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A concentration rebound method for measuring particle penetrationand deposition in the indoor environment

Description: Continuous, size resolved particle measurements were performed in two houses in order to determine size-dependent particle penetration and deposition in the indoor environment. The experiments consisted of three parts: (1) measurement of the particle loss rate following artificial elevation of indoor particle concentrations, (2) rapid reduction in particle concentration through induced ventilation by pressurization of the houses with HEPA-filtered air, and (3) measurement of the particle concentration rebound after house pressurization stopped. During the particle concentration decay period, when indoor concentrations are very high, losses due to deposition are large compared to gains due to particle infiltration. During the concentration rebound period, the opposite is true. The large variation in indoor concentration allows the effects of penetration and deposition losses to be separated by the transient, two-parameter model we employed to analyze the data. We found penetration factors between 0.3 and 1 and deposition loss rates between 0.1 and 5 h{sup -1}, for particles between 0.1 and 10 {micro}m.
Date: September 1, 2002
Creator: tlthatcher@lbl.gov
Partner: UNT Libraries Government Documents Department

New Methods of Energy Efficient Radon Mitigation

Description: Two new radon mitigation techniques are introduced and their evaluation in a field study complemented by numerical model predictions is described. Based on numerical predictions, installation of a sub gravel membrane at the study site resulted in a factor of two reduction in indoor radon concentrations. Experimental data indicated that installation of 'short-circuit' pipes extending between the subslab gravel and outdoors, caused an additional factor of two decrease in the radon concentration. Consequently, the combination of these two passive radon mitigation features, called the membrane and short-circuit (MASC) technique, was associated with a factor of four reduction in indoor radon concentration. The energy-efficient active radon mitigation method, called efficient active subslab pressurization (EASP), required only 20% of the fan energy of conventional active subslab depressurization and reduced the indoor radon concentration by approximately a factor of 15, including the numerically-predicted impact of the sub-gravel membrane.
Date: May 1, 1994
Creator: Fisk, W.J.; Prill, R.J.; Wooley, J.; Bonnefous, Y.C.; Gadgil, A.J. & Riley, W.J.
Partner: UNT Libraries Government Documents Department

A new casting defect healing technology

Description: A new technology is presented for healing of defects in 356 aluminium alloys that provides economic upgrading of these cast alloys. It uses pneumatic isostatic forging (PIF) to produce high quality Al alloys products with enhanced mechanical properties uniform throughout the part, allowing higher design allowables and increased usage of Al alloy castings. The fundamental mechanism underlying PIF is a single mode plastic deformation process that uses isostatic application of pressures for 10-30 seconds at temperature. The process can be integrated in-line with other production operations, i.e., using the latent heat from the previous casting step. Results of applying the PIF process indicate lower cost and significant improvement in mechanical properties that rival and often exceed corresponding properties of other technologies like hot isostatic pressing and related processes. This process offers many advantages that are described in this paper in addition to presenting case histories of property enhancement by PIF and the mechanism responsible for property enhancement.
Date: January 1, 1997
Creator: Hodge, E.S.; Reddoch, T.W. & Viswanathan, S.
Partner: UNT Libraries Government Documents Department

Multi-Canister overpack design pressure rating

Description: The SNF project was directed to increase the MCO pressure rating by the U.S. Department of Energy, Richland Operations Office (RL) unless the action was shown to be cost prohibitive. This guidance was driven by RL's assessment that there was a need to improve margin and reduce risks associated with assumptions supporting the bounding pressure calculation for the MCO Sealing Strategy. Although more recent pressure analyses show a bounding MCO pressure of 50 psig, RL still considers it prudent to retain the pressure margin the 450 psig rating provides. This rating creates a real, clearly definable margin and significantly reduces the risk that the safety basis will be challenged.
Date: November 3, 1998
Creator: Smith, K. E.
Partner: UNT Libraries Government Documents Department


Description: With increasing intensity of gold and proton beams during recent RHIC operations, pressure rises of several decades were observed at a few RHIC warm vacuum sections. The pressure increases were analyzed and compared with the beam parameters such as ion species, bunch intensity, total intensity, number ofbunches, bunch spacing and beam loss. Most of these pressure increases were found to be consistent with those induced by either beam loss and/or electron multipacting.
Date: June 2, 2002
Creator: HSEUH,H.C.; SMART,L.A. & ZHANG,S.Y.
Partner: UNT Libraries Government Documents Department

