Brookhaven Science Associates
otherStony Brook, New York, United States
Research output, citation impact, and the most-cited recent papers from Brookhaven Science Associates (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Brookhaven Science Associates
The discovery of the top quark in 1995, by the CDF and DØ collaborations at the Fermilab Tevatron, marked the dawn of a new era in particle physics. Since then, enormous efforts have been made to study the properties of this remarkable particle, especially its mass and production cross section. In this article, we review the status of top quark physics as studied by the two collaborations using the [Formula: see text] collider data at [Formula: see text] TeV. The combined measurement of the top quark mass, m t =173.8±5.0 GeV /c 2 , makes it known to a fractional precision better than any other quark mass. The production cross sections are measured as [Formula: see text] pb by CDF and [Formula: see text] pb by DØ. Further investigations of [Formula: see text] decays and future prospects are briefly discussed.
Over 1,140 yd{sup 3} of radioactively contaminated soil containing toxic mercury (Hg) and several liters of mixed-waste elemental mercury were generated during a Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) removal action at Brookhaven National Laboratory (BNL). The US Department of Energy's (DOE) Office of Science and Technology Mixed Waste Focus Area (DOE MWFA) is sponsoring a comparison of several technologies that may be used to treat these wastes and similar wastes at BNL and other sites across the DOE complex. This report describes work conducted at BNL on the application and pilot-scale demonstration of the newly developed Sulfur Polymer Stabilization/Solidification (SPSS) process for treatment of contaminated mixed-waste soils containing high concentrations ({approximately} 5,000 mg/L) of mercury and liquid elemental mercury. BNL's SPSS (patent pending) process chemically stabilizes the mercury to reduce vapor pressure and leachability and physically encapsulates the waste in a solid matrix to eliminate dispersion and provide long-term durability. Two 55-gallon drums of mixed-waste soil containing high concentrations of mercury and about 62 kg of radioactive contaminated elemental mercury were successfully treated. Waste loadings of 60 wt% soil were achieved without resulting in any increase in waste volume, while elemental mercury was solidified at a waste loading of 33 wt% mercury. Toxicity Characteristic Leaching Procedure (TCLP) analyses indicate the final waste form products pass current Environmental Protection Agency (EPA) allowable TCLP concentrations as well as the more stringent proposed Universal Treatment Standards. Mass balance measurements show that 99.7% of the mercury treated was successfully retained within the waste form, while only 0.3% was captured in the off gas system.
This report examines different alternatives for replacing, treating, and recycling greenhouse gases. It is concluded that treatment (abatement) is the only viable short-term option. Three options for abatement that were tested for use in semiconductor facilities are reviewed, and their performance and costs compared. This study shows that effective abatement options are available to the photovoltaic (PV) industry, at reasonable cost.
The Department of Energy (DOE) Environmental Management (EM) office has committed itself to an accelerated cleanup of its national facilities. The goal is to have much of the DOE legacy waste sites remediated by 2006. This includes closure of several sites (e.g., Rocky Flats and Fernald). With the increased focus on accelerated cleanup, there has been considerable concern about long-term stewardship issues in general, and verification and long-term monitoring (LTM) of caps and covers, in particular. Cap and cover systems (covers) are vital remedial options that will be extensively used in meeting these 2006 cleanup goals. Every buried waste site within the DOE complex will require some form of cover system. These covers are expected to last from 100 to 1000 years or more. The stakeholders can be expected to focus on system durability and sustained performance. DOE EM has set up a national committee of experts to develop a long-term capping (LTC) guidance document. Covers are subject to subsidence, erosion, desiccation, animal intrusion, plant root infiltration, etc., all of which will affect the overall performance of the cover. Very little is available in terms of long-term monitoring other than downstream groundwater or surface water monitoring. By its very nature, this can only indicate that failure of the cover system has already occurred and contaminants have been transported away from the site. This is unacceptable. Methods that indicate early cover failure (prior to contaminant release) or predict approaching cover failure are needed. The LTC committee has identified predictive monitoring technologies as a high priority need for DOE, both for new covers as well as existing covers. The same committee identified a Brookhaven National Laboratory (BNL) technology as one approach that may be capable of meeting the requirements for LTM. The Environmental Research and Technology Division (ERTD) at BNL developed a novel methodology for verifying and monitoring subsurface barriers (1,2). The technology uses perfluorocarbon tracers (PFTs) to determine flaws (e.g., holes or cracks) and high permeability areas in subsurface barriers. Gaseous tracers are injected on one side of the barrier and searched for on the opposite side of the barrier. The sampling grid, concentration, and time of arrival of the tracer(s) on the opposite side are used to determine the size and location of flaws and relative permeability of the barrier. In addition, there are multiple tracers available, which allows different tracers to be injected in different quadrants of the barrier. This yields additional information on transport phenomena of the barrier.
