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Sample records for incorporating tritium control

  1. Radioactive waste tank ventilation system incorporating tritium control

    SciTech Connect

    Rice, P.D.

    1997-08-01

    This paper describes the development of a ventilation system for radioactive waste tanks at the U.S. Department of Energy`s (DOE) Hanford Site in Richland, Washington. The unique design of the system is aimed at cost-effective control of tritiated water vapor. The system includes recirculation ventilation and cooling for each tank in the facility and a central exhaust air clean-up train that includes a low-temperature vapor condenser and high-efficiency mist eliminator (HEME). A one-seventh scale pilot plant was built and tested to verify predicted performance of the low-temperature tritium removal system. Tests were conducted to determine the effectiveness of the removal of condensable vapor and soluble and insoluble aerosols and to estimate the operating life of the mist eliminator. Definitive design of the ventilation system relied heavily on the test data. The unique design features of the ventilation system will result in far less release of tritium to the atmosphere than from conventional high-volume dilution systems and will greatly reduce operating costs. NESHAPs and TAPs NOC applications have been approved, and field construction is nearly complete. Start-up is scheduled for late 1996. 3 refs., 4 figs., 2 tabs.

  2. Tritium transport and control in the FED

    SciTech Connect

    Rogers, M.L.

    1981-01-01

    The tritium systems for the FED have three primary purposes. The first is to provide tritium and deuterium fuel for the reactor. This fuel can be new tritium or deuterium delivered to the plant site, or recycled DT from the reactor that must be processed before it can be recycled. The second purpose of the FED tritium systems is to provide state-of-the-art tritium handling to limit worker radiation exposure and to minimize tritium losses to the environment. The final major objective of the FED tritium systems is to provide an integrated system test of the tritium handling technology necessary to support the fusion reactor program. Every effort is being made to incorporate available information from the Tritium System Test Assembly (TSTA) at Los Alamos National Laboratory, the Tokamak Fusion Test Reactor (TFTR) tritium systems, and the tritium handling information generated within DOE for the past 20 years.

  3. Tritium waste control: April-September 1981

    SciTech Connect

    Lamberger, P.H.; Rogers, M.L.

    1982-05-17

    Progress reports are presented for the following: electrolysis of tritiated water; impurity removal from combined Electrolysis Catalytic Exchange (CECE) feed water; gas generation measurements on tritiated waste materials; fixation of aqueous tritiated waste in polymer-impregnated concrete; management of high specific activity tritiated liquid wastes; and tritium assay of low specific activity (LSA) laboratory and LSA shoe cover waste. Some of the highlights are as follows: (1) gas generation rates caused by radiolysis of tritium waste materials were determined for polymer and nonpolymer-impregnated, tritiated concrete and fixated and nonfixated, tritiated waste vacuum pump oil; (2) the drum study monitoring the release of tritium from actual burial packages showed that the maximum fractional release rate for the three types of high activity, tritiated liquid waste generated is 1.25 x 10/sup -5/, and the maximum total permeation is 122 mCi after 5.5 y. These two values represent a 9 to 20% increase for the past six months. Tritium release from the polymer-impregnated, tritiated concrete (PITC) and the control (non-PITC) remains very low. Two assays were performed on low specific activity, tritium-contaminated waste generated at Mound. In one, four LSA drums were assayed for total tritium content by leaching the contents with water. The tritium content of all four drums was well within the LSA limit of less than 25 Ci per drum. In the second study a drum of discarded shoe covers from tritium-handling areas was filled with a measureed quantity of water for leaching tritium from the shoe covers. The minimum amount of tritium within the drum was determined. An annual average estimate of tritium removed and buried as LSA shoe cover trash was also made.

  4. Tritium control: October 1982-March 1983

    SciTech Connect

    Lamberger, P.H.; Rogers, M.L.

    1983-10-07

    Surveys in gloveboxes indicated surface activity on stainless steel and its apparent dependence on time and atmospheric tritium levels. Surveys in fumehoods were completed to investigate the extent of surface contamination on surfaces of various materials. Gas generation rates caused by radiolysis of tritiated waste materials were determined for polymer and nonpolymer-impregnated tritiated concrete and fixated and nonfixated tritiated waste vacuum pump oil. In addition, the pressure change of hydrogen cover gas over tritiated water on cement-plaster was determined. The test program to measure and compare the release of tritium from tritiated concrete with and without styrene impregnation continued. Tritium permeation data from small test blocks are given. The drum study monitoring the release of tritium from actual burial packages continued. The maximum fractional release rate for the three types of high activity, tritiated liquid waste generated is 5.1 x 10/sup -5/, and the maximum total permeation is 179 mCi after 8.5 yr. These two values represent a 13% increase for the past 6 months. Tritium release from the polymer-impregnated, tritiated concrete (PITC) and from the control (non-PITC) remains very low. The Emergency Containment System (ECS), an automatically actuated system developed at Mound to remove tritium from room air, has been modified and upgraded to support new applications. The leakage rate in the ECS area has been lowered, a fast-start system installed for greater conversion efficiency at startup, and the alumina beds regenerated.

  5. Tritium waste control: April-September 1980

    SciTech Connect

    Lamberger, P.H.; Rogers, M.L.

