samples. Compressive strengths for other waste types varied depending upon the waste. The strengths of all waste types exceeded the minimum criterion by at least a factor of four, up to a factor of forty. The higher waste loadings exhibit strengths less than the lower waste loadings

Radioactive Waste Management Complex low-level waste radiological performance assessment

Energy Technology Data Exchange (ETDEWEB)

Maheras, S.J.; Rood, A.S.; Magnuson, S.O.; Sussman, M.E.; Bhatt, R.N.

1994-04-01

This report documents the projected radiological dose impacts associated with the disposal of radioactive low-level waste at the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. This radiological performance assessment was conducted to evaluate compliance with applicable radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the public and the environment. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the public via air, groundwater, and food chain pathways. Projections of doses were made for both offsite receptors and individuals inadvertently intruding onto the site after closure. In addition, uncertainty and sensitivity analyses were performed. The results of the analyses indicate compliance with established radiological criteria and provide reasonable assurance that public health and safety will be protected.

Radioactive Waste Management Complex low-level waste radiological performance assessment

International Nuclear Information System (INIS)

Maheras, S.J.; Rood, A.S.; Magnuson, S.O.; Sussman, M.E.; Bhatt, R.N.

1994-04-01

This report documents the projected radiological dose impacts associated with the disposal of radioactive low-level waste at the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. This radiological performance assessment was conducted to evaluate compliance with applicable radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the public and the environment. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the public via air, groundwater, and food chain pathways. Projections of doses were made for both offsite receptors and individuals inadvertently intruding onto the site after closure. In addition, uncertainty and sensitivity analyses were performed. The results of the analyses indicate compliance with established radiological criteria and provide reasonable assurance that public health and safety will be protected

Performance assessment for underground radioactive waste disposal systems

International Nuclear Information System (INIS)

1985-01-01

A waste disposal system comprises a number of subsystems and components. The performance of most systems can be demonstrated only indirectly because of the long period that would be required to test them. This report gives special attention to performance assessment of subsystems within the total waste disposal system, and is an extension of an IAEA report on Safety Assessment for the Underground Disposal of Radioactive Wastes

Demonstration of sulfur solubility determinations in high waste loading, low-activity waste glasses

Energy Technology Data Exchange (ETDEWEB)

Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-04-25

A method recommended by Pacific Northwest National Laboratory (PNNL) for sulfate solubility determinations in simulated low-activity waste glasses was demonstrated using three compositions from a recent Hanford high waste loading glass study. Sodium and sulfate concentrations in the glasses increased after each re-melting step. Visual observations of the glasses during the re-melting process reflected the changes in composition. The measured compositions showed that the glasses met the targeted values. The amount of SO₃ retained in the glasses after washing was relatively high, ranging from 1.6 to 2.6 weight percent (wt %). Measured SnO₂ concentrations were notably low in all of the study glasses. The composition of the wash solutions should be measured in future work to determine whether SnO₂ is present with the excess sulfate washed from the glass. Increases in batch size and the amount of sodium sulfate added did not have a measureable impact on the amount of sulfate retained in the glass, although this was tested for only a single glass composition. A batch size of 250 g and a sodium sulfate addition targeting 7 wt %, as recommended by PNNL, will be used in future experiments.

Hanford immobilized low-activity tank waste performance assessment

International Nuclear Information System (INIS)

Mann, F.M.

1998-01-01

The Hanford Immobilized Low-Activity Tank Waste Performance Assessment examines the long-term environmental and human health effects associated with the planned disposal of the vitrified low-level fraction of waste presently contained in Hanford Site tanks. The tank waste is the by-product of separating special nuclear materials from irradiated nuclear fuels over the past 50 years. This waste has been stored in underground single and double-shell tanks. The tank waste is to be retrieved, separated into low and high-activity fractions, and then immobilized by private vendors. The US Department of Energy (DOE) will receive the vitrified waste from private vendors and plans to dispose of the low-activity fraction in the Hanford Site 200 East Area. The high-level fraction will be stored at Hanford until a national repository is approved. This report provides the site-specific long-term environmental information needed by the DOE to issue a Disposal Authorization Statement that would allow the modification of the four existing concrete disposal vaults to provide better access for emplacement of the immobilized low-activity waste (ILAW) containers; filling of the modified vaults with the approximately 5,000 ILAW containers and filler material with the intent to dispose of the containers; construction of the first set of next-generation disposal facilities. The performance assessment activity will continue beyond this assessment. The activity will collect additional data on the geotechnical features of the disposal sites, the disposal facility design and construction, and the long-term performance of the waste. Better estimates of long-term performance will be produced and reviewed on a regular basis. Performance assessments supporting closure of filled facilities will be issued seeking approval of those actions necessary to conclude active disposal facility operations. This report also analyzes the long-term performance of the currently planned disposal system as a basis

Hanford immobilized low-activity tank waste performance assessment

Energy Technology Data Exchange (ETDEWEB)

Mann, F.M.

1998-03-26

The Hanford Immobilized Low-Activity Tank Waste Performance Assessment examines the long-term environmental and human health effects associated with the planned disposal of the vitrified low-level fraction of waste presently contained in Hanford Site tanks. The tank waste is the by-product of separating special nuclear materials from irradiated nuclear fuels over the past 50 years. This waste has been stored in underground single and double-shell tanks. The tank waste is to be retrieved, separated into low and high-activity fractions, and then immobilized by private vendors. The US Department of Energy (DOE) will receive the vitrified waste from private vendors and plans to dispose of the low-activity fraction in the Hanford Site 200 East Area. The high-level fraction will be stored at Hanford until a national repository is approved. This report provides the site-specific long-term environmental information needed by the DOE to issue a Disposal Authorization Statement that would allow the modification of the four existing concrete disposal vaults to provide better access for emplacement of the immobilized low-activity waste (ILAW) containers; filling of the modified vaults with the approximately 5,000 ILAW containers and filler material with the intent to dispose of the containers; construction of the first set of next-generation disposal facilities. The performance assessment activity will continue beyond this assessment. The activity will collect additional data on the geotechnical features of the disposal sites, the disposal facility design and construction, and the long-term performance of the waste. Better estimates of long-term performance will be produced and reviewed on a regular basis. Performance assessments supporting closure of filled facilities will be issued seeking approval of those actions necessary to conclude active disposal facility operations. This report also analyzes the long-term performance of the currently planned disposal system as a basis

Performance assessment for future low-level waste disposal facilities at ORNL

International Nuclear Information System (INIS)

Lee, D.W.; Kocher, D.C.

1989-01-01

This paper discusses the strategy for waste management on the Oak Ridge Reservation (ORR) and the approach to preparing future performance assessments that has evolved from previous performance assessment studies of low-level radioactive waste disposal on the ORR. The strategy for waste management is based on the concept that waste classification should be determined by performance assessment other than the sources of waste. This dose-based strategy for waste classification and management places special importance on the preparation and interpretation of waste disposal performance assessments for selecting appropriate disposal technologies and developing waste acceptance criteria. Additionally, the challenges to be overcome in the preparation of performance assessments are discussed. 7 refs

Waste Disposal: Long-term Performance Studies for Radioactive Waste Disposal and Hydrogeological Modelling

Energy Technology Data Exchange (ETDEWEB)

Marivoet, J

2000-07-01

The main objectives of SCK-CEN's R and D programme on long-term performance studies are: (1) to develop a methodology and associated tools for assessing the long-term safety of geological disposal of all types of radioactive waste in clay formations and of the shallow-land burial of low-level waste; (2) to assess the performance and to identify the most influential elements of integrated repository systems for the disposal of radioactive waste; (3) to collect geological, piezometric and hydraulic data required for studying the hydrogeological system in north-eastern Belgium; (4) to develop a regional aquifer model for north-easter Belgium and to apply it in the performance assessments for the Mol site; (5) to test, verify and improve computer codes used in the performance assessment calculations of waste disposal concepts and contaminated sites (the computer codes simulate water flow and transport of radionuclides in engineered barriers, aquifers and contaminated sites). The scientific programme and achievements in 1999 are described.

Admissible thermal loading in geological formations. Consequences on radioactive waste disposal methods

International Nuclear Information System (INIS)

1982-01-01

The thermal loading in salt formation is studied for the disposal of high-level radioactive waste embedded in glass. Temperature effect on glass leaching, stability of gel layer on glass surface, quantity of leaching solution available in the borehole and corrosion resistance of materials used for containers are examined. The geological storage medium must satisfy particularly complex requirements: stratigraphy, brine migration, permeability, fissuring, mechanical strength, creep, thermal expansion, cavity structure ..

Integrated waste load allocation for river water pollution control under uncertainty: a case study of Tuojiang River, China.

Science.gov (United States)

Xu, Jiuping; Hou, Shuhua; Yao, Liming; Li, Chaozhi

2017-07-01

This paper presents a bi-level optimization waste load allocation programming model under a fuzzy random environment to assist integrated river pollution control. Taking account of the leader-follower decision-making in the water function zones framework, the proposed approach examines the decision making feedback relationships and conflict coordination between the river basin authority and the regional Environmental Protection Agency (EPA) based on the Stackelberg-Nash equilibrium strategy. In the pollution control system, the river basin authority, as the leader, allocates equitable emissions rights to different subareas, and the then subarea EPA, as the followers, reallocates the limited resources to various functional zones to minimize pollution costs. This research also considers the uncertainty in the water pollution management, and the uncertain input information is expressed as fuzzy random variables. The proposed methodological approach is then applied to Tuojiang River in China and the bi-level linear programming model solutions are achieved using the Karush-Kuhn-Tucker condition. Based on the waste load allocation scheme results and various scenario analyses and discussion, some operational policies are proposed to assist decision makers (DMs) cope with waste load allocation problem for integrated river pollution control for the overall benefits.

Load Disaggregation Technologies: Real World and Laboratory Performance

Energy Technology Data Exchange (ETDEWEB)

Mayhorn, Ebony T.; Sullivan, Greg P.; Petersen, Joseph M.; Butner, Ryan S.; Johnson, Erica M.

2016-09-28

Low cost interval metering and communication technology improvements over the past ten years have enabled the maturity of load disaggregation (or non-intrusive load monitoring) technologies to better estimate and report energy consumption of individual end-use loads. With the appropriate performance characteristics, these technologies have the potential to enable many utility and customer facing applications such as billing transparency, itemized demand and energy consumption, appliance diagnostics, commissioning, energy efficiency savings verification, load shape research, and demand response measurement. However, there has been much skepticism concerning the ability of load disaggregation products to accurately identify and estimate energy consumption of end-uses; which has hindered wide-spread market adoption. A contributing factor is that common test methods and metrics are not available to evaluate performance without having to perform large scale field demonstrations and pilots, which can be costly when developing such products. Without common and cost-effective methods of evaluation, more developed disaggregation technologies will continue to be slow to market and potential users will remain uncertain about their capabilities. This paper reviews recent field studies and laboratory tests of disaggregation technologies. Several factors are identified that are important to consider in test protocols, so that the results reflect real world performance. Potential metrics are examined to highlight their effectiveness in quantifying disaggregation performance. This analysis is then used to suggest performance metrics that are meaningful and of value to potential users and that will enable researchers/developers to identify beneficial ways to improve their technologies.

Creatine Loading, Resistance Exercise Performance, and Muscle Mechanics.

Science.gov (United States)

Stevenson, Scott W.; Dudley, Gary A.

2001-01-01

Examined whether creatine (CR) monohydrate loading would alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with placebo loading in resistance-trained athletes. Overall, CR loading did not provide an ergogenic benefit for the unilateral dynamic knee extension…

Position paper: Live load design criteria for Project W-236A Multi-Function Waste Tank Facility

International Nuclear Information System (INIS)

Giller, R.A.

1995-01-01

The purpose of this paper is to discuss the live loads applied to the underground storage tanks of the Multi Function Waste Tank Facility, and to provide the basis for Project W-236A live load criteria. Project 236A provides encompasses building a Weather Enclosure over the two underground storage tanks at the 200-West area. According to the Material Handling Study, the Groves AT 1100 crane used within the Weather Enclosure will have a gross vehicle weight of 66.5 tons. Therefore, a 100-ton concentrated live load is being used for the planning of the construction of the Weather Enclosure

NNWSI waste form performance test development

International Nuclear Information System (INIS)

Bates, J.K.; Gerding, T.J.

1984-01-01

A test method has been developed to measure the release of radionuclides from the waste package under simulated NNWSI repository conditions, and to provide information concerning materials interactions that may occur in the repository. Data from 13 weeks of unsaturated testing are discussed and compared to that from a 13-week analog test. The data indicate that the waste form test is capable of producing consistent, reproducible results that will be useful in evaluating the role of the waste in the long-term performance of the repository. 6 references, 3 figures

Replacement divider plate performance under LOCA loading

International Nuclear Information System (INIS)

Huynk, H.M.; MClellan, G.H.; Schneider, W.G.

1997-01-01

A primary divider plate in a nuclear steam generator is required to perform its partitioning function with a minimum of cross leakage, without degradation in operating performance and without loss of structural integrity resulting from normal and accident loading. The design of the replacement divider plate for normal operating conditions is discussed in some detail in reference 1 and 2. This paper describes the structural response of the replacement divider plate to the severe loading resulting from a burst primary pipe. The loads for which the divider plate structural performance must be evaluated are mild to severe differential pressure transients resulting from several postulated sizes and types of pipe break scenarios. In the unlikely event of a severe Loss of Coolant Accident (LOCA) the divider plate or parts thereof must not exit the steam generator nor completely block the outlet nozzle. For the milder LOCA loads, the integrity of the divider plate and seat bars must be maintained. Analysis for the milder LOCA loads was carried out employing a conservative approach which ignores the actual interaction between the structure and the primary fluid. For these load cases it was shown that the divider plate does not become disengaged from the seat bars. For the more severe pipe breaks, the thermal-hydraulic analysis was coupled iteratively with the structural analysis, thereby taking into account divider plate deformation, in order to obtain a better prediction of the behaviour of the divider plate. In this manner substantial reduction in divider plate response to the more severe LOCA loading was achieved. It has been shown that, for the case of a postulated large LOCA (100% reactor inlet header), the disengagement of the divider plate from the seat bars resulted in an opening smaller than 1% of the divider plate area. (author)

Low-level waste disposal performance assessments - Total source-term analysis

Energy Technology Data Exchange (ETDEWEB)

Wilhite, E.L.

1995-12-31

Disposal of low-level radioactive waste at Department of Energy (DOE) facilities is regulated by DOE. DOE Order 5820.2A establishes policies, guidelines, and minimum requirements for managing radioactive waste. Requirements for disposal of low-level waste emplaced after September 1988 include providing reasonable assurance of meeting stated performance objectives by completing a radiological performance assessment. Recently, the Defense Nuclear Facilities Safety Board issued Recommendation 94-2, {open_quotes}Conformance with Safety Standards at Department of Energy Low-Level Nuclear Waste and Disposal Sites.{close_quotes} One of the elements of the recommendation is that low-level waste performance assessments do not include the entire source term because low-level waste emplaced prior to September 1988, as well as other DOE sources of radioactivity in the ground, are excluded. DOE has developed and issued guidance for preliminary assessments of the impact of including the total source term in performance assessments. This paper will present issues resulting from the inclusion of all DOE sources of radioactivity in performance assessments of low-level waste disposal facilities.

Performance Demonstration Program Plan for Nondestructive Assay of Boxed Wastes for the TRU Waste Characterization Program

International Nuclear Information System (INIS)

2001-01-01

The Performance Demonstration Program (PDP) for nondestructive assay (NDA) consists of a series of tests to evaluate the capability for NDA of transuranic (TRU) waste throughout the Department of Energy (DOE) complex. Each test is termed a PDP cycle. These evaluation cycles provide an objective measure of the reliability of measurements obtained from NDA systems used to characterize the radiological constituents of TRU waste. The primary documents governing the conduct of the PDP are the Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC; DOE 1999a) and the Quality Assurance Program Document (QAPD; DOE 1999b). The WAC requires participation in the PDP; the PDP must comply with the QAPD and the WAC. The WAC contains technical and quality requirements for acceptable NDA. This plan implements the general requirements of the QAPD and applicable requirements of the WAC for the NDA PDP for boxed waste assay systems. Measurement facilities demonstrate acceptable performance by the successful testing of simulated waste containers according to the criteria set by this PDP Plan. Comparison among DOE measurement groups and commercial assay services is achieved by comparing the results of measurements on similar simulated waste containers reported by the different measurement facilities. These tests are used as an independent means to assess the performance of measurement groups regarding compliance with established quality assurance objectives (QAO's). Measurement facilities must analyze the simulated waste containers using the same procedures used for normal waste characterization activities. For the boxed waste PDP, a simulated waste container consists of a modified standard waste box (SWB) emplaced with radioactive standards and fabricated matrix inserts. An SWB is a waste box with ends designed specifically to fit the TRUPACT-II shipping container. SWB's will be used to package a substantial volume of the TRU waste for disposal. These PDP sample components

Performance assessment strategy for low-level waste disposal sites

International Nuclear Information System (INIS)

Starmer, R.J.; Deering, L.G.; Weber, M.F.

1988-01-01

This paper describes US Nuclear Regulatory Commission (NRC) staff views on predicting the performance of low-level radioactive waste disposal facilities. Under the Atomic Energy Act, as amended, and the Low Level Radioactive Waste Policy Act, as amended, the NRC and Agreement States license land disposal of low-level radioactive waste (LLW) using the requirements in 10 CFR Part 61 or comparable state requirements. The purpose of this paper is to briefly describe regulatory requirements for performance assessment in low-level waste licensing, a strategy for performance assessments to support license applications, and NRC staff licensing evaluation of performance assessments. NRC's current activities in developing a performance assessment methodology will provide an overall systems modeling approach for assessing the performance of LLW disposal facilities. NRC staff will use the methodology to evaluate performance assessments conducted by applicants for LLW disposal facilities. The methodology will be made available to states and other interested parties

Centralized cement solidification technique for low-level radioactive wastes

International Nuclear Information System (INIS)

Matsuda, Masami; Nishi, Takashi; Izumida, Tatsuo; Tsuchiya, Hiroyuki.

1996-01-01

A centralized cement solidification system has been developed to enable a single facility to solidify such low-level radioactive wastes as liquid waste, spent ion exchange resin, incineration ash, and miscellaneous solid wastes. Since the system uses newly developed high-performance cement, waste loading is raised and deterioration of waste forms after land burial prevented. This paper describes the centralized cement solidification system and the features of the high-performance cement. Results of full-scale pilot plant tests are also shown from the viewpoint of industrial applicability. (author)

Proposed waste form performance criteria and testing methods for low-level mixed waste

International Nuclear Information System (INIS)

Franz, E.M.; Fuhrmann, M.; Bowerman, B.

1995-01-01

Proposed waste form performance criteria and testing methods were developed as guidance in judging the suitability of solidified waste as a physico-chemical barrier to releases of radionuclides and RCRA regulated hazardous components. The criteria follow from the assumption that release of contaminants by leaching is the single most important property for judging the effectiveness of a waste form. A two-tier regimen is proposed. The first tier consists of a leach test designed to determine the net, forward leach rate of the solidified waste and a leach test required by the Environmental Protection Agency (EPA). The second tier of tests is to determine if a set of stresses (i.e., radiation, freeze-thaw, wet-dry cycling) on the waste form adversely impacts its ability to retain contaminants and remain physically intact. In the absence of site-specific performance assessments (PA), two generic modeling exercises are described which were used to calculate proposed acceptable leachates

241-AY/AZ waste storage tanks: Supplemental gravity load analysis. Volume 1

International Nuclear Information System (INIS)

Baliga, R.

1994-01-01

An analysis of the 241SY tanks performed by ADVENT(1994b) to resolve dome overload issues indicated that the tank can sustain the dome loads resulting from additional soil overburden depth, increased soil density, and increased concentrated load. Similar issues exist for the 241AY/AZ tanks and therefore, an interim analysis of the 241AY/AZ tanks is presented herein. The scope of this effort is to review and compare all design drawings pertaining to the 241AY and 241AZ tanks with those pertaining to the 241SY tanks; to modify the axisymmetric model of the 241SY tanks to represent the 241AY/AZ tanks; and to evaluate the effect of additional dome load on the 241AY/AZ tanks by performing a structural analysis for gravity loads (dead load + live load). ADVENTS's additional scope of work is to perform a qualitative evaluation of the 241AY/AZ tanks for seismic and thermal loadings (Vollert 1982 and Blume 1971). This qualitative evaluation does not include any detailed finite element analysis of the tanks. The following design-based gravity loading conditions are used in this interim analysis of the 241AY/AZ tanks to determine a baseline for the tank stresses or section loads

Proposed waste form performance criteria and testing methods for low-level mixed waste

International Nuclear Information System (INIS)

Franz, E.M.; Fuhrmann, M.; Bowerman, B.; Bates, S.; Peters, R.

1994-08-01

This document describes proposed waste form performance criteria and testing method that could be used as guidance in judging viability of a waste form as a physico-chemical barrier to releases of radionuclides and RCRA regulated hazardous components. It is assumed that release of contaminants by leaching is the single most important property by which the effectiveness of a waste form is judged. A two-tier regimen is proposed. The first tier includes a leach test required by the Environmental Protection Agency and a leach test designed to determine the net forward leach rate for a variety of materials. The second tier of tests are to determine if a set of stresses (i.e., radiation, freeze-thaw, wet-dry cycling) on the waste form adversely impact its ability to retain contaminants and remain physically intact. It is recommended that the first tier tests be performed first to determine acceptability. Only on passing the given specifications for the leach tests should other tests be performed. In the absence of site-specific performance assessments (PA), two generic modeling exercises are described which were used to calculate proposed acceptable leach rates

Performance Demonstration Program Plan for Nondestructive Assay of Drummed Wastes for the TRU Waste Characterization Program

International Nuclear Information System (INIS)

2005-01-01

The Performance Demonstration Program (PDP) for Nondestructive Assay (NDA) is a test program designed to yield data on measurement system capability to characterize drummed transuranic (TRU) waste generated throughout the Department of Energy (DOE) complex. The tests are conducted periodically and provide a mechanism for the independent and objective assessment of NDA system performance and capability relative to the radiological characterization objectives and criteria of the Office of Characterization and Transportation (OCT). The primary documents requiring an NDA PDP are the Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC), which requires annual characterization facility participation in the PDP, and the Quality Assurance Program Document (QAPD). This NDA PDP implements the general requirements of the QAPD and applicable requirements of the WAC. Measurement facilities must demonstrate acceptable radiological characterization performance through measurement of test samples comprised of pre-specified PDP matrix drum/radioactive source configurations. Measurement facilities are required to analyze the NDA PDP drum samples using the same procedures approved and implemented for routine operational waste characterization activities. The test samples provide an independent means to assess NDA measurement system performance and compliance per criteria delineated in the NDA PDP Plan. General inter-comparison of NDA measurement system performance among DOE measurement facilities and commercial NDA services can also be evaluated using measurement results on similar NDA PDP test samples. A PDP test sample consists of a 55-gallon matrix drum containing a waste matrix type representative of a particular category of the DOE waste inventory and nuclear material standards of known radionuclide and isotopic composition typical of DOE radioactive material. The PDP sample components are made available to participating measurement facilities as designated by the

Performance Demonstration Program Plan for Nondestructive Assay of Drummed Wastes for the TRU Waste Characterization Program

International Nuclear Information System (INIS)

DOE Carlsbad Field Office

2001-01-01

The Performance Demonstration Program (PDP) for nondestructive assay (NDA) consists of a series of tests to evaluate the capability for NDA of transuranic (TRU) waste throughout the Department of Energy (DOE) complex. Each test is termed a PDP cycle. These evaluation cycles provide an objective measure of the reliability of measurements obtained from NDA systems used to characterize the radiological constituents of TRU waste. The primary documents governing the conduct of the PDP are the Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC; DOE 1999a) and the Quality Assurance Program Document (QAPD; DOE 1999b). The WAC requires participation in the PDP; the PDP must comply with the QAPD and the WAC. The WAC contains technical and quality requirements for acceptable NDA. This plan implements the general requirements of the QAPD and applicable requirements of the WAC for the NDA PDP. Measurement facilities demonstrate acceptable performance by the successful testing of simulated waste containers according to the criteria set by this PDP Plan. Comparison among DOE measurement groups and commercial assay services is achieved by comparing the results of measurements on similar simulated waste containers reported by the different measurement facilities. These tests are used as an independent means to assess the performance of measurement groups regarding compliance with established quality assurance objectives (QAO's). Measurement facilities must analyze the simulated waste containers using the same procedures used for normal waste characterization activities. For the drummed waste PDP, a simulated waste container consists of a 55-gallon matrix drum emplaced with radioactive standards and fabricated matrix inserts. These PDP sample components are distributed to the participating measurement facilities that have been designated and authorized by the Carlsbad Field Office (CBFO). The NDA Drum PDP materials are stored at these sites under secure conditions to

Characteristics of borosilicate waste glass form for high-level radioactive waste

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Soo; Chun, Kwan Sik; Choi, Jong Won; Kang, Chul Hyung

2001-03-01

Basic data, required for the design and the performance assessment of a repository of HLW, suchas the chemical composition and the characteristics of the borosilicate waste glass have been identified according to the burn-ups of spent PWR fuels. The diemnsion of waste canister is 430mm in diameter and 1135mm in length, and the canister should hold less than 2kwatts of heat from their decay of radionuclides contained in the HLW. Based on the reprocessing of 5 years-cooled spent fuel, one canister could hold about 11.5wt.% and 10.8wt.% of oxidized HLW corresponding to their burn-ups of 45,000MWD/MTU and 55,000MWD/MTU, respectively. These waste forms have been recommanded as the reference waste forms of HLW. The characteristics of these wastes as a function of decay time been evaluated. However, after a specific waste form and a specific site for the disposal would be selected, the characteristics of the waste should be reevaluated under the consideration of solidification period, loaded waste, storage condition and duration, site circumstances for the repository system and its performance assessment.

Survey of computer codes applicable to waste facility performance evaluations

International Nuclear Information System (INIS)

Alsharif, M.; Pung, D.L.; Rivera, A.L.; Dole, L.R.

1988-01-01

This study is an effort to review existing information that is useful to develop an integrated model for predicting the performance of a radioactive waste facility. A summary description of 162 computer codes is given. The identified computer programs address the performance of waste packages, waste transport and equilibrium geochemistry, hydrological processes in unsaturated and saturated zones, and general waste facility performance assessment. Some programs also deal with thermal analysis, structural analysis, and special purposes. A number of these computer programs are being used by the US Department of Energy, the US Nuclear Regulatory Commission, and their contractors to analyze various aspects of waste package performance. Fifty-five of these codes were identified as being potentially useful on the analysis of low-level radioactive waste facilities located above the water table. The code summaries include authors, identification data, model types, and pertinent references. 14 refs., 5 tabs

Load requirements for maintaining structural integrity of Hanford single-shell tanks during waste feed delivery and retrieval activities

International Nuclear Information System (INIS)

JULYK, L.J.

1999-01-01

This document provides structural load requirements and their basis for maintaining the structural integrity of the Hanford Single-Shell Tanks during waste feed delivery and retrieval activities. The requirements are based on a review of previous requirements and their basis documents as well as load histories with particular emphasis on the proposed lead transfer feed tanks for the privatized vitrification plant

Study on the barrier performance of molten solidified waste (I). Review of the performance assessment research

Energy Technology Data Exchange (ETDEWEB)

Maeda, Toshikatsu; Sakamoto, Yoshiaki; Nakayama, Shinichi; Yamaguchi, Tetsuji; Ogawa, Hiromichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-02-01

Application of melting technique is thought as one of the effective methods to treatment of the waste from the view point of its homogeneity and waste volume reduction. Solidified products by melting are expected as potential candidates of engineered barrier in a repository due to the good properties for their stabilization of radionuclides and hazardous elements. However, the methodology of performance evaluation has not been estimated so far. In this report, a literature survey on the properties of molten solidified waste was performed. It is clarified that the leachability of waste elements such as Co or Sr in molten waste form would be controlled by the corrosion behaviors of iron or silica which are the matrix elements of the waste form. While, no investigations into the durability of waste form have performed so far. Also noticed that the research items on performance evaluation such as the leachability for long-lived radionuclides and durability of waste form would be necessary for the long-term barrier assessment on the disposal. (author)

Computational Efficient Upscaling Methodology for Predicting Thermal Conductivity of Nuclear Waste forms

International Nuclear Information System (INIS)

Li, Dongsheng; Sun, Xin; Khaleel, Mohammad A.

2011-01-01

This study evaluated different upscaling methods to predict thermal conductivity in loaded nuclear waste form, a heterogeneous material system. The efficiency and accuracy of these methods were compared. Thermal conductivity in loaded nuclear waste form is an important property specific to scientific researchers, in waste form Integrated performance and safety code (IPSC). The effective thermal conductivity obtained from microstructure information and local thermal conductivity of different components is critical in predicting the life and performance of waste form during storage. How the heat generated during storage is directly related to thermal conductivity, which in turn determining the mechanical deformation behavior, corrosion resistance and aging performance. Several methods, including the Taylor model, Sachs model, self-consistent model, and statistical upscaling models were developed and implemented. Due to the absence of experimental data, prediction results from finite element method (FEM) were used as reference to determine the accuracy of different upscaling models. Micrographs from different loading of nuclear waste were used in the prediction of thermal conductivity. Prediction results demonstrated that in term of efficiency, boundary models (Taylor and Sachs model) are better than self consistent model, statistical upscaling method and FEM. Balancing the computation resource and accuracy, statistical upscaling is a computational efficient method in predicting effective thermal conductivity for nuclear waste form.

Performance Enhancements to the Hanford Waste Treatment and Immobilization Plant Low-Activity Waste Vitrification System

International Nuclear Information System (INIS)

Hamel, W. F.; Gerdes, K.; Holton, L. K.; Pegg, I.L.; Bowan, B.W.

2006-01-01

The U.S Department of Energy Office of River Protection (DOE-ORP) is constructing a Waste Treatment and Immobilization Plant (WTP) for the treatment and vitrification of underground tank wastes stored at the Hanford Site in Washington State. The WTP comprises four major facilities: a pretreatment facility to separate the tank waste into high level waste (HLW) and low-activity waste (LAW) process streams, a HLW vitrification facility to immobilize the HLW fraction; a LAW vitrification facility to immobilize the LAW fraction, and an analytical laboratory to support the operations of all four treatment facilities. DOE has established strategic objectives to optimize the performance of the WTP facilities and the LAW and HLW waste forms to reduce the overall schedule and cost for treatment and vitrification of the Hanford tank wastes. This strategy has been implemented by establishing performance expectations in the WTP contract for the facilities and waste forms. In addition, DOE, as owner-operator of the WTP facilities, continues to evaluate 1) the design, to determine the potential for performance above the requirements specified in the WTP contract; and 2) improvements in production of the LAW and HLW waste forms. This paper reports recent progress directed at improving production of the LAW waste form. DOE's initial assessment, which is based on the work reported in this paper, is that the treatment rate of the WTP LAW vitrification facility can be increased by a factor of 2 to 4 with a combination of revised glass formulations, modest increases in melter glass operating temperatures, and a second-generation LAW melter with a larger surface area. Implementing these improvements in the LAW waste immobilization capability can benefit the LAW treatment mission by reducing the cost of waste treatment. (authors)

Advanced waste form and Melter development for treatment of troublesome high-level wastes

Energy Technology Data Exchange (ETDEWEB)

Marra, James [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kim, Dong -Sang [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maio, Vincent [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-10-01

A number of waste components in US defense high level radioactive wastes (HLW) have proven challenging for current Joule heated ceramic melter (JHCM) operations and have limited the ability to increase waste loadings beyond already realized levels. Many of these “troublesome" waste species cause crystallization in the glass melt that can negatively impact product quality or have a deleterious effect on melter processing. Recent efforts at US Department of Energy laboratories have focused on understanding crystallization behavior within HLW glass melts and investigating approaches to mitigate the impacts of crystallization so that increases in waste loading can be realized. Advanced glass formulations have been developed to highlight the unique benefits of next-generation melter technologies such as the Cold Crucible Induction Melter (CCIM). Crystal-tolerant HLW glasses have been investigated to allow sparingly soluble components such as chromium to crystallize in the melter but pass out of the melter before accumulating.The Hanford site AZ-101 tank waste composition represents a waste group that is waste loading limited primarily due to high concentrations of Fe₂O₃ (also with high Al₂O₃ concentrations). Systematic glass formulation development utilizing slightly higher process temperatures and higher tolerance to spinel crystals demonstrated that an increase in waste loading of more than 20% could be achieved for this waste composition, and by extension higher loadings for wastes in the same group. An extended duration CCIM melter test was conducted on an AZ-101 waste simulant using the CCIM platform at the Idaho National Laboratory (INL). The melter was continually operated for approximately 80 hours demonstrating that the AZ-101 high waste loading glass composition could be readily processed using the CCIM technology. The resulting glass was close to the targeted composition and exhibited excellent durability in both

Treatment of uncertainty in low-level waste performance assessment

International Nuclear Information System (INIS)

Kozak, M.W.; Olague, N.E.; Gallegos, D.P.; Rao, R.R.

1991-01-01

Uncertainties arise from a number of different sources in low-level waste performance assessment. In this paper the types of uncertainty are reviewed, and existing methods for quantifying and reducing each type of uncertainty are discussed. These approaches are examined in the context of the current low-level radioactive waste regulatory performance objectives, which are deterministic. The types of uncertainty discussed in this paper are model uncertainty, uncertainty about future conditions, and parameter uncertainty. The advantages and disadvantages of available methods for addressing uncertainty in low-level waste performance assessment are presented. 25 refs

High solids co-digestion of food and landscape waste and the potential for ammonia toxicity

Energy Technology Data Exchange (ETDEWEB)

Drennan, Margaret F.; DiStefano, Thomas D., E-mail: thomas.distefano@bucknell.edu

2014-07-15

Highlights: • We evaluated co-digestion of food and landscape waste with a pilot-scale anaerobic dry digester. • We evaluated reactor performance at 35 °C under low and high organic loading rates. • Performance was stable under low organic loading rate, but declined under high organic loading rate. • Respirometry was employed to investigate potential inhibition due to ammonia. • Landscape waste was unsuitable in increasing the C:N ratio during codigestion. - Abstract: A pilot-scale study was completed to determine the feasibility of high-solids anaerobic digestion (HSAD) of a mixture of food and landscape wastes at a university in central Pennsylvania (USA). HSAD was stable at low loadings (2 g COD/L-day), but developed inhibitory ammonia concentrations at high loadings (15 g COD/L-day). At low loadings, methane yields were 232 L CH{sub 4}/kg COD fed and 229 L CH{sub 4}/kg VS fed, and at high loadings yields were 211 L CH{sub 4}/kg COD fed and 272 L CH{sub 4}/kg VS fed. Based on characterization and biodegradability studies, food waste appears to be a good candidate for HSAD at low organic loading rates; however, the development of ammonia inhibition at high loading rates suggests that the C:N ratio is too low for use as a single substrate. The relatively low biodegradability of landscape waste as reported herein made it an unsuitable substrate to increase the C:N ratio. Codigestion of food waste with a substrate high in bioavailable carbon is recommended to increase the C:N ratio sufficiently to allow HSAD at loading rates of 15 g COD/L-day.

Determination of performance criteria for high-level solidified nuclear waste

Energy Technology Data Exchange (ETDEWEB)

Heckman, R.A.; Holdsworth, T.

1979-05-07

To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste.

Determination of performance criteria for high-level solidified nuclear waste

International Nuclear Information System (INIS)

Heckman, R.A.; Holdsworth, T.