The Environmental Protection Agency (EPA) is currently seeking to validate technologies that can directly treat radioactively contaminated high mercury (Hg) subcategory wastes without removing the mercury from the waste. The Sulfur Polymer Stabilization/Solidification (SPSS) process developed at Brookhaven National Laboratory is one of several candidate technologies capable of successfully treating various Hg waste streams. To supplement previously supplied data on treatment of soils, EPA needs additional data concerning stabilization of high Hg subcategory waste sludges. To this end, a 5000 ppm sludge surrogate, containing approximately 50 wt% water, was successfully treated by pilot-scale SPSS processing. In two process runs, 85 and 95 wt% of water was recovered from the sludge during processing. At waste loadings of 30 wt% dry sludge, the treated waste form had no detectable mercury (<10 ppb) in TCLP leachates. Data gathered from the demonstration of treatment of this sludge will provide EPA with information to support revisions to current treatment requirements for high Hg subcategory wastes.
Currently, containment system failures are detected by monitoring wells downstream of the waste site. Clearly this approach is inefficient, as the contaminants will have migrated from the disposal area before they are detected. Methods that indicate early cover failure (prior to contaminant release) or predict impending cover failure are needed. The Brookhaven National Laboratory (BNL) Perfluorocarbon Tracer (PFT) technology can measure performance changes and integrity losses as the cover ages. This allows early detection of cover failure or pending failure so that repair or replacement can be made before contaminants leave the disposal cell. The PFT technology has been successfully applied to four subsurface barrier problems, one leak detection problem from underground ducts, and one surface cover problem. Testing has demonstrated that the PFTs are capable of accurately detecting and locating leaks down to fractions of an inch. The PFT technology has several advantages over competing approaches. The ability to simultaneously use multiple PFTs separates it from other gas tracer technologies. Using multiple tracers provides independent confirmation of flaw location, helps to clearly define transport pathways, and can be used for confirmatory testing (e.g., repeat the test using a new tracer). The PFT tests provide a direct measure of flaws in a barrier, whereas other measurements (pressure, moisture content, temperature, subsidence) provide indirect measures that need interpretation. The focus of the six PFT demonstrations has been on engineering aspects of the technology with the intent of finding if a flaw existed in the barrier. Work remains to be done on the scientific basis for this technology. This includes determining PFT diffusion rates through various materials (soils and barrier) as a function of moisture content, determining the effects of barometric pumping on PFT flow for cover systems, and determining wind effects on side slopes of cover systems and their impact on PFT performance. It also includes application of models to assist in the design of the monitoring system and the interpretation of the data. The set of demonstrations was performed on small sites (< 1/4 acre). Future work also needs to consider scaling issues to develop and design optimal techniques for delivery and monitoring of the PFTs.
The focus of this program was the characterization of the soils beneath the main air ducts connecting the exhaust plenums with the Fan House. The air plenums experienced water intrusion during BGRR operations and after shutdown. The water intrusions were attributed to rainwater leaks into degraded parts of the system and to internal cooling water system leaks. As part of the overall characterization efforts, a state-of-the-art gaseous perfluorocarbon tracer technology was utilized to characterize leak pathways from the ducts. This in turn suggests what soil regions under or adjacent to the ductwork should be emphasized in the characterization process. Knowledge of where gaseous tracers leak from the ducts yields a conservative picture of where water transport, out of or into, the ducts might have occurred.