    1980-11-26

    The Combined Electrolysis Catalytic Exchange (CECE) pilot system was operated using Maxey Flats trench water as feed. Two pneumatic seal electrolysis cells were procured. One will be used as a control (operated with nontritiated water) for the high-level tritiated water electrolysis tests. A test system for the cells was designed, built and successfully tested. Several additional impurity analyses were completed on effluent recovery system (ERS) water. Bench-scale experiments were conducted to define methods and parameters for removal of oil-organics from ERS water. Four types of activated carbon were used to absorb vacuum pump oil from 1 to 10% mixtures in water. Two experiments were conducted to determine the efficiency of the catalytic reactor to oxidize elemental tritium and also to determine the efficiency of the adsorption columns to capture the oxidized tritium. The resulting data indicate that reactor efficiency is >90% for concentrations on the order of 10 mCi/m/sup 3/, and about 50% at 0.5 mCi/m/sup 3/. The adsorption columns were also found to have less than the assumed 100% efficiency at capturing the HTO. Concentration data indicate possible channeling instead of breakthrough. The study of tritium release from representative burial packages continued. The two waste-water drums which have the highest tritium release (29 mCi and 85 mCi) also contain the highest amounts of tritium, originally 34,480 Ci and 52,128 Ci, respectively. The tritium release from the polymer-impregnated, tritiated concrete and the control remain too low to be illustrated on the current figures.

  6. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, Terry R. [Berkeley, CA

    1980-04-01

    An improvement in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release.

  7. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, T.R.

    1980-04-01

    An improvement is described in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release. 1 fig.

  8. Tritium control: April-September 1983

    SciTech Connect

    Lamberger, P.H.; Rogers, M.L.

    1984-01-27

    The Combined Electrolysis Catalytic Exchange (CECE) and Water Feed Cleanup (WFCU) systems were decommissioned, and the associated glovebox lines were decontaminated. Previously predicted correlations between atmospheric tritium concentrations and surface contamination and rates of atmospheric decontamination were examined during the decommissioning of the three gloveboxes. To expedite this procedure, the boxline was purged with air and N/sub 2/ by employing high volumetric flow rates of up to 1.7 vol %/min. The relationship between atmospheric concentration and cleanup times was examined for this purge rate. Results from surveys taken inside the boxline were compared to results expected according to the correlations predicted by previous surveys. Gas generation rates caused by radiolysis of tritiated waste materials were determined for polymer and nonpolymer-impregnated tritiated concrete and fixated and nonfixated tritiated waste vacuum pump oil. In addition, the pressure change of hydrogen cover gas over tritiated water on cement-plaster was determined. The test program to measure and compare the release of tritium from tritiated concrete with and without styrene impregnation continued. Tritium permeation data from small test blocks are given. The drum study monitoring the release of tritium from actual burial packages continued. The maximum fractional release rate for the three types of high activity, tritiated liquid waste generated is 7.05 x 10/sup -6/, and the maximum total permeation is 241 mCi after 9 yr. These two values represent a 7% increase for the past 6 months. Tritium release from the polymer-impregnated, tritiated concrete (PITC) and from the control (non-PITC) remains very low. A sample of the 10-year-old catalyst from the Emergency Containment System (ECS) reactor was tested to determine its efficiency. Preliminary results indicate a conversion rate of 90 +- 10%.

  9. Catabolism of tritiated thymidine by aquatic microbial communities and incorporation of tritium into RNA and protein

    SciTech Connect

    Brittain, A.M.; Karl, D.M. )

    1990-05-01

    The incorporation of tritiated thymidine by five microbial ecosystems and the distribution of tritium into DNA, RNA, and protein were determined. Nonspecific labeling was greatest in sediment samples, for which {>=}95% of the tritium was recovered with the RNA and protein fractions. The percentage of tritium recovered in the DNA fraction ranged from 15 to 38% of the total labeled macromolecules recovered. Nonspecific labeling was independent of both incubation time and thymidine concentration over very wide ranges. We also evaluated the specificity of (2-{sup 3}H) adenine incorporation into adenylate residues in both RNA and DNA in parallel with the ({sup 3}H) thymidine experiments and compared the degree of nonspecific labeling by ({sup 3}H) adenine with that derived from ({sup 3}H)thymidine. Rapid catabolism of tritiated thymidine was evaluated by determining the disappearance of tritiated thymidine from the incubation medium and the appearance of degradation products. Degradation product formation, including that of both volatile and nonvolatile compounds, was much greater than the rate of incorporation of tritium into stable macromolecules. The standard degradation pathway for thymidine coupled with utilization of Krebs cycle intermediates for the biosynthesis of amino acids, purines, and pyrimidines readily accounts for the observed nonspecific labeling in environmental samples.

  10. Measurement and Control Systems of Tritium Facilities for Scientific Research

    SciTech Connect

    Vinogradov, Yu.I.; Kuryakin, A.V.; Yukhimchuk, A.A.

    2005-07-15

    The technical approach, equipment and software developed during the creation of measurement and control systems for two complexes are described. The first one is a complex that prepares the gas mixture and targets of the 'TRITON' facility. The 'TRITON' facility is designed for studying muon catalyzed fusion reactions in triple mixtures of H/D/T hydrogen isotopes over wide ranges of temperature and pressure. The second one is 'ACCULINNA' - the liquid tritium target designed to investigate the neutron overloaded hydrogen and helium nuclei. These neutron-overloaded nuclei are produced in reactions of tritium beams on a heavy hydrogen and tritium target.

  11. Tritium waste control: October 1981-March 1982

    SciTech Connect

    Lamberger, P.H.; Rogers, M.L.

    1982-08-16

    Progress reports and summaries are presented for the following: electrolysis of tritiated water; impurity removal from the Combined Electrolysis Catalytic Exchange (CECE) feed water; gas generation measurements on tritiated waste materials; fixation of aqueous tritiated waste in polymer-impregnated concrete; management of high specific activity tritiated liquid wastes; and treatment of tritium contaminated water at Three Mile Island. (ATT)

  12. Tritium waste control, October 1979-March 1980

    SciTech Connect

    Not Available

    1980-05-19

    Modifications were made to the Combined Electrolysis Catalytic Exchange (CECE) pilot unit. After the SPE cell was dismantled to investigate a water circulation problem, an internal short circuit developed. Analyses were done for impurities in the CECE system; the problem appears to be a 1 to 2% oil (mostly insoluble organics) layer. A polystyrene-impregnated, tritiated-concrete waste package was prepared with 7921 Ci of tritium. The study of tritium release from representative burial packages was continued. Gas generation rates were determined for polymer and non-polymer impregnated tritiated concrete and fixated and non-fixated tritiated waste vacuum pump oil. The pressure change of hydrogen cover gas over tritiated water on cement-plaster was determined.