1979-01-01

To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste

Loading and transport of high-active waste (HAW) with the TN85 flask in 2008

International Nuclear Information System (INIS)

Rys, Michael; Horn, Thomas; Graf, Wilhelm; Bonface, Jean-Michael

2009-01-01

As a part of the operation of nuclear power plants, it is essential to safely manage the radioactive waste. With new developments in science and technology, it is a dynamic process to adapt procedures, equipment and flasks to be used in the future. This is a task for specialists - a task for GNS Gesellschaft fuer Nuklear-Service mbH and for TN International. Until 1994 reprocessing of spent fuel from German nuclear power plants was mandatory for the Utilities (EVU) in Germany. Basis for the reprocessing was the German Atomic Act. The German Utilities concluded contracts on reprocessing with Compagnie Generale des Matieres Nucleaires (COGEMA, now AREVA NC) in France and British Nuclear Fuels plc (BNFL, now INS) in England. The total amount to be reprocessed comes to 5309 t HM contracted to AREVA NC and 768 t HM contracted to INS. The waste generated from reprocessing - or an equivalent amount of radioactive material - has to be returned to the country of origin. In 1979 already an exchange of notes took place between the German and the French government with the obligation of both sides to enable and support the return of reprocessing residues or equivalents. The return of high-active waste (HAW) from France has started in 1996 with the first attribution of 28 glass canisters (one flask) to German Utilities by AREVA NC. Until 2007, 75 flasks loaded with vitrified residue (VR) canisters have been transported to Gorleben. For these transports CASTOR registered HAW 20/28 CG flasks have been used. This presentation will give some background information about the last HAW transport in 2008 with the new flask generation of the type TN85. It will also describe the assembly of the new flask, the preparation of the flask for the loading campaign as well as the loading procedure. (orig.)

Loading and transport of high-active waste (HAW) with the TN85 flask in 2008

Energy Technology Data Exchange (ETDEWEB)

Rys, Michael; Horn, Thomas; Graf, Wilhelm [GNS Gesellschaft fuer Nuklear-Service mbH (Germany); Bonface, Jean-Michael [TN International, Montigny-le-Bretonneux (France)

2009-07-01

As a part of the operation of nuclear power plants, it is essential to safely manage the radioactive waste. With new developments in science and technology, it is a dynamic process to adapt procedures, equipment and flasks to be used in the future. This is a task for specialists - a task for GNS Gesellschaft fuer Nuklear-Service mbH and for TN International. Until 1994 reprocessing of spent fuel from German nuclear power plants was mandatory for the Utilities (EVU) in Germany. Basis for the reprocessing was the German Atomic Act. The German Utilities concluded contracts on reprocessing with Compagnie Generale des Matieres Nucleaires (COGEMA, now AREVA NC) in France and British Nuclear Fuels plc (BNFL, now INS) in England. The total amount to be reprocessed comes to 5309 t HM contracted to AREVA NC and 768 t HM contracted to INS. The waste generated from reprocessing - or an equivalent amount of radioactive material - has to be returned to the country of origin. In 1979 already an exchange of notes took place between the German and the French government with the obligation of both sides to enable and support the return of reprocessing residues or equivalents. The return of high-active waste (HAW) from France has started in 1996 with the first attribution of 28 glass canisters (one flask) to German Utilities by AREVA NC. Until 2007, 75 flasks loaded with vitrified residue (VR) canisters have been transported to Gorleben. For these transports CASTOR {sup registered} HAW 20/28 CG flasks have been used. This presentation will give some background information about the last HAW transport in 2008 with the new flask generation of the type TN85. It will also describe the assembly of the new flask, the preparation of the flask for the loading campaign as well as the loading procedure. (orig.)

Hanford low-level tank waste interim performance assessment

International Nuclear Information System (INIS)

Mann, F.M.

1997-01-01

The Hanford Low-Level Tank Waste Interim Performance Assessment examines the long-term environmental and human health effects associated with the disposal of the low-level fraction of the Hanford single and double-shell tank waste in the Hanford Site 200 East Area. This report was prepared as a good management practice to provide needed information about the relationship between the disposal system design and performance early in the disposal system project cycle. The calculations in this performance assessment show that the disposal of the low-level fraction can meet environmental and health performance objectives

Load Loss Performance of an Autonomous Self-Excited Induction ...

African Journals Online (AJOL)

This paper presents a dynamic analysis of an autonomous Self-Excited Induction Generator (SEIG) showing dynamic loss of load performance. In stand-alone operation of the SEIG, especially when supplying a low power utility, an interesting performance of the SEIG observed for various power factor loads can be ...

Ceramic stabilization of hazardous wastes: a high performance room temperature process

International Nuclear Information System (INIS)

Maloney, M.D.

1996-01-01

ANL has developed a room-temperature process for converting hazardous materials to a ceramic structure. It is similar to vitrification but is achieved at low cost, similar to conventional cement stabilization. The waste constituents are both chemically stabilized and physically encapsulated, producing very low leaching levels and the potential for delisting. The process, which is pH-insensitive, is ideal for inorganic sludges and liquids, as well as mixed chemical-radioactive wastes, but can also handle significant percentages of salts and even halogenated organics. High waste loadings are possible and densification occurs,so that volumes are only slightly increased and in some cases (eg, incinerator ash) are reduced. The ceramic product has strength and weathering properties far superior to cement products

Relaxation of the lower frit loading constraint for DWPF process control

International Nuclear Information System (INIS)

Brown, K.G.

2000-01-01

The lower limit on the frit loading parameter when measurement uncertainty is introduced has impacted DWPF performance during immobilization of Tank 42 Sludge; therefore, any defensible relaxation or omission of this constraint should correspondingly increase DWPF waste loading and efficiency. Waste loading should be increased because the addition of frit is the current remedy for exceeding the lower frit loading constraint. For example, frit was added to DWPF SME Batches 94, 97 and 98 to remedy these batches for low frit loading. Attempts were also made to add frit in addition to the optimum computed to assure the lower frit loading constraint would be satisfied; however, approximately half of the SME Batches produced after Batch 98 have violated the lower frit loading constraint. If the DWPF batches did not have to be remediated and additional frit added because of the lower frit loading limit, then both, the performance of the DWPF process and the waste loading in the glass produced would be increased. Before determining whether or not the lower frit loading limit can be relaxed or omitted, the origin of this and the other constraints related to durability prediction must be examined. The lower limit loading constraint results from the need to make highly durable glass in DWPF. It is required that DWPF demonstrate that the glass produced would have durability that is at least two standard deviations greater than that of the Environmental Assessment (EA) glass. Glass durability cannot be measured in situ, it must be predicted from composition which can be measured. Fortunately, the leaching characteristics of homogeneous waste glasses is strongly related to the total molar free energy of the constituent species. Thus the waste acceptance specification has been translated into a requirement that the total molar free energy associated with the glass composition that would be produced from a DWPF melter feed batch be less than that of the EA glass accounting for

Waste package performance assessment

International Nuclear Information System (INIS)

Lester, D.H.

1981-01-01

This paper describes work undertaken to assess the life-expectancy and post-failure nuclide release behavior of high-level and waste packages in a geologic repository. The work involved integrating models of individual phenomena (such as heat transfer, corrosion, package deformation, and nuclide transport) and using existing data to make estimates of post-emplacement behavior of waste packages. A package performance assessment code was developed to predict time to package failure in a flooded repository and subsequent transport of nuclides out of the leaking package. The model has been used to evaluate preliminary package designs. The results indicate, that within the limitation of model assumptions and data base, packages lasting a few hundreds of years could be developed. Very long lived packages may be possible but more comprehensive data are needed to confirm this

Performance Demonstration Program Plan for Nondestructive Assay of Drummed Wastes for the TRU Waste Characterization Program

International Nuclear Information System (INIS)

2009-01-01

Each testing and analytical facility performing waste characterization activities for the Waste Isolation Pilot Plant (WIPP) participates in the Performance Demonstration Program (PDP) to comply with the Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC) (DOE/WIPP-02-3122) and the Quality Assurance Program Document (QAPD) (CBFO-94-1012). The PDP serves as a quality control check for data generated in the characterization of waste destined for WIPP. Single blind audit samples are prepared and distributed to each of the facilities participating in the PDP. The PDP evaluates analyses of simulated headspace gases, constituents of the Resource Conservation and Recovery Act (RCRA), and transuranic (TRU) radionuclides using nondestructive assay (NDA) techniques.

WIPP [Waste Isolation Pilot Plant] test phase plan: Performance assessment

International Nuclear Information System (INIS)

1990-04-01

The U.S. Department of Energy (DOE) is responsible for managing the disposition of transuranic (TRU) wastes resulting from nuclear weapons production activities of the United States. These wastes are currently stored nationwide at several of the DOE's waste generating/storage sites. The goal is to eliminate interim waste storage and achieve environmentally and institutionally acceptable permanent disposal of these TRU wastes. The Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico is being considered as a disposal facility for these TRU wastes. This document describes the first of the following two major programs planned for the Test Phase of WIPP: Performance Assessment -- determination of the long-term performance of the WIPP disposal system in accordance with the requirements of the EPA Standard; and Operations Demonstration -- evaluation of the safety and effectiveness of the DOE TRU waste management system's ability to emplace design throughput quantities of TRU waste in the WIPP underground facility. 120 refs., 19 figs., 8 tabs

Performance assessment of nuclear waste isolation systems

International Nuclear Information System (INIS)

Lee, W.L.

1984-01-01

A number of concepts have been proposed for the isolation of highly radioactive wastes, and it will be necessary to demonstrate the safety of such systems. In many countries including the U.S., the waste isolation system of choice is deep mined geologic repositories. Because of the complex nature of the multiple isolation barriers afforded by mined geologic disposal systems, and the long isolation periods involved, this demonstration can only be indirect. In recent years this indirect demonstration, mostly through mathematical modeling, is called performance assessment. Performance Assessment can be defined to mean the development, testing, and application of a series of mathematical models and computer codes which traces the movement of radionuclides from a waste isolation system to the biosphere and any resultant dose to man. In modeling such a repository system, it is often convenient to divide it into a number of subsystems, there may be several different processes that need to be modeled, individually and interactively. For instance, this waste package will probably consist of a waste form such as borosilicate glass containing the radioisotopes, a canister, an overpack material such as steel or copper, and a buffer material such as bentonite. The processes to be modeled at the waste package scale include radioisotope inventory and decay, thermal radiation, radiolysis effects, corrosion, leading and fluid flow. In tracing radionuclide transport through rock, the processes of importance are probably groundwater flow, and sorption and retardation of radionuclide movement

Preliminary performance assessment strategy for single-shell tank waste disposal

International Nuclear Information System (INIS)

Sonnichsen, J.C. Jr.

1991-10-01

The disposal of the waste stored in single-shell tanks at the Hanford Site is recognized as a major environmental concern. A comprehensive program has been initiated to evaluate the various alternatives available for disposal of these wastes. Theses wastes will be disposed of in a manner consistent with applicable laws and regulations. Long-term waste isolation is one measure of performance that will be used for purposes of selection. The performance of each disposal alternative will be simulated using numerical models. Contained herein is a discussion of the strategy that has and continues to evolve to establish a general analytical framework to evaluate this performance. This general framework will be used to construct individual models of each waste disposal alternative selected for purposes of evaluation. 30 refs., 3 figs

Temperature loading and rocks mechanics at final storage of radioactive waste

International Nuclear Information System (INIS)

Leijon, B.; Stephansson, O.

1979-01-01

This report describes the rock mechanical effects - in the far field - from the thermal loading at a final storage of radioactive waste in crystalline rocks. The stress distribution of a two-storey storage is described in more details. The temperature rise in a final storage of radiactive waste will create thermal stresses which may cause a failure of the rock mass, and thereby an increase of its permeability. However, the state of stress in the Earth's crust is able to neutralize the thermal stresses. By this analysis we have been able to demonstrate that the thermal stresses due to heat conduction from the final storage are compensated by the state of stress in the upper part of the crust. The absolute stress, which is the superposition of thermal stress and virgin rock stress, is in all cases found to be below the limit of failure due to frictional resistance between surfaces of constituent blocks in the rock mass. Failure by sliding friction is the most conservative failure criterion for a rock mass. (author)

Load carriage, human performance, and employment standards.

Science.gov (United States)

Taylor, Nigel A S; Peoples, Gregory E; Petersen, Stewart R

2016-06-01

The focus of this review is on the physiological considerations necessary for developing employment standards within occupations that have a heavy reliance on load carriage. Employees within military, fire fighting, law enforcement, and search and rescue occupations regularly work with heavy loads. For example, soldiers often carry loads >50 kg, whilst structural firefighters wear 20-25 kg of protective clothing and equipment, in addition to carrying external loads. It has long been known that heavy loads modify gait, mobility, metabolic rate, and efficiency, while concurrently elevating the risk of muscle fatigue and injury. In addition, load carriage often occurs within environmentally stressful conditions, with protective ensembles adding to the thermal burden of the workplace. Indeed, physiological strain relates not just to the mass and dimensions of carried objects, but to how those loads are positioned on and around the body. Yet heavy loads must be borne by men and women of varying body size, and with the expectation that operational capability will not be impinged. This presents a recruitment conundrum. How do employers identify capable and injury-resistant individuals while simultaneously avoiding discriminatory selection practices? In this communication, the relevant metabolic, cardiopulmonary, and thermoregulatory consequences of loaded work are reviewed, along with concomitant impediments to physical endurance and mobility. Also emphasised is the importance of including occupation-specific clothing, protective equipment, and loads during work-performance testing. Finally, recommendations are presented for how to address these issues when evaluating readiness for duty.

Challenges when Performing Economic Optimization of Waste Treatment

DEFF Research Database (Denmark)

Juul, Nina; Münster, Marie; Ravn, Hans

2011-01-01

New investments in waste treatment facilities are needed due to a number of factors including continuously increasing waste amounts, political demands for efficient utilization of the waste resources in terms of recycling or energy production, and decommissioning of existing waste treatment...... facilities due to age and stricter environmental regulation. Optimization models can assist in ensuring that these investment strategies will be economically feasible. Various economic optimization models for waste treatment have been developed which focus on different parameters. Models focusing...... in multi criteria analysis have been developed. A thorough updated review of the existing models is presented and the main challenges and the crucial parameters to take into account when assessing the economic performance of waste treatment alternatives are identified. The review article will assist both...

Designing Advanced Ceramic Waste Forms for Electrochemical Processing Salt Waste

International Nuclear Information System (INIS)

Ebert, W. L.; Snyder, C. T.; Frank, Steven; Riley, Brian

2016-01-01

This report describes the scientific basis underlying the approach being followed to design and develop ''advanced'' glass-bonded sodalite ceramic waste form (ACWF) materials that can (1) accommodate higher salt waste loadings than the waste form developed in the 1990s for EBR-II waste salt and (2) provide greater flexibility for immobilizing extreme waste salt compositions. This is accomplished by using a binder glass having a much higher Na_2O content than glass compositions used previously to provide enough Na+ to react with all of the Cl- in the waste salt and generate the maximum amount of sodalite. The phase compositions and degradation behaviors of prototype ACWF products that were made using five new binder glass formulations and with 11-14 mass% representative LiCl/KCl-based salt waste were evaluated and compared with results of similar tests run with CWF products made using the original binder glass with 8 mass% of the same salt to demonstrate the approach and select a composition for further studies. About twice the amount of sodalite was generated in all ACWF materials and the microstructures and degradation behaviors confirmed our understanding of the reactions occurring during waste form production and the efficacy of the approach. However, the porosities of the resulting ACWF materials were higher than is desired. These results indicate the capacity of these ACWF waste forms to accommodate LiCl/KCl-based salt wastes becomes limited by porosity due to the low glass-to-sodalite volume ratio. Three of the new binder glass compositions were acceptable and there is no benefit to further increasing the Na content as initially planned. Instead, further studies are needed to develop and evaluate alternative production methods to decrease the porosity, such as by increasing the amount of binder glass in the formulation or by processing waste forms in a hot isostatic press. Increasing the amount of binder glass to eliminate porosity will decrease the waste

Designing Advanced Ceramic Waste Forms for Electrochemical Processing Salt Waste

Energy Technology Data Exchange (ETDEWEB)

Ebert, W. L. [Argonne National Lab. (ANL), Argonne, IL (United States); Snyder, C. T. [Argonne National Lab. (ANL), Argonne, IL (United States); Frank, Steven [Argonne National Lab. (ANL), Argonne, IL (United States); Riley, Brian [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-03-01

This report describes the scientific basis underlying the approach being followed to design and develop “advanced” glass-bonded sodalite ceramic waste form (ACWF) materials that can (1) accommodate higher salt waste loadings than the waste form developed in the 1990s for EBR-II waste salt and (2) provide greater flexibility for immobilizing extreme waste salt compositions. This is accomplished by using a binder glass having a much higher Na₂O content than glass compositions used previously to provide enough Na+ to react with all of the Cl– in the waste salt and generate the maximum amount of sodalite. The phase compositions and degradation behaviors of prototype ACWF products that were made using five new binder glass formulations and with 11-14 mass% representative LiCl/KCl-based salt waste were evaluated and compared with results of similar tests run with CWF products made using the original binder glass with 8 mass% of the same salt to demonstrate the approach and select a composition for further studies. About twice the amount of sodalite was generated in all ACWF materials and the microstructures and degradation behaviors confirmed our understanding of the reactions occurring during waste form production and the efficacy of the approach. However, the porosities of the resulting ACWF materials were higher than is desired. These results indicate the capacity of these ACWF waste forms to accommodate LiCl/KCl-based salt wastes becomes limited by porosity due to the low glass-to-sodalite volume ratio. Three of the new binder glass compositions were acceptable and there is no benefit to further increasing the Na content as initially planned. Instead, further studies are needed to develop and evaluate alternative production methods to decrease the porosity, such as by increasing the amount of binder glass in the formulation or by processing waste forms in a hot isostatic press. Increasing the amount of binder glass to eliminate porosity will decrease

Performance validation of commercially available mobile waste-assay systems: Preliminary report

International Nuclear Information System (INIS)

Schanfein, M.; Bonner, C.; Maez, R.

1997-01-01

Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems' performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims of guaranteeing any system's performance for specific waste types, the standardized systems' performance be evaluated. 7 figs., 11 tabs

Performance validation of commercially available mobile waste-assay systems: Preliminary report

Energy Technology Data Exchange (ETDEWEB)

Schanfein, M.; Bonner, C.; Maez, R. [Los Alamos National Lab., NM (United States)] [and others

1997-11-01

Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems` performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims of guaranteeing any system`s performance for specific waste types, the standardized systems` performance be evaluated. 7 figs., 11 tabs.

Development and Performance Evaluation of a Low Cost Waste ...

African Journals Online (AJOL)

The design, development and performance evaluation of a low cost waste-water treatment plant had been carried out. The aim was to harness the usefulness of waste-waters from residential, institutional and commercial sources. The facultative lagoon method of waste-water treatment was adopted. Biological analysis of ...

Performance objectives for the Hanford immobilized low-activity waste (ILAW) performance assessment

International Nuclear Information System (INIS)

MANN, F.M.

1999-01-01

Before low-level waste may be disposed of, a performance assessment must be written and then approved by the DOE (DOE 1988a, DOE 1999a). The performance assessment is to determine whether ''reasonable assurance'' exists that the performance objectives of the disposal facility will be met. The DOE requirements for waste disposal (DOE 1988a, DOE 1999a) require (see Appendix B): The protection of public health and safety; and The protection of the environment. Although quantitative limits are sometimes stated (for example, the all-pathways exposure limit is 25 mredyear), usually the requirements are stated in a general nature. Quantitative limits were established by: investigating all potentially applicable regulations as well as interpretations of the review panels which DOE has established to review performance assessments; interacting with program management to establish the additional requirements of the program; and interacting with the public (i.e., the Hanford Advisory Board members; as well as affected Tribal Governments) to understand the values of residents in the Pacific Northwest. Because of space considerations, not all radionuclides and dangerous chemicals are listed in this document. The radionuclides listed here are those which were explicitly treated in the ILAW PA (Mann 1998). The dangerous chemicals listed here are those most often detected in Hanford tank waste as documented in the Regulatory Data Quality Objectives Supporting Tank Waste Remediation System Privatization Project (Wiemers 1998)

Improving plant performance through efficient nuclear waste management - The French experience

International Nuclear Information System (INIS)

Peterson, C.H.

1986-01-01

This paper discusses high and low level waste management and its effect on Plant Performance. In France, high level waste policy is an improtant factor in plant performance. The LLW section of the paper discusses the role of French Industry organization as well as the benefits of standard plants with standard practices. The regulation of the production of waste and the waste processing by utilities is covered

Vitrification of liquid waste from nuclear power plants

International Nuclear Information System (INIS)

Sheng Jiawei; Choi, Kwansik; Song, Myung-Jae

2001-01-01

Glass is an acceptable waste form to solidify the low-level waste from nuclear power plants (NPPs) because of the simplicity of processing and its unique ability to accept a wide variety of waste streams. Vitrification is being considered to solidify the high-boron-containing liquid waste generated from Korean NPPs. This study dealt with the development of a glass formulation to solidify the liquid waste. Studies were conducted in a borosilicate glass system. Crucible studies have been performed with surrogate waste. Several developed glass frits were evaluated to determine their suitability for vitrifying the liquid waste. The results indicated that the 20 wt% waste oxides loading required could not be obtained using these glass frits. Flyash produced from coal-burning electric power stations, whose major components are SiO 2 and Al 2 O 3 , is a desirable glass network former. Detailed product evaluations including waste loading, homogeneity, chemical durability and viscosity, etc., were carried out on selected formulations using flyash. Up to 30 wt% of the waste oxides was successfully solidified into the flyash after the addition of 5-10 wt% Na 2 O at 1200 deg. C

Secondary Waste Cementitious Waste Form Data Package for the Integrated Disposal Facility Performance Assessment

Energy Technology Data Exchange (ETDEWEB)

Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Serne, R Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Um, Wooyong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cozzi, Alex D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-05-16

A review of the most up-to-date and relevant data currently available was conducted to develop a set of recommended values for use in the Integrated Disposal Facility (IDF) performance assessment (PA) to model contaminant release from a cementitious waste form for aqueous wastes treated at the Hanford Effluent Treatment Facility (ETF). This data package relies primarily upon recent data collected on Cast Stone formulations fabricated with simulants of low-activity waste (LAW) and liquid secondary wastes expected to be produced at Hanford. These data were supplemented, when necessary, with data developed for saltstone (a similar grout waste form used at the Savannah River Site). Work is currently underway to collect data on cementitious waste forms that are similar to Cast Stone and saltstone but are tailored to the characteristics of ETF-treated liquid secondary wastes. Recommended values for key parameters to conduct PA modeling of contaminant release from ETF-treated liquid waste are provided.

Performance of Railway Sleepers with Holes under Impact Loading

Science.gov (United States)

Lim, Chie Hong; Kaewunruen, Sakdirat; Mlilo, Nhlanganiso

2017-12-01

Prestressed concrete sleepers are essential structural components of railway track structures, with the purpose of redistributing wheel loads from the rails to the ground. To facilitate cables and signalling equipment, holes are often generated in these prestressed concrete sleepers. However, the performance of these sleepers under impact loading may be a concern with the addition of these holes. Numerical modelling using finite element analysis (FEA) is an ideal tool that enables static and dynamic simulation and can perform analyses of basic/advanced linear and nonlinear problems, without incurring a huge cost in resources like standard experimental test methods would. This paper will utilize the three-dimensional FE modelling software ABAQUS to investigate the behaviour of the prestressed concrete sleepers with holes of varying sizes upon impact loading. To obtain the results that resemble real-life behaviour of the sleepers under impact loading, the material properties, element types, mesh sizes, contact and interactions and boundary conditions will be defined as accurately as possible. Both Concrete Damaged Plasticity (CDP) and Brittle Cracking models will be used in this study. With a better understanding of how the introduction of holes will influence the performance of prestressed sleepers under impact loading, track and railway engineers will be able to generate them in prestressed concrete sleepers without compromising the sleepers’ performance during operation

Effect of Physical Load on Aerobic Exercise Performance during Heat Stress.

Science.gov (United States)

Kenefick, Robert W; Heavens, Kristen R; Luippold, Adam J; Charkoudian, Nisha; Schwartz, Steven A; Cheuvront, Samuel N

2017-12-01

This study aimed to investigate the effect of increasing external loads on 5-km treadmill time trial (TT) performance in 20°C and 40°C environmental conditions and to construct an ecologically relevant performance prediction decision aid. Twenty-six male and four female volunteers (age, 23.5 ± 6.9 yr; weight, 76.0 ± 8.9 kg; height, 1.75 ± 0.07 m; V˙O2peak, 50.7 ± 4.5 mL·kg·min) participated in a counterbalanced, mixed-model design, with each subject assigned to a load group (20%, 30%, or 50% body mass (BM); n = 10 per group). Volunteers performed three, self-paced 5-km familiarization TT (treadmill) without external load. Each volunteer then performed a 5-km TT in each environment with loads of either 20% (n = 10), 30% (n = 10), or 50% (n = 10) of BM. 1) Loads of (20%, 30%, and 50% of BM) impaired 5-km TT performance compared with that when unloaded (P exercise trials, an ecologically valid decision aid was developed from self-paced data, in which pace (km·h) can be predicted for individual levels of heat, load, or heat + load in combination.

Peer Review of the Waste Package Material Performance Interim Report

International Nuclear Information System (INIS)

J. A. Beavers; T. M. Devine, Jr.; G. S. Frankel; R. H. Jones; R. G. Kelly; R. M. Latanision; J. H. Payer

2001-01-01

At the request of the U.S. Department of Energy, Bechtel SAIC Company, LLC, formed the Waste Package Materials Performance Peer Review Panel (the Panel) to review the technical basis for evaluating the long-term performance of waste package materials in a proposed repository at Yucca Mountain, Nevada. This is the interim report of the Panel; a final report will be issued in February 2002. In its work to date, the Panel has identified important issues regarding waste package materials performance. In the remainder of its work, the Panel will address approaches and plans to resolve these issues. In its review to date, the Panel has not found a technical basis to conclude that the waste package materials are unsuitable for long-term containment at the proposed Yucca Mountain Repository. Nevertheless, significant technical issues remain unsettled and, primarily because of the extremely long life required for the waste packages, there will always be some uncertainty in the assessment. A significant base of scientific and engineering knowledge for assessing materials performance does exist and, therefore, the likelihood is great that uncertainty about the long-term performance can be substantially reduced through further experiments and analysis

RIP INPUT TABLES FROM WAPDEG FOR LA DESIGN SELECTION: HIGHER THERMAL LOADING

International Nuclear Information System (INIS)

K. Mon

1999-01-01

The purpose of this calculation is to document (1) the Waste Package Degradation (WAPDEG) version 3.09 (CRWMS M and O 1998b. Software Routine Report for WAPDEG (Version 3.09)) simulations used to analyze waste package degradation and failure under the repository exposure conditions characterized by the higher thermal loading repository design feature and, (2) post-processing of these results into tables of waste package degradation time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems version 5.19.01 (RIP) computer program (Golder Associates 1998). Specifically, the WAPDEG simulations discussed in this calculation correspond to waste package emplacement conditions (repository environment and design) defined in the Total System Performance Assessment-Viability Assessment (TSPA-VA), with the exception that the higher thermal loading Design Feature (Design Feature 26) of the License Application Design Selection (LADS) analysis was analyzed. Higher thermal loading would keep the drift temperature above the boiling point of water for a longer period of time, thereby minimizing moisture around the waste packages during a longer post-closure period. The higher thermal loading would also affect the surrounding rock, which may have adverse effects. The only failure mechanism of this feature would be if the effects on the surrounding rock were determined to be unacceptable. As a result of the change in waste package placement relative to the TSPA-VA base-case design, different temperature and relative humidity time histories at the waste package surface are calculated (input to the WAPDEG simulations), and consequently different waste package failure histories (as calculated by WAPDEG) result

Hydrothermal modeling for the efficient design of thermal loading in a nuclear waste repository

International Nuclear Information System (INIS)

Cho, Won-Jin; Kim, Jin-Seop; Choi, Heui-Joo

2014-01-01

Highlights: • Three-dimensional hydrothermal modeling for HLW repository is performed. • The model reduces the peak temperature in the repository by about 10 °C. • Decreasing the tunnel distance is more efficient to improve the disposal density. • The EDZ surrounding the deposition hole increases the peak temperature. • The peak temperature for the double-layer repository remains below the limit. - Abstract: The thermal analysis of a geological repository for nuclear waste using the three-dimensional hydrothermal model is performed. The hydrothermal model reduces the maximum peak temperature in the repository by about 10 °C compared to the heat conduction model with constant thermal conductivities. Decreasing the tunnel distance is more efficient than decreasing the deposition hole spacing to improve the disposal density for a given thermal load. The annular excavation damaged zone surrounding the deposition hole has a considerable effect on the peak temperature. The possibility of double-layer repository is analyzed from the viewpoint of the thermal constraints of the repository. The maximum peak temperature for the double-layer repository is slightly higher than that for the single-layer repository, but remains below the temperature limit

Biomethanization of citrus waste: Effect of waste characteristics and of storage on treatability and evaluation of limonene degradation.

Science.gov (United States)

Lotito, Adriana Maria; De Sanctis, Marco; Pastore, Carlo; Di Iaconi, Claudio

2018-06-01

This study proposes the evaluation of the suitability of mesophilic anaerobic digestion as a simple technology for the treatment of the citrus waste produced by small-medium agro-industrial enterprises involved in the transformation of Citrus fruits. Two different stocks of citrus peel waste were used (i.e., fresh and stored citrus peel waste), to evaluate the influence of waste composition (variability in the type of processed Citrus fruits) and of storage (potentially necessary to operate the anaerobic digester continuously over the whole year due to the seasonality of the production) on anaerobic degradation treatability. A thorough characterization of the two waste types has been performed, showing that the fresh one has a higher solid and organic content, and that, in spite of the similar values of oil fraction amounts, the two stocks are significantly different in the composition of essential oils (43% of limonene and 34% of linalyl acetate in the fresh citrus waste and 20% of limonene and 74% of linalyl acetate in the stored citrus waste). Contrarily to what observed in previous studies, anaerobic digestion was successful and no reactor acidification occurred. No inhibition by limonene and linalyl acetate even at the maximum applied organic load value (i.e., 2.72 gCOD waste /gVS inoculum ) was observed in the treatment of the stored waste, with limonene and linalyl acetate concentrations of 104 mg/l and 385 mg/l, respectively. On the contrary, some inhibition was detected with fresh citrus peel waste when the organic load increased from 2.21 to 2.88 gCOD waste /gVS inoculum , ascribable to limonene at initial concentration higher than 150 mg/l. A good conversion into methane was observed with fresh peel waste, up to 0.33  [Formula: see text] at the highest organic load, very close to the maximum theoretical value of 0.35 [Formula: see text] , while a lower efficiency was achieved with stored peel waste, with a reduction down to 0.24  [Formula: see

Waste-to-energy plants - a solution for a cleaner future

International Nuclear Information System (INIS)

Pfeiffer, J.

2007-01-01

Waste-to-energy plants reduce the municipal solid waste volume by about 80% and convert it into residue. The residue quality naturally depends on the burned waste quality and also on the combustion parameters. Hence, tighter control of the plant can improve the residue quality. The generated combustion energy is regarded as renewable energy and is typically used to feed a turbine to generate electricity. Waste-to-energy furnaces react slowly on changing waste charge, so they are not used for peak load generation. The generated electrical power is a plant by product and is sold as base load generation. Usually the waste is burned on a grate which limits the plant size to about 160,000 tons of waste per year or 20 tons of waste per hour or about 28 MW. More recent technology utilizes fluidized bed combustion, which allows larger plant sizes up to 50 MW. Due to the unknown waste composition and stringent environmental standards involved, waste-to-energy plants employ sophisticated flue gas cleaning devices for emission control. ABB's Performance Monitoring continuously compares actual plant and equipment performance to expected performance. This includes the on-line calculation of the waste calorific heat allowing operator decision support and automated control system responses. Dedicated reports offer detailed data on operations, maintenance and emissions to plant management staff. ABB combustion optimization solutions use model based predictive control techniques to reliably find the most suitable set-points for improving the heat rate and reducing emissions like NO x . (author)

Thermal loading study for FY 1995

International Nuclear Information System (INIS)

1996-01-01

This report provides the results of sensitivity analyses designed to assist the test planners in focusing their in-situ measurements on parameters that appear to be important to waste isolation. Additionally, the study provides a preliminary assessment of the feasibility of certain thermal management options. A decision on thermal loading is a critical part of the scientific and engineering basis for evaluating regulatory compliance of the potential repository for waste isolation. To show, with reasonable assurance, that the natural and engineered barriers will perform adequately under expected repository conditions (thermally perturbed) will require an integrated approach based on thermal testing (laboratory, and in-situ), natural analog observations, and analytic modeling. The Office of Civilian Radioactive Waste Management needed input to assist in the planning of the thermal testing program. Additionally, designers required information on the viability of various thermal management concepts. An approximately 18-month Thermal Loading Study was conducted from March, 1994 until September 30, 1995 to address these issues. This report documents the findings of that study. 89 refs., 71 figs., 33 tabs

The Waste Isolation Pilot Plant Performance Assessment Program

International Nuclear Information System (INIS)

Myers, J.; Coons, W.E.; Eastmond, R.; Morse, J.; Chakrabarti, S.; Zurkoff, J.; Colton, I.D.; Banz, I.

1986-01-01

The Waste Isolation Pilot Plant (WIPP) Performance Assessment Program involves a comprehensive analysis of the WIPP project with respect to the recently finalized Environmental Protection Agency regulations regarding the long-term geologic isolation of radioactive wastes. The performance assessment brings together the results of site characterization, underground experimental, and environmental studies into a rigorous determination of the performance of WIPP as a disposal system for transuranic radioactive waste. The Program consists of scenario development, geochemical, hydrologic, and thermomechanical support analyses and will address the specific containment and individual protection requirements specified in 40 CFR 191 sub-part B. Calculated releases from these interrelated analyses will be reported as an overall probability distribution of cumulative release resulting from all processes and events occurring over the 10,000 year post-closure period. In addition, results will include any doses to the public resulting from natural processes occurring over the 1,000 year post-closure period. The overall plan for the WIPP Performance Assessment Program is presented along with approaches to issues specific to the WIPP project

Methodologies for predicting the part-load performance of aero-derivative gas turbines

DEFF Research Database (Denmark)

Haglind, Fredrik; Elmegaard, Brian

2009-01-01

Prediction of the part-load performance of gas turbines is advantageous in various applications. Sometimes reasonable part-load performance is sufficient, while in other cases complete agreement with the performance of an existing machine is desirable. This paper is aimed at providing some guidance...... on methodologies for predicting part-load performance of aero-derivative gas turbines. Two different design models – one simple and one more complex – are created. Subsequently, for each of these models, the part-load performance is predicted using component maps and turbine constants, respectively. Comparisons...... with manufacturer data are made. With respect to the design models, the simple model, featuring a compressor, combustor and turbines, results in equally good performance prediction in terms of thermal efficiency and exhaust temperature as does a more complex model. As for part-load predictions, the results suggest...

Formulation Efforts for Direct Vitrification of INEEL Blend Calcine Waste Simulate: Fiscal Year 2000

Energy Technology Data Exchange (ETDEWEB)

Crum, Jarrod V.; Vienna, John D.; Peeler, David K.; Reamer, I. A.

2001-03-30

This report documents the results of glass formulation efforts for Idaho National Engineering and Environmental Laboratory (INEEL) high level waste (HWL) calcine. Two waste compositions were used during testing. Testing started by using the Run 78 calcine composition and switched to simulated Blend calcine composition when it became available. The goal of the glass formulation efforts was to develop a frit composition that will accept higher waste loading that satisfies the glass processing and product acceptance constraints. 1. Melting temperature of 1125 ? 25?C 2. Viscosity between 2 and 10 Pa?s at the melting temperature 3. Liquidus temperature at least 100?C below the melting temperature 4. Normalized release of B, Li and Na each below 1 g/m2 (per ASTM C 1285-97) Glass formulation efforts tested several frit compositions with variable waste loadings of Run 78 calcine waste simulant. Frit 107 was selected as the primary candidate for processing since it met all process and performance criteria up to 45 mass% waste loading. When the simulated Blend calcine waste composition became available Frits 107 and 108 compositions were retested and again Frit 107 remained the primary candidate. However, both frits suffered a decrease in waste loading when switching from the Run 78 calcine to simulated Blend calcine waste composition. This was due to increase concentrations of both F and Al2O3 along with a decrease in CaO and Na2O in the simulate Blend calcine waste all of which have strong impacts on the glass properties that limit waste loading of this type of waste.