Photovoltaic solar cells based on a dye-sensitized nanocrystalline titanium dioxide photoelectrode have been researched and reported since the early 1990's. Commercial production of dye-sensitized photovoltaic solar cells has recently been reported in Australia. In this report, current manufacturing methods are described, and estimates are made of annual chemical use and emissions during production. Environmental, health and safety considerations for handling these materials are discussed. This preliminary EH and S evaluation of dye-sensitized titanium dioxide solar cells indicates that some precautions will be necessary to mitigate hazards that could result in worker exposure. Additional information required for a more complete assessment is identified.
The levels of CO2 in the atmosphere have been growing since the beginning of the industrial revolution. The current level is 391 ppm. If there are no efforts to mitigate CO2 emissions, the levels will rise to 750 ppm by 2100. Geologic carbon sequestration is one strategy that may be used to begin to reduce emissions. Sequestration will not be effective unless reservoir leak rates are significantly less than 1%. There must be rigorous monitoring protocols in place to ensure sequestration projects meet regulatory and environmental goals. Monitoring for CO2 leakage directly is difficult because of the large background levels and variability of CO2 in the atmosphere. Using tracers to tag the sequestered CO2 can mitigate some of the difficulties of direct measurement but a tracer monitoring network and the levels of tagging need to be carefully designed. Simple diffusion and dispersion models are used to predict the surface and atmospheric concentrations that would be seen by a network monitoring a sequestration site. Levels of tracer necessary to detect leaks from 0.01 to 1% are presented and suggestions for effective monitoring and protection of global tracer utility are presented.
In FY 1998, following the 50th Anniversary Year of Brookhaven National Laboratory, Brookhaven Science Associates became the new Managers of BNL. The new start is an appropriate time to take stock of past achievements and to renew or confirm future goals. During the 1998 NSLS Annual Users Meeting (described in Part 3 of this Activity Report), the DOE Laboratory Operations Board, Chaired by the Under Secretary for Energy, Ernest Moniz met at BNL. By chance all the NSLS Chairmen except Martin Blume (acting NSLS Chair 84-85) were present as recorded in the picture. Under their leadership the NSLS has improved dramatically: (1) The VUV Ring current has increased from 100 mA in October 1982 to nearly 1 A today. For the following few years 10 Ahrs of current were delivered most weeks - NSLS now exceeds that every day. (2) When the first experiments were performed on the X-ray ring during FY1985 the electron energy was 2 GeV and the current up to 100 mA - the X-Ray Ring now runs routinely at 2.5 GeV and at 2.8 GeV with up to 350 mA of current, with a very much longer beam half-life and improved reliability. (3) Starting in FY 1984 the proposal for the Phase II upgrade, mainly for a building extension and a suite of insertion devices and their associated beamlines, was pursued - the promises were delivered in full so that for some years now the NSLS has been running with two undulators in the VUV Ring and three wigglers and an undulator in the X-Ray Ring. In addition two novel insertion devices have been commissioned in the X13 straight. (4) At the start of FY 1998 the NSLS welcomed its 7000th user - attracted by the opportunity for pursuing research with high quality beams, guaranteed not to be interrupted by 'delivery failures', and welcomed by an efficient and caring user office and first class teams of PRT and NSLS staff. R & D have lead to the possibility of running the X-Ray Ring at the higher energy of 2.8 GeV. Figure 1 shows the first user beam, which was provided thereafter for half of the running time in FY 1998. In combination with the development of narrow gap undulators this mode opens the possibility of new undulators which could produce hard X-rays in the fundamental, perhaps up to 10 keV. On 27 September 1998, a low horizontal emittance lattice became operational at 2.584 GeV. This results in approximately a 50% decrease in the horizontal beam-size on dipole bending magnet beamlines, and somewhat less of a decrease on the insertion device lines. The beam lifetime is not degraded by the low emittance lattice. This represents an important achievement, enhancing for all users the x-ray ring brightness. The reduced horizontal emittance electron beam will produce brighter x-ray beams for all the beamlines, both bending magnets and insertion devices, adding to other recent increases in the X-Ray ring brightness. During FY 1999 users will gain experience of the new running mode and plans are in place to do the same at 2.8GeV during further studies sessions. Independent evidence of the reduced emittance is shown in Figure 2. This is a pinhole camera scan showing the X-ray beam profile, obtained on the diagnostic beamline X28. Finally, work has begun to update and refine the proposal of the Phase III upgrade endorsed by the Birgeneau panel and BESAC last year. With the whole NSLS facility in teenage years and with many demonstrated enhancements available, the time has come to herald in the next stage of life at the Light Source.