  13. Report of the Task Group on operation Department of Energy tritium facilities

    SciTech Connect

    Not Available

    1991-10-01

    This report discusses the following topics on the operation of DOE Tritium facilities: Environment, Safety, and Health Aspects of Tritium; Management of Operations and Maintenance Functions; Safe Shutdown of Tritium Facilities; Management of the Facility Safety Envelope; Maintenance of Qualified Tritium Handling Personnel; DOE Tritium Management Strategy; Radiological Control Philosophy; Implementation of DOE Requirements; Management of Tritium Residues; Inconsistent Application of Requirements for Measurement of Tritium Effluents; Interdependence of Tritium Facilities; Technical Communication among Facilities; Incorporation of Confinement Technologies into New Facilities; Operation/Management Requirements for New Tritium Facilities; and Safety Management Issues at Department of Energy Tritium Facilities.

  14. Catabolism of Tritiated Thymidine by Aquatic Microbial Communities and Incorporation of Tritium into RNA and Protein †

    PubMed Central

    Brittain, Andrew M.; Karl, David M.

    1990-01-01

    The incorporation of tritiated thymidine by five microbial ecosystems and the distribution of tritium into DNA, RNA, and protein were determined. All microbial assemblages tested exhibited significant labeling of RNA and protein (i.e., nonspecific labeling), as determined by differential acid-base hydrolysis. Nonspecific labeling was greatest in sediment samples, for which ≥95% of the tritium was recovered with the RNA and protein fractions. The percentage of tritium recovered in the DNA fraction ranged from 15 to 38% of the total labeled macromolecules recovered. Nonspecific labeling was independent of both incubation time and thymidine concentration over very wide ranges. Four different RNA hydrolysis reagents (KOH, NaOH, piperidine, and enzymes) solubilized tritium from cold trichloroacetic acid precipitates. High-pressure liquid chromatography separation of piperidine hydrolysates followed by measurement of isolated monophosphates confirmed the labeling of RNA and indicated that tritium was recovered primarily in CMP and AMP residues. We also evaluated the specificity of [2-3H]adenine incorporation into adenylate residues in both RNA and DNA in parallel with the [3H]thymidine experiments and compared the degree of nonspecific labeling by [3H]adenine with that derived from [3H]thymidine. Rapid catabolism of tritiated thymidine was evaluated by determining the disappearance of tritiated thymidine from the incubation medium and the appearance of degradation products by high-pressure liquid chromatography separation of the cell-free medium. Degradation product formation, including that of both volatile and nonvolatile compounds, was much greater than the rate of incorporation of tritium into stable macromolecules. The standard degradation pathway for thymidine coupled with utilization of Krebs cycle intermediates for the biosynthesis of amino acids, purines, and pyrimidines readily accounts for the observed nonspecific labeling in environmental samples. PMID

  15. Collection and control of tritium bioassay samples at Pantex

    SciTech Connect

    Fairrow, N.L.; Ivie, W.E.

    1992-01-01

    Pantex is the final assembly/disassembly point for US nuclear weapons. The Pantex internal dosimetry section monitors radiation workers once a month for tritium exposure. In order to manage collection and control of the bioassay specimens efficiently, a bar code system for collection of samples was developed and implemented to speed up the process and decrease the number of errors probable when transferring data. In the past, all the bioassay data from samples were entered manually into a computer database. Transferring the bioassay data from the liquid scintillation counter to each individual's dosimetry record required as much as two weeks of concentrated effort.

  16. Collection and control of tritium bioassay samples at Pantex

    SciTech Connect

    Fairrow, N.L.; Ivie, W.E.

    1992-12-31

    Pantex is the final assembly/disassembly point for US nuclear weapons. The Pantex internal dosimetry section monitors radiation workers once a month for tritium exposure. In order to manage collection and control of the bioassay specimens efficiently, a bar code system for collection of samples was developed and implemented to speed up the process and decrease the number of errors probable when transferring data. In the past, all the bioassay data from samples were entered manually into a computer database. Transferring the bioassay data from the liquid scintillation counter to each individual`s dosimetry record required as much as two weeks of concentrated effort.

  17. Field Deployable Tritium Assay System Remote Control Software

    Energy Science and Technology Software Center (ESTSC)

    1998-05-12

    The FDTASREM software is a command control based application for the Field Deployable Tritium Assay System (FDTAS-Invention Disclosure SRS-96-091 has been submitted). The program runs on the Remote computer which is located at the field site with the FDTAS sampling and analysis components. The application executes commands received over the connected phone line from the operator via the FDTAS Host GUI running in the laboratory some distance away. The FDTASREM controls interface with the FDTASmore » auto sampler and the analysis systems. It tells the sampler to take a sample from a specified location and send it to the analyzer. Once the sample is sent to the analyzer, FDTASREM sequences the internal valves and pumps to deliver the sample and cocktail to the counting chamber. Once the analysis is complete, the program can execute the clean command and prepare the system for the next sample.« less

  18. In vivo incorporation of tritium from 3H2O into pulmonary lipids of meal-fed and starved rats

    SciTech Connect

    Todhunter, D.A.; Scholz, R.W.