Performance demonstration program plan for RCRA constituent analysis of solidified wastes

International Nuclear Information System (INIS)

1995-06-01

Performance Demonstration Programs (PDPS) are designed to help ensure compliance with the Quality Assurance Objectives (QAOs) for the Waste Isolation Pilot Plant (WIPP). The PDPs are intended for use by the Department of Energy (DOE) Carlsbad Area Office (CAO) to assess and approve the laboratories and other measurement facilities supplying services for the characterization of WIPP TRU waste. The PDPs may also be used by CAO in qualifying laboratories proposing to supply additional analytical services that are required for other than waste characterization, such as WIPP site operations. The purpose of this PDP is to test laboratory performance for the analysis of solidified waste samples for TRU waste characterization. This performance will be demonstrated by the successful analysis of blind audit samples of simulated, solidified TRU waste according to the criteria established in this plan. Blind audit samples (hereinafter referred to as PDP samples) will be used as an independent means to assess laboratory performance regarding compliance with the QAOs. The concentration of analytes in the PDP samples will address levels of regulatory concern and will encompass the range of concentrations anticipated in actual waste characterization samples. Analyses that are required by the WIPP to demonstrate compliance with various regulatory requirements and which are included in the PDP must be performed by laboratories that demonstrate acceptable performance in the PDP. These analyses are referred to as WIPP analyses and the samples on which they are performed are referred to as WIPP samples for the balance of this document

Integrated waste and water management system

Science.gov (United States)

Murray, R. W.; Sauer, R. L.

1986-01-01

The performance requirements of the NASA Space Station have prompted a reexamination of a previously developed integrated waste and water management system that used distillation and catalytic oxydation to purify waste water, and microbial digestion and incineration for waste solids disposal. This system successfully operated continuously for 206 days, for a 4-man equivalent load of urine, feces, wash water, condensate, and trash. Attention is given to synergisms that could be established with other life support systems, in the cases of thermal integration, design commonality, and novel technologies.

The effect of load reductions on repetition performance for commonly performed multijoint resistance exercises.

Science.gov (United States)

Willardson, Jeffrey M; Simão, Roberto; Fontana, Fabio E

2012-11-01

The purpose of this study was to compare 4 different loading schemes for the free weight bench press, wide grip front lat pull-down, and free weight back squat to determine the extent of progressive load reductions necessary to maintain repetition performance. Thirty-two recreationally trained women (age = 29.34 ± 4.58 years, body mass = 59.61 ± 4.72 kg, height = 162.06 ± 4.04 cm) performed 4 resistance exercise sessions that involved 3 sets of the free weight bench press, wide grip front lat pull-down, and free weight back squat, performed in this exercise order during all 4 sessions. Each of the 4 sessions was conducted under different randomly ordered loading schemes, including (a) a constant 10 repetition maximum (RM) load for all 3 sets and for all 3 exercises, (b) a 5% reduction after the first and second sets for all the 3 exercises, (c) a 10% reduction after the first and second sets for all the 3 exercises, and (d) a 15% reduction after the first and second sets for all the 3 exercises. The results indicated that for the wide grip front lat pull-down and free weight back squat, a 10% load reduction was necessary after the first and second sets to accomplish 10 repetitions on all the 3 sets. For the free weight bench press, a load reduction between 10 and 15% was necessary; specifically, a 10% reduction was insufficient and a 15% reduction was excessive, as evidenced by significantly >10 repetitions on the second and third sets for this exercise (p ≤ 0.05). In conclusion, the results of this study indicate that a resistance training prescription that involves 1-minute rest intervals between multiple 10RM sets does require load reductions to maintain repetition performance. Practitioners might apply these results by considering an approximate 10% load reduction after the first and second sets for the exercises examined, when training women of similar characteristics as in this study.

Measuring cognitive load: performance, mental effort and simulation task complexity.

Science.gov (United States)

Haji, Faizal A; Rojas, David; Childs, Ruth; de Ribaupierre, Sandrine; Dubrowski, Adam

2015-08-01

Interest in applying cognitive load theory in health care simulation is growing. This line of inquiry requires measures that are sensitive to changes in cognitive load arising from different instructional designs. Recently, mental effort ratings and secondary task performance have shown promise as measures of cognitive load in health care simulation. We investigate the sensitivity of these measures to predicted differences in intrinsic load arising from variations in task complexity and learner expertise during simulation-based surgical skills training. We randomly assigned 28 novice medical students to simulation training on a simple or complex surgical knot-tying task. Participants completed 13 practice trials, interspersed with computer-based video instruction. On trials 1, 5, 9 and 13, knot-tying performance was assessed using time and movement efficiency measures, and cognitive load was assessed using subjective rating of mental effort (SRME) and simple reaction time (SRT) on a vibrotactile stimulus-monitoring secondary task. Significant improvements in knot-tying performance (F(1.04,24.95)  = 41.1, p cognitive load (F(2.3,58.5)  = 57.7, p load among novices engaged in simulation-based learning. These measures can be used to track cognitive load during skills training. Mental effort ratings are also sensitive to small differences in intrinsic load arising from variations in the physical complexity of a simulation task. The complementary nature of these subjective and objective measures suggests their combined use is advantageous in simulation instructional design research. © 2015 John Wiley & Sons Ltd.

Criticality safety of transuranic storage arrays at the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Boyd, W.A.; Fecteau, M.W.

1993-01-01

The Waste Isolation Pilot Plant (WIPP) facility is designed to store transuranic waste that will consist mainly of surface contaminate articles and sludge. The fissile material in the waste is predominantly 239 Pu. The waste is grouped into two categories: contact-handled waste, which will be stored in 55-gal steel drums or in steel boxes, and remote-handled waste, which will be stored in specially designed cylindrical steel canisters. To show that criticality safety will be acceptable, criticality analyses were performed to demonstrate that a large number of containers with limiting loadings of fissile material could be stored at the site and meet a k eff limit of 0.95. Criticality analyses based on the classic worst-case moderated plutonium sphere approach would severely limit the capacity for storage of waste at the facility. Therefore, these analyses use realistic or credible worst-case assumptions to better represent the actual storage situation without compromising the margin of safety. Numerous sensitivity studies were performed to determine the importance of various parameters on the criticality of the configuration. It was determined that the plutonium loading has the dominant effect on the system reactivity. Nearly all other reactivity variations from the sensitivity studies were found to be relatively small. The analysis shows that criticality of the contact-handled waste storage drums and boxes and the remote-handled canisters is prevented by restrictions on maximum fissile loading per container and on the size of handling/storage areas

Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

Energy Technology Data Exchange (ETDEWEB)

Schultz, Peter Andrew

2011-12-01

The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC)

International Nuclear Information System (INIS)

Schultz, Peter Andrew

2011-01-01

The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M and S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V and V) is required throughout the system to establish evidence-based metrics for the level of confidence in M and S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V and V challenge at the subcontinuum scale, an approach to incorporate V and V concepts into subcontinuum scale modeling and simulation (M and S), and a plan to incrementally incorporate effective V and V into subcontinuum scale M and S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

Radioactive Waste Management Complex performance assessment: Draft

Energy Technology Data Exchange (ETDEWEB)

Case, M.J.; Maheras, S.J.; McKenzie-Carter, M.A.; Sussman, M.E.; Voilleque, P.

1990-06-01

A radiological performance assessment of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory was conducted to demonstrate compliance with appropriate radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the general public. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the general public via air, ground water, and food chain pathways. Projections of doses were made for both offsite receptors and individuals intruding onto the site after closure. In addition, uncertainty analyses were performed. Results of calculations made using nominal data indicate that the radiological doses will be below appropriate radiological criteria throughout operations and after closure of the facility. Recommendations were made for future performance assessment calculations.

Radioactive Waste Management Complex performance assessment: Draft

International Nuclear Information System (INIS)

Case, M.J.; Maheras, S.J.; McKenzie-Carter, M.A.; Sussman, M.E.; Voilleque, P.

1990-06-01

A radiological performance assessment of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory was conducted to demonstrate compliance with appropriate radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the general public. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the general public via air, ground water, and food chain pathways. Projections of doses were made for both offsite receptors and individuals intruding onto the site after closure. In addition, uncertainty analyses were performed. Results of calculations made using nominal data indicate that the radiological doses will be below appropriate radiological criteria throughout operations and after closure of the facility. Recommendations were made for future performance assessment calculations

Modeling and Performance of Waste Tires as Media in Fixed Bed Sequence Batch Reactor

Directory of Open Access Journals (Sweden)

Zahra Derakhshan

2016-12-01

Results: The maximum removal efficiencies of dissolved chemical oxygen demand for FBSBR and SBR reactors were 98.3 % and 97.9 %, respectively. In addition, Stover-Kincannon model provided a very suitable fitness (R2   > 0.99 for loading the bioreactor FBSBR. Conclusion: According to the results, not only waste tires can be reused, but also these wastes can be employed as a proper biological bed in wastewater refineries to improve their efficiency.

Vitrified waste form performance modeling applied to the treatment and disposal of mixed-waste sludge at the Savannah River Site

International Nuclear Information System (INIS)

Whited, A.R.; Fjeld, R.A.

1998-01-01

Vitrification, the conversion of source components into a solid amorphous glass matrix, has emerged as a viable treatment technology for low-level radioactive waste and mixed waste. To dispose of vitrified low-level waste at US Department of Energy facilities, site-specific radiological performance assessments must be conducted to demonstrate that waste glass satisfies performance objectives for environmental protection. More than 2,500 m 3 of F0006-listed low-level mixed-waste sludge stored in the Reactor Materials Department (M-Area) at the Savannah River Site (SRS) is scheduled for vitrification. This study evaluates the feasibility of on-site disposal of vitrified M-Area waste at SRS. Laboratory leaching tests that accelerate the glass corrosion process are currently the best indicators of vitrified waste form durability. A method to incorporate laboratory leaching data into performance assessments is presented. A screening-level performance assessments code is used to model trench disposal of M-Area waste glass. The allowable leach rate for vitrified M-Area waste is determined based on both a maximum radiological dose equivalent of 4 mrem/yr for the drinking water pathway and a maximum uranium concentration of 20 microg/ell in groundwater. The allowable leach rate is compared with published long-term leaching data for a wide range of waste glass compositions and test conditions. This analysis demonstrates that trench disposal of the waste glass is likely to meet applicable performance objectives if the glass is of above average durability compared with the reference set of glasses

Combined Waste Form Cost Trade Study

International Nuclear Information System (INIS)

Gombert, Dirk; Piet, Steve; Trickel, Timothy; Carter, Joe; Vienna, John; Ebert, Bill; Matthern, Gretchen

2008-01-01

A new generation of aqueous nuclear fuel reprocessing, now in development under the auspices of the DOE Office of Nuclear Energy (NE), separates fuel into several fractions, thereby partitioning the wastes into groups of common chemistry. This technology advance enables development of waste management strategies that were not conceivable with simple PUREX reprocessing. Conventional wisdom suggests minimizing high level waste (HLW) volume is desirable, but logical extrapolation of this concept suggests that at some point the cost of reducing volume further will reach a point of diminishing return and may cease to be cost-effective. This report summarizes an evaluation considering three groupings of wastes in terms of cost-benefit for the reprocessing system. Internationally, the typical waste form for HLW from the PUREX process is borosilicate glass containing waste elements as oxides. Unfortunately several fission products (primarily Mo and the noble metals Ru, Rh, Pd) have limited solubility in glass, yielding relatively low waste loading, producing more glass, and greater disposal costs. Advanced separations allow matching the waste form to waste stream chemistry, allowing the disposal system to achieve more optimum waste loading with improved performance. Metals can be segregated from oxides and each can be stabilized in forms to minimize the HLW volume for repository disposal. Thus, a more efficient waste management system making the most effective use of advanced waste forms and disposal design for each waste is enabled by advanced separations and how the waste streams are combined. This trade-study was designed to juxtapose a combined waste form baseline waste treatment scheme with two options and to evaluate the cost-benefit using available data from the conceptual design studies supported by DOE-NE

The role of frit in nuclear waste vitrification

International Nuclear Information System (INIS)

Vienna, J.D.; Smith, P.A.; Dorn, D.A.; Hrma, P.

1994-04-01

Vitrification of nuclear waste requires additives which are often vitrified independently to form a frit. Frit composition is formulated to meet the needs of glass composition and processing. The effects of frit on melter feed and melt processing, glass acceptance, and waste loading is of practical interest in understanding the trade-offs associated with the competing demands placed on frit composition. Melter feed yield stress, viscosity and durability of frits and corresponding waste glasses as well as the kinetics of elementary melting processes have been measured. The results illustrate the competing requirements on frit. Four frits (FY91, FY93, HW39-4, and SR202) and simulated neutralized current acid waste (NCAW) were used in this study. The experimental evidence shows that optimization of frit for one processing related property often results in poorer performance for the remaining properties. The difficulties associated with maximum waste loading and durability are elucidated for glasses which could be processed using technology available for the previously proposed Hanford Waste Vitrification Plant

Lawrence Livermore National Laboratory low-level waste systems performance assessment

International Nuclear Information System (INIS)

1990-11-01

This Low-Level Radioactive Waste (LLW) Systems Performance Assessment (PA) presents a systematic analysis of the potential risks posed by the Lawrence Livermore National Laboratory (LLNL) waste management system. Potential risks to the public and environment are compared to established performance objectives as required by DOE Order 5820.2A. The report determines the associated maximum individual committed effective dose equivalent (CEDE) to a member of the public from LLW and mixed waste. A maximum annual CEDE of 0.01 mrem could result from routine radioactive liquid effluents. A maximum annual CEDE of 0.003 mrem could result from routine radioactive gaseous effluents. No other pathways for radiation exposure of the public indicated detectable levels of exposure. The dose rate, monitoring, and waste acceptance performance objectives were found to be adequately addressed by the LLNL Program. 88 refs., 3 figs., 17 tabs

Final waste forms project: Performance criteria for phase I treatability studies

International Nuclear Information System (INIS)

Gilliam, T.M.; Hutchins, D.A.; Chodak, P. III

1994-06-01

This document defines the product performance criteria to be used in Phase I of the Final Waste Forms Project. In Phase I, treatability studies will be performed to provide open-quotes proof-of-principleclose quotes data to establish the viability of stabilization/solidification (S/S) technologies. This information is required by March 1995. In Phase II, further treatability studies, some at the pilot scale, will be performed to provide sufficient data to allow treatment alternatives identified in Phase I to be more fully developed and evaluated, as well as to reduce performance uncertainties for those methods chosen to treat a specific waste. Three main factors influence the development and selection of an optimum waste form formulation and hence affect selection of performance criteria. These factors are regulatory, process-specific, and site-specific waste form standards or requirements. Clearly, the optimum waste form formulation will require consideration of performance criteria constraints from each of the three categories. Phase I will focus only on the regulatory criteria. These criteria may be considered the minimum criteria for an acceptable waste form. In other words, a S/S technology is considered viable only if it meet applicable regulatory criteria. The criteria to be utilized in the Phase I treatability studies were primarily taken from Environmental Protection Agency regulations addressed in 40 CFR 260 through 265 and 268; and Nuclear Regulatory Commission regulations addressed in 10 CFR 61. Thus the majority of the identified criteria are independent of waste form matrix composition (i.e., applicable to cement, glass, organic binders etc.)

Final waste forms project: Performance criteria for phase I treatability studies

Energy Technology Data Exchange (ETDEWEB)

Gilliam, T.M. [Oak Ridge National Lab., TN (United States); Hutchins, D.A. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States); Chodak, P. III [Massachusetts Institute of Technology (United States)

1994-06-01

This document defines the product performance criteria to be used in Phase I of the Final Waste Forms Project. In Phase I, treatability studies will be performed to provide {open_quotes}proof-of-principle{close_quotes} data to establish the viability of stabilization/solidification (S/S) technologies. This information is required by March 1995. In Phase II, further treatability studies, some at the pilot scale, will be performed to provide sufficient data to allow treatment alternatives identified in Phase I to be more fully developed and evaluated, as well as to reduce performance uncertainties for those methods chosen to treat a specific waste. Three main factors influence the development and selection of an optimum waste form formulation and hence affect selection of performance criteria. These factors are regulatory, process-specific, and site-specific waste form standards or requirements. Clearly, the optimum waste form formulation will require consideration of performance criteria constraints from each of the three categories. Phase I will focus only on the regulatory criteria. These criteria may be considered the minimum criteria for an acceptable waste form. In other words, a S/S technology is considered viable only if it meet applicable regulatory criteria. The criteria to be utilized in the Phase I treatability studies were primarily taken from Environmental Protection Agency regulations addressed in 40 CFR 260 through 265 and 268; and Nuclear Regulatory Commission regulations addressed in 10 CFR 61. Thus the majority of the identified criteria are independent of waste form matrix composition (i.e., applicable to cement, glass, organic binders etc.).

Performance Evaluation of Concrete using Marble Mining Waste

Science.gov (United States)

Kore, Sudarshan Dattatraya; Vyas, A. K.

2016-12-01

A huge amount waste (approximately 60%) is generated during mining and processing in marble industries. Such waste can be best utilized in infrastructure development works. Coarse aggregate 75% by weight was replaced by aggregate obtained from marble mining waste. The impact of marble waste as a partial replacement for conventional coarse aggregate on the properties of concrete mixes such as workability, compressive strength, permeability, abrasion, etc. was evaluated. The test results revealed that the compressive strength was comparable to that of control concrete. Other properties such as workability of concrete increased, water absorption reduced by 17%, and resistance to abrasion was marginally increased by 2% as compared to that of control concrete. Ultrasonic pulse velocity and FTIR results show improvement in quality of concrete with crushed marble waste. From the TGA analysis it was confirmed that, aggregate produced from marble waste shows better performance under elevated temperature than that of conventional aggregates.

Performance Assessment of a Generic Repository in Bedded Salt for DOE-Managed Nuclear Waste

Science.gov (United States)

Stein, E. R.; Sevougian, S. D.; Hammond, G. E.; Frederick, J. M.; Mariner, P. E.

2016-12-01

A mined repository in salt is one of the concepts under consideration for disposal of DOE-managed defense-related spent nuclear fuel (SNF) and high level waste (HLW). Bedded salt is a favorable medium for disposal of nuclear waste due to its low permeability, high thermal conductivity, and ability to self-heal. Sandia's Generic Disposal System Analysis framework is used to assess the ability of a generic repository in bedded salt to isolate radionuclides from the biosphere. The performance assessment considers multiple waste types of varying thermal load and radionuclide inventory, the engineered barrier system comprising the waste packages, backfill, and emplacement drifts, and the natural barrier system formed by a bedded salt deposit and the overlying sedimentary sequence (including an aquifer). The model simulates disposal of nearly the entire inventory of DOE-managed, defense-related SNF (excluding Naval SNF) and HLW in a half-symmetry domain containing approximately 6 million grid cells. Grid refinement captures the detail of 25,200 individual waste packages in 180 disposal panels, associated access halls, and 4 shafts connecting the land surface to the repository. Equations describing coupled heat and fluid flow and reactive transport are solved numerically with PFLOTRAN, a massively parallel flow and transport code. Simulated processes include heat conduction and convection, waste package failure, waste form dissolution, radioactive decay and ingrowth, sorption, solubility limits, advection, dispersion, and diffusion. Simulations are run to 1 million years, and radionuclide concentrations are observed within an aquifer at a point approximately 4 kilometers downgradient of the repository. The software package DAKOTA is used to sample likely ranges of input parameters including waste form dissolution rates and properties of engineered and natural materials in order to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia

Interim performance specifications for conceptual waste-package designs for geologic isolation in salt repositories

International Nuclear Information System (INIS)

1983-06-01

The interim performance specifications and data requirements presented apply to conceptual waste package designs for all waste forms which will be isolated in salt geologic repositories. The waste package performance specifications and data requirements respond to the waste package performance criteria. Subject areas treated include: containment and controlled release, operational period safety, criticality control, identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available

Influence of loading distribution on the performance of high pressure turbine blades

Science.gov (United States)

Corriveau, Daniel

Midspan measurements were made in a transonic wind tunnel for three High Pressure (HP) turbine blade cascades at both design and off-design incidences. Comparisons with two-dimensional numerical simulations of the cascade flow were also made. The baseline profile is the midspan section of a HP turbine blade of fairly recent design. It is considered mid-loaded. To gain a better understanding of blade loading limits and the influence of loading distributions, the profile of the baseline airfoil was modified to create two new airfoils having aft-loaded and front-loaded pressure distributions. Tests were performed for exit Mach numbers between 0.6 and 1.2. In addition, measurements were made for an extended range of Reynolds numbers for constant Mach numbers of 0.6, 0.85, 0.95 and 1.05. At the design exit Mach number of 1.05 and at design incidence, the aft-loaded airfoil showed a reduction of almost 20% in the total pressure losses compared with the baseline airfoil. Based on the analysis of wake traverse data and base pressure measurements combined with numerical results, it was found that the poorer loss performance of the baseline mid-loaded profile compared to the aft-loaded blade could be attributed to the former's higher rear suction side curvature, which resulted in higher flow velocity in that region, which, in turn, contributed to reducing the base pressure. The lower base pressure at the trailing edge resulted in a stronger trailing edge shock system for the mid-loaded blade. This shock system increased the losses for the mid-loaded baseline profile when compared to the aft-loaded profile. On the negative side, it was also found that as Mach numbers were increased beyond the design value the performance of the aft-loaded blade deteriorated rapidly. Under such conditions, the front-loaded airfoil showed generally inferior performance compared with the baseline airfoil. At off-design incidence, the aft-loaded blade maintained a superior loss performance over a

Nuclear waste repository ventilation system studies

International Nuclear Information System (INIS)

Smith, P.R.; Hensel, E.C.; Leslie, I.H.; Schultheis, T.M.; Walls, J.R.; Gregory, W.S.

1993-01-01

Ventilation studies of the Waste Isolation Pilot Plant described in this article were performed by personnel from New Mexico State University in collaboration with Sandia National Laboratories, Los Alamos National Laboratory, and Westinghouse Corporation. The following research tasks were performed: 1) High-efficiency particulate air filters of the type used at the Waste Isolation Pilot Plant were loaded with salt aerosol from the site, 2) Filter resistance as a function of salt mass and flow rate was established for later use in computer simulations, 3) Filter efficiency was measured during the loading tests to establish a relation between efficiency and salt loading, 4) The structural strength of the salt-loaded high-efficiency filters was investigated by subjecting the filters to pressure transients of the types expected from fires, explosions and tornados, 5) Computer codes, obtained from Los Alamos National Laboratory, were used to model the ventilation systems and study their response to accident-induced pressure transients and heat fluxes, 6) Partial verification of the computer simulations was obtained by comparing normal operation of the ventilation systems to predicted normal operation, 7) A feasibility study using model-based control of the ventilation systems was initiated and will be completed during the second year of the project. (author) 12 figs., 16 refs

Evaluation of thermo-hydrological performance in support of the thermal loading systems study

International Nuclear Information System (INIS)

Buscheck, T.A.; Nitao, J.J.

1994-01-01

Heat generated as a result of emplacing spent nuclear fuel will significantly affect the pre- and post-closure performance of the Mined Geological Disposal System (MGDS) at the potential repository site in Yucca Mountain. Understanding thermo-hydrological behavior under repository thermal loads is essential in (a) planning and conducting the site characterization and testing program, (b) designing the repository and engineered barrier system, and (c) assessing performance. The greatest concern for hydrological performance is source of water that would contact a waste package, accelerate its failure rate, and eventually transport radionuclides to the water table. The primary sources of liquid water are: (1) natural infiltration, (2) condensate generated under boiling conditions, and (3) condensate generated under sub-boiling conditions. Buoyant vapor flow, occurring either on a sub-repository scale or on a mountain scale, any affect the generation of the second and third sources of liquid water. A system of connected fractures facilitates repository-heat-driven gas and liquid flow as well as natural infiltration. With the use of repository-scale and sub-repository-scale models, the authors analyze thermo-hydrological behavior for Areal Mass Loadings (AMLs) of 24.2, 35.9, 55.3, 83.4, and 110.5 MTU/acre for a wide range of bulk permeability. They examine the temporal and spatial extent of the temperature and saturation changes during the first 100,000 yr. They also examine the sensitivity of mountain scale moisture redistribution to a range of AMLs and bulk permeabilities. In addition, they investigate how boiling and buoyant, gas-phase convection influence thermo-hydrological behavior in the vicinity of emplacement drifts containing spent nuclear fuel

Temperature effects on waste glass performance

International Nuclear Information System (INIS)

Mazer, J.J.

1991-02-01

The temperature dependence of glass durability, particularly that of nuclear waste glasses, is assessed by reviewing past studies. The reaction mechanism for glass dissolution in water is complex and involves multiple simultaneous reaction proceeded, including molecular water diffusion, ion exchange, surface reaction, and precipitation. These processes can change in relative importance or dominance with time or changes in temperature. The temperature dependence of each reaction process has been shown to follow an Arrhenius relationship in studies where the reaction process has been isolated, but the overall temperature dependence for nuclear waste glass reaction mechanisms is less well understood, Nuclear waste glass studies have often neglected to identify and characterize the reaction mechanism because of difficulties in performing microanalyses; thus, it is unclear if such results can be extrapolated to other temperatures or reaction times. Recent developments in analytical capabilities suggest that investigations of nuclear waste glass reactions with water can lead to better understandings of their reaction mechanisms and their temperature dependences. Until a better understanding of glass reaction mechanisms is available, caution should be exercised in using temperature as an accelerating parameter. 76 refs., 1 tab

Development of a working set of waste package performance criteria for deepsea disposal of low-level radioactive waste. Final report

International Nuclear Information System (INIS)

Columbo, P.; Fuhrmann, M.; Neilson, R.M. Jr; Sailor, V.L.

1982-11-01

The United States ocean dumping regulations developed pursuant to PL92-532, the Marine Protection, Research, and Sanctuaries Act of 1972, as amended, provide for a general policy of isolation and containment of low-level radioactive waste after disposal into the ocean. In order to determine whether any particular waste packaging system is adequate to meet this general requirement, it is necessary to establish a set of performance criteria against which to evaluate a particular packaging system. These performance criteria must present requirements for the behavior of the waste in combination with its immobilization agent and outer container in a deepsea environment. This report presents a working set of waste package performance criteria, and includes a glossary of terms, characteristics of low-level radioactive waste, radioisotopes of importance in low-level radioactive waste, and a summary of domestic and international regulations which control the ocean disposal of these wastes

Demonstration of a performance assessment methodology for nuclear waste isolation in basalt formations

International Nuclear Information System (INIS)

Bonano, E.J.; Davis, P.A.

1988-01-01

This paper summarizes the results of the demonstration of a performance assessment methodology developed by Sandia National Laboratories, Albuquerque for the US Nuclear Regulatory Commission for use in the analysis of high-level radioactive waste disposal in deep basalts. Seven scenarios that could affect the performance of a repository in basalts were analyzed. One of these scenarios, normal ground-water flow, was called the base-case scenario. This was used to demonstrate the modeling capabilities in the methodology necessary to assess compliance with the ground-water travel time criterion. The scenario analysis consisted of both scenario screening and consequence modeling. Preliminary analyses of scenarios considering heat released from the waste and the alteration of the hydraulic properties of the rock mass due to loads created by a glacier suggested that these effects would not be significant. The analysis of other scenarios indicated that those changing the flow field in the vicinity of the repository would have an impact on radionuclide discharges, while changes far from the repository may not be significant. The analysis of the base-case scenario was used to show the importance of matrix diffusion as a radionuclide retardation mechanism in fractured media. The demonstration of the methodology also included an overall sensitivity analysis to identify important parameters and/or processes. 15 refs., 13 figs., 2 tabs

The immobilization of High Level Waste Into Glass

International Nuclear Information System (INIS)

Aisyah; Martono, H.

1998-01-01

High level liquid waste is generated from the first step extraction in the nuclear fuel reprocessing. The waste is immobilized with boro-silicate glass. A certain composition of glass is needed for a certain type of waste, so that the properties of waste glass would meet the requirement either for further process or for disposal. The effect of waste loading on either density, thermal expansion, softening point and leaching rate has been studied. The composition of the high level liquid waste has been determined by ORIGEN 2 and the result has been used to prepare simulated high level waste. The waste loading in the waste glass has been set to be 19.48; 22.32; 25.27; and 26.59 weight percent. The result shows that increasing the waste loading has resulted in the higher density with no thermal expansion and softening point significant change. The increase in the waste loading increase that leaching rate. The properties of the waste glass in this research have not shown any deviation from the standard waste glass properties

Application of systems engineering to determine performance requirements for repository waste packages

International Nuclear Information System (INIS)

Aitken, E.A.; Stimmell, G.L.

1987-01-01

The waste package for a nuclear waste repository in salt must contribute substantially to the performance objectives defined by the Salt Repository Project (SRP) general requirements document governing disposal of high-level waste. The waste package is one of the engineered barriers providing containment. In establishing the performance requirements for a project focused on design and fabrication of the waste package, the systems engineering methodology has been used to translate the hierarchy requirements for the repository system to specific performance requirements for design and fabrication of the waste package, a subsystem of the repository. This activity is ongoing and requires a methodology that provides traceability and is capable of iteration as baseline requirements are refined or changed. The purpose of this summary is to describe the methodology being used and the way it can be applied to similar activities in the nuclear industry

Optimal loading and protection of multi-state systems considering performance sharing mechanism

International Nuclear Information System (INIS)

Xiao, Hui; Shi, Daimin; Ding, Yi; Peng, Rui

2016-01-01

Engineering systems are designed to carry the load. The performance of the system largely depends on how much load it carries. On the other hand, the failure rate of the system is strongly affected by its load. Besides internal failures, such as fatigue and aging process, systems may also fail due to external impacts such as nature disasters and terrorism. In this paper, we integrate the effect of loading and protection of external impacts on multi-state systems with performance sharing mechanism. The objective of this research is to determine how to balance the load and protection on system elements. An availability evaluation algorithm of the proposed system is suggested and the corresponding optimization problem is solved utilizing genetic algorithms. - Highlights: • Performance sharing of multi-state systems is considered. • The effect of load on system elements is analyzed. • Joint optimization model of element loading and protection is formulated. • Genetic Algorithms are adapted to solve the reliability optimization problem.

An analytical one-dimensional model for predicting waste package performance

International Nuclear Information System (INIS)

Relyea, J.F.; Wood, M.I.

1984-01-01

A method for allocating waste package performance requirements among waste package components with regard to radionuclide isolation has been developed. Modification or change in this approach can be expected as the understanding of radionuclide behavior in the waste package improves. Thus, the performance requirements derived in this document are preliminary and subject to change. However, this kind of analysis is a useful starting point. It has also proved useful for identifying a small group of radionuclides which should be emphasized in a laboratory experimental program designed to characterize the behavior of specific radionuclides in the waste package environment. A simple one-dimensional, two media transport model has been derived and used to calculate radionuclide transport from the waste form-packing material interface of the waste package into the host rock. Cumulative release over 10,000 years, maximum yearly releases and release rates at the packing material-host rock interface were evaluated on a radionuclide-by radionuclide basis. The major parameters controlling radionuclide release were found to be: radionuclide solubility, porosity of the rock, isotopic ratio of the radionuclide and surface area of the waste form-packing material interface. 15 refs., 2 figs., 16 tabs

Performance of Llampuedken with short circuit and plasma loads

International Nuclear Information System (INIS)

Chuaqui, Hernan; Mitchell, Ian H.; Aliaga-Rossel, Raul; Favre, Mario; Wyndham, Edmund S.

2002-01-01

Llampuedken is a pulsed power generator designed to deliver a 1 MA, 250 ns risetime current pulse into a dense plasma load. The main novel feature of this generator is the two auxiliary transmission lines which transmit the energy not absorbed by the load, reflect it at the open end of the line and deliver it to the load when the energy from the main lines is decreasing. With the auxiliary lines an increase of 30% on the current as well as a decrease of the voltage at the load is obtained. To date Llampuedken has been operated up to the 400 kA level, into both short circuit and plasma loads. Details of actual performance of the pulse power generator are presented and compared with simulations

Uncertainty evaluation methods for waste package performance assessment

International Nuclear Information System (INIS)

Wu, Y.T.; Nair, P.K.; Journel, A.G.; Abramson, L.R.

1991-01-01

This report identifies and investigates methodologies to deal with uncertainties in assessing high-level nuclear waste package performance. Four uncertainty evaluation methods (probability-distribution approach, bounding approach, expert judgment, and sensitivity analysis) are suggested as the elements of a methodology that, without either diminishing or enhancing the input uncertainties, can evaluate performance uncertainty. Such a methodology can also help identify critical inputs as a guide to reducing uncertainty so as to provide reasonable assurance that the risk objectives are met. This report examines the current qualitative waste containment regulation and shows how, in conjunction with the identified uncertainty evaluation methodology, a framework for a quantitative probability-based rule can be developed that takes account of the uncertainties. Current US Nuclear Regulatory Commission (NRC) regulation requires that the waste packages provide ''substantially complete containment'' (SCC) during the containment period. The term ''SCC'' is ambiguous and subject to interpretation. This report, together with an accompanying report that describes the technical considerations that must be addressed to satisfy high-level waste containment requirements, provides a basis for a third report to develop recommendations for regulatory uncertainty reduction in the ''containment''requirement of 10 CFR Part 60. 25 refs., 3 figs., 2 tabs

Effects of Cognitive Load on Driving Performance: The Cognitive Control Hypothesis.

Science.gov (United States)

Engström, Johan; Markkula, Gustav; Victor, Trent; Merat, Natasha

2017-08-01

The objective of this paper was to outline an explanatory framework for understanding effects of cognitive load on driving performance and to review the existing experimental literature in the light of this framework. Although there is general consensus that taking the eyes off the forward roadway significantly impairs most aspects of driving, the effects of primarily cognitively loading tasks on driving performance are not well understood. Based on existing models of driver attention, an explanatory framework was outlined. This framework can be summarized in terms of the cognitive control hypothesis: Cognitive load selectively impairs driving subtasks that rely on cognitive control but leaves automatic performance unaffected. An extensive literature review was conducted wherein existing results were reinterpreted based on the proposed framework. It was demonstrated that the general pattern of experimental results reported in the literature aligns well with the cognitive control hypothesis and that several apparent discrepancies between studies can be reconciled based on the proposed framework. More specifically, performance on nonpracticed or inherently variable tasks, relying on cognitive control, is consistently impaired by cognitive load, whereas the performance on automatized (well-practiced and consistently mapped) tasks is unaffected and sometimes even improved. Effects of cognitive load on driving are strongly selective and task dependent. The present results have important implications for the generalization of results obtained from experimental studies to real-world driving. The proposed framework can also serve to guide future research on the potential causal role of cognitive load in real-world crashes.

Performance of evaporators in high level radioactive chemical waste service

International Nuclear Information System (INIS)

Jenkins, C.F.

