24 research outputs found
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The design and performance of the research reactor fuel counter
This paper describes the design features, hardware specifications, and performance characteristics of the Research Reactor Fuel Counter (RRFC) System. The system is an active mode neutron coincidence counter intended to assay material test reactor fuel assemblies under water. The RRFC contains 12 {sup 3}He tubes, each with its own preamplifier, and a single ion chamber. The neutron counting electronics are based on the Los Alamos Portable Shift Register (PSR) and the gamma readout is a manual-range pico-ammeter of Los Alamos design. The RRFC is connected to the surface by a 20-m-long cable bundle. The PSR is controlled by a portable IBM computer running a modified version of the Los Alamos neutron coincidence counting code also called RRFC. There is a manual that describes the RRFC software
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Layered and segmented system organization (LASSO) for highly reliable inventory monitoring systems (IMS)
The Trilateral Initiative is preparing for International Atomic Energy Agency (LUiA) verification of excess fissile material released itom the defense programs of the United States and the Russian Federation. Following acceptance of the material using an Attribute Verification System, the IAEA will depend on an Inventory Monitoring System to maintain Continuity of Knowledge of the large inventory of thousands of items. Recovery fiom a total loss of Continuity of Knowledge in such a large storage facility would involve an extremely costly inventory re-verification This paper presents the framework for a Layered and Segmented System Organization that is the basis for a highly reliable IMS with protection-in-depth
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RRFC hardware operation manual
The Research Reactor Fuel Counter (RRFC) system was developed to assay the {sup 235}U content in spent Material Test Reactor (MTR) type fuel elements underwater in a spent fuel pool. RRFC assays the {sup 235}U content using active neutron coincidence counting and also incorporates an ion chamber for gross gamma-ray measurements. This manual describes RRFC hardware, including detectors, electronics, and performance characteristics
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High-Temperature Engineering Test Reactor door valve monitor system
This manual describes the detector design features, performance, and operating characteristics of the High-Temperature Engineering Test Reactor (HTTR) Door Valve Monitor System spent-fuel monitor. The HTTR Door Valve Monitor System (HDVM) is installed in the HTTR door valve to provide unattended monitoring data for the transfer of spent fuel through the door valve on the top of the reactor. The system includes a pair of detectors to provide direction of travel and redundancy. The fission product gamma rays are measured using ion chambers (ICs) and the curium neutrons are measured using shielded {sup 3}He detectors. There are two ICs and one {sup 3}He tube inside each detector package. Gamma-ray and neutron detector (GRAND) electronics supply power to the ICs and {sup 3}He tubes, and the data are collected in the GRAND and the Field Works computer. The system is designed to operate unattended with data pickup by the inspectors on a 90-day period. This manual gives the performance and calibration procedures
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Capability of environmental sampling to detect undeclared cask openings
The goal of this study is to determine the signatures that would allow monitors to detect diversion of nuclear fuel (by a diverter) from a storage area such as a geological repository. Due to the complexity of operations surrounding disposal of spent nuclear fuel in a geologic repository, there are several places that a diversion of fuel could take place. After the canister that contains the fuel rods is breached, the diverter would require a hot cell to process or repackage the fuel. A reference repository and possible diversion scenarios are discussed. When a canister is breached, or during reprocessing to extract nuclear weapons material (primarily Pu), several important isotopes or signatures including tritium, {sup 85}Kr, and {sup 129}I are released to the surrounding environment and have the potential for analysis. Estimates of release concentrations of the key signatures from the repository under a hypothetical diversion scenario are presented and discussed. Gas analysis data collected from above-ground storage casks at Idaho National Engineering and Environmental Laboratory (INEEL) Test Area North (TAN) are included and discussed in the report. In addition, LANL participated in gas sampling of one TAN cask, the Castor V/21, in July 1997. Results of xenon analysis from the cask gas sample are presented and discussed. The importance of global fallout and recent commercial reprocessing activities and their effects on repository monitoring are discussed. Monitoring and instrumental equipment for analysis of the key signature isotopes are discussed along with limits of detection. A key factor in determining if diversion activities are in progress at a repository is the timeliness of detection and analysis of the signatures. Once a clandestine operation is suspected, analytical data should be collected as quickly as possible to support any evidence of diversion