    1980-12-01

    In vivo fatty acid synthesis, as measured by tritium incorporation from 3H2O into fatty acids, was examined in the lungs of meal-fed and starved rats. In meal-fed animals, 74% of the radioactivity isolated from pulmonary lipids was found in the phospholipid fraction. Starving rats for 72 h markedly reduced in vivo 3H2O incorporation into pulmonary lipids. These studies demonstrated net in vivo synthesis of fatty acids in pulmonary tissue of rats using a method that is not complicated by potential differences in metabolic pool sizes or peculiarities of specific carbon substrate sources. Synthesis of fatty acids in vivo was affected by the nutritional state of the animal and citrate appears to be a significant source of cytoplasmic acetyl-CoA for de novo pulmonary lipogenesis in the fed rat.

  19. TRITIUM LABORATORY, TRA666, INTERIOR. MAIN INSTRUMENT PANEL INSIDE CONTROL ROOM. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TRITIUM LABORATORY, TRA-666, INTERIOR. MAIN INSTRUMENT PANEL INSIDE CONTROL ROOM. INL NEGATIVE NO. HD30-2-4. Mike Crane, Photographer, 6/2001 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  20. Control of Tritium at the Fast Flux Test Facility

    SciTech Connect

    Prevo, P. R.

    1989-06-01

    The Fast Flux Test Facility (FFTF) is located on the Hanford Site near Richland, Washington, and is operated by the Westinghouse Hanford Company for the US Department of Energy (DOE). The facility features a 400 MW(t) three-loop sodium-cooled, mixed-oxide-fueled reactor that was designed for irradiation testing of fuels and materials to support the commercial development of liquid metal fast reactors. The mission has subsequently been expanded to include a passive safety test program, irradiation of fusion and space reactor materials, and isotope production. The FFTF has been in operation for about 7 yr, which includes over 1600 d of full power operation of the fast test reactor (FTR). Radiological operating experience at the FFTF has been excellent. Collective dose equivalents received by operating personnel have been very low (5 person-rem/yr average). No major contamination problems have been encountered in operating and maintaining the plant, and release of radioactivity to the environment has been well below acceptable limits (Bunch and Prevo 1987). Skin contamination events have averaged less than two per year. There have been no internal depositions. This paper discusses the generation, transport and distribution, and radiological aspects of tritium control at the FFTF. 3 refs., 1 fig., 2 tabs.

  1. Tritium Reduction and Control in the Vacuum Vessel during TFTR Outage and Decommissioning

    SciTech Connect

    Blanchard, W.; Camp, R.; Carnevale, H.; Casey, M.; Collins, J.; et al

    1997-11-01

    In the summer/fall of 1996 after nearly three years of D-T operations, TFTR underwent an extended outage during which large port covers were removed from the vacuum vessel in order to complete upgrades to the tokamak. Following the venting of the torus, a three tier system was developed for the outage in order to reduce and control the free tritium in the vacuum vessel so as to minimize the exposure to personnel during port cover removal and reinstallation. The first phase of the program to reduce the free tritium consisted of direct flowthrough of room air through the vacuum vessel to the molecular sieve beds using the Torus Cleanup System. Real time measurements of the effluent tritium concentration were used to derive the amount of tritium removed from the torus. Once the free tritium in the vessel had been reduced to approximately 50 Ci, a second phase was initiated using a 55 Gallon Drum Bubbler System for the direct processing of the vacuum vessel to further lower the tritium level in the torus. Tritium oxide is absorbed by the bubbler system with the exhaust vented to one of the tritium monitored HVAC ventilation stacks. To preclude the release of tritium to the Test Cell location of TFTR and to minimize the exposure of workers, a variable flow exhaust system was employed in order to maintain a negative pressure in the vacuum vessel between 0.05" and 1.5" w.c. during the removal of port covers ranging in size from approximately 5 to 1000 in(superscript2). These systems were completely successful in reducing and controlling the free tritium in TFTR and were instrumental in maintaining ALARA (As Low As Reasonably Achievable) exposures to tritium during the 1996 outage. These systems are again being utilized during the safe shutdown and decommissioning of TFTR which commenced in April of 1997. This paper describes in detail the configuration of these systems and the data obtained during the outage and safe shutdown of TFTR.

  2. Evidence for an adaptive response to radiation damage in plant cells conditioned with X-rays or incorporated tritium.

    PubMed

    Cortés, F; Domínguez, I; Mateos, S; Piñero, J; Mateos, J C

    1990-03-01

    Allium cepa root-tip cells were first exposed to low 'conditioning' doses of ionizing radiation: to X-rays (0.06 or 0.26 Gy) or to incorporated tritium (1.8 x 10(4) or 7.2 x 10(4) Bq/ml; specific activity: 740.0 GBq/mmol) and subsequently given a 'challenge' dose of 1.5 Gy of X-rays. A reduction in X-ray-induced chromosomal damage was brought about by prior exposure to 0.26 Gy of X-rays, while cells receiving the lower conditioning dose (0.06 Gy of X-rays) did not show any significant reduction. In cells grown in the presence of [3H]TdR on the other hand, the adaptive response was evident after both doses given. The results are essentially in agreement with those published by Wolff's group for human lymphocytes in showing that plant cells in vivo can become 'adapted' by exposure to low-level irradiation so that they become more resistant to the clastogenic effects of X-rays delivered subsequently. PMID:1968946

  3. Export Control Requirements for Tritium Processing Design and R&D

    SciTech Connect

    Hollis, William Kirk; Maynard, Sarah-Jane Wadsworth

    2015-10-30

    This document will address requirements of export control associated with tritium plant design and processes. Los Alamos National Laboratory has been working in the area of tritium plant system design and research and development (R&D) since the early 1970’s at the Tritium Systems Test Assembly (TSTA). This work has continued to the current date with projects associated with the ITER project and other Office of Science Fusion Energy Science (OS-FES) funded programs. ITER is currently the highest funding area for the DOE OS-FES. Although export control issues have been integrated into these projects in the past a general guidance document has not been available for reference in this area. To address concerns with currently funded tritium plant programs and assist future projects for FES, this document will identify the key reference documents and specific sections within related to tritium research. Guidance as to the application of these sections will be discussed with specific detail to publications and work with foreign nationals.