1997-01-01

Chemical processing of nuclear fuels and targets at Savannah River Site resulted in generation of millions of gallons of liquid wastes. The wastes were further processed to reduce volume and allow for extended temporary storage of a more concentrated material. Waste evaporators have been a central point for waste reduction for many years. Currently, the transfer and processing of the concentrated wastes for permanent storage requires dilution and results in generation of significant quantities of additional liquid wastes. A new round of volume reduction is required to fit existing storage capacity and to allow for removal of older vessels from service. Evaporator design, performance and repairs are discussed in this report

Combustion characteristics, performance and exhaust emissions of a diesel engine fueled with a waste cooking oil biodiesel mixture

International Nuclear Information System (INIS)

Can, Özer

2014-01-01

Highlights: • High quality biodiesel fuels can be produced by using different waste cooking oils. • Biodiesel fuel blends (in 5 and 10% vol) can be used without any negative effects. • Effects of biodiesel addition on the combustion and exhaust emissions were investigated. - Abstract: In this study, a mixture of biodiesel fuels produced from two different kinds of waste cooking oils was blended in 5% and 10% with No. 2 diesel fuel. The biodiesel/No. 2 diesel fuel blends were tested in a single-cylinder, direct injection, four-stroke, natural aspirated diesel engine under four different engine loads (BMEP 0.48–0.36–0.24–0.12 MPa) and 2200 rpm engine speed. Despite of the earlier start of injection, the detailed combustion and engine performance results showed that the ignition delay with the biodiesel addition was decreased for the all engine loads with the earlier combustion timings due to higher cetane number of biodiesel fuel. Meanwhile the maximum heat release rate and the in-cylinder pressure rise rate were slightly decreased and the combustion duration was generally increased with the biodiesel addition. However, significant changings were not observed on the maximum in-cylinder pressures. In addition, it was observed that the indicated mean effective pressure values were slightly varied depending on the start of combustion timing and the center of heat release location. It was found that 5% and 10% biodiesel fuel addition resulted in slightly increment on break specific fuel consumption (up to 4%) and reduction on break thermal efficiency (up to 2.8%). The biodiesel additions also increased NO x emissions up to 8.7% and decreased smoke and total hydrocarbon emissions for the all engine loads. Although there were no significant changes on CO emissions at the low and medium engine loads, some reductions were observed at the full engine load. Also, CO 2 emissions were slightly increased for the all engine loads

Combustion Performance and Exhaust Emission of DI Diesel Engine Using Various Sources of Waste Cooking Oil

Science.gov (United States)

Afiq, Mohd; Azuhairi, Mohd; Jazair, Wira

2010-06-01

In Malaysia, more than 200-tone of cooking oil are used by domestic users everyday. After frying process, about a quarter of these cooking oil was remained and drained into sewage system. This will pollutes waterways and affects the ecosystem. The use of waste cooking oil (WCO) for producing bio-diesel was considered in economical factor which current production cost of bio-diesel production is higher in Malaysia due to higher price of palm oil. Thus, the aim of this study is to investigate the most suitable source of WCO to become a main source of bio-diesel for bio-diesel production in this country. To perform this research, three type of WCO were obtained from house's kitchen, cafeteria and mamak's restaurant. In this study, prospect of these bio-diesel source was evaluated based on its combustion performance and exhaust emissions operated in diesel engine in the form of waste cooking oil methyl ester (WCOME) and have been compared with pure diesel fuel. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads and constant engine speed. As the result, among three stated WCOMEs, the one collected from house's kitchen gives the best performance in term of brake specific fuel consumption (bsfc) and brake power (BP) with lowest soot emission.

Assessing the performance of reinforced concrete structures under impact loads

International Nuclear Information System (INIS)

Sharma, Akanshu; Reddy, G.R.; Vaze, K.K.; Ozbolt, Josko; Hofmann, J.

2011-01-01

Reinforced concrete (RC) structures housing nuclear facilities must qualify against much stringent requirements of operating and accidental loads than conventional structures. One such accidental load that must be considered while assessing the performance of safety related RC structures is impact load. It is known that the behavior of concrete/reinforced concrete structures is strongly influenced by the loading rate. The RC structural members subjected to impact loads behave quite differently as compared to the same subjected to quasi-static loading due to the strain-rate influence on strength, stiffness, and ductility as well as to the activation of inertia forces. Moreover, for concrete structures, which exhibit damage and fracture phenomena, the failure mode and cracking pattern depend significantly on loading rate. In general, there is a tendency that with the increase of loading rate the failure mode changes from mode-I to mixed mode. In order to assess the performance of existing structures against impact loads that may be generated mainly due to man-made accidental conditions, it is important to have models that can realistically predict the impact behavior of concrete structures. The present paper focuses on a relatively new approach for 3D finite element analysis of RC structures under impact loads. The approach uses rate sensitive micro-plane model as constitutive law for concrete, while the strain-rate influence is captured by the activation energy. Inertia forces are implicitly accounted for through dynamic finite element analysis. It is shown with the help of different examples that the approach can very well simulate the behavior of RC structural elements under high rate loading. (author)

Impacts of cathodic protection on waste package performance

International Nuclear Information System (INIS)

Atkins, J.E.; Lee, J.H.; Andrews, R.W.

1996-01-01

The current design concept for a multi-barrier waste container for the potential repository at Yucca Mountain, Nevada, calls for an outer barrier of 100 mm thick corrosion-allowance material (CAM) (carbon steel) and an inner barrier of 20 mm thick corrosion-resistant material (CRM) (Alloy 825). Fulfillment of the NRC subsystem requirements (10 CFR 60.113) of substantially complete containment and controlled release of radionuclides from the engineered barrier system (EBS) will rely mostly upon the robust waste container design, among other EBS components. In the current waste container design, some degree of cathodic protection of CRM will be provided by CAM. This paper discusses a sensitivity case study for the impacts of cathodic protection of the inner barrier by the outer barrier on the performance of waste package

Performance objectives of the tank waste remediation system low-level waste disposal program

International Nuclear Information System (INIS)

1994-01-01

Before low-level waste may be disposed of, a performance assessment must be written and then approved by the U.S. Department of Energy. The performance assessment is to determine whether open-quotes reasonable assuranceclose quotes exists that the performance objectives of the disposal facility will be met. The DOE requirements for waste disposal require: the protection of public health and safety; and the protection of the environment. Although quantitative limits are sometimes stated (for example, the all exposure pathways exposure limit is 25 mrem/year), usually the requirements are stated in a general nature. Quantitative limits were established by: investigating all potentially applicable regulations as well as interpretations of the Peer Review Panel which DOE has established to review performance assessments, interacting with program management to establish their needs, and interacting with the public (i.e., the Hanford Advisory Board members; as well as affected Indian tribes) to understand the values of residents in the Pacific Northwest

Performance Demonstration Program Plan for RCRA Constituent Analysis of Solidified Wastes

International Nuclear Information System (INIS)

2006-01-01

The Performance Demonstration Program (PDP) for Resource Conservation and Recovery Act (RCRA) constituents distributes test samples for analysis of volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), and metals in solid matrices. Each distribution of test samples is termed a PDP cycle. These evaluation cycles provide an objective measure of the reliability of measurements performed for transuranic (TRU) waste characterization. The primary documents governing the conduct of the PDP are the Quality Assurance Program Document (QAPD; DOE/CBFO-94-1012) and the Waste Isolation Pilot Plant (WIPP) Waste Analysis Plan (WAP) contained in the Hazardous Waste Facility Permit (NM4890139088-TSDF) issued by the New Mexico Environment Department. The WAP requires participation in the PDP; the PDP must comply with the QAPD and the WAP. This plan implements the general requirements of the QAPD and the applicable requirements of the WAP for the RCRA PDP. Participating laboratories demonstrate acceptable performance by successfully analyzing single-blind performance evaluation samples (subsequently referred to as PDP samples) according to the criteria established in this plan. PDP samples are used as an independent means to assess laboratory performance regarding compliance with the WAP quality assurance objectives (QAOs). The concentrations of analytes in the PDP samples address levels of regulatory concern and encompass the range of concentrations anticipated in waste characterization samples. The WIPP requires analyses of homogeneous solid wastes to demonstrate compliance with regulatory requirements. These analyses must be performed by laboratories that demonstrate acceptable performance in this PDP. These analyses are referred to as WIPP analyses, and the samples on which they are performed are referred to as WIPP samples. Participating laboratories must analyze PDP samples using the same procedures used for WIPP samples.

Challenges when performing economic optimization of waste treatment: A review

International Nuclear Information System (INIS)

Juul, N.; Münster, M.; Ravn, H.; Söderman, M. Ljunggren

2013-01-01

Highlights: • Review of main optimization tools in the field of waste management. • Different optimization methods are applied. • Different fractions are analyzed. • There is focus on different parameters in different geographical regions. • More research is needed which encompasses both recycling and energy solutions. - Abstract: Strategic and operational decisions in waste management, in particular with respect to investments in new treatment facilities, are needed due to a number of factors, including continuously increasing amounts of waste, political demands for efficient utilization of waste resources, and the decommissioning of existing waste treatment facilities. Optimization models can assist in ensuring that these investment strategies are economically feasible. Various economic optimization models for waste treatment have been developed which focus on different parameters. Models focusing on transport are one example, but models focusing on energy production have also been developed, as well as models which take into account a plant’s economies of scale, environmental impact, material recovery and social costs. Finally, models combining different criteria for the selection of waste treatment methods in multi-criteria analysis have been developed. A thorough updated review of the existing models is presented, and the main challenges and crucial parameters that need to be taken into account when assessing the economic performance of waste treatment alternatives are identified. The review article will assist both policy-makers and model-developers involved in assessing the economic performance of waste treatment alternatives

Challenges when performing economic optimization of waste treatment: A review

Energy Technology Data Exchange (ETDEWEB)

Juul, N., E-mail: njua@dtu.dk [DTU Management, Risø Campus, Technical University of Denmark (Denmark); Münster, M., E-mail: maem@dtu.dk [DTU Management, Risø Campus, Technical University of Denmark (Denmark); Ravn, H., E-mail: hans.ravn@aeblevangen.dk [RAM-løse edb, Æblevangen 55, 2765 Smørum (Denmark); Söderman, M. Ljunggren, E-mail: maria.ljunggren@chalmers.se [Energy and Environment, Chalmers University of Technology, Gothenburg (Sweden); IVL Swedish Environmental Research Institute, Gothenburg (Sweden)

2013-09-15

Highlights: • Review of main optimization tools in the field of waste management. • Different optimization methods are applied. • Different fractions are analyzed. • There is focus on different parameters in different geographical regions. • More research is needed which encompasses both recycling and energy solutions. - Abstract: Strategic and operational decisions in waste management, in particular with respect to investments in new treatment facilities, are needed due to a number of factors, including continuously increasing amounts of waste, political demands for efficient utilization of waste resources, and the decommissioning of existing waste treatment facilities. Optimization models can assist in ensuring that these investment strategies are economically feasible. Various economic optimization models for waste treatment have been developed which focus on different parameters. Models focusing on transport are one example, but models focusing on energy production have also been developed, as well as models which take into account a plant’s economies of scale, environmental impact, material recovery and social costs. Finally, models combining different criteria for the selection of waste treatment methods in multi-criteria analysis have been developed. A thorough updated review of the existing models is presented, and the main challenges and crucial parameters that need to be taken into account when assessing the economic performance of waste treatment alternatives are identified. The review article will assist both policy-makers and model-developers involved in assessing the economic performance of waste treatment alternatives.

Methodologies for assessing long-term performance of high-level radioactive waste packages

International Nuclear Information System (INIS)

Stephens, K.; Boesch, L.; Crane, B.; Johnson, R.; Moler, R.; Smith, S.; Zaremba, L.

1986-01-01

Several methods the Nuclear Regulatory Commission (NRC) can use to independently assess Department of Energy (DOE) waste package performance were identified by The Aerospace Corporation. The report includes an overview of the necessary attributes of performance assessment, followed by discussions of DOE methods, probabilistic methods capable of predicting waste package lifetime and radionuclide releases, process modeling of waste package barriers, sufficiency of the necessary input data, and the applicability of probability density functions. It is recommended that the initial NRC performance assessment (for the basalt conceptual waste package design) should apply modular simulation, using available process models and data, to demonstrate this assessment method

Loaded Gelled Bipropellants for Optimized Performance, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The focus of this program is the development and validation of formulations, and development methodologies, for optimizing high-performance particulate-loaded...

Study of organic waste for production of hydrogen in reactor

International Nuclear Information System (INIS)

Guzmán Chinea, Jesús Manuel; Guzmán Marrero, Elizabeth; Pérez Ponce, Alejandro

2015-01-01

Biological processes have long been used for the treatment of organic waste makes, especially our study is based on the anaerobic process in reactors, using residual organic industry. Without excluding other non-industrial we have studied. Fundamental objectives treating organic waste is to reduce the pollutant load to the environment, another aim is to recover the waste recovering the energy contained in it. In this context, the biological hydrogen production from organic waste is an interesting alternative because it has low operating costs and raw material is being used as a residue in any way should be treated before final disposal. Hydrogen can be produced sustainable by anaerobic bacteria that grow in the dark with rich carbohydrate substrates giving as final products H 2 , CO 2 and volatile fatty acids. The whey byproduct from cheese production, has great potential to be used for the generation of hydrogen as it has a high carbohydrate content and a high organic load. The main advantages of using anaerobic processes in biological treatment of organic waste, are the low operating costs, low power consumption, the ability to degrade high organic loads, resistance biomass to stay long in the absence of substrate, without lose their metabolic activity, and low nutritional requirements and increase the performance of 0.9 mol H2 / mol lactose. (full text)Biological processes have long been used for the treatment of organic waste makes, especially our study is based on the anaerobic process in reactors, using residual organic industry. Without excluding other non-industrial we have studied. Fundamental objectives treating organic waste is to reduce the pollutant load to the environment, another aim is to recover the waste recovering the energy contained in it. In this context, the biological hydrogen production from organic waste is an interesting alternative because it has low operating costs and raw material is being used as a residue in any way should be treated

Admissible thermal loading in geological formations. Consequences on radioactive waste disposal methods

International Nuclear Information System (INIS)

1982-01-01

Every granite formation possesses, the following main characteristics: presence of fissures; physico-chemical alterability; presence of internal or peripheral heterogeneities. From samples at ambient temperature, sound granite is found to have the properties of a hard, elastic rock with a relatively low thermal conductivity. Its natural permeability is low or very low, and most of the percolating water passes through fissures affecting the rock mass. In this report are examined: effects of heat on cavity stability, mechanical interaction between conditioned wastes and the geological environment, effects on the stability of infilling materials, heat effects on the host rock and underground water, assessment of the permissible thermal load and design of the storage facility

Scenarios for the Hanford Immobilized Low-Activity Waste (ILAW) performance assessment

International Nuclear Information System (INIS)

MANN, F.M.

1999-01-01

Scenarios describing representative exposure cases associated with the disposal of low activity waste from the Hanford Waste Tanks have been defined. These scenarios are based on guidance from the Department of Energy, the U.S. Nuclear Regulatory Commission, and previous Hanford waste disposal performance assessments

Polymer-filled microcontainers for oral delivery loaded using supercritical impregnation

DEFF Research Database (Denmark)

Marizza, Paolo; Keller, Stephan Sylvest; Müllertz, Anette

2014-01-01

with a quasi-no-waste performance. Then ketoprofen is impregnated in the polymer matrix by using supercritical carbon dioxide (scCO2) as loading medium. The amount of polymer is controlled by the volume and the number of droplets of dispensed polymer and drug loading is tuned by varying the impregnation...... procedures. This work proposes an effective loading technique for a poorly soluble model drug in microcontainers, by combining inkjet printing and supercritical fluid impregnation. Well defined quantities of poly(vinyl pyrrolidone) (PVP) solutions are dispensed into microcontainers by inkjet printing...

Performance of a cognitive load inventory during simulated handoffs: Evidence for validity.

Science.gov (United States)

Young, John Q; Boscardin, Christy K; van Dijk, Savannah M; Abdullah, Ruqayyah; Irby, David M; Sewell, Justin L; Ten Cate, Olle; O'Sullivan, Patricia S

2016-01-01

Advancing patient safety during handoffs remains a public health priority. The application of cognitive load theory offers promise, but is currently limited by the inability to measure cognitive load types. To develop and collect validity evidence for a revised self-report inventory that measures cognitive load types during a handoff. Based on prior published work, input from experts in cognitive load theory and handoffs, and a think-aloud exercise with residents, a revised Cognitive Load Inventory for Handoffs was developed. The Cognitive Load Inventory for Handoffs has items for intrinsic, extraneous, and germane load. Students who were second- and sixth-year students recruited from a Dutch medical school participated in four simulated handoffs (two simple and two complex cases). At the end of each handoff, study participants completed the Cognitive Load Inventory for Handoffs, Paas' Cognitive Load Scale, and one global rating item for intrinsic load, extraneous load, and germane load, respectively. Factor and correlational analyses were performed to collect evidence for validity. Confirmatory factor analysis yielded a single factor that combined intrinsic and germane loads. The extraneous load items performed poorly and were removed from the model. The score from the combined intrinsic and germane load items associated, as predicted by cognitive load theory, with a commonly used measure of overall cognitive load (Pearson's r = 0.83, p load during handoffs may be measured via a self-report measure. Additional work is required to develop an adequate measure of extraneous load.

Loads and loads and loads: The influence of prospective load, retrospective load, and ongoing task load in prospective memory

Directory of Open Access Journals (Sweden)

Beat eMeier

2015-06-01

Full Text Available In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of prospective load on costs in the ongoing task for categorical targets (Experiment 2, but not for specific targets (Experiment 1. Retrospective load and ongoing task load both affected remembering the retrospective component of the prospective memory task. We suggest that prospective load can enhance costs in the ongoing task due to additional monitoring requirements. Retrospective load and ongoing task load seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

LWR high burn-up operation and MOX introduction. Fuel cycle performance from the viewpoint of waste management

International Nuclear Information System (INIS)

Inagaki, Yaohiro; Iwasaki, Tomohiko; Niibori, Yuichi; Sato, Seichi; Ohe, Toshiaki; Kato, Kazuyuki; Torikai, Seishi; Nagasaki, Shinya; Kitayama, Kazumi

2009-01-01

From the viewpoint of waste management, a quantitative evaluation of LWR nuclear fuel cycle system performance was carried out, considering both higher burn-up operation of UO 2 fuel coupled with the introduction of MOX fuel. A major parameter to quantify this performance is the number of high-level waste (HLW) glass units generated per GWd (gigawatt-day based on reactor thermal power generation before electrical conversion). This parameter was evaluated for each system up to a maximum burn-up of 70GWd/THM (gigawatt-day per ton of heavy metal) assuming current conventional reprocessing and vitrification conditions where the waste loading of glass is restricted by the heat generation rate, the MoO 3 content, or the noble metal content. The results showed that higher burn-up operation has no significant influence on the number of glass units generated per GWd for UO 2 fuel, though the number of glass units per THM increases linearly with burn-up and is restricted by the heat generation rate. On the other hand, the introduction of MOX fuel causes the number of glass units per GWd to double owing to the increase in the heat generation rate. An extended cooling period of the spent fuel prior to reprocessing effectively reduces the heat generation rate for UO 2 fuel, while a separation of minor actinides (Np, Am, and Cm) from the high-level waste provides additional reduction for MOX fuel. However, neither of these leads to a substantial reduction in the number of glass units, since the MoO 3 content or the noble metal content restricts the number of glass units rather than the heat generation rate. These results suggest that both the MoO 3 content and the noble metal content provide the key to reducing the amount of waste glass that is generated, leading to an overall improvement in fuel cycle system performance. (author)

DOE's performance evaluation project for mixed low-level waste disposal

International Nuclear Information System (INIS)

Waters, R.D.; Chu, M.S.Y.; Gruebel, M.M.; Lee, D.W.

1995-01-01

A performance evaluation (PE) is an analysis that estimates radionuclide concentration limits for 16 potential Department of Energy (DOE) mixed low-level waste (ULLW) disposal sites based on the analysis of two environmental exposure pathways (air and water) to an off-site individual and an inadvertent-intruder exposure pathway. Sites are analyzed for their ability to attenuate concentrations of specific radionuclides that could be released from wastes in a hypothetical ULLW disposal facility. Site-specific data and knowledge are used within a generic framework that is consistent across all sites being evaluated. After estimates of waste concentrations for the three pathways are calculated, the minimum of the waste concentration values is selected as the permissible waste concentration for each radionuclide. The PE results will be used as input to the process for DOE's ULLW disposal configuration. Preliminary comparisons of results from the PE and site-specific performance assessments indicate that the simple PE results generally agree with results of the performance assessments, even when site conditions are complex. This agreement with performance-assessment results increases confidence that similar results can be obtained at other sites that have good characterization data. In addition, the simple analyses contained in the PE illustrate a potential method to satisfy the needs of many regulators and the general public for a simple, conservative, defensible, and easily understandable analysis that provides results similar to those of more complex analyses

E AREA LOW LEVEL WASTE FACILITY DOE 435.1 PERFORMANCE ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

Wilhite, E

2008-03-31

This Performance Assessment for the Savannah River Site E-Area Low-Level Waste Facility was prepared to meet requirements of Chapter IV of the Department of Energy Order 435.1-1. The Order specifies that a Performance Assessment should provide reasonable assurance that a low-level waste disposal facility will comply with the performance objectives of the Order. The Order also requires assessments of impacts to water resources and to hypothetical inadvertent intruders for purposes of establishing limits on radionuclides that may be disposed near-surface. According to the Order, calculations of potential doses and releases from the facility should address a 1,000-year period after facility closure. The point of compliance for the performance measures relevant to the all pathways and air pathway performance objective, as well as to the impact on water resources assessment requirement, must correspond to the point of highest projected dose or concentration beyond a 100-m buffer zone surrounding the disposed waste following the assumed end of active institutional controls 100 years after facility closure. During the operational and institutional control periods, the point of compliance for the all pathways and air pathway performance measures is the SRS boundary. However, for the water resources impact assessment, the point of compliance remains the point of highest projected dose or concentration beyond a 100-m buffer zone surrounding the disposed waste during the operational and institutional control periods. For performance measures relevant to radon and inadvertent intruders, the points of compliance are the disposal facility surface for all time periods and the disposal facility after the assumed loss of active institutional controls 100 years after facility closure, respectively. The E-Area Low-Level Waste Facility is located in the central region of the SRS known as the General Separations Area. It is an elbow-shaped, cleared area, which curves to the northwest

Performance of photocatalyst based carbon nanodots from waste frying oil in water purification

International Nuclear Information System (INIS)

Aji, Mahardika Prasetya; Wiguna, Pradita Ajeng; Susanto,; Rosita, Nita; Suciningtyas, Siti Aisyah; Sulhadi

2016-01-01

Carbon Nanodots (C-Dots) from waste frying oil could be used as a photocatalyst in water purification with solar light irradiation. Performance of C-Dots as a photocatalyst was tested in the process of water purification with a given synthetic sewage methylene blue. The tested was also conducted by comparing the performance C-Dots made from frying oil, waste fryng oil as a photocatalyst and solution of methylene blue without photocatalyst C-Dots. Performance of C-Dots from waste frying oil were estimated by the results of absorbance spectrum. The results of measurement absorbance spectrum from the process of water purification with photocatalyst C-Dots showed that the highest intensity at a wavelength 664 nm of methylene blue decreased. The test results showed that the performance of photocatalyst C-Dots from waste frying oil was better in water purification. This estimated that number of particles C-dots is more in waste frying oil because have experieced repeated the heating process so that the higher particles concentration make the photocatalyst process more effective. The observation of the performance C-Dots from waste frying oil as a photocatalyst in the water purification processes become important invention for solving the problems of waste and water purification.

Performance of photocatalyst based carbon nanodots from waste frying oil in water purification

Energy Technology Data Exchange (ETDEWEB)

Aji, Mahardika Prasetya, E-mail: mahardika190@gmail.com; Wiguna, Pradita Ajeng; Susanto,; Rosita, Nita; Suciningtyas, Siti Aisyah; Sulhadi [Department of Physics, Faculty of Mathematics and Natural Science Universitas Negeri Semarang, Jalan Raya Sekaran Gunungpati 50229 Indonesia (Indonesia)

2016-04-19

Carbon Nanodots (C-Dots) from waste frying oil could be used as a photocatalyst in water purification with solar light irradiation. Performance of C-Dots as a photocatalyst was tested in the process of water purification with a given synthetic sewage methylene blue. The tested was also conducted by comparing the performance C-Dots made from frying oil, waste fryng oil as a photocatalyst and solution of methylene blue without photocatalyst C-Dots. Performance of C-Dots from waste frying oil were estimated by the results of absorbance spectrum. The results of measurement absorbance spectrum from the process of water purification with photocatalyst C-Dots showed that the highest intensity at a wavelength 664 nm of methylene blue decreased. The test results showed that the performance of photocatalyst C-Dots from waste frying oil was better in water purification. This estimated that number of particles C-dots is more in waste frying oil because have experieced repeated the heating process so that the higher particles concentration make the photocatalyst process more effective. The observation of the performance C-Dots from waste frying oil as a photocatalyst in the water purification processes become important invention for solving the problems of waste and water purification.

Biodegradation of uranium-contaminated waste oil

International Nuclear Information System (INIS)

Hary, L.F.

1983-01-01

The Portsmouth Gaseous Diffusion Plant routinely generates quantities of uranium-contaminated waste oil. The current generation rate of waste oil is approximately 2000 gallons per year. The waste is presently biodegraded by landfarming on open field soil plots. However, due to the environmental concerns associated with this treatment process, studies were conducted to determine the optimum biodegradation conditions required for the destruction of this waste. Tests using respirometric flasks were conducted to determine the biodegradation rate for various types of Portsmouth waste oil. These tests were performed at three different loading rates, and on unfertilized and fertilized soil. Additional studies were conducted to evaluate the effectiveness of open field landfarming versus treatment at a greenhouse-like enclosure for the purpose of maintaining soil temperatures above ambient conditions. The respirometric tests concluded that the optimum waste oil loading rate is 10% weight of oil-carbon/weight of soil (30,600 gallons of uranium-contaminated waste oil/acre) on soils with adjusted carbon:nitrogen and carbon:phosphorus ratios of 60:1 and 800:1, respectively. Also, calculational results indicated that greenhouse technology does not provide a significant increase in biodegradation efficiency. Based on these study results, a 6300 ft. 2 abandoned anaerobic digester sludge drying bed is being modified into a permanent waste oil biodegradation facility. The advantage of using this area is that uranium contamination will be contained by the bed's existing leachate collection system. This modified facility will be capable of handling approximately 4500 gallons of waste oil per year; accordingly current waste generation quantities will be satisfactorily treated. 15 refs., 14 figs., 4 tabs

Performance in tactical decision making on the physical load in the game.

OpenAIRE

Navara, Ondřej

2015-01-01

Title: Performance in tactical decision-making on the physical load in the game. Objectives: Determine the relationship between the physical load and tactical decision making. Methods: Watching. Results: The greater the physical load, the smaller the rightness of tactical decision-making. Keywords: Tactical decision-making, soccer, physical load.

Performance Of The Akosombo Waste Stabilization Ponds In Ghana ...

African Journals Online (AJOL)

A study was conducted to determine the treatment performance of the Akosombo waste stabilization ponds and the effect of seasonal changes on the final effluent quality. The waste water quality parameters ... Une étude était entreprise pour déterminer le résultat de traitement de bassins de stabilisation du déchet d' ...

Impact of advanced fuel cycle options on waste management policies

International Nuclear Information System (INIS)

Gordelier, Stan; Cavedon, Jean-Marc

2006-01-01

OECD/NEA has performed a study on the impact of advanced fuel cycle options on waste management policies with 33 experts from 12 member countries, 1 non-member country and 2 international organizations. The study extends a series of previous ones on partitioning and transmutation (P and T) issues, focusing on the performance assessments for repositories of high-level waste (HLW) arising from advanced fuel cycles. This study covers a broader spectrum than previous studies, from present industrial practice to fully closed cycles via partially closed cycles (in terms of transuranic elements); 9 fuel cycle schemes and 4 variants. Elements of fuel cycles are considered primarily as sources of waste, the internal mass flows of each scheme being kept for the sake of mass conservation. The compositions, activities and heat loads of all waste flows are also tracked. Their impact is finally assessed on the waste repository concepts. The study result confirms the findings from the previous NEA studies on P and T on maximal reduction of the waste source term and maximal use of uranium resources. In advanced fuel cycle schemes the activity of the waste is reduced by burning first plutonium and then minor actinides and also the uranium consumption is reduced, as the fraction of fast reactors in the park is increased to 100%. The result of the repository performance assessments, analysing the effect of different HLW isotopic composition on repository performance and on repository capacity, shows that the maximum dose released to biosphere at any time in normal conditions remains, for all schemes and for all the repository concepts examined, well below accepted radiation protection thresholds. The major impact is on the detailed concept of the repositories, through heat load and waste volume. Advanced fuel cycles could allow a repository to cover waste produced from 5 to 20 times more electricity generation than PWR once-through cycle. Given the flexibility of the advanced fuel

Scientific basis for long-term prediction of waste-form performance under repository conditions

International Nuclear Information System (INIS)

Mendel, J.E.

1982-10-01

This paper presents an overview of the fundamental principles involved in predicting long-term performance of waste forms by the as-low-as-reasonably-achievable approach. Repository conditions which make up the waste-form environment, the aging of the waste form, the important radionuclides in the waste form, the chemistry of repository fluids, and multicomponent interactions testing were considered in order to describe these principles. The need for confidence limits on the prediction of waste-form performance and ways of achieving a definition of the confidence limits are discussed

Effect of loading rate on creep of phosphorous doped copper

Energy Technology Data Exchange (ETDEWEB)

Andersson-Oestling, Henrik C.M.; Sandstroem, Rolf (Swerea KIMAB (Sweden))

2011-12-15

Creep testing of copper intended for nuclear waste disposal has been performed on continuous creep tests machines at a temperature of 75 deg C. The loading time has been varied from 1 hour to 6 months. The rupture strain including both loading and creep strains does not differ from traditional dead weight lever creep test rigs. The loading strain increases with increasing loading time, at the expense of the creep strain. The time dependence of the creep strain has been modelled taking athermal plastic deformation and creep into account. During loading the contribution to the strain from the athermal plastic deformation dominates until the stress is close to the constant load level. When the constant load has been reached there is no more athermal strain and all of the strain comes from creep

Performance assessment handbook for low-level radioactive waste disposal facilities

International Nuclear Information System (INIS)

Seitz, R.R.; Garcia, R.S.; Kostelnik, K.M.; Starmer, R.J.

1992-02-01

Performance assessments of proposed low-level radioactive waste disposal facilities must be conducted to support licensing. This handbook provides a reference document that can be used as a resource by management and staff responsible for performance assessments. Brief discussions describe the performance assessment process and emphasize selected critical aspects of the process. References are also provided for additional information on many aspects of the performance assessment process. The user's manual for the National Low-Level Waste Management Program's Performance Assessment Center (PAC) on the Idaho National Engineering Laboratory Cray computer is included as Appendix A. The PAC provides users an opportunity to experiment with a number of performance assessment computer codes on a Cray computer. Appendix B describes input data required for 22 performance assessment codes

Property of filler-loaded magnetic ferrite from plastic waste bottle used to treat municipal domestic sewage.

Science.gov (United States)

Zhao, Ru-Jin; Gong, Li-Ying; Zhu, Hai-Dong; Liu, Qiao; Xu, Li-Xia; Lu, Lu; Yang, Qi-Zhi

2018-06-01

The present work investigates the properties of self-made magnetic filler from plastic waste bottle and explores a new technology approach of waste plastic resource utilization. The magnetic filler was prepared by air plasma modification and loading magnetic ferrite on the plastic strip from waste plastic bottle. The surface properties of magnetic filler were characterized by Atomic Force Microscope (AFM), contact angle system and Fourier Transform Infrared (FTIR). AFM images of original and modified plastic strip showed that low-temperature plasma treatment markedly increased the surface roughness of plastic strip. The mean roughness (Ra) of plastic strip rose from 1.116 to 5.024 nm. FTIR spectra indicated that a lot of polar oxygenic groups were introduced onto the surface of plastic by plasma modification. Modification by low-temperature plasma increased the hydrophilicity of plastic strip surface. When treatment time is 40 s, water contact angle of plastic strip surface reduced from 78.2° of original plastic strip to 25.3°. When used in bioreactor, magnetic filler had very favorable microenvironment for microorganism growth. Magnetic filler was more efficient for removing chemical oxygen demand (COD) and [Formula: see text] in sewage than nonmagnetic filler. The resource utilization of plastic wastes will become reality if the magnetic filler is applied widely.

A proposal to improve e-waste collection efficiency in urban mining: Container loading and vehicle routing problems - A case study of Poland.

Science.gov (United States)

Nowakowski, Piotr

2017-02-01

Waste electrical and electronic equipment (WEEE), also known as e-waste, is one of the most important waste streams with high recycling potential. Materials used in these products are valuable, but some of them are hazardous. The urban mining approach attempts to recycle as many materials as possible, so efficiency in collection is vital. There are two main methods used to collect WEEE: stationary and mobile, each with different variants. The responsibility of WEEE organizations and waste collection companies is to assure all resources required for these activities - bins, containers, collection vehicles and staff - are available, taking into account cost minimization. Therefore, it is necessary to correctly determine the capacity of containers and number of collection vehicles for an area where WEEE need to be collected. There are two main problems encountered in collection, storage and transportation of WEEE: container loading problems and vehicle routing problems. In this study, an adaptation of these two models for packing and collecting WEEE is proposed, along with a practical implementation plan designed to be useful for collection companies' guidelines for container loading and route optimization. The solutions are presented in the case studies of real-world conditions for WEEE collection companies in Poland. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimal Control Allocation with Load Sensor Feedback for Active Load Suppression, Flight-Test Performance

Science.gov (United States)

Miller, Christopher J.; Goodrick, Dan

2017-01-01

The problem of control command and maneuver induced structural loads is an important aspect of any control system design. The aircraft structure and the control architecture must be designed to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to utilize high structural margins, restrict control surface commands to a limited set of analyzed combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage. An optimal control technique has been explored and shown to achieve desirable vehicle control performance while limiting sensed structural loads to specified values. This technique has been implemented and flown on the National Aeronautics and Space Administration Full-scale Advanced Systems Testbed aircraft. The flight tests illustrate that the approach achieves the desired performance and show promising potential benefits. The flights also uncovered some important issues that will need to be addressed for production application.

Testing waste forms containing high radionuclide loadings

International Nuclear Information System (INIS)

McConnell, J.W. Jr.; Neilson, R.M. Jr.; Rogers, R.D.

1986-01-01

The Low-Level Waste Data Base Development - EPICOR-II Resin/Liner Investigation Program of the US Nuclear Regulatory Commission (NRC) is obtaining information on radioactive waste during NRC-prescribed tests and in a disposal environment. This paper describes the resin solidification task of that program, including the present status and results to date

Evaluation of performance loss of paraffin oil loaded filtering facepieces.

Science.gov (United States)

Tombolini, Francesca; Listrani, Stefano; Campopiano, Antonella; Plebani, Carmela

2016-01-01

Penetration measurements through commercially available filtering facepieces were performed with monodisperse DEHS aerosols ranging from 0.03 μm to 0.40 μm (either singly charged or neutralized), before and after 500 mg of paraffin oil loading. The distinct behavior of Coulomb and polarization capture efficiency is studied: as in the case of non loading also in the case of loading 500 mg of paraffin oil, the electrostatic capture mechanisms are mainly due to the Coulomb contribution up to aerosol particle diameter of about 0.10 μm, just when the polarization contribution becomes substantial. Both Coulomb and polarization capture mechanisms are influenced by the presence of 500 mg of paraffin oil, resulting less effective than the oil unloaded case of about 12% and 11%, respectively. By the occupational hygiene point of view, there is a degradation in the filter performance due to oil loading that the user does not realize because there is no remarkable variation in the breathing resistance.

Testing and Performance Validation of a Shielded Waste Segregation and Clearance Monitor Designed for the Measurement of Low Level Waste-13043

International Nuclear Information System (INIS)

Mason, John A.; Burke, Kevin J.; Towner, Antony C.N.; Beaven, Graham; Spence, Robert

2013-01-01

This paper describes the development, testing and validation of a shielded waste segregation and clearance monitor designed for the measurement of low-density low-level waste (LLW). The monitor is made of a measurement chamber surrounded by detectors and a shielded outer frame. The shielded chamber consists of a steel frame, which contains typically 1.5 inches (3.81 cm) of lead and 0.5 inches (1.27 cm) of steel shielding. Inside the shielding are plastic scintillator panels, which serve as gross gamma ray detectors. The detector panels, with embedded photomultipliers, completely surround the internal measurement chamber on all 6 sides. Care has been taken to distribute the plastic scintillator detectors in order to optimise both the efficiency for gamma ray detection and at the same time achieve a volumetric sensitivity, which is as uniform as possible. A common high voltage power supply provides the bias voltage for each of the six photomultipliers. The voltage signals arising from the detectors and photomultipliers are amplified by six sensitive amplifiers. Each amplifier incorporates a single channel analyser with both upper and lower thresholds and the digitised counts from each detector are recorded on six scalars. Operation of the device is by means of a microprocessor from which the scalars are controlled. An internal load cell linked to the microprocessor determines the weight of the waste object, and this information is used to calculate the specific activity of the waste. The monitor makes background measurements when the shielded door is closed and a sample, usually a bag of low-density waste, is not present in the measurement chamber. Measurements of the minimum detectable activity (MDA) of an earlier large volume prototype instrument are reported as part of the development of the Waste Segregation and Clearance Monitor (WSCM) described in the paper. For the optimised WSCM a detection efficiency of greater than 32% was measured using a small Cs-137

Structural testing of salt loaded HEPA filters for WIPP

International Nuclear Information System (INIS)

Smith, P.R.; Leslie, I.H.; Hensel, E.C.; Shultheis, T.M.; Walls, J.R.

