Dispersion Modeling of Natural Radionuclides 238u, 232th, 226ra, 40k in Muria Coastal Waters

Dispersion modeling of natural radionuclides 238U, 232Th, 226Ra, 40K in Muria coastal waters has been carried out in sea water and sediment surounding Tanjungjati B coal-fire power plant and nuclear power plant site's candidate by applying the hydrodynamics model of unsteady 2-dimensional flexible grid. Oceanography data collecting of bathimetry, current, wave, tide and wind had been carried out on May 28, 2006 until June 2006. Updating data was conducted on April 27 up to April 29, 2011 by using Acoustic Doppler Current Meter Profiler (ADCP) to measure the wave and subsurface current with duration of 2x24 hours. Sea water and sediment samples were collected on April 22, 2011 in six locations (surounding Tanjungjati CPP) and on April 23, 2011 in 10 locations (surounding NPP site's candidate). Samples were analyzed at Research Center for Safety Technology and Radiation Metrology Laboratory, National Nuclear Energy Agency, Jakarta on May 2011 until September 2011 by using spectrometri-γ analysis. Result shows that it can be identified and measured the natural radionuclides of 238U, 232Th, 226Ra, 40K in sea water and sediment. The study can be justified that natural radionuclides of 238U, 232Th, 226Ra, 40K was leachated from fly ash and bottom ash of coal burned Tanjungjati CPP to sea water. The hiyrodynamics model of unsteady 2-dimensional fexible grid by using CD Oceanography software for current plotting, ArcView GIS 3.3 software for bathimetric contouring and SMS 8.1 software for modeling of natural radionuclides dispersion in coastal waters one can applied for radionuclides dispersion of 238U, 232Th, 226Ra, 40K in Muria coastal waters

Gas Dispersion Modeling

Involvement of flammable or toxic materials in a process plant causes the risk of accidents. Hazard analysis and risk-based management are important to prevent escalation of dangerous event. Due to ill-defined leakage conditions, there are a few areas of uncertainty which lead to difficulty in positioning gas detectors. In industry, positioning of gas detectors has always been based on personal expertise rather than computer modeling. This method lacks of consistency and it tends to focus on locations of potential leakage but not locations of total gas accumulation. Development of gas dispersion modeling tool aids in better understanding of possible path of gas distribution and accumulation. Based on the dispersion results, possible locations of gas detector can be indicated. Gaussian plume model is being employed in this project to study dispersion of natural gas. Natural gas is a type of light gas and neutrally buoyant. Effects of meteorological parameters and gas emission rate are factors affecting dispersion pattern. After filtering the concentrations fall out of flammable range, locations where concentrations within flammable range occur are identified using top view plot and front view plot. Consequently, locations of gas detector can be determined

On the coalescence-dispersion modeling of turbulent molecular mixing

The general coalescence-dispersion (C/D) closure provides phenomenological modeling of turbulent molecular mixing. The models of Curl and Dopazo and O'Brien appear as two limiting C/D models that bracket the range of results one can obtain by various models. This finding is used to investigate the sensitivtiy of the results to the choice of the model. Inert scalar mixing is found to be less model-sensitive than mixing accompanied by chemical reaction. Infinitely fast chemistry approximation is used to relate the C/D approach to Toor's earlier results. Pure mixing and infinite rate chemistry calculations are compared to study further a recent result of Hsieh and O'Brien who found that higher concentration moments are not sensitive to chemistry

Review of CFD Guidelines for Dispersion Modeling

This is the review of CFD (Computational Fluid Dynamics) guidelines for dispersion modeling in the USA, Japan and Germany. Most parts of this review are based on the short report of the special meeting on CFD Guidelines held at the International Symposium on Computational Wind Engineering (CWE2014), University of Hamburg, June 2014. The objective of this meeting was to introduce and discuss the action program to make worldwide guidelines of CFD gas-dispersion modeling. The following six gas-dispersion guidelines including Verification and Validation (V&V) schemes are introduced by each author; (1) US CFD guidelines; (2) COST/ES1006; (3) German VDI (Verein Deutscher Ingenieure) guidelines; (4) Atomic Energy Society of Japan; (5) Japan Society of Atmospheric Environment; (6) Architectural Institute of Japan. All guidelines were summarized in the same format table shown in the main chapters in order to compare them with each other. In addition to the summary of guidelines, the overview of V&V schemes and many guidelines of CFD modeling in the USA are explained

Significant dust dispersion models for mining operations

"Dust dispersion modeling is a subject that has had a large amount of research activity. Much of the research has focused on large-scale global or regional dispersion models. Other models have been created for industry-specific purposes. Furthermore, some of the past research has focused on dust dispersion modeling in the mining industry. This report presents the various dust dispersion models that have been developed specifically for the mining industry. The report first gives a brief background of the regulatory environment that helped to promote development of such models. It then presents an overview of the mathematical concepts used in this dispersion modeling. Finally, each of the various models developed for the mining industry are described, along with their associated mathematical algorithms and any field validation conducted on the different models." - NIOSHTIC-2by W.R. Reed."September 2005."Also available via Internet.Also available via the World Wide Web.Includes bibliographical references (p. 18-19)