Fluor-Hanford 3013 Digital Radiography Dead Zone Mitigation Project Pressure Test Report

Description: The use of digital radiographic (DR) measurement of lid deflection as an indication of pressurization of the 3013 inner can was first reported by the Savannah River Technology Center (SRTC). The conclusions of this report were that for cans with relatively large initial concavity, lid deflection could be used to meet the 3013 standard (DOE-STD-3013-2000) requirement for a nondestructive indication of a pressurization of 100 psig. During acceptance testing of the system in the Spring of 2003, it was confirmed that for some cans the DR measured lid deflection could become insensitive to the change in lid deflection when compared to actual mechanical measurements. The basic explanation of this phenomenon is that characteristics of the lid geometry such as tilt and wobble can obfuscate the bottom of the lid where the deflection is measured. The purpose of this report is to document the results of the pressure testing and the efficacy of the alternate imaging and analysis methods developed to mitigate the dead zone problem. Prior to review of the results, a review of the current method and an introduction to the newly developed methods and techniques is provided.
Date: November 21, 2003
Creator: Gibbs, K.
Partner: UNT Libraries Government Documents Department

Hydrogen transport and storage in engineered glass microspheres

Description: New, high strength glass microspheres filled with pressurized hydrogen exhibit densities which make them attractive for bulk hydrogen storage and transport. The membrane tensile stress at failure for our engineered glass microspheres is about 150,000 psi, permitting a threefold increase in pressure limit and storage capacity above commercial microspheres, which have been studied a decade ago and have been shown to fail at membrane stresses of 50,000 psi. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics, indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as pressurized tube transports and liquid hydrogen trailers.
Date: April 18, 1995
Creator: Rambach, G.D.
Partner: UNT Libraries Government Documents Department

Water injection as a means for reducing non-condensible andcorrosive gases in steam produced from vapor-dominated reservoirs

Description: Large-scale water injection at The Geysers, California, hasgenerated substantial benefits in terms of sustaining reservoir pressuresand production rates, as well as improving steam composition by reducingthe content of non-condensible gases (NCGs). Two effects have beenrecognized and discussed in the literature as contributing to improvedsteam composition, (1) boiling of injectate provides a source of "clean"steam to production wells, and (2) pressurization effects induced byboiling of injected water reduce upflow of native steam with large NCGconcentrations from depth. In this paper we focus on a possibleadditional effect that could reduce NCGs in produced steam by dissolutionin a condensed aqueous phase.Boiling of injectate causes pressurizationeffects that will fairly rapidly migrate outward, away from the injectionpoint. Pressure increases will cause an increase in the saturation ofcondensed phase due to vapor adsorption on mineral surfaces, andcapillary condensation in small pores. NCGs will dissolve in theadditional condensed phase which, depending upon their solubility, mayreduce NCG concentrations in residual steam.We have analyzed thepartitioning of HCl between vapor and aqueous phases, and have performednumerical simulations of injection into superheated vapor zones. Oursimulations provide evidence that dissolution in the condensed phase canindeed reduce NCG concentrations in produced steam.
Date: January 8, 2007
Creator: Pruess, Karsten; Spycher, Nicolas & Kneafsey, Timothy J.
Partner: UNT Libraries Government Documents Department

Review of Residential Ventilation Technologies

Description: This paper reviews current and potential ventilation technologies for residential buildings in North America and a few in Europe. The major technologies reviewed include a variety of mechanical systems, natural ventilation, and passive ventilation. Key parameters that are related to each system include operating costs, installation costs, ventilation rates, heat recovery potential. It also examines related issues such as infiltration, duct systems, filtration options, noise, and construction issues. This report describes a wide variety of systems currently on the market that can be used to meet ASHRAE standard 62.2. While these systems generally fall into the categories of supply, exhaust or balanced, the specifics of each system are driven by concerns that extend beyond those in the standard and are discussed. Some of these systems go beyond the current standard by providing additional features (such as air distribution or pressurization control). The market will decide the immediate value of such features, but ASHRAE may wish to consider modifications to the standard in the future.
Date: March 1, 2005
Creator: Russell, Marion L.; Sherman, Max H. & Rudd, Armin
Partner: UNT Libraries Government Documents Department