1993-01-01

The ventilation studies of the Waste Isolation Pilot Plant described in this paper were performed by personnel from New Mexico State Univ. in collaboration with Sandia National Laboratories, Los Alamos National Laboratory and Westinghouse Corporation. High efficiency particulate air filters (0.61m by 0.61m by 0.3m) of the type in use at the Waste Isolation Pilot Plant were loaded with salt aerosol provided from that site. The structural strength of salt-loaded, high-efficiency filters was investigated at two humidity levels, high (75%RH) and low (13-14% RH), by subjecting the filters to pressure transients of the types expected from tornadoes. Filters loaded under the high humidity condition proved to have a greater structural strength than did the filters loaded under the low humidity conditions, when both types were subjected to tornado-like pressure pulses. This unexpected results was apparently due to the crystallization of salt upon the wire face guard of the HEPA filter loaded under the high humidity condition which kept salt from penetrating the filter medium while still providing a substantial pressure drop at the standard flow rate. Results are also presented for HEPA filters pre-conditioned at 100% RH before structural testing and for HEPA filters in series with pre-filters

Performance of Reinforced Concrete Beam with Differently Positioned Replacement Zones of Block Infill under Low Impact Loads

Directory of Open Access Journals (Sweden)

Mokhatar Shahrul Niza

2017-01-01

Full Text Available This paper reveals a study performed on reinforced concrete with artificial aggregate concrete block infill composite beams to innovate a lightweight reinforced concrete utilizing polyethylene (PE waste materials, such as waste plastic bags. Six beam specimens of normal reinforced concrete (NRC and different block infill replacement zone positions RCAI (RZ1 beams containing 100% MAPEA with 50, 95, and 1,000 mm width, height, and length, respectively, were provided for the block infill, whereas RCAI (RZ2 with different block infill positions containing a 100% MAPEA with 50, 115, and 1000 mm width, height, and length were provided and tested under low impact load. The steel impactor with blunt nose dropped at 0.6 m height which equivalent to 3.5 m/s. The behaviors of the beams were studied relative to the impact force-time and displacement-time histories, the flexural/ bending cracks, and the impact failure. Results show that the overall failure modes of all the beam specimens were successfully recorded. In addition, the residual displacements of the RZ2 was almost same than those of the RZ1 and the significantly lower than those of the NRC. In the reinforced concrete beams, less stressed concrete near the neutral axis can be replaced by certain light weight material like waste plastic bags as modified artificial polyethylene aggregates to serve as an artificial aggregate.

Effect of load carriage and natural terrain conditions on cognitive performance in desert environments.

Science.gov (United States)

Bhattacharyya, Debojyoti; Pal, Madhusudan; Chatterjee, Tirthankar; Majumdar, Dhurjati

2017-10-01

Correct decision making is a critical component of cognitive performance of a soldier, which may be influenced by the load carriage and terrain conditions during their deployment in desert environment. The present study was aimed to investigate the effects of loads and terrain conditions on the cognitive performance in a group of twelve healthy heat acclimatized infantry soldiers under natural desert environment. The soldiers participated in a 10min walking trial during carrying no load and also carrying 10.7, 21.4 and 30kg at two terrain conditions viz., sandy and hard. We studied attention, memory and executive function, which are having immense functional importance in military operations. Standardized cognitive test battery was applied to the participants after carrying each magnitude of load at each terrain. Baseline cognitive performance was recorded on a separate day and was compared with the performances recorded after the load carriage trials. An attempt was made to reveal the relationship between physiological workload (relative workload) and cognitive performance at the point of completion of load carriage trials. Load, terrains and load×terrain interaction did not produce any significant effect (p>0.05) on the cognitive performance. Attention and relative workload were found significantly correlated at hard terrain under no load, 21.4kg and 30kg. Significant correlation was found between executive function and relative workload at hard terrain under no load. Carrying upto 30kg load for 10min at 3.5-4kmph walking speed resulted in improvement in attention at sandy terrain, decrement in memory at both sandy and hard terrains and improvement in executive function at sandy terrain. Copyright © 2017 Elsevier Inc. All rights reserved.

Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Combined cycle performance

DEFF Research Database (Denmark)

Haglind, Fredrik

2011-01-01

The part-load performance of combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry gas turbines on the part-load efficiency for combined...... cycles used for ship propulsion. Moreover, the paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis of various components within combined cycle power plants. Two different gas turbine configurations are studied, a two-shaft aero......-derivative configuration and a single-shaft industrial configuration. The results suggest that by the use of variable geometry gas turbines, the combined cycle part-load performance can be improved. In order to minimise the voyage fuel consumption, a combined cycle featuring two-shaft gas turbines with VAN control...

Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Gas turbine performance

DEFF Research Database (Denmark)

Haglind, Fredrik

2010-01-01

The part-load performance of gas and steam turbine combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry on the gas turbine part...... of various components within gas turbines. Two different gas turbine configurations are studied, a two-shaft aero-derivative configuration and a single-shaft industrial configuration. When both gas turbine configurations are running in part-load using fuel flow control, the results indicate better part......-load performance for the two-shaft gas turbine. Reducing the load this way is accompanied by a much larger decrease in exhaust gas temperature for the single-shaft gas turbine than for the two-shaft configuration. As used here, the results suggest that variable geometry generally deteriorates the gas turbine part...

Performance of borosilicate glass, Synroc and spent fuel as nuclear waste forms

International Nuclear Information System (INIS)

Lutze, W.; Grambow, B.; Ewing, R.C.

1990-01-01

Presently, there are three prominent waste forms under consideration for the disposal of high-level waste: Borosilicate glass and Synroc for high-level radioactive waste from fuel reprocessing and spent fuel as the waste form for non-reprocessed fuel. Using the present experimental data base, one may compare the performance of these three waste forms under repository relevant conditions. In low water flow regimes and at temperatures less than 100 degree C, the fractional release rates of all three waste forms are low, on the order of 10-7/d or less and may decrease with time. Under these conditions the three waste forms behave similarly. At elevated temperatures or in high flow regimes, the durability of borosilicate glass will be much less than that of Synroc, and thus, for certain disposal schemes (e.g., deep burial) Synroc is preferable. All predictions of the long-term behavior are based on the extrapolation of short term experimental data, we point out that appropriate and useful natural analogues are available for each of these waste forms and should be used in the performance assessment of each waste form's long-term behavior. 14 refs

Evaluation the anaerobic digestion performance of solid residual kitchen waste by NaHCO3 buffering

International Nuclear Information System (INIS)

Gao, Shumei; Huang, Yue; Yang, Lili; Wang, Hao; Zhao, Mingxing; Xu, Zhiyang; Huang, Zhenxing; Ruan, Wenquan

2015-01-01

Highlights: • The maximum methane production of SRKW was 479 mL/gTS added . • Anaerobic digestion capacity increased by 33.3% through NaHCO 3 buffering. • Protease activity was mainly affected by high organic load. - Abstract: Anaerobic digestion has been considered as a promising energy-producing process for kitchen waste treatment. In this paper, the anaerobic digestion (AD) performances of solid residual kitchen waste (SRKW) with or without NaHCO 3 buffering were investigated. The results indicated that the methane production reached the maximum of 479 mL/gTS added at the inoculum to substrate ratio (ISR, based on VS) of 1:1.4 without buffering, accompanied by VS removal rate of 78.91%. Moreover, the anaerobic digestion capacity increased by 33.3% through NaHCO 3 buffering, and the methane yield at ISR 1:2.8 was improved by 48.5% with NaHCO 3 addition. However, the methanogenesis with or without NaHCO 3 buffer was suppressed at ISR 1:3.5, indicated from the lowest methane yield of 55.50 mL/gTS added and high volatile fatty acids concentration of more than 14,000 mg/L. Furthermore, proteins in SRKW were not degraded completely at excessive organic loading, since the concentrations of ammonia nitrogen in ISR 1:3.5 groups with (2738 mg/L) and without NaHCO 3 buffering (2654 mg/L) were lower than the theoretical value of 3500 mg/L and the protease activities in ISR 1:3.5 groups were also inhibited

Performance of fuzzy approach in Malaysia short-term electricity load forecasting

Science.gov (United States)

Mansor, Rosnalini; Zulkifli, Malina; Yusof, Muhammad Mat; Ismail, Mohd Isfahani; Ismail, Suzilah; Yin, Yip Chee

2014-12-01

Many activities such as economic, education and manafucturing would paralyse with limited supply of electricity but surplus contribute to high operating cost. Therefore electricity load forecasting is important in order to avoid shortage or excess. Previous finding showed festive celebration has effect on short-term electricity load forecasting. Being a multi culture country Malaysia has many major festive celebrations such as Eidul Fitri, Chinese New Year and Deepavali but they are moving holidays due to non-fixed dates on the Gregorian calendar. This study emphasis on the performance of fuzzy approach in forecasting electricity load when considering the presence of moving holidays. Autoregressive Distributed Lag model was estimated using simulated data by including model simplification concept (manual or automatic), day types (weekdays or weekend), public holidays and lags of electricity load. The result indicated that day types, public holidays and several lags of electricity load were significant in the model. Overall, model simplification improves fuzzy performance due to less variables and rules.

HOLD MODE BASED DYNAMIC PRIORITY LOAD ADAPTIVE INTERPICONET SCHEDULING FOR BLUETOOTH SCATTERNETS

Directory of Open Access Journals (Sweden)

G.S. Mahalakshmi

2011-09-01

Full Text Available Scheduling in piconets has emerged as a challenging research area. Interpiconet scheduling focuses on when a bridge is switched among various piconets and how a bridge node communicates with the masters in different piconets. This paper proposes an interpiconet scheduling algorithm named, hold mode based dynamic traffic priority load adaptive scheduling. The bridges are adaptively switched between the piconets according to various traffic loads. The main goal is to maximize the utilization of the bridge by reducing the bridge switch wastes, utilize intelligent decision making algorithm, resolve conflict between the masters, and allow negotiation for bridge utilization in HDPLIS using bridge failure-bridge repair procedure . The Hold mode - dynamic traffic - priority based - load adaptive scheduling reduces the number of bridge switch wastes and hence increases the efficiency of the bridge which results in increased performance of the system.

Waste package performance assessment for the Yucca Mountain project

International Nuclear Information System (INIS)

O'Connell, W.J.; Lappa, D.A.; Thatcher, R.M.

1989-01-01

The authors completed a first cycle of model development from a specification to a computer program, PANDORA-1, for long-term performance assessment of waste packages. The model for one waste package at a time incorporates processes specific to the unsaturated environment at the proposed Yucca Mountain, NV, site. PANDORA-1 models the most likely processes and several modes of waste alteration and release. The development identified information needs for future models; many processes, local details, and combinations will have to be examined. Integration of ensemble performance and quantification of uncertainties are modeling steps at higher aggregation. Methodologies for these steps include sampling, which is well studied; we have focused on several open questions. The authors can now calculate the amount of variance reduction available from Latin hypercube sampling; it is a limited reduction. A new method, uncertainty analysis test-bed program compares the new with old sampling methods

Remediation of Hanford tank waste using magnetic separation

International Nuclear Information System (INIS)

Worl, L.A.; Avens, L.R.; de Aguero, K.J.; Coyne Prenger, F.; Stewart, W.F.; Hill, D.D.

1992-01-01

Large volumes of high-level radioactive waste are stored at the Department of Energy's Hanford site. Magnetic separation, a physical separation, process, can be used to segregate actinides and certain fission products from the waste. High gradient magnetic separation (HGMS) tests have been performed successfully using a simulated, nonradioactive underground storage tank (UST) waste. Variations in HGMS test parameters included separator matrix material, magnetic field strength, slurry surfactant, and slurry solids loading. Cerium was added to the simulated tank waste to act as a uranium surrogate. Results show that over 77% of the uranium surrogate can be captured and concentrated from the original bulk with a simple procedure. The results of these tests and the feasibility of magnetic separation for pretreatment of UST waste are discussed

Waste Treatment Plant LAW Evaporation: Antifoam Performance

International Nuclear Information System (INIS)

BAICH, MARKA

2004-01-01

This report describes the work performed to determine the performance and fate of several commercial antifoams during evaporation of various simulants of Envelope A, B, and C mixed with simulated River Protection Project Waste Treatment Plant (RPP-WTP) recycle streams. Chemical and radiation stability of selected antifoams was also investigated.Contributors to this effort include: Illinois Institute of Technology (IIT), DOW Corning Analytical, and Savannah River Technology Center (SRTC)

Simulating tokamak PFC performance using simultaneous dual beam particle loading with pulsed heat loading

Science.gov (United States)

Sinclair, Gregory; Gonderman, Sean; Tripathi, Jitendra; Ray, Tyler; Hassanein, Ahmed

2017-10-01

The performance of plasma facing components (PFCs) in a fusion device are expected to change due to high flux particle loading during operation. Tungsten (W) is a promising PFC candidate material, due to its high melting point, high thermal conductivity, and low tritium retention. However, ion irradiation of D and He have each shown to diminish the thermal strength of W. This work investigates the synergistic effect between ion species, using dual beam irradiation, on the thermal response of W during ELM-like pulsed heat loading. Experiments studied three different loading conditions: laser, laser + He+, and laser + He+ + D+. 100 eV He+ and D+ exposures used a flux of 3.0-3.5 x 1020 m-2 s-1. ELM-like loading was applied using a pulsed Nd:YAG laser at an energy density of 0.38-1.51 MJ m-2 (3600 1 ms pulses at 1 Hz). SEM imaging revealed that laser + He+ loading at 0.76 MJ m-2 caused surface melting, inhibiting fuzz formation. Increasing the laser fluence decreased grain size and increased surface pore density. Thermally-enhanced migration of trapped gases appear to reflect resultant molten morphology. This work was supported by the National Science Foundation PIRE project.

Performance analysis of waste heat recovery with a dual loop organic Rankine cycle (ORC) system for diesel engine under various operating conditions

International Nuclear Information System (INIS)

Yang, Fubin; Dong, Xiaorui; Zhang, Hongguang; Wang, Zhen; Yang, Kai; Zhang, Jian; Wang, Enhua; Liu, Hao; Zhao, Guangyao

2014-01-01

Highlights: • Dual loop ORC system is designed to recover waste heat from a diesel engine. • R245fa is used as working fluid for the dual loop ORC system. • Waste heat characteristic under engine various operating conditions is analyzed. • Performance of the combined system under various operating conditions is studied. • The waste heat from coolant and intake air has considerable potential for recovery. - Abstract: To take full advantage of the waste heat from a diesel engine, a set of dual loop organic Rankine cycle (ORC) system is designed to recover exhaust energy, waste heat from the coolant system, and released heat from turbocharged air in the intercooler of a six-cylinder diesel engine. The dual loop ORC system consists of a high temperature loop ORC system and a low temperature loop ORC system. R245fa is selected as the working fluid for both loops. Through the engine test, based on the first and second laws of thermodynamics, the performance of the dual loop ORC system for waste heat recovery is discussed based on the analysis of its waste heat characteristics under engine various operating conditions. Subsequently, the diesel engine-dual loop ORC combined system is presented, and the effective thermal efficiency and the brake specific fuel consumption (BSFC) are chosen to evaluate the operating performances of the diesel engine-dual loop ORC combined system. The results show that, the maximum waste heat recovery efficiency (WHRE) of the dual loop ORC system can reach 5.4% under engine various operating conditions. At the engine rated condition, the dual loop ORC system achieves the largest net power output at 27.85 kW. Compared with the diesel engine, the thermal efficiency of the combined system can be increased by 13%. When the diesel engine is operating at the high load region, the BSFC can be reduced by a maximum 4%

Operation window and part-load performance study of a syngas fired gas turbine

International Nuclear Information System (INIS)

He, Fen; Li, Zheng; Liu, Pei; Ma, Linwei; Pistikopoulos, Efstratios N.

2012-01-01

Integrated coal gasification combined cycle (IGCC) provides a great opportunity for clean utilization of coal while maintaining the advantage of high energy efficiency brought by gas turbines. A challenging problem arising from the integration of an existing gas turbine to an IGCC system is the performance change of the gas turbine due to the shift of fuel from natural gas to synthesis gas, or syngas, mainly consisting of carbon monoxide and hydrogen. Besides the change of base-load performance, which has been extensively studied, the change of part-load performance is also of great significance for the operation of a gas turbine and an IGCC plant. In this paper, a detailed mathematical model of a syngas fired gas turbine is developed to study its part-load performance. A baseline is firstly established using the part-load performance of a natural gas fired gas turbine, then the part-load performance of the gas turbine running with different compositions of syngas is investigated and compared with the baseline. Particularly, the impacts of the variable inlet guide vane, the degree of fuel dilution, and the degree of air bleed are investigated. Results indicate that insufficient cooling of turbine blades and a reduced compressor surge margin are the major factors that constrain the part-load performance of a syngas fired gas turbine. Results also show that air bleed from the compressor can greatly improve the working condition of a syngas fired gas turbine, especially for those fired with low lower heating value syngas. The regulating strategy of a syngas fired gas turbine should also be adjusted in accordance to the changes of part-load performance, and a reduced scope of constant TAT (turbine exhaust temperature) control mode is required.

Vitrification Studies with DOE Low-Level Mixed Waste Wastewater Treatment Sludges

International Nuclear Information System (INIS)

Cicero, C.A.; Andrews, M.K.; Bickford, D.F.; Hewlett, K.J.; Bennert, D.M.; Overcamp, T.J.

1995-01-01

Vitrification studies with simulated Low Level Mixed Waste (LLMW) sludges were performed at the Savannah River Technology Center (SRTC). These studies focused on finding the optimum glass compositions for four simulated LLMW wastewater treatment sludges and were based on both crucible-scale and pilot-scale studies. Optimum compositions were determined based on the maximum waste loading achievable without sacrificing glass integrity

Development of a smart key performance indicator for in-situ load tests

NARCIS (Netherlands)

Dieteren, G.; Bigaj-van Vliet, A.J.; Yang, Y.; Sangers, A.

2017-01-01

In-situ load testing of reinforced concrete (RC) structures is often performed to confirm the presence of the required resistance for the intended use (Conformity Load Testing) or to support the assessments of the residual capacity by models (Supplementary Load Testing for Condition Assessment).

Safety Analysis of 'Older/Aged' Handling and Transportation Equipment for Heavy Loads, Radioactive Waste and Materials in Accordance with German Nuclear Standards KTA 3902, 3903 and 3905

International Nuclear Information System (INIS)

Macias, P.; Prucker, E.; Stang, W.

2006-01-01

The purpose of this paper is to present a general safety analysis of important handling and transportation processes and their related equipment ('load chains' consisting of cranes, load-bearing equipment and load-attaching points). This project was arranged by the responsible Bavarian ministry for environment, health and consumer protection (StMUGV) in agreement with the power plant operators of all Bavarian nuclear power plants to work out potential safety improvements. The range of the equipment (e.g. reactor building, crane, refuelling machine, load-bearing equipment and load-attaching points) covers the handling and transportation of fuel elements (e. g. with fuel flasks), heavy loads (e.g. reactor pressure vessel closure head, shielding slabs) and radioactive materials and waste (e.g. waste flasks, control elements, fuel channels, structure elements). The handling equipment was subjected to a general safety analysis taking into account the ageing of the equipment and the progress of standards. Compliance with the current valid requirements of the state of science and technology as required by German Atomic Act and particularly of the nuclear safety KTA-standards (3902, 3903 and 3905) was examined. The higher protection aims 'safe handling and transportation of heavy loads and safe handling of radioactive materials and waste' of the whole analysis are to avoid a criticality accident, the release of radioactivity and inadmissible effects on important technical equipment and buildings. The scope of the analysis was to check whether these protection aims were fulfilled for all important technical handling and transportation processes. In particularly the design and manufacturing of the components and the regulations of the handling itself were examined. (authors)

US DOE Initiated Performance Enhancements to the Hanford Waste Treatment and Immobilization Plant (WTP) Low-activity Waste Vitrification (LAW) System

International Nuclear Information System (INIS)

Hamel, William F.; Gerdes, Kurt D.; Holton, Langdon K.; Pegg, Ian L.; Bowen, Brad W.

2006-01-01

The U.S Department of Energy Office of River Protection (DOE-ORP) is constructing a Waste Treatment and Immobilization Plant (WTP) for the treatment and vitrification of underground tank wastes stored at the Hanford Site in Washington State. The WTP comprises four major facilities: a pretreatment facility to separate the tank waste into high level waste (HLW) and low-activity waste (LAW) process streams, a HLW vitrification facility to immobilize the HLW fraction; a LAW vitrification facility to immobilize the LAW fraction, and an analytical laboratory to support the operations of all four treatment facilities. DOE has established strategic objectives to optimize the performance of the WTP facilities and the LAW and HLW waste forms to reduce the overall schedule and cost for treatment and vitrification of the Hanford tank wastes. This strategy has been implemented by establishing performance expectations in the WTP contract for the facilities and waste forms. In addition, DOE, as owner-operator of the WTP facilities, continues to evaluate (1) the design, to determine the potential for performance above the requirements specified in the WTP contract; and (2) improvements in production of the LAW and HLW waste forms. This paper reports recent progress directed at improving production of the LAW waste form. DOE's initial assessment, which is based on the work reported in this paper, is that the capacity of the WTP LAW vitrification facility can be increased by a factor of 2 to 4 with a combination of revised glass formulations, modest increases in melter glass operating temperatures, and a second-generation LAW melter with a larger surface area. Implementing these improvements in the LAW waste immobilization capability can benefit the LAW treatment mission by reducing both processing time and cost

Enhanced HLW glass formulations for the waste treatment and immobilization plant

Energy Technology Data Exchange (ETDEWEB)

Kruger, Albert A. [DOE-WTP Project Office, US Department of Energy, Richland, Washington (United States)

2013-07-01

Current estimates and glass formulation efforts are conservative vis-a-vis achievable waste loadings. These formulations have been specified to ensure that glasses are homogenous, contain essentially no crystalline phases, are processable in joule-heated, ceramic-lined melters and meet WTP Contract terms. The WTP's overall mission will require the immobilization of tank waste compositions that are dominated by mixtures of aluminum, chromium, bismuth, iron, phosphorous, zirconium, and sulfur compounds as waste-limiting components. Glass compositions for these waste mixtures have been developed based upon previous experience and current glass property models. DOE has a testing program to develop and characterize HLW glasses with higher waste loadings. This work has demonstrated the feasibility of increases in waste loading from 25 wt% to 33-50 wt% (based on oxide loading) in the glass depending on the waste stream. It is expected these higher waste loading glasses will reduce the HLW canister production requirement by 25% or more. (authors)

Sediment filtration can reduce the N load of the waste water discharge - a full-scale lake experiment

Science.gov (United States)

Aalto, Sanni L.; Saarenheimo, Jatta; Karvinen, Anu; Rissanen, Antti J.; Ropponen, Janne; Juntunen, Janne; Tiirola, Marja

2016-04-01

European commission has obliged Baltic states to reduce nitrate load, which requires high investments on the nitrate removal processes and may increase emissions of greenhouse gases, e.g. N2O, in the waste water treatment plants. We used ecosystem-scale experimental approach to test a novel sediment filtration method for economical waste water N removal in Lake Keurusselkä, Finland between 2014 and 2015. By spatially optimizing the waste water discharge, the contact area and time of nitrified waste water with the reducing microbes of the sediment was increased. This was expected to enhance microbial-driven N transformation and to alter microbial community composition. We utilized 15N isotope pairing technique to follow changes in the actual and potential denitrification rates, nitrous oxide formation and dissimilatory nitrate reduction to ammonium (DNRA) in the lake sediments receiving nitrate-rich waste water input and in the control site. In addition, we investigated the connections between observed process rates and microbial community composition and functioning by using next generation sequencing and quantitative PCR. Furthermore, we estimated the effect of sediment filtration method on waste water contact time with sediment using the 3D hydrodynamic model. We sampled one year before the full-scale experiment and observed strong seasonal patterns in the process rates, which reflects the seasonal variation in the temperature-related mixing patterns of the waste water within the lake. During the experiment, we found that spatial optimization enhanced both actual and potential denitrification rates of the sediment. Furthermore, it did not significantly promote N2O emissions, or N retention through DNRA. Overall, our results indicate that sediment filtration can be utilized as a supplemental or even alternative method for the waste water N removal.

Flexible fermentation of organically loaded industrial waste waters using a beverage manufacturer as an example; Flexible Vergaerung organisch belasteter Industrie-Abwaesser am Beispiel eines Getraenkeherstellers

Energy Technology Data Exchange (ETDEWEB)

Ganagin, Waldemar; Loewen, Achim; Nelles, Michael [HAWK Hochschule fuer Angewandte Wissenschaft und Kunst Hildesheim/Holzminden/Goettingen, Goettingen (Germany). Fachgebiet Nachhaltige Energie- und Umwelttechnik (NEUTec)

2013-10-01

Industrial organic waste water is usually treated directly in an own or public sewage treatment plant which is highly cost-intensive. The anaerobic digestion of those waste waters is sometimes difficult to control. HAWK is working in a project about this topic, where a fixed bed reactor is investigated for the operation as a flexible plant. For this reason a semi-industrial pilot plant was developed and the capability will be tested on several sites. The gas production ought to run according to the companies demands and is integrated in the operation and processes. This flexible plant is specifically designed to deal with small amounts of waste water with low organic components and even sometimes discontinuously loads. This process is tested in a beverage factory. The reactor was implemented in the existing infrastructure and their waste water is treated. The assessment of the measurements shows, that the fixed bed reactor can handle the organic compounds of the waste water very well and reduce them significantly. Even fluctuating loads and a low organic concentration do not harm the process. The effect of power generation is an additional benefit for this system This innovative approach with low energy input and additional profit from the power sale makes the waste water treatment on site as a real alternative to the conventional treatment. (orig.)

Locomotion With Loads: Practical Techniques for Predicting Performance Outcomes

Science.gov (United States)

2015-05-01

Metabolic energy consumption as a function of speed and body size in birds and mammals. J Exp Biol. 97, 1-21. Weyand, P., Smith, B., Puyau, M. and...height, weight (including load), speed, and grade algorithms proposed will allow walking metabolic rates to be predicted to within 6.0 and 12.0% in...gait, metabolism , performance, load carriage 16. SECURITY CLASSIFICATION OF: Unclassified 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME

Evaluating and controlling the characteristics of the nuclear waste in the FWMS using waste stream analysis model

International Nuclear Information System (INIS)

Andress, D.; McLeod, N.B.; Joy, D.S.

1990-01-01

The Waste Stream Analysis (WSA) Model is used by the Department of Energy to model the item and location dependent properties of the nuclear waste stream in the Federal Waste Managements System and at utility spent fuel storage facilities. WSA can simulate a wide variety of FWMS configurations and operating strategies and can select and sequence spent fuel for optimal efficiency in the FWMS while minimizing adverse impact on the utility sector. WSA tracks each assembly from the time of discharge to ultimate geologic disposal including all shipping cask and waste package loadings and both at-reactor and FWMS consolidation. WSA selects the highest capacity shipping cask or waste package that does not violate external dose rate or heat limitations for a group of spent fuel assemblies to be containerized. This paper presents an overview of the Waste Stream Analysis Model and a number of key results from a set of coordinated SIMS runs, which illustrates both the impact of waste characteristics on system performance and the ability to control waste characteristics by use of selection and sequencing strategies. 7 refs., 6 figs

An overview of U.S. plant performance improvement through effective radioactive waste management

International Nuclear Information System (INIS)

Sieberling, R.; Lyons, P.W.

1986-01-01

Radioactive waste volumes in the United States commercial nuclear power industry have declined over the last five years after increasing steadily in the late 1970's. This decline is considered to be especially significant because major backfits/modifications and major component repair/replacement at U.S. nuclear power stations have been accomplished during this period. This paper analyzes the key reasons for this performance and outlines the positive effects that this trend has upon overall nuclear plant performance. In reviewing plant performance data, there appears to be a direct correlation between overall plant performance and radioactive waste performance. For example, plants with high capacity factors, strong industrial safety programs, low collective man-rem, and good contamination controls, generally have a history of low radioactive waste volumes. The reasons for this excellent performance is the result of direct management and supervisory involvement in plant operations, implementation of high standards of performance, and monitoring performance against these standards. Using the techniques outlined in this paper, the U.S. nuclear power industry can continue to reduce the volume of low-level solid radioactive waste being generated

DOE progress in assessing the long term performance of waste package materials

International Nuclear Information System (INIS)

Berusch, A.; Gause, E.

1987-01-01

Under the Nuclear Waste Policy Act of 1982 (NWPA)[1], the US Dept. of Energy (DOE) is conducting activities to select and characterize candidate sites suitable for the construction and operation of a geologic repository for the disposal of high-level nuclear wastes. DOE is funding three first repository projects: Basalt Waste Isolation Project, BWIP; Nevada Nuclear Waste Isolation Project, NNWSI; and Salt Repository Project Office, SRPO. It is essential in the licensing process that DOE demonstrate to the NRC that the long-term performance of the materials and design will be in compliance with the requirements of 10 CFR 60.113 on substantially complete containment within the waste packages for 300 to 1000 years and a controlled release rate from the engineered barrier system (EBS) for 10,000 years of 1 part in 10 5 per year for radionuclides present in defined quantities 100 years after permanent closure. Obviously, the time spans involved make it impractical to base the assessment of the long term performance of waste package materials on real time, prototypical testing. The assessment of performance will be implemented by the use of models that are supported by real time field and laboratory tests, monitoring, and natural analog studies. Each of the repository projects is developing a plan for demonstrating long-term waste package material performance depending on the particular materials and the package-perturbed, time-dependent environment under which the materials must function. An overview of progress in each of these activities for each of the projects is provided in the following

Treadmill Exercise with Increased Body Loading Enhances Post Flight Functional Performance

Science.gov (United States)

Bloomberg, J. J.; Batson, C. D.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Laurie, S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Peters, B. T.;

Environmental performance of an innovative waste refinery based on enzymatic treatment

DEFF Research Database (Denmark)

Tonini, Davide; Astrup, Thomas

2011-01-01

for virgin material and saving fossil resources. In this paper a life-cycle assessment of a pilot-scale waste refinery for the enzymatic treatment of municipal solid waste (MSW) is presented. The refinery produced a liquid (liquefied organic materials and paper) and a solid fraction (non-degradable materials......Decrease of fossil fuel dependence and global warming mitigation has become increasingly important issues during the last decades. With respect to waste management higher recycling rates for valuable materials as well as energy recovery from waste streams could play a significant role substituting......) from the waste. The waste refinery was compared to alternative treatments such as incineration, bioreactor landfill and mechanical-biological treatment followed by utilization of the RDF (refuse-derived fuel) for energy. The performance of the waste refinery turned out to be comparable...

Waste package performance assessment for the Yucca Mountain Project

International Nuclear Information System (INIS)

O'Connell, W.J.; Lappa, D.A.; Thatcher, R.M.

1989-02-01

We completed a first cycle of model development from a specification to a computer program, PANDORA-1, for long-term performance assessment of waste packages. The model for one waste package at a time incorporates processes specific to the unsaturated environment at the proposed Yucca Mountain, NV, site. PANDORA-1 models the most likely processes and several modes of waste alteration and release. The development identified information needs for future models; many processes, local details, and combinations will have to be examined. Integration of ensemble performance and quantification of uncertainties are modeling steps at higher aggregation. Methodologies for these steps include sampling, which is well studied; we have focused on several open questions. We can now calculate the amount of variance reduction available from Latin hypercube sampling; it is a limited reduction. A new method, controlled sampling, provides substantial variance reduction for a broad range of model functions. An uncertainty analysis test-bed program compares the new with old sampling methods. 7 refs., 1 tab

Biodiesel production from waste cotton seed oil using low cost catalyst: Engine performance and emission characteristics

Directory of Open Access Journals (Sweden)

Duple Sinha

2016-09-01

Full Text Available Production of fatty acid methyl esters from waste cotton seed oil through transesterification was reported. The GC–MS analysis of WCCO oil was studied and the major fatty acids were found to be palmitic acid (27.76% and linoleic acid (42.84%. The molecular weight of the oil was 881.039 g/mol. A maximum yield of 92% biodiesel was reported when the reaction temperature, time, methanol/oil ratio and catalyst loading rate were 60 °C, 50 min, 12:1 and 3% (wt.%, respectively. The calcined egg shell catalyst was prepared and characterized. Partial purification of the fatty acid methyl esters was proposed for increasing the purity of the biodiesel and better engine performance. The flash point and the fire point of the biodiesel were found to be 128 °C and 136 °C, respectively. The Brake thermal efficiency of WCCO B10 biodiesel was 26.04% for maximum load, specific fuel consumption for diesel was 0.32 kg/kW h at maximum load. The use of biodiesel blends showed a reduction of carbon monoxide and hydrocarbon emissions and a marginal increase in nitrogen oxides (NOx emissions improved emission characteristics.

US Department of Energy Mixed Waste Integrated Program performance systems analysis

International Nuclear Information System (INIS)

Ferrada, J.J.; Berry, J.B.

1994-01-01

The primary goal of this project is to support decision making for the U.S. Department of Energy (DOE)/EM-50 Mixed Waste Integrated Program (MWIP) and the Mixed Low-Level Waste Program. A systems approach to the assessment of enhanced waste form(s) production will be employed including, coordination and configuration management of activities in specific technology development tasks. The purpose of this paper is to describe the development and application of a methodology for implementing a performance systems analysis on mixed waste treatment process technologies. The second section describes a conventional approach to process systems analysis followed by a methodology to estimate uncertainties when analyzing innovative technologies. Principles from these methodologies have been used to develop a performance systems analysis for MWIP. The third section describes the systems analysis tools. The fourth section explains how the performance systems analysis will be used to analyze MWIP process alternatives. The fifth and sixth sections summarize this paper and describe future work for this project. Baseline treatment process technologies (i.e., commercially available technologies) and waste management strategies are evaluated systematically using the ASPEN PLUS program applications developed by the DOE Mixed Waste Treatment Project (MWTP). Alternatives to the baseline (i.e., technologies developed by DOE's Office of Technology Development) are analyzed using FLOW, a user-friendly program developed at Oak Ridge National Laboratory (ORNL). Currently, this program is capable of calculating rough order-of-magnitude mass and energy balances to assess the performance of the alternative technologies as compared to the baseline process. In the future, FLOW will be capable of communicating information to the ASPEN PLUS program

Spent Nuclear Fuel Option Study on Hybrid Reactor for Waste Transmutation

International Nuclear Information System (INIS)

Hong, Seong Hee; Kim, Myung Hyun

2016-01-01

DUPIC nuclear fuel can be used in hybrid reactor by compensation of subcritical level through (U-10Zr) fuel. Energy production performance of Hyb-WT with DUPIC is grateful because it has high EM factor and performs waste transmutation at the same time. However, waste transmutation performance should be improved by different fissile fuel instead of (U-10Zr) fuel. SNF (Spent Nuclear Fuel) disposal is one of the problems in the nuclear industry. FFHR (Fusion-Fission Hybrid Reactor) is one of the most attractive option on reuse of SNF as a waste transmutation system. Because subcritical system like FFHR has some advantages compared to critical system. Subcritical systems have higher safety potential than critical system. Also, there is suppressed excess reactivity at BOC (Beginning of Cycle) in critical system, on the other hand there is no suppressed reactivity in subcritical system. Our research team could have designed FFHR for waste transmutation; Hyb-WT. Various researches have been conducted on fuel and coolant option for optimization of transmutation performance. However, Hyb-WT has technical disadvantage. It is required fusion power (Pfus) which is the key design parameter in FFHR is increased for compensation of decreasing subcritical level. As a result, structure material integrity is damaged under high irradiation condition by increasing Pfus. Also, deep burn of reprocessed SNF is limited by weakened integrity of structure material. Therefore, in this research, SNF option study will be conducted on DUPIC (Direct Use of Spent PWR Fuel in CANDU Reactor) fuel, TRU fuel and DUPIC + TRU mixed fuel for optimization of Hyb-WT performance. Goal of this research is design check for low required fusion power and high waste transmutation. In this paper, neutronic analysis is conducted on Hyb-WT with DUPIC nuclear fuel. When DUPIC nuclear fuel is loaded in fast neutron system, supplement fissile materials need to be loaded together for compensation of low criticality

Spent Nuclear Fuel Option Study on Hybrid Reactor for Waste Transmutation

Energy Technology Data Exchange (ETDEWEB)

Hong, Seong Hee; Kim, Myung Hyun [Kyung Hee University, Yongin (Korea, Republic of)

2016-05-15

DUPIC nuclear fuel can be used in hybrid reactor by compensation of subcritical level through (U-10Zr) fuel. Energy production performance of Hyb-WT with DUPIC is grateful because it has high EM factor and performs waste transmutation at the same time. However, waste transmutation performance should be improved by different fissile fuel instead of (U-10Zr) fuel. SNF (Spent Nuclear Fuel) disposal is one of the problems in the nuclear industry. FFHR (Fusion-Fission Hybrid Reactor) is one of the most attractive option on reuse of SNF as a waste transmutation system. Because subcritical system like FFHR has some advantages compared to critical system. Subcritical systems have higher safety potential than critical system. Also, there is suppressed excess reactivity at BOC (Beginning of Cycle) in critical system, on the other hand there is no suppressed reactivity in subcritical system. Our research team could have designed FFHR for waste transmutation; Hyb-WT. Various researches have been conducted on fuel and coolant option for optimization of transmutation performance. However, Hyb-WT has technical disadvantage. It is required fusion power (Pfus) which is the key design parameter in FFHR is increased for compensation of decreasing subcritical level. As a result, structure material integrity is damaged under high irradiation condition by increasing Pfus. Also, deep burn of reprocessed SNF is limited by weakened integrity of structure material. Therefore, in this research, SNF option study will be conducted on DUPIC (Direct Use of Spent PWR Fuel in CANDU Reactor) fuel, TRU fuel and DUPIC + TRU mixed fuel for optimization of Hyb-WT performance. Goal of this research is design check for low required fusion power and high waste transmutation. In this paper, neutronic analysis is conducted on Hyb-WT with DUPIC nuclear fuel. When DUPIC nuclear fuel is loaded in fast neutron system, supplement fissile materials need to be loaded together for compensation of low criticality

Performance of engineered barriers for low-level waste

International Nuclear Information System (INIS)

Taplin, D.; Claridge, F.B.