MicroPoem: experimental investigation of birch pollen emissions

Diseases due to aeroallergens constantly increased over the last decades and affect more and more people. Adequate protective and pre-emptive measures require both reliable assessment of production and release of various pollen species, and the forecasting of their atmospheric dispersion. Pollen forecast models, which may be either based on statistical knowledge or full physical transport and dispersion modeling, can provide pollen forecasts with full spatial coverage. Such models are currently being developed in many countries. The most important shortcoming in these pollen transport systems is the description of emissions, namely the dependence of the emission rate on physical processes such as turbulent exchange or mean transport and biological processes such as ripening (temperature) and preparedness for release. Thus the quantification of pollen emissions and determination of the governing mesoscale and micrometeorological factors are subject of the present project MicroPoem, which includes experimental field work as well as numerical modeling. The overall goal of the project is to derive an emission parameterization based on meteorological parameters, eventually leading to enhanced pollen forecasts. In order to have a well-defined source location, an isolated birch pollen stand was chosen for the set-up of a ‘natural tracer experiment', which was conducted during the birch pollen season in spring 2009. The site was located in a broad valley, where a mountain-plains wind system usually became effective during clear weather periods. This condition allowed to presume a rather persistent wind direction and considerable velocity during day- and nighttime. Several micrometeorological towers were operated up- and downwind of this reference source and an array of 26 pollen traps was laid out to observe the spatio-temporal variability of pollen concentrations. Additionally, the lower boundary layer was probed by means of a sodar and a tethered balloon system (also yielding a pollen concentration profile). In the present contribution a project overview is given and first results are presented. An emphasis is put on the relative performance of different sample technologies and the corresponding relative calibration in the lab and the field. The concentration distribution downwind of the birch stand exhibits a significant spatial (and temporal) variability. Small-scale numerical dispersion modeling will be used to infer the emission characteristics that optimally explain the observed concentration patterns

Gas Dispersion Modeling

Involvement of flammable or toxic materials in a process plant causes the risk of accidents. Hazard analysis and risk-based management are important to prevent escalation of dangerous event. Due to ill-defined leakage conditions, there are a few areas of uncertainty which lead to difficulty in positioning gas detectors. In industry, positioning of gas detectors has always been based on personal expertise rather than computer modeling. This method lacks of consistency and it tends to focus on locations of potential leakage but not locations of total gas accumulation. Development of gas dispersion modeling tool aids in better understanding of possible path of gas distribution and accumulation. Based on the dispersion results, possible locations of gas detector can be indicated. Gaussian plume model is being employed in this project to study dispersion of natural gas. Natural gas is a type of light gas and neutrally buoyant. Effects of meteorological parameters and gas emission rate are factors affecting dispersion pattern. After filtering the concentrations fall out of flammable range, locations where concentrations within flammable range occur are identified using top view plot and front view plot. Consequently, locations of gas detector can be determined

A cost-benefit analysis of a pellet boiler with electrostatic precipitator versus conventional biomass technology: A case study of an institutional boiler in Syracuse, New York

BACKGROUND: Biomass facilities have received increasing attention as a strategy to increase the use of renewable fuels and decrease greenhouse gas emissions from the electric generation and heating sectors, but these facilities can potentially increase local air pollution and associated health effects. Comparing the economic costs and public health benefits of alternative biomass fuel, heating technology, and pollution control technology options provides decision-makers with the necessary information to make optimal choices in a given location. METHODS: For a case study of a combined heat and power biomass facility in Syracuse, New York, we used stack testing to estimate emissions of fine particulate matter (PM2.5) for both the deployed technology (staged combustion pellet boiler with an electrostatic precipitator) and a conventional alternative (wood chip stoker boiler with a multicyclone). We used the atmospheric dispersion model AERMOD to calculate the contribution of either fuel-technology configuration to ambient primary PM2.5 in a 10 km x 10 km region surrounding the facility, and we quantified the incremental contribution to population mortality and morbidity. We assigned economic values to health outcomes and compared the health benefits of the lower-emitting technology with the incremental costs. RESULTS: In total, the incremental annualized cost of the lower-emitting pellet boiler was $190,000 greater, driven by a greater cost of the pellet fuel and pollution control technology, offset in part by reduced fuel storage costs. PM2.5 emissions were a factor of 23 lower with the pellet boiler with electrostatic precipitator, with corresponding differences in contributions to ambient primary PM2.5 concentrations. The monetary value of the public health benefits of selecting the pellet-fired boiler technology with electrostatic precipitator was$1.7 million annually, greatly exceeding the differential costs even when accounting for uncertainties. Our analyses also showed complex spatial patterns of health benefits given non-uniform age distributions and air pollution levels. CONCLUSIONS: The incremental investment in a lower-emitting staged combustion pellet boiler with an electrostatic precipitator was well justified by the population health improvements over the conventional wood chip technology with a multicyclone, even given the focus on only primary PM2.5 within a small spatial domain. Our analytical framework could be generalized to other settings to inform optimal strategies for proposed new facilities or populations.This research was supported by the New York State Energy Research and Development Authority (NYSERDA), via an award to the Northeast States for Coordinated Air Use Management (Agreement #92229). The SCICHEM work of KMZ was supported by the Electric Power Research Institute (EPRI)