Description: This report documents the determination of the cause of pressurization that led to bulging deformation of a 55 gallon wastewater drum stored in L-Area. Drum samples were sent to SRNL for evaluation. The interior surface of these samples revealed blistering and holes in the epoxy phenolic drum liner and corrosion of the carbon steel drum. It is suspected that osmotic pressure drove permeation of the water through the epoxy phenolic coating which was weakened from exposure to low pH water. The coating failed at locations throughout the drum interior. Subsequent corrosion of the carbon steel released hydrogen which pressurized the drum causing deformation of the drum lid. Additional samples from other wastewater drums on the same pallet were also evaluated and limited corrosion was visible on the interior surfaces. It is suspected that, with time, the corrosion would have advanced to cause pressurization of these sealed drums.
Date: November 30, 2007
Creator: Vormelker, P; Cynthia Foreman, C; Zane Nelson, Z; David Hathcock, D & Dennis Vinson, D
Partner: UNT Libraries Government Documents Department


Description: Two high-pressure bioassay vessels failed at the Savannah River Site during a microwave heating process for biosample testing. Improper installation of the thermal shield in the first failure caused the vessel to burst during microwave heating. The second vessel failure is attributed to overpressurization during a test run. Vessel failure appeared to initiate in the mold parting line, the thinnest cross-section of the octagonal vessel. No material flaws were found in the vessel that would impair its structural performance. Content weight should be minimized to reduce operating temperature and pressure. Outer vessel life is dependent on actual temperature exposure. Since thermal aging of the vessels can be detrimental to their performance, it was recommended that the vessels be used for a limited number of cycles to be determined by additional testing.
Date: September 22, 2008
Creator: Vormelker, P
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Summary of Warm-Up After Draining for the D-Zero LAr Calorimeters

Description: After a very successful physics run, the D-Zero detector Liquid Argon Calorimeters were drained in preparation of the detector rollout. During the roll out process, the calorimeters were without cooling. Information regarding the temperatures, estimated heat transfer, and pressure maintenance are documented in this engineering note.
Date: March 14, 1996
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

Over-Pressurized Drums: Their Causes and Mitigation

Description: Having to contend with bulging or over-pressurized drums is, unfortunately, a common event for people storing chemicals and chemical wastes. (Figure 1) The Department of Energy alone reported over 120 incidents of bulging drums between 1992 and 1999 (1). Bulging drums can be caused by many different mechanisms, represent a number of significant hazards and can be tricky to mitigate. In this article, we will discuss reasons or mechanisms by which drums can become over-pressurized, recognition of the hazards associated with and mitigation of over-pressurized drums, and methods that can be used to prevent drum over-pressurization from ever occurring. Drum pressurization can represent a significant safety hazard. Unless recognized and properly mitigated, improperly manipulated pressurized drums can result in employee exposure, employee injury, and environmental contamination. Therefore, recognition of when a drum is pressurized and knowledge of pressurized drum mitigation techniques is essential.
Date: July 10, 2009
Creator: Simmons, Fred; Kuntamukkula, Murty; Quigley, David; Robertson, Janeen & Freshwater, David
Partner: UNT Libraries Government Documents Department

Analysis of reinjectiion strategies for The Geysers

Description: The Geysers has undergone severe pressure decline in recent years, and reinjection of condensate is thought to be one key to sustaining current steam production. Other methods of pressure maintenance include load cycling, or reduction of steam production during off-peak hours. It is likely that a combination of these two will prove to be optimum in providing pressure and fluid maintenance. This paper presents preliminary results of a study of various injection schemes for The Geysers. A number of injection scenarios are investigated, and an optimum scheme (based on specific parameters) is identified for two different quantities of reinjection.
Date: January 1, 1991
Creator: Shook, Mike & Faulder, D.D.
Partner: UNT Libraries Government Documents Department