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General technical requirements (GTR) for inventory monitoring systems (IMS) for the trilateral initiative
Pursuant to the Trilateral Initiative, the three parties (The Russian Federation, the United States, and the International Atomic Energy Agency) have been engaged in discussions concerning the structure of reliable monitoring systems for storage facilities having large inventories. The intent of these monitoring systems is to provide the capability for the IAEA to maintain continuity of knowledge in a sufficiently reliable manner that should there be equipment failure, loss of continuity of knowledge would be restricted to a small population of the inventory, and thus reinventory of the stored items would be minimized These facility-specific monitoring systems, referred to as Inventory Monitoring Systems (IMS) are to provide the principal means for the M A to assure that the containers of fissile material remain accounted under the Verification Agreements which are to be concluded between the IAEA and the Russian Federation and the lAEA and the United States for the verification of weapon-origin and other fissile material specified by each State as released from its defense programs. A technical experts working group for inventory monitoring systems has been meeting since Feb- of 2000 to formulate General Technical Requirements (GTR) for Inventory Monitoring Systems for the Trilateral Initiative. Although provisional agreement has been reached by the three parties concerning the GTR, it is considered a living document that can be updated as warranted by the three parties. This paper provides a summary of the GTR as it currently exists
Tobacco Industry Research on Smoking Cessation: Recapturing Young Adults and Other Recent Quitters
BACKGROUND: Smoking rates are declining in the United States, except for young adults (age 18 to 24). Few organized programs target smoking cessation specifically for young adults, except programs for pregnant women. In contrast, the tobacco industry has invested much time and money studying young adult smoking patterns. Some of these data are now available in documents released through litigation. OBJECTIVE: Review tobacco industry marketing research on smoking cessation to guide new interventions and improve clinical practice, particularly to address young adult smokers’ needs. METHODS: Analysis of previously secret tobacco industry documents. RESULTS: Compared to their share of the smoking population, young adult smokers have the highest spontaneous quitting rates. About 10% to 30% of smokers want to quit; light smokers and brand switchers are more likely to try. Tobacco companies attempted to deter quitting by developing products that appeared to be less addictive or more socially acceptable. Contrary to consumer expectations, “ultra low tar” cigarette smokers were actually less likely to quit. CONCLUSIONS: Tobacco industry views of young adult quitting behavior contrast with clinical practice. Tobacco marketers concentrate on recapturing young quitters, while organized smoking cessation programs are primarily used by older smokers. As young people have both the greatest propensity to quit and the greatest potential benefits from smoking cessation, targeted programs for young adults are needed. Tobacco marketing data suggest that aspirational messages that decrease the social acceptability of smoking and support smoke-free environments resonate best with young adult smokers’ motivations
Inhibition of STAT3, FAK and Src mediated signaling reduces cancer stem cell load, tumorigenic potential and metastasis in breast cancer
Cancer stem cells (CSCs) are responsible for aggressive tumor growth, metastasis and therapy resistance. In this study, we evaluated the effects of Shikonin (Shk) on breast cancer and found its anti-CSC potential. Shk treatment decreased the expression of various epithelial to mesenchymal transition (EMT) and CSC associated markers. Kinase profiling array and western blot analysis indicated that Shk inhibits STAT3, FAK and Src activation. Inhibition of these signaling proteins using standard inhibitors revealed that STAT3 inhibition affected CSCs properties more significantly than FAK or Src inhibition. We observed a significant decrease in cell migration upon FAK and Src inhibition and decrease in invasion upon inhibition of STAT3, FAK and Src. Combined inhibition of STAT3 with Src or FAK reduced the mammosphere formation, migration and invasion more significantly than the individual inhibitions. These observations indicated that the anti-breast cancer properties of Shk are due to its potential to inhibit multiple signaling proteins. Shk also reduced the activation and expression of STAT3, FAK and Src in vivo and reduced tumorigenicity, growth and metastasis of 4T1 cells. Collectively, this study underscores the translational relevance of using a single inhibitor (Shk) for compromising multiple tumor-associated signaling pathways to check cancer metastasis and stem cell load