The Building 830 Gamma Irradiation Facility (GIF) at Brookhaven National Laboratory (BNL) was decommissioned because its design was not in compliance with current hazardous tank standards and its cobalt-60 sources were approaching the end of their useful life. The facility contained 354 stainless steel encapsulated cobalt-60 sources in a pool, which provided shielding. Total cobalt-60 inventory amounted to 24,000 Curies when the sources were shipped for disposal. The decommissioning project included packaging, transport, and disposal of the sources and dismantling and disposing of all other equipment associated with the facility. Worker exposure was a major concern in planning for the packaging and disposal of the sources. These activities were planned carefully according to ALARA (As Low As Reasonably Achievable) principles. As a result, the actual occupational exposures experienced during the work were within the planned levels. Disposal of the pool water required addressing environmental concerns, since the planned method was to discharge the slightly contaminated water to the BNL sewage treatment plant. After the BNL evaluation procedure for discharge to the sewage treatment plant was revised and reviewed by regulators and BNL's Community Advisory Council, the pool water was discharged to the Building 830 sanitary system. Because the sources were sealed and the pool water contamination levels were low, most of the remaining equipment was not contaminated; therefore disposal was straightforward, as scrap metal and construction debris.
No abstract prepared.
Brookhaven National Laboratory (BNL) was established in 1947 on the former Army Camp Upton site located in central Long Island, New York. From the very beginning, BNL has monitored the environment on and around the Laboratory site to assess the effects of its operations on the environment. This document summarizes the environmental data collected for the years 1967, 1968, 1969, and 1970. Thus, it fills a gap in the series of BNL annual environmental reports beginning in 1962. The data in this document reflect measurements for those four years of concentrations and/or amounts of airborne radioactivity, radioactivity in streams and ground water, and external radiation levels in the vicinity of BNL. Also included are estimates, made at that time, of BNL`s contribution to radioactivity in the environment. Among the major scientific facilities operated at BNL are the High Flux Beam Reactor, Medical Research Reactor, Brookhaven Graphite Research Reactor, Alternating Gradient Synchrotron, and the 60-inch Cyclotron.
The Relativistic Heavy Ion Collider (RHIC) was commissioned in 1999 and 2000. RHIC requires power supplies to supply currents to highly inductive superconducting magnets. The RHIC Insertion Region contains many shunt power supplies to trim the current of different magnet elements in a large superconducting magnet circuit. Power Supply current error measurements were performed during the commissioning of RHIC. Models of these power supply systems were produced to predict and improve these power supply current errors using the circuit analysis program MicroCap V by Spectrum Software (TM). Results of the power supply current errors are presented from the models and from the measurements performed during the commissioning of RHIC.