  4. Controlling particulates, temperature, and tritium in an inert glovebox for a weapons program

    SciTech Connect

    Purson, J.D.; Powers, D.; Walthers, C.; Navarro, C.; Newman, E.; Romero, J.; Jenkins, R.

    1996-07-01

    A glovebox is described in which several environmental parameters are controlled and monitored. Included in these are particulate, tritium, water vapor, oxygen and temperature. The paper details the design rationale and process and describes the glovebox, presently in use for neutron generator production.

  5. TRITIUM LABORATORY, TRA666, INTERIOR. COOLANT LOOP PIPING DETAIL AND CONTROL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TRITIUM LABORATORY, TRA-666, INTERIOR. COOLANT LOOP PIPING DETAIL AND CONTROL VALVE EQUIPMENT ALONG EAST WALL. INL NEGATIVE NO. HD30-2-2. Mike Crane, Photographer, 6/2001 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. Tritium autoradiography

    SciTech Connect

    Caskey, G.R. Jr.

    1981-01-01

    Hydrogen distribution and diffusion within many materials may be investigated by autoradiography if the radioactive isotope tritium is used in the study. Tritium is unstable and decays to helium-3 by emission of a low energy (18 keV) beta particle which may be detected photographically. The basic principles of tritium autoradiography will be discussed. Limitations are imposed on the technique by: (1) the low energy of the beta particles; (2) the solubility and diffusivity of hydrogen in materials; and (3) the response of the photographic emulsion to beta particles. These factors control the possible range of application of tritium autoradiography. The technique has been applied successfully to studies of hydrogen solubility and distribution in materials and to studies of hydrogen damage.

  7. What controls boron incorporation into foraminiferal calcite?

    NASA Astrophysics Data System (ADS)

    Allen, K. A.; Hoenisch, B.; Eggins, S. M.; Rosenthal, Y.; Spero, H. J.

    2012-12-01

    In recent years, the ratio of boron to calcium (B/Ca) in foraminiferal calcite has emerged as a new and promising candidate for reconstructing marine carbonate chemistry. In addition to the expected primary control of aqueous borate and bicarbonate concentrations, calcification temperature and aqueous carbonate ion ([CO32-]) appear to exert secondary influences on B/Ca, based on sediment coretop data. In these studies, partitioning of B between seawater and calcite was described by an empirical coefficient, KD, and application of temperature- and [CO32-]-dependent KD calibrations to fossil calcite yielded pCO2 reconstructions that appeared consistent with ice-core records. Identification of controlling parameters from coretop samples alone can be difficult because many environmental parameters covary in the surface ocean (e.g., temperature and [CO32-]). To quantify the different controls on B/Ca, we performed culture experiments with live planktic foraminifers that enabled us to test the respective influences of pH, temperature, salinity, dissolved boron, and dissolved inorganic carbon. Unlike prior studies, we did not discern any influence of temperature on B partitioning. This result prompted us to reconsider KD calibrations and their corresponding pH and pCO2 reconstructions. The new culture calibrations (salinity and carbonate system) allow prediction of coretop planktic foraminiferal B/Ca from surface seawater properties, suggesting that these culture relationships are applicable to specimens growing in the open ocean. Benthic foraminiferal B/Ca, however, is not well-described by planktic culture calibrations. Instead, it is most closely correlated with bottom water carbonate saturation (ΔCO32-), suggesting that planktic and benthic foraminifera may incorporate B via different mechanisms. Here, we discuss existing B/Ca calibrations and KD-based pH reconstructions, and suggest directions for proxy applications and further development.

  8. TRITIUM LABORATORY, TRA666, INTERIOR. MAIN FLOOR. CONTROL ROOM ENCLOSURE AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TRITIUM LABORATORY, TRA-666, INTERIOR. MAIN FLOOR. CONTROL ROOM ENCLOSURE AT CENTER OF VIEW. SIGN ABOVE DOOR SAYS "HYDRAULIC TEST FACILITY CONTROL ROOM." SIGN IN WINDOW SAYS "EATING AREA." "EVACUATION AND EMERGENCY INFORMATION" IS POSTED ON CABINET AT LEFT OF VIEW. INL NEGATIVE NO. HD30-2-3. Mike Crane, Photographer, 6/2001 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  9. Tritium in the aquatic environment

    SciTech Connect

    Blaylock, B.G.; Hoffman, F.O.; Frank, M.L.

    1986-02-01

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products.

  10. Exposure Control for Operations and Maintenance at the Accelerator Production of Tritium

    SciTech Connect

    McGuire, D.H.

    1998-09-01

    The APT will be designed and operated to support continuous tritium production. Tritium is an essential ingredient in U.S. nuclear weapons. The APT will be designed and staffed to support continuous production of tritium by trained, qualified, and certified personnel.

  11. Enhanced incorporation of tritium into glycolate during photosynthesis by tobacco leaf tissue in the presence of tritiated water

    SciTech Connect

    Peterson, R.B.