1987-09-01

Geotechnical Resources Ltd., in association with Komex Consultants Ltd., was retained to collect, synthesize and evaluate the available information on the long term performance of engineered barriers for low-level radioactive wastes disposed in Canada. Literature was researched from Canadian, United States and European sources. A variety of barrier materials were assessed in the study and included natural clays, concrete and cement, metals, bentonite-sand admixes, bitumen and bituminous admixes, soil cement and polymeric membranes. The generalized geological and geotechnical conditions encountered within the soil and rock host media currently under consideration for disposal sites in southern Ontario were also summarized. Both internal barriers, or buffers, to immobilize the waste material and reduce radionuclide mobility, as well as external barriers to limit the migration of contaminants were examined. Microbial activities within the waste forms were analyzed, including cellulose degradation, methanogenesis and bicarbonate and organic reactions. Microbial interactions with the various engineered barrier materials under consideration were also assessed. Finally, the anticipated long term performances of the respective barrier materials under consideration were evaluated, along with the general suitability of the geological host media being proposed for disposal sites

White paper updating conclusions of 1998 ILAW performance assessment

International Nuclear Information System (INIS)

MANN, F.M.

2000-01-01

The purpose of this document is to provide a comparison of the estimated immobilized low-activity waste (LAW) disposal system performance against established performance objectives using the beat estimates for parameters and models to describe the system. The principal advances in knowledge since the last performance assessment (known as the 1998 ILAW PA [Mann 1998a]) have been in site specific information and data on the waste form performance for BNFL, Inc. relevant glass formulations. The white paper also estimates the maximum release rates for technetium and other key radionuclides and chemicals from the waste form. Finally, this white paper provides limited information on the impact of changes in waste form loading

White paper updating conclusions of 1998 ILAW performance assessment

Energy Technology Data Exchange (ETDEWEB)

MANN, F.M.

2000-05-11

The purpose of this document is to provide a comparison of the estimated immobilized low-activity waste (LAW) disposal system performance against established performance objectives using the beat estimates for parameters and models to describe the system. The principal advances in knowledge since the last performance assessment (known as the 1998 ILAW PA [Mann 1998a]) have been in site specific information and data on the waste form performance for BNFL, Inc. relevant glass formulations. The white paper also estimates the maximum release rates for technetium and other key radionuclides and chemicals from the waste form. Finally, this white paper provides limited information on the impact of changes in waste form loading.

Chemical and mechanical performance properties for various final waste forms -- PSPI scoping study

International Nuclear Information System (INIS)

Farnsworth, R.K.; Larsen, E.D.; Sears, J.W.; Eddy, T.L.; Anderson, G.L.

1996-09-01

The US DOE is obtaining data on the performance properties of the various final waste forms that may be chosen as primary treatment products for the alpha-contaminated low-level and transuranic waste at the INEL's Transuranic Storage Area. This report collects and compares selected properties that are key indicators of mechanical and chemical durability for Portland cement concrete, concrete formed under elevated temperature and pressure, sulfur polymer cement, borosilicate glass, and various forms of alumino-silicate glass, including in situ vitrification glass and various compositions of iron-enriched basalt (IEB) and iron-enriched basalt IV (IEB4). Compressive strength and impact resistance properties were used as performance indicators in comparative evaluation of the mechanical durability of each waste form, while various leachability data were used in comparative evaluation of each waste form's chemical durability. The vitrified waste forms were generally more durable than the non-vitrified waste forms, with the iron-enriched alumino-silicate glasses and glass/ceramics exhibiting the most favorable chemical and mechanical durabilities. It appears that the addition of zirconia and titania to IEB (forming IEB4) increases the leach resistance of the lanthanides. The large compositional ranges for IEB and IEB4 more easily accommodate the compositions of the waste stored at the INEL than does the composition of borosilicate glass. It appears, however, that the large potential variation in IEB and IEB4 compositions resulting from differing waste feed compositions can impact waste form durability. Further work is needed to determine the range of waste stream feed compositions and rates of waste form cooling that will result in acceptable and optimized IEB or IEB4 waste form performance. 43 refs

Symmetric Rock Fall on Waste Package

International Nuclear Information System (INIS)

Sreten Mastilovic

2001-01-01

The objective of this calculation is to determine the structural response of the Naval SNF (spent nuclear fuel) Waste Package (WP) and the emplacement pallet (EP) subjected to the rock fall DBE (design basis event) dynamic loads. The scope of this calculation is limited to reporting the calculation results in terms of stress intensities and residual stresses in the WP, and stress intensities and maximum permanent downward displacements of the EP-lifting surface. The information provided by the sketches (Attachment I) is that of the potential design of the type of WP and EP considered in this calculation, and all obtained results are valid for those designs only. This calculation is associated with the waste package design and is performed by the Waste Package Design Section in accordance with Reference 24. AP-3.124, ''Calculations'', is used to perform the calculation and develop the document

Cognitive Load Theory: An Empirical Study of Anxiety and Task Performance in Language Learning

Science.gov (United States)

Chen, I-Jung; Chang, Chi-Cheng

2009-01-01

Introduction: This study explores the relationship among three variables--cognitive load, foreign language anxiety, and task performance. Cognitive load refers to the load imposed on working memory while performing a particular task. The authors hypothesized that anxiety consumes the resources of working memory, leaving less capacity for cognitive…

Performance assessment requirements for the identification and tracking of transuranic waste intended for disposal at the Waste Isolation Pilot Plant

Energy Technology Data Exchange (ETDEWEB)

Snider, C.A. [Department of Energy, Carlsbad, NM (United States); Weston, W.W. [Westinghouse Electric Corp., Carlsbad, NM (United States)

1997-11-01

To demonstrate compliance with environmental radiation protection standards for management and disposal of transuranic (TRU) radioactive wastes, a performance assessment (PA) of the Waste Isolation Pilot Plant (WIPP) was made of waste-waste and waste-repository interactions and impacts on disposal system performance. An estimate of waste components and accumulated quantities was derived from a roll-up of the generator/storage sites` TRU waste inventories. Waste components of significance, and some of negligible effect, were fixed input parameters in the model. The results identified several waste components that require identification and tracking of quantities to ensure that repository limits are not exceeded. The rationale used to establish waste component limits based on input estimates is discussed. The distinction between repository limits and waste container limits is explained. Controls used to ensure that no limits are exceeded are identified. For waste components with no explicit repository based limits, other applicable limits are contained in the WIPP Waste Acceptance Criteria (WAC). The 10 radionuclides targeted for identification and tracking on either a waste container or a waste stream basis include Am-241, Pu-238, Pu-239, Pu-240, Pu-242, U-233, U-234, U-238, Sr-90, and Cs-137. The accumulative activities of these radionuclides are to be inventoried at the time of emplacement in the WIPP. Changes in inventory curie content as a function of radionuclide decay and ingrowth over time will be calculated and tracked. Due to the large margin of compliance demonstrated by PA with the 10,000 year release limits specified, the quality assurance objective for radioassay of the 10 radionuclides need to be no more restrictive than those already identified for addressing the requirements imposed by transportation and WIPP disposal operations in Section 9 of the TRU Waste Characterization Quality Assurance Program Plan. 6 refs.

Stabilization Using Phosphate Bonded Ceramics. Salt Containing Mixed Waste Treatment. Mixed Waste Focus Area. OST Reference No. 117

International Nuclear Information System (INIS)

1999-01-01

Throughout the Department of Energy (DOE) complex there are large inventories of homogeneous mixed waste solids, such as wastewater treatment residues, fly ashes, and sludges that contain relatively high concentrations (greater than 15% by weight) of salts. The inherent solubility of salts (e.g., nitrates, chlorides, and sulfates) makes traditional treatment of these waste streams difficult, expensive, and challenging. One alternative is low-temperature stabilization by chemically bonded phosphate ceramics (CBPCs). The process involves reacting magnesium oxide with monopotassium phosphate with the salt waste to produce a dense monolith. The ceramic makes a strong environmental barrier, and the metals are converted to insoluble, low-leaching phosphate salts. The process has been tested on a variety of surrogates and actual mixed waste streams, including soils, wastewater, flyashes, and crushed debris. It has also been demonstrated at scales ranging from 5 to 55 gallons. In some applications, the CBPC technology provides higher waste loadings and a more durable salt waste form than the baseline method of cementitious grouting. Waste form test specimens were subjected to a variety of performance tests. Results of waste form performance testing concluded that CBPC forms made with salt wastes meet or exceed both RCRA and recommended Nuclear Regulatory Commission (NRC) low-level waste (LLW) disposal criteria. Application of a polymer coating to the CBPC may decrease the leaching of salt anions, but continued waste form evaluations are needed to fully assess the deteriorating effects of this leaching, if any, over time.

Structural evaluations of existing underground reinforced concrete tanks for radioactive waste storage

International Nuclear Information System (INIS)

Vollert, F.R.

1979-10-01

Structural integrity evaluations are being conducted for underground, steel-lined reinforced concrete tanks for storing radioactive wastes. The tanks sustain large soil overburden loads and elevated temperatures from the waste for long time periods. The evaluations include laboratory experiments to determine the long-term effects of elevated temperatures on the elastic properties of concrete, and to estimate the effect of the waste chemicals on concrete durability. Available concrete samples from the tanks were also tested to determine the quality of the concrete in the tanks and for comparison with the laboratory data. Finite element, nonlinear, time-dependent analyses are performed to show the thermal creep, cracking, and stresses occurring in the concrete tanks due to the service conditions. Ultimate load analyses are made to assess the safety margin in the tanks. Finally, seismic analyses of a tank in the stressed condition due to the soil and thermal loadings were conducted to determine that the structure has sufficient reserve capacity to withstand 0.25 g earthquake accelerations

Reliable predictions of waste performance in a geologic repository

International Nuclear Information System (INIS)

Pigford, T.H.; Chambre, P.L.

1985-08-01

Establishing reliable estimates of long-term performance of a waste repository requires emphasis upon valid theories to predict performance. Predicting rates that radionuclides are released from waste packages cannot rest upon empirical extrapolations of laboratory leach data. Reliable predictions can be based on simple bounding theoretical models, such as solubility-limited bulk-flow, if the assumed parameters are reliably known or defensibly conservative. Wherever possible, performance analysis should proceed beyond simple bounding calculations to obtain more realistic - and usually more favorable - estimates of expected performance. Desire for greater realism must be balanced against increasing uncertainties in prediction and loss of reliability. Theoretical predictions of release rate based on mass-transfer analysis are bounding and the theory can be verified. Postulated repository analogues to simulate laboratory leach experiments introduce arbitrary and fictitious repository parameters and are shown not to agree with well-established theory. 34 refs., 3 figs., 2 tabs

Optimization of waste water discharge and waste water cleaning on the basis of measurements of the organic pollutant load; Optimierung von Abwasserableitung und Abwasserreinigung durch Messung der organischen Abwasserbelastung

Energy Technology Data Exchange (ETDEWEB)

Haeck, M. [Dr. Bruno Lange GmbH Berlin, Duesseldorf (Germany)

1999-07-01

The spectral absorption coefficient (SAC) is a sum parameter for describing the organic pollutant load of waste water. It is based on a purely physical measuring technique and can be monitored continuously and directly in the medium by means of the described UV process probe. From this arise numerous opportunities for optimizing waste water discharge and cleaning. (orig.) [German] Der spektrale Absorptionskoeffizient (SAK) ist ein Summenparameter zur Beschreibung der organischen Abwasserbelastung. Er basiert auf einem rein physikalischen Messverfahren und kann mit der hier vorgestellten UV-Prozess-Sonde kontinuierlich und direkt im Medium erfasst werden. Daraus ergeben sich zahlreiche Moeglichkeiten zur Optimierung von Abwasserableitung und -reinigung. (orig.)

Performance Assessment for the Idaho National Laboratory Remote-Handled Low-Level Waste Disposal Facility

Energy Technology Data Exchange (ETDEWEB)

Annette L. Schafer; A. Jeffrey Sondrup; Arthur S. Rood

2012-05-01

This performance assessment for the Remote-Handled Low-Level Radioactive Waste Disposal Facility at the Idaho National Laboratory documents the projected radiological dose impacts associated with the disposal of low-level radioactive waste at the facility. This assessment evaluates compliance with the applicable radiological criteria of the U.S. Department of Energy and the U.S. Environmental Protection Agency for protection of the public and the environment. The calculations involve modeling transport of radionuclides from buried waste to surface soil and subsurface media, and eventually to members of the public via air, groundwater, and food chain pathways. Projections of doses are calculated for both offsite receptors and individuals who inadvertently intrude into the waste after site closure. The results of the calculations are used to evaluate the future performance of the low-level radioactive waste disposal facility and to provide input for establishment of waste acceptance criteria. In addition, one-factor-at-a-time, Monte Carlo, and rank correlation analyses are included for sensitivity and uncertainty analysis. The comparison of the performance assessment results to the applicable performance objectives provides reasonable expectation that the performance objectives will be met

Ceramic Single Phase High-Level Nuclear Waste Forms: Hollandite, Perovskite, and Pyrochlore

Science.gov (United States)

Vetter, M.; Wang, J.

2017-12-01

The lack of viable options for the safe, reliable, and long-term storage of nuclear waste is one of the primary roadblocks of nuclear energy's sustainable future. The method being researched is the incorporation and immobilization of harmful radionuclides (Cs, Sr, Actinides, and Lanthanides) into the structure of glasses and ceramics. Borosilicate glasses are the main waste form that is accepted and used by today's nuclear industry, but they aren't the most efficient in terms of waste loading, and durability is still not fully understood. Synroc-phase ceramics (i.e. hollandite, perovskite, pyrochlore, zirconolite) have many attractive qualities that glass waste forms do not: high waste loading, moderate thermal expansion and conductivity, high chemical durability, and high radiation stability. The only downside to ceramics is that they are more complex to process than glass. New compositions can be discovered by using an Artificial Neural Network (ANN) to have more options to optimize the composition, loading for performance by analyzing the non-linear relationships between ionic radii, electronegativity, channel size, and a mineral's ability to incorporate radionuclides into its structure. Cesium can be incorporated into hollandite's A-site, while pyrochlore and perovskite can incorporate actinides and lanthanides into their A-site. The ANN is used to predict new compositions based on hollandite's channel size, as well as the A-O bond distances of pyrochlore and perovskite, and determine which ions can be incorporated. These new compositions will provide more options for more experiments to potentially improve chemical and thermodynamic properties, as well as increased waste loading capabilities.

French radioactive wastes performance assessment and the natural analogues approach: an overview

International Nuclear Information System (INIS)

Escalier des Orres, P.

1988-10-01

One of the main difficulties linked to the Radioactive Waste Performance Assessment calculations lies in the scale of time and space underlying these calculations: mechanisms and parameters can directly be affected by time or space dependency. The ''natural analogues'' approach has evident advantages, at least qualitative, to enlighten these aspects. It may also provide confidence in our ability to model partial or overall natural systems. The following paper gives the headlines of the use of the ''natural analogues'' methodology in the French Radioactive Wastes Performance Assessment in the field of waste disposal

Peristaltic pumps for waste disposal

International Nuclear Information System (INIS)

Griffith, G.W.

1992-09-01

Laboratory robots are capable of generating large volumes of hazardous liquid wastes when they are used to perform chemical analyses of metal finishing solutions. A robot at Allied-Signal Inc., Kansas City Division, generates 30 gallons of acid waste each month. This waste contains mineral acids, heavy metals, metal fluorides, and other materials. The waste must be contained in special drums that are closed to the atmosphere. The initial disposal method was to have the robot pour the waste into a collecting funnel, which contained a liquid-sensing valve to admit the waste into the drum. Spills were inevitable, splashing occurred, and the special valve often didn't work well. The device also occupied a large amount of premium bench space. Peristaltic pumps are made to handle hazardous liquids quickly and efficiently. A variable-speed pump, equipped with a quick-loading pump head, was mounted below the robot bench near the waste barrel. The pump inlet tube was mounted above the bench within easy reach of the robot, while the outlet tube was connected directly to the barrel. During operation, the robot brings the waste liquid up to the pump inlet tube and activates the pump. When the waste has been removed, the pump stops. The procedure is quick, simple, inexpensive, safe, and reliable

Proposal of a Global Training Load Measure Predicting Match Performance in an Elite Team Sport

Directory of Open Access Journals (Sweden)

Brendan H. Lazarus

2017-11-01

Full Text Available Aim: The use of external and internal load is an important aspect of monitoring systems in team sport. The aim of this study was to validate a novel measure of training load by quantifying the training-performance relationship of elite Australian footballers.Methods: The primary training measure of each of 36 players was weekly load derived from a weighted combination of Global Positioning System (GPS data and perceived wellness over a 24-week season. Smoothed loads representing an exponentially weighted rolling average were derived with decay time constants of 1.5, 2, 3, and 4 weeks. Differential loads representing rate of change in load were generated in similar fashion. Other derived measures of training included monotony, strain and acute:chronic ratio. Performance was a proprietary score derived from match performance indicators. Effects of a 1 SD within-player change below and above the mean of each training measure were quantified with a quadratic mixed model for each position (defenders, forwards, midfielders, and rucks. Effects were interpreted using standardization and magnitude-based inferences.Results: Performance was generally highest near the mean or ~1 SD below the mean of each training measure, and 1 SD increases in the following measures produced small impairments: weekly load (defenders, forwards, and midfielders; 1.5-week smoothed load (midfielders; 4-week differential load (defenders, forwards, and midfielders; and acute:chronic ratio (defenders and forwards. Effects of other measures in other positions were either trivial or unclear.Conclusion: The innovative combination of load was sensitive to performance in this elite Australian football cohort. Periods of high acute load and sustained increases in load impaired match performance. Positional differences should be taken into account for individual training prescription.

Effects of Reducing the Cognitive Load of Mathematics Test Items on Student Performance

Directory of Open Access Journals (Sweden)

Susan C. Gillmor

2015-01-01

Full Text Available This study explores a new item-writing framework for improving the validity of math assessment items. The authors transfer insights from Cognitive Load Theory (CLT, traditionally used in instructional design, to educational measurement. Fifteen, multiple-choice math assessment items were modified using research-based strategies for reducing extraneous cognitive load. An experimental design with 222 middle-school students tested the effects of the reduced cognitive load items on student performance and anxiety. Significant findings confirm the main research hypothesis that reducing the cognitive load of math assessment items improves student performance. Three load-reducing item modifications are identified as particularly effective for reducing item difficulty: signalling important information, aesthetic item organization, and removing extraneous content. Load reduction was not shown to impact student anxiety. Implications for classroom assessment and future research are discussed.

Nuclear hazardous waste cost control management

International Nuclear Information System (INIS)

Selg, R.A.

1991-01-01

The effects of the waste content of glass waste forms on Savannah River high-level waste disposal costs are currently under study to adjust the glass frit content to optimize the glass waste loadings and therefore significantly reduce the overall waste disposal cost. Changes in waste content affect onsite Defense Waste Changes in waste contents affect onsite Defense Waste Processing Facility (DWPF) costs as well as offsite shipping and repository emplacement charges. A nominal 1% increase over the 28 wt% waste loading of DWPF glass would reduce disposal costs by about $50 million for Savannah River wastes generated to the year 2000. Optimization of the glass waste forms to be produced in the SWPF is being supported by economic evaluations of the impact of the forms on waste disposal costs. Glass compositions are specified for acceptable melt processing and durability characteristics, with economic effects tracked by the number of waste canisters produced. This paper presents an evaluation of the effects of variations in waste content of the glass waste forms on the overall cost of the disposal, including offsite shipment and repository emplacement, of the Savannah River high-level wastes

Phosphate bonded ceramics as candidate final-waste-form materials

International Nuclear Information System (INIS)

Singh, D.; Wagh, A.S.; Cunnane, J.; Sutaria, M.; Kurokawa, S.; Mayberry, J.

1994-04-01

Room-temperature setting phosphate-bonded ceramics were studied as candidate materials for stabilization of DOE low-level problem mixed wastes which cannot be treated by other established stabilization techniques. Phosphates of Mg, Mg-Na, Al and Zr were studied to stabilize ash surrogate waste containing RCRA metals as nitrates and RCRA organics. We show that for a typical loading of 35 wt.% of the ash waste, the phosphate ceramics pass the TCLP test. The waste forms have high compression strength exceeding ASTM recommendations for final waste forms. Detailed X-ray diffraction studies and differential thermal analyses of the waste forms show evidence of chemical reaction of the waste with phosphoric acid and the host matrix. The SEM studies show evidence of physical bonding. The excellent performance in the leaching tests is attributed to a chemical solidification and physical as well as chemical bonding of ash wastes in these phosphate ceramics

Performance of Geosynthetic-Reinforced Soils Under Static and Cyclic Loading

Directory of Open Access Journals (Sweden)

M. Touahmia

2017-04-01

Full Text Available This paper investigates and discusses the composite behavior of geosynthetic reinforced soil mass. It presents the results of a series of large-scale laboratory tests supported by analytical methods to examine the performance of geogrid reinforcement subjected to static and cyclic pullout loading. The testing equipment and procedures used for this investigation are outlined. The results show that geosynthetic reinforcement can mobilize great resistance to static pulling load under high confining pressures. The reinforcement exhibits gradual deformation under cyclic loading showing no sign of imminent pullout failure for all levels of applied loads. In general, the results demonstrate that geosynthetic can be used in situations where loads are non-static, although care will be required in ensuring that appropriate factors of safety are applied to control the resulting deformation. A simplified analytical model for calculating the pulling capacity of geosynthetic reinforcement is proposed.

Estimation of waste package performance requirements for a nuclear waste repository in basalt

International Nuclear Information System (INIS)

Wood, B.J.

1980-07-01

A method of developing waste package performance requirements for specific nuclides is described, and based on federal regulations concerning permissible concentrations in solution at the point of discharge to the accessible environment, a simple and conservative transport model, and baseline and potential worst-case release scenarios

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D.

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory.

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

The Impact of Waste Loading on Viscosity in the Frit 418-SB3 System

International Nuclear Information System (INIS)

PEELER, DAVID

2004-01-01

In this report, data are provided to gain insight into the potential impact of a lower viscosity glass on melter stability (i.e., pressure spikes, cold cap behavior) and/or pour stream stability. High temperature viscosity data are generated for the Frit 418-SB3 system as a function of waste loading (from 30 to 45 percent) and compared to similar data from other systems that have been (or are currently being) processed through the Defense Waste Processing Facility (DWPF) melter. The data are presented in various formats to potentially align the viscosity data with physical observations at various points in the melter system or critical DWPF processing unit operations. The expectations is that the data will be provided adequate insight into the vitrification parameters which might evolve into working solutions as DWPF strives to maximize waste throughput. This report attempts to provide insight into a physical interpretation of the data from a DWPF perspective. The theories present ed are certainly not an all inclusive list and the order in which they are present does imply a ranking, probability, or likelihood that the proposed theory is even plausible. The intent of this discussion is to provide a forum in which the viscosity data can be discussed in relation to possible mechanisms which could potentially lead to a workable solution as discussed in relation to possible solution as higher overall attainment is striven for during processing of the current or future sludge batches

The development of radioactive waste treatment technology (III)

International Nuclear Information System (INIS)

Kim, Joon Hyung; Jung, Ki Jung; Lee, Kune Woo; Park, Hun Hwee

1991-03-01

Most PWR stations have experienced leakages of boric acid and oil into liquid radwaste systems. Typically, these wastes have been concentrated by an evaporator system. Based on operating plant experiences, boric acid and oil are the majority of the solid loading for disposal and tend to decrease the efficiency significantly. The objective of these studies is to develop pretreatment techniques for the recovery of boric acid and for the removal of oil from such wastes for improving the evaporator performance. To these objectives, lab. scale reverse osmosis (RO) membrane and filtration/coalescence processes are introduced, which can separate boric acid and oil into waste streams. (Author)

Mercury separation from mixed wastes. Annual report

International Nuclear Information System (INIS)

Taylor, P.A.; Klasson, K.T.; Corder, S.L.; Carlson, T.R.; McCandless, K.R.

1995-11-01

This is an assessment of new sorbents for removing Hg from wastes at US DOE sites. Four aqueous wastes were used for the laboratory tests: a simulant of a high-salt, acidic waste currently stored at INEL, a simulant of a high-salt, alkaline waste stored at Savannah River (SRS), a dilute LiOH solution stored at Y-12, and a low-salt, neutral groundwater generated at Y-12. Eight adsorbents covering a wide range of cost and capability were tested. Screening tests identified the most promising adsorbents, and column tests were performed using at least two adsorbents for each waste stream. No one adsorbent is effective in all of these waste streams. Based on loading capacity and compatibility, the most effect adsorbents to date are SuperLig 618 for the INEL tank waste simulant, Mersorb and Ionac SR-3 for the SRS tank waste simulant, Durasil 70 and Ionac SR-3 for the LiOH solution, and Ionac SR-3, followed by Ionac SR-4 and Mersorb, for the Y-12 groundwater

Combustion and fuel loading characteristics of Hanford Site transuranic solid waste

International Nuclear Information System (INIS)

Greenhalgh, W.O.

1994-01-01

The Waste Receiving and Processing (WRAP) Facility is being designed for construction in the north end of the Central Waste Complex. The WRAP Facility will receive, store, and process radioactive solid waste of both transuranic (TRU) and mixed waste (mixed radioactive-chemical waste) categories. Most of the waste is in 208-L (55-gal) steel drums. Other containers such as wood and steel boxes, and various sized drums will also be processed in the facility. The largest volume of waste and the type addressed in this report is TRU in 208-L (55-gal) drums that is scheduled to be processed in the Waste Receiving and Processing Facility Module 1 (WRAP 1). Half of the TRU waste processed by WRAP 1 is expected to be retrieved stored waste and the other half newly generated waste. Both the stored and new waste will be processed to certify it for permanent storage in the Waste Isolation Pilot Plant (WIPP) or disposal. The stored waste will go through a process of retrieval, examination, analysis, segregation, repackaging, relabeling, and documentation before certification and WIPP shipment. Newly generated waste should be much easier to process and certify. However, a substantial number of drums of both retrievable and newly generated waste will require temporary storage and handling in WRAP. Most of the TRU waste is combustible or has combustible components. Therefore, the presence of a substantial volume of drummed combustible waste raises concern about fire safety in WRAP and similar waste drum storage facilities. This report analyzes the fire related characteristics of the expected WRAP TRU waste stream

Waste forms based on Cs-loaded silicotitanates

International Nuclear Information System (INIS)

Balmer, M.L.; Bunker, B.C.

1995-04-01

Silicotitanate ion exchange materials are being considered for removal of radioactive Cs and Sr from tank wastes at the Hanford site. The phase evolution as a function of heat treatment temperature for several sol gel derived compositions within the Cs 2 O-SiO 2 -TiO 2 system was investigated, in order to determine if an adequate waste form can be achieved by direct thermal conversion. The Cs leach rates and Cs loss during heat treatment of select materials were measured. Some compositions which contain large amounts of Ti melt to form a glass with reasonably low aqueous leach rates. A new Cs-silicotitanate material with a structure isomorphous to pollucite was discovered. This material forms at low temperatures (700--800 C) where Cs volatility is negligible. The silicotitanate-pollucite exhibits extremely low leach rates (1.42 g/m 2 day ) at 90 C, and has been identified as a promising waste form for Cs containment

Maintenance Plan for the Hanford Immobilized Low-Activity Tank Waste Performance Assessment

International Nuclear Information System (INIS)

MANN, F.M.

2000-01-01

The plan for maintaining the Hanford Immobilized Low-Activity Tank Waste Performance Assessment (PA) is described. The plan includes expected work on PA reviews and revisions, waste reports, monitoring, other operational activities, etc

Sex differences in muscular load among house painters performing identical work tasks

DEFF Research Database (Denmark)

Meyland, Jacob; Heilskov-Hansen, Thomas; Alkjær, Tine

2014-01-01

PURPOSE: The present study aimed to estimate possible differences in upper body muscular load between male and female house painters performing identical work tasks. Sex-related differences in muscular load may help explain why women, in general, have more musculoskeletal complaints than men....... METHODS: In a laboratory setting, 16 male and 16 female house painters performed nine standardised work tasks common to house painters. Unilateral electromyography (EMG) recordings were obtained from the supraspinatus muscle by intramuscular electrodes and from the trapezius, extensor and flexor carpi...... radialis muscles by surface electrodes. Relative muscular loads in %EMGmax as well as exerted force in Newton, based on ramp calibrations, were assessed. Sex differences were tested using a mixed model approach. RESULTS: Women worked at about 50% higher relative muscular loads than men in the supraspinatus...

HIGH ALUMINUM HLW (HIGH LEVEL WASTE) GLASSES FOR HANFORD'S WTP (WASTE TREATMENT PROJECT)

International Nuclear Information System (INIS)

Kruger, A.A.; Bowan, B.W.; Joseph, I.; Gan, H.; Kot, W.K.; Matlack, K.S.; Pegg, I.L.

2010-01-01

This paper presents the results of glass formulation development and melter testing to identify high waste loading glasses to treat high-Al high level waste (HLW) at Hanford. Previous glass formulations developed for this HLW had high waste loadings but their processing rates were lower that desired. The present work was aimed at improving the glass processing rate while maintaining high waste loadings. Glass formulations were designed, prepared at crucible-scale and characterized to determine their properties relevant to processing and product quality. Glass formulations that met these requirements were screened for melt rates using small-scale tests. The small-scale melt rate screening included vertical gradient furnace (VGF) and direct feed consumption (DFC) melter tests. Based on the results of these tests, modified glass formulations were developed and selected for larger scale melter tests to determine their processing rate. Melter tests were conducted on the DuraMelter 100 (DMIOO) with a melt surface area of 0.11 m 2 and the DuraMelter 1200 (DMI200) HLW Pilot Melter with a melt surface area of 1.2 m 2 . The newly developed glass formulations had waste loadings as high as 50 wt%, with corresponding Al 2 O 3 concentration in the glass of 26.63 wt%. The new glass formulations showed glass production rates as high as 1900 kg/(m 2 .day) under nominal melter operating conditions. The demonstrated glass production rates are much higher than the current requirement of 800 kg/(m 2 .day) and anticipated future enhanced Hanford Tank Waste Treatment and Immobilization Plant (WTP) requirement of 1000 kg/(m 2 .day).

Performance of the IEEE 802.3 EPON registration scheme under high load

Science.gov (United States)

Bhatia, Swapnil P.; Bartos, Radim

2004-09-01

The proposed standard for the IEEE 802.3 Ethernet Passive Optical Network includes a random delayed transmission scheme for registration of new nodes. Although the scheme performs well on low loads, our simulation demonstrates the degraded and undesirable performance of the scheme at higher loads. We propose a simple modification to the current scheme that increases its range of operation and is compatible with the IEEE draft standard. We demonstrate the improvement in performance gained without any significant increase in registration delay.

Management of cesium loaded AMP- Part I preparation of 137Cesium concentrate and cementation of secondary wastes

International Nuclear Information System (INIS)

Singh, I.J.; Sathi Sasidharan, N.; Yalmali, Vrunda S.; Deshingkar, D.S.; Wattal, P.K.

2005-11-01

Separation of 137 cesium from High Level Waste can be achieved by use of composite-AMP, an engineered form of Ammonium Molybdo-Phosphate(AMP). Direct vitrification of cesium loaded composite AMP in borosilicate glass matrix leads to separation of water soluble molybdate phase. A proposed process describes two different routes of selective separation of molybdates and phosphate to obtain solutions of cesium concentrates. Elution of 137 Cesium from composite-AMP by decomposing it under flow conditions using saturated barium hydroxide was investigated. This method leaves molybdate and phosphate embedded in the column but only 70% of total cesium loaded on column could be eluted. Alternatively composite-AMP was dissolved in sodium hydroxide and precipitation of barium molybdate-phosphate from the resultant solution, using barium nitrate was investigated by batch methods. The precipitation technique gave over 99.9% of 137 Cesium activity in solutions, free of molybdates and phosphates, which is ideally suited for immobilization in borosilicate glass matrix. Detailed studies were carried out to immobilize secondary waste of 137 Cesium contaminated barium molybdate-phosphate precipitates in the slag cement matrix using vermiculite and bentonite as admixtures. The cumulative fraction of 137 Cs leached from the cement matrix blocks was 0.05 in 140 days while the 137 Cs leach rate was 0.001 gm/cm 2 /d. (author)

Performance of high level waste forms and engineered barriers under repository conditions

International Nuclear Information System (INIS)

1991-02-01

The IAEA initiated in 1977 a co-ordinated research programme on the ''Evaluation of Solidified High-Level Waste Forms'' which was terminated in 1983. As there was a continuing need for international collaboration in research on solidified high-level waste form and spent fuel, the IAEA initiated a new programme in 1984. The new programme, besides including spent fuel and SYNROC, also placed greater emphasis on the effect of the engineered barriers of future repositories on the properties of the waste form. These engineered barriers included containers, overpacks, buffer and backfill materials etc. as components of the ''near-field'' of the repository. The Co-ordinated Research Programme on the Performance of High-Level Waste Forms and Engineered Barriers Under Repository Conditions had the objectives of promoting the exchange of information on the experience gained by different Member States in experimental performance data and technical model evaluation of solidified high level waste forms, components of the waste package and the complete waste management system under conditions relevant to final repository disposal. The programme includes studies on both irradiated spent fuel and glass and ceramic forms as the final solidified waste forms. The following topics were discussed: Leaching of vitrified high-level wastes, modelling of glass behaviour in clay, salt and granite repositories, environmental impacts of radionuclide release, synroc use for high--level waste solidification, leachate-rock interactions, spent fuel disposal in deep geologic repositories and radionuclide release mechanisms from various fuel types, radiolysis and selective leaching correlated with matrix alteration. Refs, figs and tabs

Advanced waste form and melter development for treatment of troublesome high-level wastes

Energy Technology Data Exchange (ETDEWEB)

Marra, James [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kim, Dong -Sang [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maio, Vincent [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-02

A number of waste components in US defense high level radioactive wastes (HLW) have proven challenging for current Joule heated ceramic melter (JHCM) operations and have limited the ability to increase waste loadings beyond already realized levels. Many of these "troublesome" waste species cause crystallization in the glass melt that can negatively impact product quality or have a deleterious effect on melter processing. Recent efforts at US Department of Energy laboratories have focused on understanding crystallization behavior within HLW glass melts and investigating approached to mitigate the impacts of crystallization so that increases in waste loading can be realized. Advanced glass formulations have been developed to highlight the unique benefits of next-generation melter technologies such as the Cold Crucible Induction Melter (CCIM). Crystal-tolerant HLW glasses have been investigated to allow sparingly soluble components such as chromium to crystallize in the melter but pass out of the melter before accumulating.