The BGRR was the world's first nuclear reactor dedicated to the peaceful exploration of atomic energy. The reactor pile consisted of a 700-ton, 25-foot cube of graphite fueled by uranium. A total of 1,369 fuel channels were available with roughly half in use at any given time. Insertion and removal of boron steel control rods controlled reactor power levels. One or more of five fans powered air-cooling. Air was brought in through two filtered plenums, flowed through and around the reactor core, through an exhaust duct containing filters, and finally out through the 320-foot high exhaust stack. Spent fuel was temporarily stored in the spent-fuel canal, and then sent to the Department of Energy's Savannah River Site (SRS). Access to the canal for removing spent fuel was through the Canal House (Building 709). The BGRR ceased operation in 1968 and was placed in a shutdown mode in which all fuel was removed and sent to SRS. Penetrations in the biological shield around the graphite cube and fuel channels were sealed. The final decontamination and decommissioning (D and D) process was initiated in 1999 and is scheduled for completion in 2005. An accelerated schedule was developed that combines characterization with removal actions for the various systems and structures. Before D and D work on a section of the BGRR facility begins, contaminant characterization is conducted to determine the types and amounts of contaminants present. The data are then used for project planning, including decisions affecting the extent of removal, waste designation, and health and safety plans.
Brookhaven National Laboratory's Sulfur Polymer Stabilization/Solidification (SPSS) process was used to treat approximately 90kg of elemental mercury mixed waste from Los Alamos National Laboratory. Treatment was carried out in a series of eight batches using a 1 ft{sup 3} pilot-scale mixer, where mercury loading in each batch was 33.3 weight percent. Although leach performance is currently not regulated for amalgamated elemental mercury (Hg) mixed waste, Toxicity Characteristic Leach Procedure (TCLP) testing of SPSS treated elemental mercury waste indicates that leachability is readily reduced to below the TCLP limit of 200 ppb (regulatory requirement following treatment by retort for wastes containing > 260 ppb Hg), and with process optimization, to levels less than the stringent Universal Treatment Standard (UTS) limit of 25 ppb that is applied to waste containing < 260 ppm Hg. In addition, mercury-contaminated debris, consisting of primary glass and plastic containers, as well as assorted mercury thermometers, switches, and labware, was first reacted with SPSS components to stabilize the mercury contamination, then macroencapsulated in the molten SPSS product. This treatment was done by vigorous agitation of the sulfur polymer powder and the comminuted debris. Larger plastic and metal containers were reacted to stabilize internal mercury contamination, and then filled with molten sulfur polymer to encapsulate the treated product.
This study investigated the use of an indirectly heated, high temperature (900 C), high vacuum (28 inch Hg) rotary kiln, developed and patented by Raduce, Inc. (subsidiary of Sepradyne Corp.), to treat a dioxin contaminated mixed waste incinerator ash from the Idaho National Engineering Lab (INEEL) Waste Experimental Reduction Facility (WERF). A 500 cm{sup 3} bench-scale rotary vacuum thermal desorption and destruction unit (DDU) was used at Brookhaven National Laboratory (BNL) to demonstrate this thermal treatment process. Dioxins and furans were successfully decomposed at both low (450 C) and high (700-800 C) temperature regimes. In addition, substantial volume and mass reduction of the ash was achieved. Stabilization of the nonvolatile residues by a post-treatment encapsulation process may be required to reduce the leachability of RCRA metals to levels below the EPA Toxicity Characteristic Leaching Procedure (TCLP) requirements.
Samples of construction materials proposed for use in both superconducting and conventional high-power linear accelerators have been activated with 800 and 2,000 MeV protons to study the decay characteristics of these activated materials. Irradiation times ranged from 10 minutes to 18.67 hours. The decay characteristics of these activated materials were measured and compared to calculated decay curves based on simplified assumptions.
No abstract prepared.
The two rings in the Relativistic Heavy Ion Collider (RHIC) were originally constructed with 24 sextupole power supplies, 12 for each ring. Before the start of run 7, 24 new sextupole power supplies were installed, 12 for each ring. Individual sextupole power supplies are now each connected to six sextupole magnets. A superconducting snake magnet and power supplies were installed in the Alternating Gradient Synchrotron (AGS) and commissioned during RHIC run 5, and used operationally in RHIC run 6. The power supply technology, connections, control systems and interfacing with the quench protection system for both these systems will be presented.