Description: A simplified mechanical model is used to simulate the deformation of a scoria cone due to pressurization of magma in a feeder conduit. The scoria cone is modeled as consisting of a cone of stabilized scoria with an axial region of loose scoria (height h{sub 1}), all overlying a vertically oriented cylindrical conduit intruded into rhyolite tuff country rock. For our analyses, the conduit is filled with basalt magma, usually with the upper length (h{sub 2}) solidified. The style of deformation of the cone depends on both h{sub 1} and h{sub 2}. If magma is prevented from hydrofracturing out of the conduit (as, for example, might be the case if the magma is surrounded by a solidified, but plastically deformable layer acting as a gasket backed up by the brittle country rock) pressures in the magma can build to 10s of MPa. When h{sub 1} is 100 m, not unusual for a small isolated basaltic cinder cone, the magma pressure needed to destabilize the cone when molten magma extends all the way to the original ground surface (h{sub 2} = 0) is only about one-third of the pressure when the upper part of the conduit is solidified (h{sub 2} = 25m). In the former case, almost the entire upper third of the cone is at failure in tension when the configuration becomes unstable. In the latter case, small portions of the surface of the cone are failing in tension when instability occurs, but a large volume in the central core of the cone is failing in shear or compressions. These results may provide insight into the status of volcanic plumbing, either past or present, beneath scoria cones. Field observations at the Lathrop Wells volcano in southern Nevada identify structures at the outer edge just below the crater rim that appear ...
Date: August 26, 2005
Creator: Gaffney, E.S.; Damjanac, B.; Krier, D. & Valentine, G.
Partner: UNT Libraries Government Documents Department


Description: The multi-barrier 3013 container used to package plutonium-bearing materials is robust and thereby highly resistant to identified degradation modes that might cause failure. The only viable degradation mechanisms identified by a panel of technical experts were pressurization within and corrosion of the containers. Evaluations of the container materials and the fabrication processes and resulting residual stresses suggest that the multi-layered containers will mitigate the potential for degradation of the outer container and prevent the release of the container contents to the environment. Additionally, the ongoing surveillance programs and laboratory studies should detect any incipient degradation of containers in the 3013 storage inventory before an outer container is compromised.
Date: November 10, 2009
Creator: Dunn, K.; Louthan, M.; Rawls, G.; Sindelar, R.; Zapp, P. & Mcclard, J.
Partner: UNT Libraries Government Documents Department

Effects of stabilization temperature on surface area and grain size of representative plutonium materials.

Description: Calcination at 400-1000C is used throughout the Department of Energy (DOE) complex to stabilize plutonium material for transportation and storage . The objectives of this stabilization are to remove moisture and other potentially water-producing phases, and to ensure that readsorption will not occur before material is placed in welded containers .Such moisture may threaten the integrity of containers through pressurization with radiolytically generated hydrogen. It is also considered valuable to reduce the fine (respirable) fraction of the material to mitigate potential impact of accidents.
Date: January 1, 2003
Creator: Boak, J. M. (Jeremy M.); Dale, D. J. (Deborah J.) & Eller, P. G. (Phillip Gary)
Partner: UNT Libraries Government Documents Department

Selection of 3013 Containers for Field Surveillance

Description: This report revises and combines three earlier reports dealing with the binning, statistical sampling, and sample selection of 3013 containers for field surveillance. It includes changes to the binning specification resulting from completion of the Savannah River Site packaging campaign and new information from the shelf-life program and field surveillance activities. The revised bin assignments result in changes to the random sample specification. These changes are necessary to meet the statistical requirements of the surveillance program. This report will be reviewed regularly and revised as needed. Section 1 of this report summarizes the results of an extensive effort to assign all of the current and projected 3013 containers in the Department of Energy (DOE) inventory to one of three bins (Innocuous, Pressure and Corrosion, or Pressure) based on potential failure mechanisms. Grouping containers into bins provides a framework to make a statistical selection of individual containers from the entire population for destructive and nondestructive field surveillance. The binning process consisted of three main steps. First, the packaged containers were binned using information in the Integrated Surveillance Program database and a decision tree. The second task was to assign those containers that could not be binned using the decision tree to a specific bin using container-by-container engineering review. The final task was to evaluate containers not yet packaged and assign them to bins using process knowledge. The technical basis for the decisions made during the binning process is included in Section 1. A composite decision tree and a summary table show all of the containers projected to be in the DOE inventory at the conclusion of packaging at all sites. Decision trees that provide an overview of the binning process and logic are included for each site. Section 2 of this report describes the approach to the statistical selection of containers ...
Date: January 1, 2007
Creator: Larry Peppers, Elizabeth Kelly, James McClard, Gary Friday, Theodore Venetz, and Jerry Stakebade
Partner: UNT Libraries Government Documents Department