Waste form performance assessment in the YUCCA Mountain engineered barrier system, American Nuclear Society

International Nuclear Information System (INIS)

Morris, E. E.; Fanning, T. H.; Wigeland, R. A.

2000-01-01

This work demonstrates a technique for comparing the performance of waste forms in a repository environment when one or more of the waste forms constitute a small part of the total amount of waste planned for the repository. In applying the technique, it is important to identify radionuclides that are highly soluble in the transport fluid since it is only for these that the release is controlled by the dissolution rate of the waste form matrix. The techniques presented here have been applied to an evaluation of the performance of waste forms from the electrometallurgical treatment of spent fuel in the proposed Yucca Mountain Repository Engineered Barrier System (EBS)

Characteristics and Performance of Existing Load Disaggregation Technologies

Energy Technology Data Exchange (ETDEWEB)

Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sullivan, Greg P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Butner, Ryan S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hao, He [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baechler, Michael C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-04-10

Non-intrusive load monitoring (NILM) or non-intrusive appliance load monitoring (NIALM) is an analytic approach to disaggregate building loads based on a single metering point. This advanced load monitoring and disaggregation technique has the potential to provide an alternative solution to high-priced traditional sub-metering and enable innovative approaches for energy conservation, energy efficiency, and demand response. However, since the inception of the concept in the 1980’s, evaluations of these technologies have focused on reporting performance accuracy without investigating sources of inaccuracies or fully understanding and articulating the meaning of the metrics used to quantify performance. As a result, the market for, as well as, advances in these technologies have been slowly maturing.To improve the market for these NILM technologies, there has to be confidence that the deployment will lead to benefits. In reality, every end-user and application that this technology may enable does not require the highest levels of performance accuracy to produce benefits. Also, there are other important characteristics that need to be considered, which may affect the appeal of NILM products to certain market targets (i.e. residential and commercial building consumers) and the suitability for particular applications. These characteristics include the following: 1) ease of use, the level of expertise/bandwidth required to properly use the product; 2) ease of installation, the level of expertise required to install along with hardware needs that impact product cost; and 3) ability to inform decisions and actions, whether the energy outputs received by end-users (e.g. third party applications, residential users, building operators, etc.) empower decisions and actions to be taken at time frames required for certain applications. Therefore, stakeholders, researchers, and other interested parties should be kept abreast of the evolving capabilities, uses, and characteristics

Fate of high loads of ammonia in a pond and wetland downstream from a hazardous waste disposal site.

Science.gov (United States)

Cutrofello, Michele; Durant, John L

2007-07-01

Halls Brook (eastern Massachusetts, USA) is a significant source of total dissolved ammonia (sum of NH(3) and NH(4)(+); (NH(3))(T)) to the Aberjona River, a water body listed for NH(3) impairment on the Clean Water Act section 303(d) list. We hypothesized (1) that (NH(3))(T) in Halls Brook derived from a hazardous waste site via groundwater discharging to a two-basin pond that feeds the brook; and (2) that transport of (NH(3))(T) to the Aberjona River was controlled by lacustrine and wetland processes. To test these hypotheses we measured (NH(3))(T) levels in the brook, the pond, and a wetlands directly downstream of the pond during both dry and wet weather over a ten month period. In addition, we analyzed sediment cores and nitrogen isotopes, and performed mass balance calculations. Groundwater discharge from beneath the hazardous waste site was the major source of (NH(3))(T) (20-67 kg d(-1)) and salinity to the north basin of the pond. The salty bottom waters of the north basin were anoxic on all sampling dates, and exhibited relatively stable (NH(3))(T) concentrations between 200 and 600 mg Nl(-1). These levels were >100-times higher than typical background levels, and 8-24-times above the acute effects level for (NH(3))(T) toxicity. Bottom waters from the north basin continuously spill over into the south basin contributing approximately 50% of the (NH(3))(T) load entering this basin. The remainder comes from Halls Brook, which receives (NH(3))(T) loadings from as yet unknown sources upstream. During storm events up to 50% of the mass of (NH(3))(T) was flushed from the south basin and into the wetlands. The wetlands acted as a (NH(3))(T) sink in dry weather in the growing season and a discharge-dependent (NH(3))(T) source to the Aberjona River during rainstorms.

MELT RATE ENHANCEMENT FOR HIGH ALUMINUM HLW (HIGH LEVEL WASTE) GLASS FORMULATION FINAL REPORT 08R1360-1

Energy Technology Data Exchange (ETDEWEB)

KRUGER AA; MATLACK KS; KOT W; PEGG IL; JOSEPH I; BARDAKCI T; GAN H; GONG W; CHAUDHURI M

2010-01-04

This report describes the development and testing of new glass formulations for high aluminum waste streams that achieve high waste loadings while maintaining high processing rates. The testing was based on the compositions of Hanford High Level Waste (HLW) with limiting concentrations of aluminum specified by the Office of River Protection (ORP). The testing identified glass formulations that optimize waste loading and waste processing rate while meeting all processing and product quality requirements. The work included preparation and characterization of crucible melts and small scale melt rate screening tests. The results were used to select compositions for subsequent testing in a DuraMelter 100 (DM100) system. These tests were used to determine processing rates for the selected formulations as well as to examine the effects of increased glass processing temperature, and the form of aluminum in the waste simulant. Finally, one of the formulations was selected for large-scale confirmatory testing on the HLW Pilot Melter (DM1200), which is a one third scale prototype of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) HLW melter and off-gas treatment system. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy (DOE) to increase waste loading and processing rates for high-iron HLW waste streams as well as previous tests conducted for ORP on the same high-aluminum waste composition used in the present work and other Hanford HLW compositions. The scope of this study was outlined in a Test Plan that was prepared in response to an ORP-supplied statement of work. It is currently estimated that the number of HLW canisters to be produced in the WTP is about 13,500 (equivalent to 40,500 MT glass). This estimate is based upon the inventory of the tank wastes, the anticipated performance of the sludge treatment processes, and current understanding of the capability of the borosilicate glass waste form

MELT RATE ENHANCEMENT FOR HIGH ALUMINUM HLW (HIGH LEVEL WASTE) GLASS FORMULATION. FINAL REPORT 08R1360-1

International Nuclear Information System (INIS)

Kruger, A.A.; Matlack, K.S.; Kot, W.; Pegg, I.L.; Joseph, I.; Bardakci, T.; Gan, H.; Gong, W.; Chaudhuri, M.

2010-01-01

This report describes the development and testing of new glass formulations for high aluminum waste streams that achieve high waste loadings while maintaining high processing rates. The testing was based on the compositions of Hanford High Level Waste (HLW) with limiting concentrations of aluminum specified by the Office of River Protection (ORP). The testing identified glass formulations that optimize waste loading and waste processing rate while meeting all processing and product quality requirements. The work included preparation and characterization of crucible melts and small scale melt rate screening tests. The results were used to select compositions for subsequent testing in a DuraMelter 100 (DM100) system. These tests were used to determine processing rates for the selected formulations as well as to examine the effects of increased glass processing temperature, and the form of aluminum in the waste simulant. Finally, one of the formulations was selected for large-scale confirmatory testing on the HLW Pilot Melter (DM1200), which is a one third scale prototype of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) HLW melter and off-gas treatment system. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy (DOE) to increase waste loading and processing rates for high-iron HLW waste streams as well as previous tests conducted for ORP on the same high-aluminum waste composition used in the present work and other Hanford HLW compositions. The scope of this study was outlined in a Test Plan that was prepared in response to an ORP-supplied statement of work. It is currently estimated that the number of HLW canisters to be produced in the WTP is about 13,500 (equivalent to 40,500 MT glass). This estimate is based upon the inventory of the tank wastes, the anticipated performance of the sludge treatment processes, and current understanding of the capability of the borosilicate glass waste form

Performance Analysis of Savonius Rotor Based Hydropower Generation Scheme with Electronic Load Controller

Directory of Open Access Journals (Sweden)

Rajen Pudur

2016-01-01

Full Text Available This paper describes the performance of electronic load controller (ELC of asynchronous generator (AG coupled to an uncontrolled Savonius turbine and variable water velocity. An AC-DC-AC converter with a dc link capacitor is employed to maintain the required frequency. The ELC which is feeding a resistive dump load is connected in parallel with the generating system and the power consumption is varied through the duty cycle of the chopper. Gate triggering of ELC is accomplished through sinusoidal pulse width modulation (SPWM by sensing the load current. A MATLAB/Simulink model of Savonius rotor, asynchronous generator, ELC, and three-phase load is presented. The proposed scheme is tested under various load conditions under varying water velocities and the performances are observed to be satisfactory.

Low-level radioactive waste performance assessments: Source term modeling

International Nuclear Information System (INIS)

Icenhour, A.S.; Godbee, H.W.; Miller, L.F.

1995-01-01

Low-level radioactive wastes (LLW) generated by government and commercial operations need to be isolated from the environment for at least 300 to 500 yr. Most existing sites for the storage or disposal of LLW employ the shallow-land burial approach. However, the U.S. Department of Energy currently emphasizes the use of engineered systems (e.g., packaging, concrete and metal barriers, and water collection systems). Future commercial LLW disposal sites may include such systems to mitigate radionuclide transport through the biosphere. Performance assessments must be conducted for LUW disposal facilities. These studies include comprehensive evaluations of radionuclide migration from the waste package, through the vadose zone, and within the water table. Atmospheric transport mechanisms are also studied. Figure I illustrates the performance assessment process. Estimates of the release of radionuclides from the waste packages (i.e., source terms) are used for subsequent hydrogeologic calculations required by a performance assessment. Computer models are typically used to describe the complex interactions of water with LLW and to determine the transport of radionuclides. Several commonly used computer programs for evaluating source terms include GWSCREEN, BLT (Breach-Leach-Transport), DUST (Disposal Unit Source Term), BARRIER (Ref. 5), as well as SOURCE1 and SOURCE2 (which are used in this study). The SOURCE1 and SOURCE2 codes were prepared by Rogers and Associates Engineering Corporation for the Oak Ridge National Laboratory (ORNL). SOURCE1 is designed for tumulus-type facilities, and SOURCE2 is tailored for silo, well-in-silo, and trench-type disposal facilities. This paper focuses on the source term for ORNL disposal facilities, and it describes improved computational methods for determining radionuclide transport from waste packages

Random spectrum loading of dental implants: An alternative approach to functional performance assessment.

Science.gov (United States)

Shemtov-Yona, K; Rittel, D

2016-09-01

The fatigue performance of dental implants is usually assessed on the basis of cyclic S/N curves. This neither provides information on the anticipated service performance of the implant, nor does it allow for detailed comparisons between implants unless a thorough statistical analysis is performed, of the kind not currently required by certification standards. The notion of endurance limit is deemed to be of limited applicability, given unavoidable stress concentrations and random load excursions, that all characterize dental implants and their service conditions. We propose a completely different approach, based on random spectrum loading, as long used in aeronautical design. The implant is randomly loaded by a sequence of loads encompassing all load levels it would endure during its service life. This approach provides a quantitative and comparable estimate of its performance in terms of lifetime, based on the very fact that the implant will fracture sooner or later, instead of defining a fatigue endurance limit of limited practical application. Five commercial monolithic Ti-6Al-4V implants were tested under cyclic, and another 5 under spectrum loading conditions, at room temperature and dry air. The failure modes and fracture planes were identical for all implants. The approach is discussed, including its potential applications, for systematic, straightforward and reliable comparisons of various implant designs and environments, without the need for cumbersome statistical analyses. It is believed that spectrum loading can be considered for the generation of new standardization procedures and design applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radioactive Demonstration Of Mineralized Waste Forms Made From Hanford Low Activity Waste (Tank Farm Blend) By Fluidized Bed Steam Reformation (FBSR)

International Nuclear Information System (INIS)

Jantzen, C. M.; Crawford, C. L.; Bannochie, C. J.; Burket, P. R.; Cozzi, A. D.; Daniel, W. E.; Hall, H. K.; Miller, D. H.; Missimer, D. M.; Nash, C. A.; Williams, M. F.

2013-01-01

Standards (UTS). Two identical Benchscale Steam Reformers (BSR) were designed and constructed at SRNL, one to treat non-radioactive simulants and the other to treat actual radioactive wastes. The results from the non-radioactive BSR were used to determine the parameters needed to operate the radioactive BSR in order to confirm the findings of non-radioactive FBSR pilot scale and engineering scale tests and to qualify an FBSR LAW waste form for applications at Hanford. Radioactive testing commenced using SRS LAW from Tank 50 chemically trimmed to look like Hanford's blended LAW known as the Rassat simulant as this simulant composition had been tested in the non-radioactive BSR, the non-radioactive pilot scale FBSR at the Science Applications International Corporation-Science and Technology Applications Research (SAIC-STAR) facility in Idaho Falls, ID and in the TTT Engineering Scale Technology Demonstration (ESTD) at Hazen Research Inc. (HRI) in Denver, CO. This provided a ''tie back'' between radioactive BSR testing and non-radioactive BSR, pilot scale, and engineering scale testing. Approximately six hundred grams of non-radioactive and radioactive BSR product were made for extensive testing and comparison to the non-radioactive pilot scale tests performed in 2004 at SAIC-STAR and the engineering scale test performed in 2008 at HRI with the Rassat simulant. The same mineral phases and off-gas species were found in the radioactive and non-radioactive testing. The granular ESTD and BSR products (radioactive and non-radioactive) were analyzed for total constituents and durability tested as a granular waste form. A subset of the granular material was stabilized in a clay based geopolymer matrix at 42% and 65% FBSR loadings and durability tested as a monolith waste form. The 65 wt% FBSR loaded monolith made with clay (radioactive) was more durable than the 67-68 wt% FBSR loaded monoliths made from fly ash (non-radioactive) based on short term PCT testing. Long term, 90 to 107

Methods of calculating the post-closure performance of high-level waste repositories

Energy Technology Data Exchange (ETDEWEB)

Ross, B. (ed.)

1989-02-01

This report is intended as an overview of post-closure performance assessment methods for high-level radioactive waste repositories and is designed to give the reader a broad sense of the state of the art of this technology. As described here, ''the state of the art'' includes only what has been reported in report, journal, and conference proceedings literature through August 1987. There is a very large literature on the performance of high-level waste repositories. In order to make a review of this breadth manageable, its scope must be carefully defined. The essential principle followed is that only methods of calculating the long-term performance of waste repositories are described. The report is organized to reflect, in a generalized way, the logical order to steps that would be taken in a typical performance assessment. Chapter 2 describes ways of identifying scenarios and estimating their probabilities. Chapter 3 presents models used to determine the physical and chemical environment of a repository, including models of heat transfer, radiation, geochemistry, rock mechanics, brine migration, radiation effects on chemistry, and coupled processes. The next two chapters address the performance of specific barriers to release of radioactivity. Chapter 4 treats engineered barriers, including containers, waste forms, backfills around waste packages, shaft and borehole seals, and repository design features. Chapter 5 discusses natural barriers, including ground water systems and stability of salt formations. The final chapters address optics of general applicability to performance assessment models. Methods of sensitivity and uncertainty analysis are described in Chapter 6, and natural analogues of repositories are treated in Chapter 7. 473 refs., 19 figs., 2 tabs.

Methods of calculating the post-closure performance of high-level waste repositories

International Nuclear Information System (INIS)

Ross, B.

1989-02-01

This report is intended as an overview of post-closure performance assessment methods for high-level radioactive waste repositories and is designed to give the reader a broad sense of the state of the art of this technology. As described here, ''the state of the art'' includes only what has been reported in report, journal, and conference proceedings literature through August 1987. There is a very large literature on the performance of high-level waste repositories. In order to make a review of this breadth manageable, its scope must be carefully defined. The essential principle followed is that only methods of calculating the long-term performance of waste repositories are described. The report is organized to reflect, in a generalized way, the logical order to steps that would be taken in a typical performance assessment. Chapter 2 describes ways of identifying scenarios and estimating their probabilities. Chapter 3 presents models used to determine the physical and chemical environment of a repository, including models of heat transfer, radiation, geochemistry, rock mechanics, brine migration, radiation effects on chemistry, and coupled processes. The next two chapters address the performance of specific barriers to release of radioactivity. Chapter 4 treats engineered barriers, including containers, waste forms, backfills around waste packages, shaft and borehole seals, and repository design features. Chapter 5 discusses natural barriers, including ground water systems and stability of salt formations. The final chapters address optics of general applicability to performance assessment models. Methods of sensitivity and uncertainty analysis are described in Chapter 6, and natural analogues of repositories are treated in Chapter 7. 473 refs., 19 figs., 2 tabs

Effects of a gradually increased load of fish waste silage in co-digestion with cow manure on methane production

International Nuclear Information System (INIS)

Solli, Linn; Bergersen, Ove; Sørheim, Roald; Briseid, Tormod

2014-01-01

Highlights: • New results from continuous anaerobic co-digestion of fish waste silage (FWS) and cow manure (CM). • Co-digestion of FWS and CM has a high biogas potential. • Optimal mixing ratio of FWS/CM is 13–16/87–84 volume%. • High input of FWS leads to accumulation of NH4+ and VFAs and process failure. - Abstract: This study examined the effects of an increased load of nitrogen-rich organic material on anaerobic digestion and methane production. Co-digestion of fish waste silage (FWS) and cow manure (CM) was studied in two parallel laboratory-scale (8 L effective volume) semi-continuous stirred tank reactors (designated R1 and R2). A reactor fed with CM only (R0) was used as control. The reactors were operated in the mesophilic range (37 °C) with a hydraulic retention time of 30 days, and the entire experiment lasted for 450 days. The rate of organic loading was raised by increasing the content of FWS in the feed stock. During the experiment, the amount (volume%) of FWS was increased stepwise in the following order: 3% – 6% – 13% – 16%, and 19%. Measurements of methane production, and analysis of volatile fatty acids, ammonium and pH in the effluents were carried out. The highest methane production from co-digestion of FWS and CM was 0.400 L CH4 gVS −1 , obtained during the period with loading of 16% FWS in R2. Compared to anaerobic digestion of CM only, the methane production was increased by 100% at most, when FWS was added to the feed stock. The biogas processes failed in R1 and R2 during the periods, with loadings of 16% and 19% FWS, respectively. In both reactors, the biogas processes failed due to overloading and accumulation of ammonia and volatile fatty acids

Draft Technical Position Subtask 1.1: waste package performance after repository closure. Volume 1

International Nuclear Information System (INIS)

Davis, M.S.; Schweitzer, D.G.

1983-08-01

This document provides guidance to the DOE on the issues and information necessary for the NRC to evaluate waste package performance after repository closure. Minimal performance objectives of the waste package are required by proposed 10 CFR 60. This Draft Technical Position describes the various options available to the DOE for compliance and discusses advantages and disadvantages of various choices. Examples are discussed dealing with demonstrability, predictability and reasonable assurance. The types of performance are considered. The document summarizes presently identified high priority issues needed to evaluate waste package performance after repository closure. 20 references, 7 tables

Performance evaluation of Genetic Algorithms on loading pattern optimization of PWRs

International Nuclear Information System (INIS)

Tombakoglu, M.; Bekar, K.B.; Erdemli, A.O.

2001-01-01

Genetic Algorithm (GA) based systems are used for search and optimization problems. There are several applications of GAs in literature successfully applied for loading pattern optimization problems. In this study, we have selected loading pattern optimization problem of Pressurised Water Reactor (PWR). The main objective of this work is to evaluate the performance of Genetic Algorithm operators such as regional crossover, crossover and mutation, and selection and construction of initial population and its size for PWR loading pattern optimization problems. The performance of GA with antithetic variates is compared to traditional GA. Antithetic variates are used to generate the initial population and its use with GA operators are also discussed. Finally, the results of multi-cycle optimization problems are discussed for objective function taking into account cycle burn-up and discharge burn-up.(author)

Durability of incinerator ash waste encapsulated in modified sulfur cement

International Nuclear Information System (INIS)

Kalb, P.D.; Heiser, J.H. III; Pietrzak, R.; Colombo, P.

1991-01-01

Waste form stability under anticipated disposal conditions is an important consideration for ensuring continued isolation of contaminants from the accessible environment. Modified sulfur cement is a relatively new material and has only recently been applied as a binder for encapsulation of mixed wastes. Little data are available concerning its long-term durability. Therefore, a series of property evaluation tests for both binder and waste-binder combinations have been conducted to examine potential waste form performance under storage and disposal conditions. These tests include compressive strength, biodegradation, radiation stability, water immersion, thermal cycling, and leaching. Waste form compressive strength increased with ash waste loadings to 30.5 MPa at a maximum incinerator ash loading of 43 wt %. Biodegradation testing resulted in no visible microbial growth of either bacteria or fungi. Initial radiation stability testing did not reveal statistically significant deterioration in structural integrity. Results of 90 day water immersion tests were dependent on the type of ash tested. There were no statistically significant changes in compressive strength detected after completion of thermal cycle testing. Radionuclides from ash waste encapsulated in modified sulfur cement leached between 5 and 8 orders of magnitude slower than the leach index criterion established by the Nuclear Regulatory Commission (NRC) for low-level radioactive waste. Modified sulfur cement waste forms containing up to 43 wt % incinerator fly ash passed EPA Toxicity Characteristic Leaching Procedure (TCLP) criteria for lead and cadmium leachability. 11 refs., 2 figs., 5 tabs

Proposal of an environmental performance index to assess solid waste treatment technologies

International Nuclear Information System (INIS)

Goulart Coelho, Hosmanny Mauro; Lange, Liséte Celina; Coelho, Lineker Max Goulart

2012-01-01

Highlights: ► Proposal of a new concept in waste management: Cleaner Treatment. ► Development of an index to assess quantitatively waste treatment technologies. ► Delphi Method was carried out so as to define environmental indicators. ► Environmental performance evaluation of waste-to-energy plants. - Abstract: Although the concern with sustainable development and environment protection has considerably grown in the last years it is noted that the majority of decision making models and tools are still either excessively tied to economic aspects or geared to the production process. Moreover, existing models focus on the priority steps of solid waste management, beyond waste energy recovery and disposal. So, in order to help the lack of models and tools aiming at the waste treatment and final disposal, a new concept is proposed: the Cleaner Treatment, which is based on the Cleaner Production principles. This paper focuses on the development and validation of the Cleaner Treatment Index (CTI), to assess environmental performance of waste treatment technologies based on the Cleaner Treatment concept. The index is formed by aggregation (summation or product) of several indicators that consists in operational parameters. The weights of the indicator were established by Delphi Method and Brazilian Environmental Laws. In addition, sensitivity analyses were carried out comparing both aggregation methods. Finally, index validation was carried out by applying the CTI to 10 waste-to-energy plants data. From sensitivity analysis and validation results it is possible to infer that summation model is the most suitable aggregation method. For summation method, CTI results were superior to 0.5 (in a scale from 0 to 1) for most facilities evaluated. So, this study demonstrates that CTI is a simple and robust tool to assess and compare the environmental performance of different treatment plants being an excellent quantitative tool to support Cleaner Treatment implementation.

Performance Values for Non-Destructive Assay (NDA) Technique Applied to Wastes: Evaluation by the ESARDA NDA Working Group

International Nuclear Information System (INIS)

Rackham, Jamie; Weber, Anne-Laure; Chard, Patrick

2012-01-01

The first evaluation of NDA performance values was undertaken by the ESARDA Working Group for Standards and Non Destructive Assay Techniques and was published in 1993. Almost ten years later in 2002 the Working Group reviewed those values and reported on improvements in performance values and new measurement techniques that had emerged since the original assessment. The 2002 evaluation of NDA performance values did not include waste measurements (although these had been incorporated into the 1993 exercise), because although the same measurement techniques are generally applied, the performance is significantly different compared to the assay of conventional Safeguarded special nuclear material. It was therefore considered more appropriate to perform a separate evaluation of performance values for waste assay. Waste assay is becoming increasingly important within the Safeguards community, particularly since the implementation of the Additional Protocol, which calls for declaration of plutonium and HEU bearing waste in addition to information on existing declared material or facilities. Improvements in the measurement performance in recent years, in particular the accuracy, mean that special nuclear materials can now be accounted for in wastes with greater certainty. This paper presents an evaluation of performance values for the NDA techniques in common usage for the assay of waste containing special nuclear material. The main topics covered by the document are: 1- Techniques for plutonium bearing solid wastes 2- Techniques for uranium bearing solid wastes 3 - Techniques for assay of fissile material in spent fuel wastes. Originally it was intended to include performance values for measurements of uranium and plutonium in liquid wastes; however, as no performance data for liquid waste measurements was obtained it was decided to exclude liquid wastes from this report. This issue of the performance values for waste assay has been evaluated and discussed by the ESARDA

Performance Values for Non-Destructive Assay (NDA) Technique Applied to Wastes: Evaluation by the ESARDA NDA Working Group

Energy Technology Data Exchange (ETDEWEB)

Rackham, Jamie [Babcock International Group, Sellafield, Seascale, Cumbria, (United Kingdom); Weber, Anne-Laure [Institut de Radioprotection et de Surete Nucleaire Fontenay-Aux-Roses (France); Chard, Patrick [Canberra, Forss Business and Technology park, Thurso, Caithness (United Kingdom)

2012-12-15

The first evaluation of NDA performance values was undertaken by the ESARDA Working Group for Standards and Non Destructive Assay Techniques and was published in 1993. Almost ten years later in 2002 the Working Group reviewed those values and reported on improvements in performance values and new measurement techniques that had emerged since the original assessment. The 2002 evaluation of NDA performance values did not include waste measurements (although these had been incorporated into the 1993 exercise), because although the same measurement techniques are generally applied, the performance is significantly different compared to the assay of conventional Safeguarded special nuclear material. It was therefore considered more appropriate to perform a separate evaluation of performance values for waste assay. Waste assay is becoming increasingly important within the Safeguards community, particularly since the implementation of the Additional Protocol, which calls for declaration of plutonium and HEU bearing waste in addition to information on existing declared material or facilities. Improvements in the measurement performance in recent years, in particular the accuracy, mean that special nuclear materials can now be accounted for in wastes with greater certainty. This paper presents an evaluation of performance values for the NDA techniques in common usage for the assay of waste containing special nuclear material. The main topics covered by the document are: 1- Techniques for plutonium bearing solid wastes 2- Techniques for uranium bearing solid wastes 3 - Techniques for assay of fissile material in spent fuel wastes. Originally it was intended to include performance values for measurements of uranium and plutonium in liquid wastes; however, as no performance data for liquid waste measurements was obtained it was decided to exclude liquid wastes from this report. This issue of the performance values for waste assay has been evaluated and discussed by the ESARDA

Radium bearing waste disposal

International Nuclear Information System (INIS)

Tope, W.G.; Nixon, D.A.; Smith, M.L.; Stone, T.J.; Vogel, R.A.; Schofield, W.D.

1995-01-01

Fernald radium bearing ore residue waste, stored within Silos 1 and 2 (K-65) and Silo 3, will be vitrified for disposal at the Nevada Test Site (NTS). A comprehensive, parametric evaluation of waste form, packaging, and transportation alternatives was completed to identify the most cost-effective approach. The impacts of waste loading, waste form, regulatory requirements, NTS waste acceptance criteria, as-low-as-reasonably-achievable principles, and material handling costs were factored into the recommended approach

The effects of self-report cognitive failures and cognitive load on antisaccade performance

Directory of Open Access Journals (Sweden)

Nick eBerggren

2011-10-01

Full Text Available Individuals reporting high levels of distractibility in everyday life show impaired performance in standard laboratory tasks measuring selective attention and inhibitory processes. Similarly, increasing cognitive load leads to more errors/distraction in a variety of cognitive tasks. How these two factors interact is currently unclear; highly distractible individuals may be affected more when their cognitive resources are taxed, or load may linearly affect performance for all individuals. We investigated the relationship between self-reported levels of cognitive failuresin daily life and performance in the antisaccade task, a widely used tool examining attentional control. Levels of concurrent cognitive demand were manipulated using a secondary auditory discrimination task. We found that both levels of self-reported cognitive failures and task load increased antisaccade latencies while having no effect on prosaccade eye-movements. However individuals rating themselves as suffering few daily life distractions showed a comparable load cost to those who experience many. These findings suggest that the likelihood of distraction is governed by the addition of both internal susceptibility and the external current load placed on working memory.

The 1996 performance assessment for the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Anderson, D.R.; Jow, H.N.; Marietta, M.G.; Chu, M.S.Y.; Shephard, L.E.; Helton, J.C.; Basabilvazo, G.

1998-01-01

The Waste Isolation Pilot Plant (WIPP) is under development by the US Department of Energy (DOE) for the geologic disposal of transuranic (TRU) waste that has been generated at government defense installations in the United States. The WIPP is located in an area of low population density in southeastern New Mexico. Waste disposal will take place in excavated chambers in a bedded salt formation approximately 655 m below the land surface. This presentation describes a performance assessment (PA) carried out at Sandia National Laboratories (SNL) to support the Compliance Certification Application (CCA) made by the DOE to the US Environmental Protection Agency (EPA) in October, 1996, for the certification of the WIPP for the disposal of TRU waste. Based on the CCA supported by the PA described in this presentation, the EPA has issued a preliminary decision to certify the WIPP for the disposal of TRU waste. At present (April 1998), it appears likely that the WIPP will be in operation by the end of 1998

Pre-aeration of food waste to augment acidogenic process at higher organic load: Valorizing biohydrogen, volatile fatty acids and biohythane.

Science.gov (United States)

Sarkar, Omprakash; Venkata Mohan, S

2017-10-01

Application of pre-aeration (AS) to waste prior to feeding was evaluated on acidogenic process in a semi-pilot scale biosystem for the production of biobased products (biohydrogen, volatile fatty acids (VFA) and biohythane) from food waste. Oxygen assisted in pre-hydrolysis of waste along with the suppression of methanogenic activity resulting in enhanced acidogenic product formation. AS operation resulted in 97% improvement in hydrogen conversion efficiency (HCE) and 10% more VFA production than the control. Increasing the organic load (OL) of food waste in association with AS application improved the productivity. The application of AS also influenced concentration and composition of fatty acid. Highest fraction of acetic (5.3g/l), butyric (0.7g/l) and propionic acid (0.84g/l) was achieved at higher OL (100g COD/l) with good degree of acidification (DOA). AS strategy showed positive influence on biofuel (biohydrogen and biohythane) production along with the biosynthesis of short chain fatty acids functioning as a low-cost pretreatment strategy in a single stage bioprocess. Copyright © 2017 Elsevier Ltd. All rights reserved.

The use of performance assessments in Yucca Mountain repository waste package design activities

International Nuclear Information System (INIS)

Jardine, L.J.

1990-01-01

The Yucca Mountain Project is developing performance assessment approaches as part of the evaluations of the suitability of Yucca Mountain as a repository site. Lawrence Livermore National Laboratory is developing design concepts and the scientific performance assessment methodologies and techniques used for the waste package and engineered barrier system components. This paper presents an overview of the approach under development for postclosure performance assessments that will guide the conceptual design activities and assist in the site suitability evaluations. This approach includes establishing and modeling for the long time periods required by regulations: near-field environment characteristics surrounding the emplaced wastes; container materials performance responses; and waste form properties. All technical work is being done under a fully qualified quality assurance program

Radioactive Demonstration Of Mineralized Waste Forms Made From Hanford Low Activity Waste (Tank Farm Blend) By Fluidized Bed Steam Reformation (FBSR)

Energy Technology Data Exchange (ETDEWEB)

Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Cozzi, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Daniel, W. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hall, H. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Miller, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Missimer, D. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2013-08-01

-radioactive testing. The granular ESTD and BSR products (radioactive and non-radioactive) were analyzed for total constituents and durability tested as a granular waste form. A subset of the granular material was stabilized in a clay based geopolymer matrix at 42% and 65% FBSR loadings and durability tested as a monolith waste form. The 65 wt% FBSR loaded monolith made with clay (radioactive) was more durable than the 67-68 wt% FBSR loaded monoliths made from fly ash (non-radioactive) based on short term PCT testing. Long term, 90 to 107 day, ASTM C1308 testing (similar to ANSI/ANS 16.1 testing) was only performed on two fly ash geopolymer monoliths at 67-68 wt% FBSR loading and three clay geopolymer monoliths at 42 wt% FBSR loading. More clay geopolymers need to be made and tested at longer times at higher FBSR loadings for comparison to the fly ash monoliths. Monoliths made with metakaolin (heat treated) clay are of a more constant composition and are very reactive as the heat treated clay is amorphous and alkali activated. The monoliths made with fly ash are subject to the inherent compositional variation found in fly ash as it is a waste product from burning coal and it contains unreactive components such as mullite. However, both the fly ash and the clay based monoliths perform well in long term ASTM C1308 testing.

The performance assessment impacts of disposal of high-moisture, low-level radioactive waste at the Nevada Test Site

International Nuclear Information System (INIS)

Crowe, B.M.; Hansen, W.; Hechnova, A.; Voss, C.; Waters, R.; Sully, M.; Levitt, D.

1999-01-01

A panel of independent scientists was convened by the Department of Energy to assess the performance impacts of disposal of low-level radioactive waste from the Fernald Environmental Management Project. This waste stream was involved in a transportation incident in December 1997. A resulting outgrowth of investigations of the transportation incident was the recognition that the waste was transported and disposed in stress-fractured metal boxes and some of the waste contained excess moisture (high volumetric water contents). The panel was charged with determining whether disposal of this waste in the Area 5 radioactive waste management site on the Nevada Test Site has impacted the conclusions of the completed performance assessment. Three questions were developed by the panel to assess performance impacts: (1) the performance impacts of reduced container integrity, (2) the impact of reduced container integrity on subsidence of waste in the disposal pits and (3) the performance impacts of excess moisture. No performance or subsidence impacts were noted from disposal of the Fernald waste. The impacts of excess moisture were assessed through simulation modeling of the movement of moisture in the vadose zone assuming high water contents (wet waste) for different percentages of the waste inventory. No performance impacts were noted for either the base-case scenario (ambient conditions) or a scenario involving subsidence and flooding of the waste cells. The absence of performance impacts results form the extreme conservatism used in the Area 5-performance assessment and the robust nature of the disposal site

Performance testing of waste forms in a tuff environment

International Nuclear Information System (INIS)

Oversby, V.M.

1983-11-01

This paper describes experimental work conducted to establish the chemical composition of water which will have reacted with Topopah Spring Member tuff prior to contact with waste packages. The experimental program to determine the behavior of spent fuel and borosilicate glass in the presence of this water is then described. Preliminary results of experiments using spent fuel segments with defects in the Zircaloy cladding are presented. Some results from parametric testing of a borosilicate glass with tuff and 304L stainless steel are also discussed. Experiments conducted using Topopah Spring tuff and J-13 well water have been conducted to provide an estimate of the post-emplacement environment for waste packages in a repository at Yucca Mountain. The results show that emplacement of waste packages should cause only small changes in the water chemistry and rock mineralogy. The changes in environment should not have any detrimental effects on the performance of metal barriers or waste forms. The NNWSI waste form testing program has provided preliminary results related to the release rate of radionuclides from the waste package. Those results indicate that release rates from both spent fuel and borosilicate glass should be below 1 part in 10 5 per year. Future testing will be directed toward making release rate testing more closely relevant to site specific conditions. 17 references, 7 figures

Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) verification and validation plan. version 1.

