Use of field experimental studies to evaluate emergency response models (open access)

Use of field experimental studies to evaluate emergency response models

The three-dimensional diagnostic wind field model (MATHEW) and the particle-in-cell atmospheric transport and diffusion model (ADPIC) are used by the Atmospheric Release Advisory Capability to estimate the environmental consequences of accidental releases of radioactivity into the atmosphere. These models have undergone extensive evaluations against field experiments conducted in a variety of environmental settings ranging from relatively flat to very complex terrain areas. Simulations of tracer experiments conducted in a complex mountain valley setting revealed that 35 to 50% of the comparisons between calculated and measured tracer concentrations were within a factor of 5. This may be compared with a factor of 2 for 50% of the comparisons for relatively flat terrain. This degradation of results in complex terrain is due to a variety of factors such as the limited representativeness of measurements in complex terrain, the limited spatial resolution afforded by the models, and the turbulence parameterization based on sigma/sub theta/ measurements to evaluate the eddy diffusivities. Measurements of sigma/sub theta/ in complex terrain exceed those measured over flat terrain by a factor of 2 to 3 leading to eddy diffusivities that are unrealistically high. The results of model evaluations are very sensitive to the quality and the representativeness of …
Date: July 16, 1985
Creator: Gudiksen, P. H.; Lange, R.; Rodriguez, D. J. & Nasstrom, J. S.
System: The UNT Digital Library
Basis for the power supply reliability study of the 1 MW neutron source (open access)

Basis for the power supply reliability study of the 1 MW neutron source

The Intense Pulsed Neutron Source (IPNS) upgrade to 1 MW requires new power supply designs. This paper describes the tools and the methodology needed to assess the reliability of the power supplies. Both the design and operation of the power supplies in the synchrotron will be taken into account. To develop a reliability budget, the experiments to be conducted with this accelerator are reviewed, and data is collected on the number and duration of interruptions possible before an experiment is required to start over. Once the budget is established, several accelerators of this type will be examined. The budget is allocated to the different accelerator systems based on their operating experience. The accelerator data is usually in terms of machine availability and system down time. It takes into account mean time to failure (MTTF), time to diagnose, time to repair or replace the failed components, and time to get the machine back online. These estimated times are used as baselines for the design. Even though we are in the early stage of design, available data can be analyzed to estimate the MTTF for the power supplies.
Date: July 1, 1993
Creator: McGhee, D. G. & Fathizadeh, M.
System: The UNT Digital Library
Comparative Plutonium-239 Dose Assessment for Three Desert Sites: Maralinga, Australia; Palomares, Spain; and the Nevada Test Site, USA - Before and After Remedial Action (open access)

Comparative Plutonium-239 Dose Assessment for Three Desert Sites: Maralinga, Australia; Palomares, Spain; and the Nevada Test Site, USA - Before and After Remedial Action

As a result of nuclear weapons testing and accidents, plutonium has been distributed into the environment. The areas close to the sites of these tests and accidental dispersions contain plutonium deposition of such a magnitude that health authorities and responsible officials have mandated that the contaminated areas be protected, generally through isolation or removal of the contaminated areas. In recent years remedial actions have taken place at all these sites. For reasons not entirely clear, the public perceives radiation exposure risk to be much greater than the evidence would suggest [1]. This perception seems to be particularly true for plutonium, which has often been ''demonized'' in various publications as the ''most hazardous substance known to man'' [2]. As the position statement adapted by the Health Physics Society explains, ''Plutonium's demonization is an example of how the public has been misled about radiation's environmental and health threats generally, and in cases like plutonium, how it has developed a warped ''risk perception'' that does not reflect reality'' [3]. As a result of this risk perception and ongoing debate surrounding environmental plutonium contamination, remedial action criteria are difficult to establish. By examining the data available before and after remedial actions taken at the …
Date: July 14, 2000
Creator: Church, B. W.; Shinn, J.; Williams, G. A.; Martin, L. J.; O'Brien, R. S. & Adams, S. R.
System: The UNT Digital Library
Polymerization of bis(triethoxysilyl)ethenes. The impact of substitution geometry on the formation of ethenyl- and vinylidene-bridged polysilsesquioxanes (open access)

Polymerization of bis(triethoxysilyl)ethenes. The impact of substitution geometry on the formation of ethenyl- and vinylidene-bridged polysilsesquioxanes