Description: Samples of four formulations of ethylene-propylene diene monomer (EPDM) elastomer were exposed to initially pure tritium gas at one atmosphere and ambient temperature for various times up to about 420 days in closed containers. Two formulations were carbon-black-filled commercial formulations, and two were the equivalent formulations without filler synthesized for this work. Tritium effects on the samples were characterized by measuring the sample volume, mass, flexibility, and dynamic mechanical properties and by noting changes in appearance. The glass transition temperature was determined by analysis of the dynamic mechanical properties. The glass transition temperature increased significantly with tritium exposure, and the unfilled formulations ceased to behave as elastomers after the longest tritium exposure. The filled formulations were more resistant to tritium exposure. Tritium exposure made all samples significantly stiffer and therefore much less able to form a reliable seal when employed as O-rings. No consistent change of volume or density was observed; there was a systematic lowering of sample mass with tritium exposure. In addition, the significant radiolytic production of gas, mainly protium (H{sub 2}) and HT, by the samples when exposed to tritium was characterized by measuring total pressure in the container at the end of each exposure and by mass spectroscopy of a gas sample at the end of each exposure. The total pressure in the containers more than doubled after {approx}420 days tritium exposure.
Date: December 11, 2009
Creator: Clark, E.
Partner: UNT Libraries Government Documents Department

Predicting runaway reaction in a solid explosive containing a single crack

Description: Mechanically damaged high explosive (HE) undergoing defiagration has recently been shown capable of generating combustion pressures and flame speeds dramatically in excess of those observed in undamaged HE. Flame penetration of HE cracks large enough to support the reaction zone serves to increase the burning surface area and the rate of gas production. Cracks confine the product gas, elevating the local pressure and reducing the reaction zone thickness such that the flame can enter smaller-width cracks. As the reaction zone decreases sufficiently to enter the smallest cracks, the flame surface area will grow appreciably, rapidly pressurizing the cracks. This runaway of pressure and burning area, termed combustion bootstrapping, can dramatically accelerate the combustion mode and in the most extreme cases may result in deflagration-to-detonation transition [3, 4]. The current study is intended to help predict the conditions required for the onset of reaction runaway in a narrow slot in HE. We review experiments [5] where flames were observed to propagate though a narrow slot (intended to simulate a well-formed crack) in high explosive at velocities up to 10 km/s, reaching pressures in excess of 1 kbar. Pressurization of the slot due to gas-dynamic choking is then used to predict the onset of runaway reaction. This model agrees with experimental pressure measurements of observed reaction runaway in slots.
Date: January 1, 2009
Creator: Jackson, Scott I & Hill, Larry G
Partner: UNT Libraries Government Documents Department

Estimation of deformation and stiffness of fractures close to tunnels using data from single-hole hydraulic testing and grouting

Description: Sealing of tunnels in fractured rocks is commonly performed by pre- or post-excavation grouting. The grouting boreholes are frequently drilled close to the tunnel wall, an area where rock stresses can be low and fractures can more easily open up during grout pressurization. In this paper we suggest that data from hydraulic testing and grouting can be used to identify grout-induced fracture opening, to estimate fracture stiffness of such fractures, and to evaluate its impact on the grout performance. A conceptual model and a method are presented for estimating fracture stiffness. The method is demonstrated using grouting data from four pre-excavation grouting boreholes at a shallow tunnel (50 m) in Nygard, Sweden, and two post-excavation grouting boreholes at a deep tunnel (450 m) in Aespoe HRL, Sweden. The estimated stiffness of intersecting fractures for the boreholes at the shallow Nygard tunnel are low (2-5 GPa/m) and in agreement with literature data from field experiments at other fractured rock sites. Higher stiffness was obtained for the deeper tunnel boreholes at Aespoe which is reasonable considering that generally higher rock stresses are expected at greater depths. Our method of identifying and evaluating the properties and impact of deforming fractures might be most applicable when grouting takes place in boreholes adjacent to the tunnel wall, where local stresses might be low and where deforming (opening) fractures may take most of the grout.
Date: May 1, 2010
Creator: Fransson, A.; Tsang, C.-F.; Rutqvist, J. & Gustafson, G.
Partner: UNT Libraries Government Documents Department