Energy Technology Data Exchange (ETDEWEB)

Bartlett, Roscoe Ainsworth; Arguello, Jose Guadalupe, Jr.; Urbina, Angel; Bouchard, Julie F.; Edwards, Harold Carter; Freeze, Geoffrey A.; Knupp, Patrick Michael; Wang, Yifeng; Schultz, Peter Andrew; Howard, Robert (Oak Ridge National Laboratory, Oak Ridge, TN); McCornack, Marjorie Turner

2011-01-01

The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. To meet this objective, NEAMS Waste IPSC M&S capabilities will be applied to challenging spatial domains, temporal domains, multiphysics couplings, and multiscale couplings. A strategic verification and validation (V&V) goal is to establish evidence-based metrics for the level of confidence in M&S codes and capabilities. Because it is economically impractical to apply the maximum V&V rigor to each and every M&S capability, M&S capabilities will be ranked for their impact on the performance assessments of various components of the repository systems. Those M&S capabilities with greater impact will require a greater level of confidence and a correspondingly greater investment in V&V. This report includes five major components: (1) a background summary of the NEAMS Waste IPSC to emphasize M&S challenges; (2) the conceptual foundation for verification, validation, and confidence assessment of NEAMS Waste IPSC M&S capabilities; (3) specifications for the planned verification, validation, and confidence-assessment practices; (4) specifications for the planned evidence information management system; and (5) a path forward for the incremental implementation of this V&V plan.

A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.

Science.gov (United States)

Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

2010-03-01

The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. 2009 Elsevier Ltd. All rights reserved.

FY 93 thermal loading systems study final report: Volume 1. Revision 1

International Nuclear Information System (INIS)

Saterlie, S.F.; Thomson, B.H.

1994-01-01

The ability to meet the overall performance requirements for the proposed Mined Geology Disposal System at Yucca Mountain, Nevada requires the two major subsystem (natural barriers and engineered barriers) to positively contribute to containment and radionuclide isolation. In addition to the postclosure performance the proposed repository must meet preclosure requirements of safety, retrievability, and operability. Cost and schedule were also considered. The thermal loading strategy chosen may significantly affect both the postclosure and preclosure performance of the proposed repository. Although the current Site Characterization Plan reference case is 57 kilowatts (kW)/acre, other thermal loading strategies (different areal mass loadings) have been proposed which possess both advantages and disadvantages. The objectives of the FY 1993 Thermal Loading Study were to (1) place bounds on the thermal loading which would establish the loading regime that is ''too hot'' and the loading regime that is ''too cold'', to (2) ''grade'' or evaluate the performance, as a function of thermal loading, of the repository to contain high level wastes against performance criteria and to (3) evaluate the performance of the various options with respect to cost, safety, and operability. Additionally, the effort was to (4) identify important uncertainties that need to be resolved by tests and/or analyses in order to complete a performance assessment on the effects of thermal loading. The FY 1993 Thermal Loading Study was conducted from December 1, 1992 to December 30, 1993 and this final report provides the findings of the study. Volume 1 contains the Introduction; Performance requirements; Input and assumptions; Near-field thermal analysis; Far-field thermal analysis; Cost analysis; Other considerations; System analysis; Additional thermal analysis; and Conclusions and recommendations. 71 refs., 54 figs

MIIT: International in-situ testing of nuclear-waste glasses: Performance of SRS simulated waste glass after five years of burial at the Waste Isolation Pilot Plant (WIPP)

International Nuclear Information System (INIS)

Wicks, G.G.; Lodding, A.R.; Macedo, P.B.; Clark, D.E.

1991-01-01

In July of 1986, the first in-situ test involving burial of simulated high-level waste (HLW) forms conducted in the United States was started. This program, called the Materials Interface Interactions Test or MIIT, comprises the largest, most cooperative field-testing venture in the international waste management community. In July of 1991, the experimental portion of the 5-year MIIT study was completed on schedule. During this time interval, many in-situ measurements were performed, thousands of brine analyses conducted, and hundreds of waste glass and package components exhumed and evaluated after 6 mo., 1 yr., 2 yr. and 5 yr. burial periods. Although analyses are still in progress, the performance of SRS waste glass based on all data currently available has been seen to be excellent thus far. Initial analyses and assessment of Savannah River (SR) waste glass after burial in WIPP at 90 degrees C for 5 years are presented in this document

IMPACT OF REDUCING THE 100 C LIQUIDUS TEMPERATURE OFFSET ON WASTE LOADING TARGETS

Energy Technology Data Exchange (ETDEWEB)

Peeler, D.; Edwards, T.

2010-11-11

The objective of this report is to assess the potential impact of reducing conservatism in the implementation of the current liquidus temperature (TL) model in the Product Composition Control System (PCCS) on the ability to target higher waste loadings (WLs) for future sludge batches. No changes to the TL model or the associated uncertainties (model or measurement) are proposed, rather only changes in the magnitude of the offset used between the nominal melt pool temperature (1150 C) and the Property Acceptance Region (PAR) value (1050 C). This strategy is consistent with that outlined and initially assessed by Brown et al. (2001). In that report, the authors stated even a fairly conservative change in this safety factor could have a significant impact on waste loading. The results of this study clearly indicate that the implementation of an 1100 C TL PAR criterion (which translates into a reduction in the TL offset from 100 C to 50 C) can have significantly positive impacts on the ability to gain access to WLs exceeding 45%. This is especially true for those frit and sludge systems that are TL limited using the current 1050 C TL criterion, and are not limited by a second constraint (such as viscosity, nepheline, or durability) until much higher WLs. Examples of various glass forming systems are provided that are currently limited to maximum WLs in the mid-40s, but could be processed in the lower 50s through implementation of this new strategy. One example is in the Sludge Batch 10 (SB10) system, where for a specific glass forming system the projected operating window of 38-41% WL (using the current constraints) became 38-52% WL with the use of an 1100 C TL PAR value. This change both provided access to significantly higher WLs, and transitioned a once infeasible flowsheet to a system that could potentially be processed in the Defense Waste Processing Facility (DWPF). This potential change in the TL constraint also provides access to frit compositions (or glass

Performance Analysis of Waste Heat Driven Pressurized Adsorption Chiller

KAUST Repository

LOH, Wai Soong; SAHA, Bidyut Baran; CHAKRABORTY, Anutosh; NG, Kim Choon; CHUN, Won Gee

2010-01-01

This article presents the transient modeling and performance of waste heat driven pressurized adsorption chillers for refrigeration at subzero applications. This innovative adsorption chiller employs pitch-based activated carbon of type Maxsorb III

The comparison of DYNA3D to approximate solutions for a partially- full waste storage tank subjected to seismic loading

International Nuclear Information System (INIS)

Zaslawsky, M.; Kennedy, W.N.

1992-01-01

Mathematical solutions to the problem consisting of a partially-full waste tank subjected to seismic loading, embedded in soil, is classically difficult in that one has to address: soil-structure interaction, fluid-structure interaction, non-linear behavior of material, dynamic effects. Separating the problem and applying numerous assumptions will yield approximate solutions. This paper explores methods for generating these solutions accurately

Overview of the geochemical code MINTEQ: applications to performance assessment for low-level wastes

International Nuclear Information System (INIS)

Graham, M.J.; Peterson, S.R.

1985-09-01

The MINTEQ geochemical computer code, developed at Pacific Northwest Laboratory, integrates many of the capabilities of its two immediate predecessors, WATEQ3 and MINEQL. MINTEQ can be used to perform the calculations necessary to simulate (model) the contact of low-level waste solutions with heterogeneous sediments or the interaction of ground water with solidified low-level wastes. The code is capable of performing calculations of ion speciation/solubility, adsorption, oxidation-reduction, gas phase equilibria, and precipitation/dissolution of solid phases. Under the Special Waste Form Lysimeters-Arid program, the composition of effluents (leachates) from column and batch experiments, using laboratory-scale waste forms, will be used to develop a geochemical model of the interaction of ground water with commercial solidified low-level wastes. The wastes being evaluated include power reactor waste streams that have been solidified in cement, vinyl ester-styrene, and bitumen. The thermodynamic database for the code is being upgraded before the geochemical modeling is performed. Thermodynamic data for cobalt, antimony, cerium, and cesium solid phases and aqueous species are being added to the database. The need to add these data was identified from the characterization of the waste streams. The geochemical model developed from the laboratory data will then be applied to predict the release from a field-lysimeter facility that contains full-scale waste samples. The contaminant concentrations migrating from the wastes predicted using MINTEQ will be compared to the long-term lysimeter data. This comparison will constitute a partical field validation of the geochemical model. 28 refs

Waste package performance analysis

International Nuclear Information System (INIS)

Lester, D.H.; Stula, R.T.; Kirstein, B.E.

1982-01-01

A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been applied to several package designs. The resulting preliminary assessments were intended for use in making decisions about package development programs. A computer model called BARIER estimates the package life and subsequent rate of release of selected nuclides. The model accounts for temperature, pressure (and resulting stresses), bulk and localized corrosion, and nuclide retardation by the backfill after water intrusion into the waste form. The assessment model assumes a post-closure, flooded, geologic repository. Calculations indicated that, within the bounds of model assumptions, packages could last for several hundred years. Intact backfills of appropriate design may be capable of nuclide release delay times on the order of 10 7 yr for uranium, plutonium, and americium. 8 references, 6 figures, 9 tables

Vitrification of hazardous and mixed wastes

International Nuclear Information System (INIS)

Jantzen, C.M.; Pickett, J.B.; Ramsey, W.G.

1992-01-01

Solidification of hazardous/mixed wastes into glass is being examined at the Savannah River Site. The first hazardous/mixed wastes glassified at SRS have been (1) incinerator and (2) nickel plating line (F006) wastes. Solidification of incinerator blowdown and mixtures of incinerator blowdown and incinerator bottom kiln ash have been achieved in Soda (Na 2 O) - Lime (CaO) - Silica (SiO 2 ) glass (SLS) at waste loadings of up to 50 wt%. Solidification of nickel-plating line waste sludges containing depleted uranium have also been achieved in both SLS and borosilicate glasses at waste loadings of 75 wt%. This corresponds to volume reductions of 97% and 81%, respectively. Further studies will examine glassification of: ion exchange zeolites, inorganic filter media, asbestos, glass fiber filters, contaminated soil, cementitious, or other materials in need of remediation

Regulatory basis for the Waste Isolation Pilot Plant performance assessment

International Nuclear Information System (INIS)

Howard, Bryan A.; Crawford, M.B.; Galson, D.A.; Marietta, Melvin G.

2000-01-01

The Waste Isolation Pilot Plant (WIPP) is the first operational repository designed for the safe disposal of transuranic (TRU) radioactive waste from the defense programs of the US Department of Energy (DOE). The US Environmental Protection Agency (EPA) is responsible for certifications and regulation of the WIPP facility for the radioactive components of the waste. The EPA has promulgated general radioactive waste disposal standards at 40 CFR Part 191. and WIPP-specific criteria to implement and interpret the generic disposal standards at 40 CFR Part 194. In October 1996. the DOE submitted its Compliance Certification Application (CCA) to the EPA to demonstrate compliance with the disposal standards at Subparts B and C of 40 CFR Part 191. This paper summarizes the development of the overall legal framework for radioactive waste disposal at the WIPP, the parallel development of the WIPP performance assessment (PA), and how the EPA disposal standards and implementing criteria formed the basis for the CCA WIPP PA. The CCA resulted in a certification in May 1998 by the EPA of the WIPP'S compliance with the EPA's disposal standard, thus enabling the WIPP to begin radioactive waste disposal

Solid Waste Disposal in Chinese Cities: An Evaluation of Local Performance

Directory of Open Access Journals (Sweden)

Boya Zhou

2017-12-01

Full Text Available China meets increasingly serious solid waste problems and has adopted various policies in response in recent years. Meanwhile, few studies have investigated the performance of solid waste disposal through statistical analysis with empirical data. This study examines provincial resource use policy’s influence on the comprehensive utilization rate of industrial solid waste in Chinese cities. Through comparing results for statistical analysis in the year 2009 and 2015 by multiple linear regression analysis, this study analyzes similarities and differences in the drivers for solid waste disposal in the era of the 11th Five-Year Plan and the 12th Five-Year Plan in China. It finds that the adoption of resource use policy positively increases the comprehensive utilization rate of industrial solid waste. Other factors such as industrial SO2 emission, local environmental regulations, GDP per capita, population density and educational level also affect industrial solid waste disposal. Therefore, China should continue implementing solid waste disposal policies, upgrade current industrial systems, push forward economic and social reform and increase environmental education to enhance the effectiveness of solid waste disposal for long-term sustainable development.

Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

Energy Technology Data Exchange (ETDEWEB)

Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

1982-08-01

The thermal effects associated with the emplacement of aged radioactive wastes in a geologic repository were studied, with emphasis on the following subjects: the waste characteristics, repository structure, and rock properties controlling the thermally induced effects; the current knowledge of the thermal, thermomechanical, and thermohydrologic impacts, determined mainly on the basis of previous studies that assume 10-year-old wastes; the thermal criteria used to determine the repository waste loading densities; and the technical advantages and disadvantages of surface cooling of the wastes prior to disposal as a means of mitigating the thermal impacts. The waste loading densities determined by repository designs for 10-year-old wastes are extended to older wastes using the near-field thermomechanical criteria based on room stability considerations. Also discussed are the effects of long surface cooling periods determined on the basis of far-field thermomechanical and thermohydrologic considerations. The extension of the surface cooling period from 10 years to longer periods can lower the near-field thermal impact but have only modest long-term effects for spent fuel. More significant long-term effects can be achieved by surface cooling of reprocessed high-level waste.

Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

International Nuclear Information System (INIS)

Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

1982-08-01

The thermal effects associated with the emplacement of aged radioactive wastes in a geologic repository were studied, with emphasis on the following subjects: the waste characteristics, repository structure, and rock properties controlling the thermally induced effects; the current knowledge of the thermal, thermomechanical, and thermohydrologic impacts, determined mainly on the basis of previous studies that assume 10-year-old wastes; the thermal criteria used to determine the repository waste loading densities; and the technical advantages and disadvantages of surface cooling of the wastes prior to disposal as a means of mitigating the thermal impacts. The waste loading densities determined by repository designs for 10-year-old wastes are extended to older wastes using the near-field thermomechanical criteria based on room stability considerations. Also discussed are the effects of long surface cooling periods determined on the basis of far-field thermomechanical and thermohydrologic considerations. The extension of the surface cooling period from 10 years to longer periods can lower the near-field thermal impact but have only modest long-term effects for spent fuel. More significant long-term effects can be achieved by surface cooling of reprocessed high-level waste

Waste degradation and mobilization in performance assessments for the Yucca Mountain disposal system for spent nuclear fuel and high-level radioactive waste

International Nuclear Information System (INIS)

Rechard, Rob P.; Stockman, Christine T.

2014-01-01

This paper summarizes modeling of waste degradation and mobilization in performance assessments (PAs) conducted between 1984 and 2008 to evaluate feasibility, viability, and assess compliance of a repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain in southern Nevada. As understanding of the Yucca Mountain disposal system increased, the waste degradation module, or succinctly called the source-term, evolved from initial assumptions in 1984 to results based on process modeling in 2008. In early PAs, waste degradation had significant influence on calculated behavior but as the robustness of the waste container was increased and modeling of the container degradation improved, waste degradation had much less influence in later PAs. The variation of dissolved concentrations of radionuclides progressed from simple probability distributions in early PAs to functions dependent upon water chemistry in later PAs. Also, transport modeling of radionuclides in the waste, container, and invert were added in 1995; and, colloid-facilitated transport of radionuclides was added in 1998. - Highlights: • Progression of modeling of waste degradation in performance assessments is discussed for the proposed repository at Yucca Mountain. • Progression of evaluating dissolved concentrations of radionuclides in the source-term is discussed. • Radionuclide transport modeling in the waste, container, and invert in 1995 and thereafter is discussed. • Colloid-facilitated transport in the waste, container, and invert in 1998 and thereafter is discussed

Integrated performance assessment model for waste package behavior and radionuclide release

International Nuclear Information System (INIS)

Kossik, R.; Miller, I.; Cunnane, M.

1992-01-01

Golder Associates Inc. (GAI) has developed a probabilistic total system performance assessment and strategy evaluation model (RIP) which can be applied in an iterative manner to evaluate repository site suitability and guide site characterization. This paper describes one component of the RIP software, the waste package behavior and radionuclide release model. The waste package component model considers waste package failure by various modes, matrix alteration/dissolution, and radionuclide mass transfer. Model parameters can be described as functions of local environmental conditions. The waste package component model is coupled to component models for far-field radionuclide transport and disruptive events. The model has recently been applied to the proposed repository at Yucca Mountain

Safety and performance assessment of geologic disposal systems for nuclear wastes

International Nuclear Information System (INIS)

Peltonen, E.

1987-01-01

This thesis presents a methodology for the safety and performance assesment of final disposal of nuclear wastes into crystalline bedrock. The applicability of radiation protection objectives is discussed, as well as the goals of the assessment in the various repository system development phases. Due consideration is given to the description of the pertinent analysis methods and to the comprehensive model system. The methodology has been applied to assess the acceptability of the basic disposal concepts and to study the possibilities for the optimization of protection. Furthermore, performance of different components in the multiple barrier disposal systems is estimated. The waste types dealt with are low- and intermediate-level waste as well as high-level spent nuclear fuel from a nuclear power plant. In addition, an option of high-level vitrified waste from reprocessing of spent fuel is taken into account. On the basis of the various analyses carried out it can be concluded that the disposal of different nuclear wastes in the Finnish bedrock in properly designed repositories meets the radiation protection objectives with good confidence. In addition, the studies indicate that the safety margins are considerable. This is due to the fact that the overall performance of the multiple barrier disposal systems analysed is not sensitive to possible unfavourable changes in barrier properties. From the optimization of protection point of view it can be concluded that there is no need to develop more effective repository designs than those analysed in this thesis. In fact, the results indicate that the most sophisticated designs have already gone beyond an optimal level of safety

Final Report - High Level Waste Vitrification System Improvements, VSL-07R1010-1, Rev 0, dated 04/16/07

Energy Technology Data Exchange (ETDEWEB)

Kruger, Albert A.; Gan, H.; Pegg, I. L.; Gong, W.; Champman, C. C.; Joseph, I.; Matlack, K. S.

2013-11-13

This report describes work conducted to support the development and testing of new glass formulations that extend beyond those that have been previously investigated for the Hanford Waste Treatment and Immobilization Plant (WTP). The principal objective was to investigate maximization of the incorporation of several waste components that are expected to limit waste loading and, consequently, high level waste (HLW) processing rates and canister count. The work was performed with four waste compositions specified by the Office of River Protection (ORP); these wastes contain high concentrations of bismuth, chromium, aluminum, and aluminum plus sodium. The tests were designed to identify glass formulations that maximize waste loading while meeting all processing and product quality requirements. The work included preparation and characterization of crucible melts in support of subsequent DuraMelter 100 (DM100) tests designed to examine the effects of enhanced glass formulations, increased glass processing temperature, increased crystallinity, and feed solids content on waste processing rate and product quality.

Vehicle Exhaust Waste Heat Recovery Model with Integrated Thermal Load Leveling

Science.gov (United States)

2015-08-01

backpressure can decrease engine power by ~1% per inch Hg.27 A specific exhaust heat exchanger design would need to take this effect into account...Materials. 2009;39:2142–2148. 4. Sprouse III C, Depcik C. Review of organic Rankine cycles for internal combustion engine exhaust waste heat recovery...Adams TG. Effect of exhaust system design on engine performance. 1980. SAE Technical Paper No. 800319. 16 1 DEFENSE TECHNICAL

Performance assessment for low-level radioactive waste disposal

International Nuclear Information System (INIS)

Cook, J.R.; Hsu, R.H.; Wilhite, E.L.; Yu, A.D.

1996-01-01

In October 1994 the Savannah River Site became the first US DOE complex to use concrete vaults to dispose of low-level radioactive solid waste and better prevent soil and groundwater contamination. This article describes the design and gives a performance assessment of the vaults. Topics include the following: Performance objectives; scope; the performance assessment process-assemble a multidisciplinary working group; collect available data; define credible pathways/scenarios; develop conceptual models; conduct screening and detailed model calculations; assess sensitivity/uncertainty; integrate and interpret results; report. 9 figs., 3 tabs

Preparation of plutonium waste forms with ICPP calcined high-level waste

Energy Technology Data Exchange (ETDEWEB)

Staples, B.A.; Knecht, D.A. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); O`Holleran, T.P. [Argonne National Lab.-West, Idaho Falls, ID (United States)] [and others

1997-05-01

Glass and glass-ceramic forms developed for the immobilization of calcined high-level wastes generated by Idaho Chemical Processing Plant (ICPP) fuel reprocessing activities have been investigated for ability to immobilize plutonium and to simultaneously incorporate calcined waste as an anti-proliferation barrier. Within the forms investigated, crystallization of host phases result in an increased loading of plutonium as well as its incorporation into potentially more durable phases than the glass. The host phases were initially formed and characterized with cerium (Ce{sup +4}) as a surrogate for plutonium (Pu{sup +4}) and samarium as a neutron absorber for criticality control. Verification of the surrogate testing results were then performed replacing cerium with plutonium. All testing was performed with surrogate calcined high-level waste. The results of these tests indicated that a potentially useful host phase, based on zirconia, can be formed either by devitrification or solid state reaction in the glass studied. This phase incorporates plutonium as well as samarium and the calcined waste becomes part of the matrix. Its ease of formation makes it potentially useful in excess plutonium dispositioning. Other durable host phases for plutonium and samarium, including zirconolite and zircon have been formed from zirconia or alumina calcine through cold press-sintering techniques and hot isostatic pressing. Host phase formation experiments conducted through vitrification or by cold press-sintering techniques are described and the results discussed. Recommendations are given for future work that extends the results of this study.

Preparation of plutonium waste forms with ICPP calcined high-level waste

International Nuclear Information System (INIS)

Staples, B.A.; Knecht, D.A.; O'Holleran, T.P.

1997-05-01

Glass and glass-ceramic forms developed for the immobilization of calcined high-level wastes generated by Idaho Chemical Processing Plant (ICPP) fuel reprocessing activities have been investigated for ability to immobilize plutonium and to simultaneously incorporate calcined waste as an anti-proliferation barrier. Within the forms investigated, crystallization of host phases result in an increased loading of plutonium as well as its incorporation into potentially more durable phases than the glass. The host phases were initially formed and characterized with cerium (Ce +4 ) as a surrogate for plutonium (Pu +4 ) and samarium as a neutron absorber for criticality control. Verification of the surrogate testing results were then performed replacing cerium with plutonium. All testing was performed with surrogate calcined high-level waste. The results of these tests indicated that a potentially useful host phase, based on zirconia, can be formed either by devitrification or solid state reaction in the glass studied. This phase incorporates plutonium as well as samarium and the calcined waste becomes part of the matrix. Its ease of formation makes it potentially useful in excess plutonium dispositioning. Other durable host phases for plutonium and samarium, including zirconolite and zircon have been formed from zirconia or alumina calcine through cold press-sintering techniques and hot isostatic pressing. Host phase formation experiments conducted through vitrification or by cold press-sintering techniques are described and the results discussed. Recommendations are given for future work that extends the results of this study

Review on Fuel Loading Process and Performance for Advanced Fuel Handling Equipment

International Nuclear Information System (INIS)

Chang, Sang-Gyoon; Lee, Dae-Hee; Kim, Young-Baik; Lee, Deuck-Soo

2007-01-01

The fuel loading process and the performance of the advanced fuel handling equipment for OPR 1000 (Optimized Power Plant) are analyzed and evaluated. The fuel handling equipment, which acts critical processes in the refueling outage, has been improved to reduce fuel handling time. The analysis of the fuel loading process can be a useful tool to improve the performance of the fuel handling equipment effectively. Some recommendations for further improvement are provided based on this study

Sleep restriction and cognitive load affect performance on a simulated marksmanship task.

Science.gov (United States)

Smith, Carl D; Cooper, Adam D; Merullo, Donna J; Cohen, Bruce S; Heaton, Kristin J; Claro, Pedro J; Smith, Tracey

2017-11-24

Sleep restriction degrades cognitive and motor performance, which can adversely impact job performance and increase the risk of accidents. Military personnel are prone to operating under sleep restriction, and previous work suggests that military marksmanship may be negatively affected under such conditions. Results of these studies, however, are mixed and have often incorporated additional stressors (e.g. energy restriction) beyond sleep restriction. Moreover, few studies have investigated how the degree of difficulty of a marksmanship task impacts performance following sleep restriction. The purpose of the current experiment was to study the effects of sleep restriction on marksmanship while minimizing the potential influence of other forms of stress. A friend-foe discrimination challenge with greater or lesser degrees of complexity (high versus low load) was used as the primary marksmanship task. Active duty Soldiers were recruited, and allowed 2 h of sleep every 24 h over a 72-h testing period. Marksmanship tasks, cognitive assessment metrics and the NASA-Task Load Index were administered daily. Results indicated that reaction times to shoot foe targets and signal friendly targets slowed over time. In addition, the ability to correctly discriminate between friend and foe targets significantly decreased in the high-cognitive-load condition over time despite shot accuracy remaining stable. The NASA-Task Load Index revealed that, although marksmanship performance degraded, participants believed their performance did not change over time. These results further characterize the consequences of sleep restriction on marksmanship performance and the perception of performance, and reinforce the importance of adequate sleep among service members when feasible. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

A quantitative measure for degree of automation and its relation to system performance and mental load.

Science.gov (United States)

Wei, Z G; Macwan, A P; Wieringa, P A

1998-06-01

In this paper we quantitatively model degree of automation (DofA) in supervisory control as a function of the number and nature of tasks to be performed by the operator and automation. This model uses a task weighting scheme in which weighting factors are obtained from task demand load, task mental load, and task effect on system performance. The computation of DofA is demonstrated using an experimental system. Based on controlled experiments using operators, analyses of the task effect on system performance, the prediction and assessment of task demand load, and the prediction of mental load were performed. Each experiment had a different DofA. The effect of a change in DofA on system performance and mental load was investigated. It was found that system performance became less sensitive to changes in DofA at higher levels of DofA. The experimental data showed that when the operator controlled a partly automated system, perceived mental load could be predicted from the task mental load for each task component, as calculated by analyzing a situation in which all tasks were manually controlled. Actual or potential applications of this research include a methodology to balance and optimize the automation of complex industrial systems.

Radioactive waste repository study

International Nuclear Information System (INIS)

1978-11-01

This is the second part of a report of a preliminary study for AECL. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) geotechnical assessment, 2) hydrogeology and waste containment, 3) thermal loading and 4) rock mechanics. (author)

EPR: High load variation performances with the 'Tmode' core control

International Nuclear Information System (INIS)

Grossetete, A.

2008-01-01

The load variation performances on a PWR are directly linked to the core control design. This design is mainly characterized by the definition of the control rod banks and the way to both perform the banks movements and to modify the core boron concentration by injection of boric acid or water. The following paper presents the principles of the T mode, the new fully automatic core control mode for the EPR which provides high performance in terms of maneuverability and optimizes the effluents. First, the paper describes the division of the control rods into two control banks (Pbank for temperature and Hbank for power distribution). Then typical movements of these banks during power changes are shown. Then, the principle of the 3 control loops (Tave, AO, Pmax), used to obtain these desired control rod movements, is given. Finally, a load following transient simulation is presented. (authors)

EPR: high load variation performances with the 'TMODE' core control

International Nuclear Information System (INIS)

Pairot, Frederic

2008-01-01

The load variation performances on a PWR are directly linked to the core control design. This design is mainly characterized by the definition of the control rod banks and the way to both perform the banks movements and to modify the core boron concentration by injection of boric acid or water. The following paper presents the principles of the T mode, the new fully automatic core control mode for the EPR which provides high performance in terms of maneuverability and optimizes the effluents. First, the paper describes the division of the control rods into two control banks (Pbank for temperature and Hbank for power distribution). Then typical movements of these banks during power changes are shown. Then, the principle of the 3 control loops (Tave, AO, Pmax), used to obtain these desired control rod movements, is given. Finally, a load following transient simulation is presented. (author)

Multipurpose optimization models for high level waste vitrification

International Nuclear Information System (INIS)

Hoza, M.

1994-08-01

Optimal Waste Loading (OWL) models have been developed as multipurpose tools for high-level waste studies for the Tank Waste Remediation Program at Hanford. Using nonlinear programming techniques, these models maximize the waste loading of the vitrified waste and optimize the glass formers composition such that the glass produced has the appropriate properties within the melter, and the resultant vitrified waste form meets the requirements for disposal. The OWL model can be used for a single waste stream or for blended streams. The models can determine optimal continuous blends or optimal discrete blends of a number of different wastes. The OWL models have been used to identify the most restrictive constraints, to evaluate prospective waste pretreatment methods, to formulate and evaluate blending strategies, and to determine the impacts of variability in the wastes. The OWL models will be used to aid in the design of frits and the maximize the waste in the glass for High-Level Waste (HLW) vitrification

Parametric study of geohydrologic performance characteristics for geologic waste repositories

International Nuclear Information System (INIS)

Bailey, C.E.; Marine, I.W.

1980-11-01

One of the major objectives of the National Waste Terminal Storage Program is to identify potential geologic sites for storage and isolation of radioactive waste (and possibly irradiated fuel). Potential sites for the storage and isolation of radioactive waste or spent fuel in a geologic rock unit are being carefully evaluated to ensure that radionuclides from the stored waste or fuel will never appear in the biosphere in amounts that would constitute a hazard to the health and safety of the public. The objective of this report is to quantify and present in graphical form the effects of significant geohydrologic and other performance characteristics that would influence the movement of radionuclides from a storage site in a rock unit to the biosphere. The effort in this study was focused on transport by groundwater because that is the most likely method of radionuclide escape. Graphs of the major performance characteristics that influence the transport of radionuclides from a repository to the biosphere by groundwater are presented. The major characteristics addressed are radioactive decay, leach rate, hydraulic conductivity, porosity, groundwater gradient, hydrodynamic dispersion, ion exchange, and distance to the biosphere. These major performance characteristics are combind with each other and with the results of certain other combinations and presented in graphical form to provide the interrelationships of values measured during field studies. The graphical form of presentation should be useful in the screening process of site selection. An appendix illustrates the use of these graphs to assess the suitability of a site

Seismic Performance Evaluation of Reinforced Concrete Frames Subjected to Seismic Loads

Science.gov (United States)

Zameeruddin, Mohd.; Sangle, Keshav K.

2017-06-01

Ten storied-3 bays reinforced concrete bare frame designed for gravity loads following the guidelines of IS 456 and IS 13920 for ductility is subjected to seismic loads. The seismic demands on this building were calculated by following IS 1893 for response spectra of 5% damping (for hard soil type). Plastic hinges were assigned to the beam and column at both ends to represent the failure mode, when member yields. Non-linear static (pushover) analysis was performed to evaluate the performance of the building in reference to first (ATC 40), second (FEMA 356) and next-generation (FEMA 440) performance based seismic design procedures. Base shear against top displacement curve of structure, known as pushover curve was obtained for two actions of plastic hinge behavior, force-controlled (brittle) and deformation-controlled (ductile) actions. Lateral deformation corresponding to performance point proves the building capability to sustain a certain level of seismic loads. The failure is represented by a sequence of formation of plastic hinges. Deformation-controlled action of hinges showed that building behaves like strong-column-weak-beam mechanism, whereas force-controlled action showed formation of hinges in the column. The study aims to understand the first, second and next generation performance based design procedure in prediction of actual building responses and their conservatism into the acceptance criteria.

On the road to WIPP: Or remote packaging of transuranic waste

International Nuclear Information System (INIS)

Ledbetter, J.M.; Field, L.R.

1994-01-01

At the Los Alamos National Laboratory (LANL) Hot Cell facility, highly productive programs in reactor research spanning three decades have generated appreciable quantities of legacy waste. Hot cell capability had become virtually useless due to the storage of this waste. As a result of concentrated efforts by LANL staff, in cooperation with Westinghouse Waste Isolation Pilot Plant (WIPP), a solution was arrived at that allowed the facility to become productive once again. Equipment has been designed and fabricated to remotely handle 55-gal. waste drums, load waste canisters, perform canister weld closure, leak test welds, grapple the waste canister and transport the canister to an interim storage site. It is our contention that the technology and acquired equipment produced from this effort should be used to further benefit other DOE sites

A system dynamics-based environmental performance simulation of construction waste reduction management in China.

Science.gov (United States)

Ding, Zhikun; Yi, Guizhen; Tam, Vivian W Y; Huang, Tengyue

2016-05-01

A huge amount of construction waste has been generated from increasingly higher number of construction activities than in the past, which has significant negative impacts on the environment if they are not properly managed. Therefore, effective construction waste management is of primary importance for future sustainable development. Based on the theory of planned behaviors, this paper develops a system dynamic model of construction waste reduction management at the construction phase to simulate the environmental benefits of construction waste reduction management. The application of the proposed model is shown using a case study in Shenzhen, China. Vensim is applied to simulate and analyze the model. The simulation results indicate that source reduction is an effective waste reduction measure which can reduce 27.05% of the total waste generation. Sorting behaviors are a premise for improving the construction waste recycling and reuse rates which account for 15.49% of the total waste generated. The environmental benefits of source reduction outweigh those of sorting behaviors. Therefore, to achieve better environmental performance of the construction waste reduction management, attention should be paid to source reduction such as low waste technologies and on-site management performance. In the meantime, sorting behaviors encouragement such as improving stakeholders' waste awareness, refining regulations, strengthening government supervision and controlling illegal dumping should be emphasized. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radioactive waste-Portland cement systems: I, radionuclide distribution

International Nuclear Information System (INIS)

Jantzen, C.M.; Glasser, F.P.; Lachowski, E.E.

1984-01-01

Crystal chemical stabilization of radioactive wastes can be achieved during clinkering of, or with, ordinary portland cement. Waste loadings of 20 to 30 wt% are achieved by dilute solid solution of waste ions into cementitious host lattices. Higher waste loadings result in compatible noncementitious radiophases. The cementitious phases hydrate without loss of compressive strength. Crystallochemical relationships predict that the radionuclide partitioning in the anhydrous clinkered phases will be maintained in the hydration products. These cementitious hydroxylated radiophases would be in internal equilibrium under anticipated repository conditions. The radionuclide distributions observed are described in the context of established phase equilibria for commercial waste cement systems, but are applicable to transuranic, medium- and low-level wastes

EPA's high-level waste standards and waste package performance

International Nuclear Information System (INIS)

Meyers, S.

1985-01-01

The seven assurance requirements EPA was considering were these: (1) Disposal systems shall not depend on active institutional controls for more than 100 years after disposal; (2) Long-term disposal system performance should be monitored for a reasonable time as a supplement to other types of protection; (3) Disposal systems shall be marked and their locations recorded in all appropriate government records; (4) Disposal systems shall be designed with several different types of barriers, both natural and engineered; (5) Sites should not be located where scarce or easily accessible resources are located; (6) Site selection should consider the relative isolation offered by potential alternatives; and (7) Wastes shall be recoverable for a reasonable time after disposal. (orig./PW)

Transient Performance of Radiator on Engine Rpm Variation with AC Loading

Directory of Open Access Journals (Sweden)

Made Ricki Murti

2012-11-01

Full Text Available Radiator is one of heat exchanger applications that has a function to remove out of heat must be able to operate properly for allowed engine temperature limit. Vehicles that operate on the street usually driving with varying rpm so that the heat produced by the combustion process is not constant and then this study analyze the performance of radiators as a function of time (transient condition. Tests is done on the condition of operating the engine with five rpm variations, each for one hour with air conditioning load and without air-conditioning load. The data to be collected includ the inlet and outlet temperature of radiator and radiator fluid volume flow. The results obtained is heat exhausted rate as a performance radiator is increasing as with increasing of engine rpm and at load conditions with the AC produces heat exhausted rate is greater than AC without AC load. The heat exhausted rate in an hour of machine operation still shows the system operates at a transient condition due to there still exists a numerical increase in the heat exhausted rate as a function of time.