    1982-01-01

    Tobacco (Nicotiana tabacum var. Havana Seed) leaf discs were allowed to photosynthesize for 3 to 20 minutes in the present of /sup 14/CO/sub 2/ and /sup 3/H/sub 2/O. Several metabolites of the Calvin cycle and photorespiratory pathway were isolated and purified and the /sup 3/H:/sup 14/C values measured. Glycolate had a 5- to 10-fold higher /sup 3/H:/sup 14/C than the Calvin cycle intermediate 3- phosphoglyceric acid, or its end product sucrose. The glycolate oxidase inhibitor ..cap alpha..-hydroxy-2-pyridinemethanesulfonic acid caused glycolate to accumulate in the tissue and lowered the /sup 3/H:/sup 14/C in glycolate to a value similar to that in 3-phosphoglyceric acid. Phosphoglycolate, a possible precursor of glycolate arising from the Calvin cycle, exhibited a /sup 3/H:/sup 14/C value similar 3-phosphoglyceric acid under all conditions. The finding of a /sup 3/H enrichment in glycolate suggests that another source of glycolate, possibly the reduction of glyoxylate, exists in leaf tissue. Analyses of incorporation of /sup 3/H into the pro-2R and pro-2S hydrogens of glycolate, in the presence and absence of ..cap alpha..-hydroxy-2-pyridinemethanesulfonic acid, suggest an alternative source of glycolate. Biochemical mechanisms to account for /sup 3/H enrichment into glycolate are evaluated.

  12. Controlled release of diclofenac sodium in glycolipid incorporated micro emulsions.

    PubMed

    Premarathne, E P N; Karunaratne, D N; Perera, A D L Chandani

    2016-09-25

    The effect of the glycolipid, hexadecyl-β-d-glucopyranoside, incorporated in microemulsions (ME(1)) towards the enhancement of skin absorption and skin permeation of Diclofenac sodium (DS(2)) was evaluated. A Franz diffusion cell with a piece of pig's ear epidermis indicated that the optimized ME formulation with glycolipid (0.05wt%) exhibited significantly higher permeability than the conventional formulations. The releasing profiles of DS from ME formulations exhibited first order release kinetics resembling a diffusion controlled release model for the first 8h. Incorporating hexadecyl-β-D glucopyranoside in ME formulations shows significant potential as a delivery vehicle in the cosmetics and pharmaceutical industry. PMID:27477103

  13. BEATRIX-II: In situ tritium test

    SciTech Connect

    Baker, D.E. ); Kuraswa, T. ); Miller, J.M. . Chalk River Nuclear Labs.); Slagle, O.D. )

    1990-01-01

    The BEATRIX-II irradiation experiment is an in-situ tritium release experiment being carried out in the Fast Flux Test Facility (FFTF) reactor to evaluate the tritium release characteristics of fusion solid breeder materials. A sophisticated tritium gas handling system has been developed to continuously monitor the tritium recovery from the specimens and facilitate tritium removal from the experiment's sweep gas flow stream. The in-situ recovery experiment accommodates two different in-reactor specimen canisters with individual gas streams and temperature monitoring/control. Ionization chambers have been specifically designed to respond to the rapid changes in the tritium release rate at the anticipated tritium concentrations. Two ceramic electrolysis cells have proved effective in reducing the moisture in the gas streams to hydrogen/tritium. A tritium getter system, capable of reducing the tritium level by a factor greater than 4000, is used to reduce the tritium in the sweep gas to a level acceptable for release.

  14. Tritium waste control: October 1980-March 1981. [Catalytic exchange detritiation; fixation of aqueous tritiated wastes in polymer impregnated concrete

    SciTech Connect

    Lamberger, P.H.; Rogers, M.L.

    1981-10-19

    The Combined Electrolysis Catalytic Exchange (CECE) pilot system was operated for 88 days and processed over 500 liters of tritiated water. Two complete electrolysis systems, each using a General Electric Company solid polymer electrolyte (SPE) cell, have been built. One of these is being used for the 10 Ci/ml tritiated water test and the other as a control with nontritiated water. The first SPE failed after seven weeks of exposure to the 10 Ci/ml water. A new SPE was installed and has been operated for eight weeks without failure at 10 Ci/ml. Analyses for 10 types of impurities were made on each of 15 Effluent Recovery System (ERS) liquid waste samples. A pilot-scale system for removal of these impurities has been designed and is being built. Gas generation rates caused by radiolysis of tritium waste materials were determined for polymer and nonpolymer impregenated tritiated concrete, and fixated and nonfixated tritiated waste vacuum pump oil. The construction of the new addition to the liquid waste handling facility was completed. The inert-atmosphere gloveboxes and other equipment are being installed for the polystyrene impregnated, tritiated-concrete wastewater process. The study of tritium release from representative burial packages was continued. The two wastewater drums which have the highest tritium release (29.8 mCi and 98.2 mCi) also contain the highest amounts of tritium, originally 34,480 Ci and 52,128 Ci, respectively. The tritium release from the polymer-impregnated, tritiated concrete (PITC) and the control (non-PITC) remain too low to be illustrated on the current figures.

  15. Overview of tritium: characteristics, sources, and problems.

    PubMed

    Okada, S; Momoshima, N

    1993-12-01

    Tritium has certain characteristics that present unique challenges for dosimetry and health-risk assessment. For example, in the gas form, tritium can diffuse through almost any container, including those made of steel, aluminum, and plastics. In the oxide form, tritium can generally not be detected by commonly used survey instruments. In the environment, tritium can be taken up by all hydrogen-containing molecules, distributing widely on a global scale. Tritium can be incorporated into humans through respiration, ingestion, and diffusion through skin. Its harmful effects are observed only when it is incorporated into the body. Several sources contribute to the inventory of tritium in our environment. These are 1) cosmic ray interaction with atmospheric molecules; 2) nuclear reactions in the earth's crust; 3) nuclear testing in the atmosphere during the 1950s and 1960s; 4) continuous release of tritium from nuclear power plants and tritium production facilities under normal operation; 5) incidental releases from these facilities; and 6) consumer products. An important future source will be nuclear fusion facilities expected to be developed for the purpose of electricity generation. The principal health physics problems associated with tritium are 1) the determination of the parameters for risk estimation with further reduction of their uncertainties (e.g., relative biological effectiveness and dose-rate dependency); 2) risk estimation from complex exposures to tritium in gas form, tritium in oxide form, tritium surface contamination, and other tritium-contaminated forms, with or without other ionizing radiations and/or nonionizing radiations; 3) the dose contributions of elemental tritium in the lung and from its oxidized tritium in the gastrointestinal tract; 4) prevention of tritium (in oxide form) intake and enhancement of tritium (oxide form) excretion from the human body; 5) precise health effects information for low-level tritium exposure; and 6) public