Preparation of organically-bridged polysilsesquioxanes has been achieved by polymerizing organic monomers with two or more trialkoxysilyl groups per monomer repeat unit. The nature of the organic bridging group has been shown to strongly impact the final properties (surface area, pore size, and thermal stability) of the end product. For example, rigid arylene bridging groups have been shown to give rise to materials with high surface areas with a relatively large contribution from micropores (< 20 {angstrom}). The length of alkylene-bridging groups can be used to control the size and dispersity of pores in hydrocarbon-bridged xerogels. In this study, the authors have examined the preparation of ethylene-bridged polysilsesquioxanes from the E-(1) and Z-(2) isomers of 1,2-bis(triethoxysilyl)ethene and vinylidene-bridged polysilsesquioxanes from 1,1-bis(triethoxysilyl)ethene-(3). This study was intended to determine the effects of substitution geometry about the carbon-carbon double bond on the condensation chemistry of the monomers and on the resulting architectures of the final materials.
Date: July 1, 1998
Creator: Carpenter, J. P.; Yamanaka, S. A.; McClain, M. D.; Loy, D. A.; Greaves, J. & Shea, K. J.
System: The UNT Digital Library
Statistical design and analysis of environmental studies for plutonium and other transuranics at NAEG ''safety-shot'' sites (open access)

Statistical design and analysis of environmental studies for plutonium and other transuranics at NAEG ''safety-shot'' sites

This paper is centered around the use of stratified random sampling for estimating the total amount (inventory) of $sup 239-240$Pu and uranium in surface soil at ten ''safety-shot'' sites on the Nevada Test Site (NTS) and Tonopah Test Range (TTR) that are currently being studied by the Nevada Applied Ecology Group (NAEG). The use of stratified random sampling has resulted in estimates of inventory at these desert study sites that have smaller standard errors than would have been the case had simple random sampling (no stratification) been used. Estimates of inventory are given for $sup 235$U, $sup 238$U, and $sup 239-240$Pu in soil at A Site of Area 11 on the NTS. Other results presented include average concentrations of one or more of these isotopes in soil and vegetation and in soil profile samples at depths to 25 cm. The regression relationship between soil and vegetation concentrations of $sup 235$U and $sup 238$U at adjacent sampling locations is also examined using three different models. The applicability of stratified random sampling to the estimation of concentration contours of $sup 239-240$Pu in surface soil using computer algorithms is also investigated. Estimates of such contours are obtained using several different methods. The planning …
Date: July 1, 1975
Creator: Gilbert, R. O.; Eberhardt, L. L.; Fowler, E. B.; Romney, E. M. & Essington, E. H.
System: The UNT Digital Library
Sharing our successes II: Changing the face of science and mathematics education through teacher-focused partnerships (open access)

Sharing our successes II: Changing the face of science and mathematics education through teacher-focused partnerships

Industry Initiatives for Science and Math Education (IISME) in the San Francisco Bay Area planned and convened the second national conference for representatives of scientific work experience programs for K-12 teachers (SWEPs) at Lawrence Hall of Science, University of California at Berkeley October 13-14, 1994. The goal of this conference was to further strengthen the growing community of SWEP managers and teacher participants by providing an opportunity for sharing expertise and strategies about the following: (1) How SWEPs can complement and stimulate systemic education reform efforts; (2) Assessment strategies piloted by the ambitious multi-site evaluation project funded by the U.S. Department of Energy (DOE) as well as smaller evaluation projects piloted by other SWEPs; (3) Expanding and strengthening the base of teachers served by SWEPs; (4) Ensuring that SWEPs adequately support teachers in affecting classroom transfer and offer {open_quotes}more than just a summerjob{close_quotes}; (5) Sustaining and expanding new programs. A special teacher strand focused on leadership development supporting teachers to become effective change agents in their classrooms and schools, and developing strong teacher communities.
Date: July 1, 1995
Creator: unknown
System: The UNT Digital Library
Proceedings of the 1996 oil heat technology conference and workshop (open access)

Proceedings of the 1996 oil heat technology conference and workshop

This Conference is a key technology transfer activity supported by the ongoing Combustion Equipment Technology (Oil-Heat R and D) program at BNL, and is aimed at providing a forum for the exchange of information among international researchers, engineers, manufacturers, and marketers of oil-fired space-conditioning equipment. The objectives of the Conference were to: identify and evaluate the state-of-the-art and recommend new initiatives for higher efficiency, a cleaner environment, and to satisfy consumer needs cost-effectively, reliably, and safely; and foster cooperation among federal and industrial representatives with the common goal of sustained national economic growth and energy security via energy conservation. The 1996 Oil Technology Conference comprised: (a) fourteen technical papers, and (b) four workshops which focused on mainstream issues in oil-heating technology, namely: oilheat research agenda forum; fan atomized burner commercialization, applications, and product development; fuel quality, storage and maintenance--industry discussion; and application of oil heat venting tables, NFPA 31 standard. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.
Date: July 1, 1996
Creator: McDonald, R. J.
System: The UNT Digital Library