  16. Optofluidics incorporating actively controlled micro- and nano-particles

    PubMed Central

    Kayani, Aminuddin A.; Khoshmanesh, Khashayar; Ward, Stephanie A.; Mitchell, Arnan; Kalantar-zadeh, Kourosh

    2012-01-01

    The advent of optofluidic systems incorporating suspended particles has resulted in the emergence of novel applications. Such systems operate based on the fact that suspended particles can be manipulated using well-appointed active forces, and their motions, locations and local concentrations can be controlled. These forces can be exerted on both individual and clusters of particles. Having the capability to manipulate suspended particles gives users the ability for tuning the physical and, to some extent, the chemical properties of the suspension media, which addresses the needs of various advanced optofluidic systems. Additionally, the incorporation of particles results in the realization of novel optofluidic solutions used for creating optical components and sensing platforms. In this review, we present different types of active forces that are used for particle manipulations and the resulting optofluidic systems incorporating them. These systems include optical components, optofluidic detection and analysis platforms, plasmonics and Raman systems, thermal and energy related systems, and platforms specifically incorporating biological particles. We conclude the review with a discussion of future perspectives, which are expected to further advance this rapidly growing field. PMID:23864925

  17. Tritium production, recovery and application in Korea.

    PubMed

    Son, Soon-Hwan; Lee, Sook-Kyung; Kim, Kwang-Sin

    2009-01-01

    Four CANDU reactors have been operating at the site of Wolsong Nuclear Power Generation in Korea. The Wolsong tritium removal facility was constructed to reduce the tritium levels in heavy water systems. This facility was designed to process 100kg/h of tritiated heavy water feed and to produce 99% pure T(2). This recovered tritium will be made available for commercial applications. The initial phases on the tritium applications are made to establish the infrastructure and the tritium controls. PMID:19307127

  18. Tritium monitor

    DOEpatents

    Chastagner, P.

    1994-06-14

    A system is described for continuously monitoring the concentration of tritium in an aqueous stream. The system pumps a sample of the stream to magnesium-filled combustion tube which reduces the sample to extract hydrogen gas. The hydrogen gas is then sent to an isotope separation device where it is separated into two groups of isotopes: a first group of isotopes containing concentrations of deuterium and tritium, and a second group of isotopes having substantially no deuterium and tritium. The first group of isotopes containing concentrations of deuterium and tritium is then passed through a tritium detector that produces an output proportional to the concentration of tritium detected. Preferably, the detection system also includes the necessary automation and data collection equipment and instrumentation for continuously monitoring an aqueous stream. 1 fig.

  19. Tritium monitor

    DOEpatents

    Chastagner, Philippe

    1994-01-01

    A system for continuously monitoring the concentration of tritium in an aqueous stream. The system pumps a sample of the stream to magnesium-filled combustion tube which reduces the sample to extract hydrogen gas. The hydrogen gas is then sent to an isotope separation device where it is separated into two groups of isotopes: a first group of isotopes containing concentrations of deuterium and tritium, and a second group of isotopes having substantially no deuterium and tritium. The first group of isotopes containing concentrations of deuterium and tritium is then passed through a tritium detector that produces an output proportional to the concentration of tritium detected. Preferably, the detection system also includes the necessary automation and data collection equipment and instrumentation for continuously monitoring an aqueous stream.

  20. Controller Design for EMA in TVC Incorporating Force Feedback

    NASA Technical Reports Server (NTRS)

    Schinstock, Dale E.; Scott, Douglas A.

    1998-01-01

    The objective of this research was to develop control schemes and control design procedures for electromechanical actuators (EMA) in thrust vector control (TVC) applications. For a variety of reasons, there is a tendency within the aerospace community to use electromechanical actuators in applications where hydraulics have traditionally been employed. TVC of rocket engines is one such application. However, there is considerable research, development, and testing to be done before EMA will be accepted by the community at large for these types of applications. Besides the development of design procedures for the basic position controller, two major concerns are dealt with in this research by incorporating force feedback: 1) the effects of resonance on the performance of EMA-TVC-rocket-engine systems, and 2) the effects of engine start transients on EMA. This report only highlights the major contributions of this research.

  1. Investigating the prevalence of queuine in Escherichia coli RNA via incorporation of the tritium-labeled precursor, preQ{sub 1}

    SciTech Connect

    Brooks, Allen F.; Velez-Martinez, Carol S.; Hollis Showalter, H.D.; Garcia, George A.

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer Escherichia coli cells deficient in preQ{sub 1} biosynthesis can utilize exogenous preQ{sub 1} from growth media. Black-Right-Pointing-Pointer Exogenous radiolabeled preQ{sub 1} is incorporated into cellular RNA in both wild-type and preQ{sub 1} deficient cells. Black-Right-Pointing-Pointer Radiolabeled preQ{sub 1} is incorporated into RNAs of differing sizes larger than tRNA. Black-Right-Pointing-Pointer Analysis of isolated ribosomes shows that radiolabeled preQ{sub 1} is incorporated into ribosomal RNA. Black-Right-Pointing-Pointer The conclusion of this study is that queuine is incorporated into many other RNAs in addition to the known tRNAs. -- Abstract: There are over 100 modified bases that occur in RNA with the majority found in transfer RNA. It has been widely believed that the queuine modification is limited to four transfer RNA species in vivo. However, given the vast amount of the human genome (60-70%) that is transcribed into non-coding RNA (Mattick ), probing the presence of modified bases in these RNAs is of fundamental importance. The mechanism of incorporation of queuine, via transglycosylation, makes this uniquely poised to probe base modification in RNA. Results of incubations of Escherichia coli cell cultures with [{sup 3}H] preQ{sub 1} (a queuine precursor in eubacteria) clearly demonstrate preQ{sub 1} incorporation into a number of RNA species of various sizes larger than transfer RNA. Specifically, significant levels of preQ{sub 1} incorporation into ribosomal RNA are observed. The modification of other large RNAs was also observed. These results confirm that non-coding RNAs contain modified bases and lead to the supposition that these modifications are necessary to control non-coding RNA structure and function as has been shown for transfer RNA.

  2. Incorporation of chemical kinetic models into process control

    SciTech Connect

    Herget, C.J.; Frazer, J.W.

    1981-07-08

    An important consideration in chemical process control is to determine the precise rationing of reactant streams, particularly when a large time delay exists between the mixing of the reactants and the measurement of the product. In this paper, a method is described for incorporating chemical kinetic models into the control strategy in order to achieve optimum operating conditions. The system is first characterized by determining a reaction rate surface as a function of all input reactant concentrations over a feasible range. A nonlinear constrained optimization program is then used to determine the combination of reactants which produces the specified yield at minimum cost. This operating condition is then used to establish the nominal concentrations of the reactants. The actual operation is determined through a feedback control system employing a Smith predictor. The method is demonstrated on a laboratory bench scale enzyme reactor.

  3. Integrated-optic polarization controllers incorporating polymer waveguide birefringence modulators.

    PubMed

    Kim, Jun-Whee; Park, Su-Hyun; Chu, Woo-Sung; Oh, Min-Cheol

    2012-05-21

    Polarization controllers based on polymer waveguide technology are demonstrated by incorporating thermo-optic birefringence modulators (BMs) and thin-film wave plates. Highly birefringent polymer materials are used to increase the efficiency of birefringence modulation in proportion to the heating power. Thin-film quarter-wave plates are fabricated by using a crosslinkable liquid crystal, reactive mesogen, and inserted between the BMs to produce static phase retardation and polarization coupling. By applying a triangular AC signal to one BM and a DC signal to another, the polarization states of the output light are modulated to cover the entire surface of the Poincaré sphere. PMID:22714231

  4. Incorporating Quality Control Information in the Sensor Web

    NASA Astrophysics Data System (ADS)

    Devaraju, Anusuriya; Kunkel, Ralf; Bogena, Heye

    2013-04-01

    The rapid development of sensing technologies had led to the creation of large amounts of heterogeneous environmental observations. The Sensor Web provides a wider access to sensors and observations via common protocols and specifications. Observations typically go through several levels of quality control, and aggregation before they are made available to end-users. Raw data are usually inspected, and related quality flags are assigned. Data are gap-filled, and errors are removed. New data series may also be derived from one or more corrected data sets. Until now, it is unclear how these kinds of information can be captured in the Sensor Web Enablement (SWE) framework. Apart from the quality measures (e.g., accuracy, precision, tolerance, or confidence), the levels of observational series, the changes applied, and the methods involved must be specified. It is important that this kind of quality control information is well described and communicated to end-users to allow for a better usage and interpretation of data products. In this paper, we describe how quality control information can be incorporated into the SWE framework. Concerning this, first, we introduce the TERENO (TERrestrial ENvironmental Observatories), an initiative funded by the large research infrastructure program of the Helmholtz Association in Germany. The main goal of the initiative is to facilitate the study of long-term effects of climate and land use changes. The TERENO Online Data RepOsitORry (TEODOOR) is a software infrastructure that supports acquisition, provision, and management of observations within TERENO via SWE specifications and several other OGC web services. Next, we specify changes made to the existing observational data model to incorporate quality control information. Here, we describe the underlying TERENO data policy in terms of provision and maintenance issues. We present data levels, and their implementation within TEODOOR. The data levels are adapted from those used by

  5. A mathematical model for incorporating biofeedback into human postural control

    PubMed Central

    2013-01-01

    Background Biofeedback of body motion can serve as a balance aid and rehabilitation tool. To date, mathematical models considering the integration of biofeedback into postural control have represented this integration as a sensory addition and limited their application to a single degree-of-freedom representation of the body. This study has two objectives: 1) to develop a scalable method for incorporating biofeedback into postural control that is independent of the model’s degrees of freedom, how it handles sensory integration, and the modeling of its postural controller; and 2) to validate this new model using multidirectional perturbation experimental results. Methods Biofeedback was modeled as an additional torque to the postural controller torque. For validation, this biofeedback modeling approach was applied to a vibrotactile biofeedback device and incorporated into a two-link multibody model with full-state-feedback control that represents the dynamics of bipedal stance. Average response trajectories of body sway and center of pressure (COP) to multidirectional surface perturbations of subjects with vestibular deficits were used for model parameterization and validation in multiple perturbation directions and for multiple display resolutions. The quality of fit was quantified using average error and cross-correlation values. Results The mean of the average errors across all tactor configurations and perturbations was 0.24° for body sway and 0.39 cm for COP. The mean of the cross-correlation value was 0.97 for both body sway and COP. Conclusions The biofeedback model developed in this study is capable of capturing experimental response trajectory shapes with low average errors and high cross-correlation values in both the anterior-posterior and medial-lateral directions for all perturbation directions and spatial resolution display configurations considered. The results validate that biofeedback can be modeled as an additional torque to the postural

  6. TFTR tritium operations lessons learned

    SciTech Connect

    Gentile, C.A.; Raftopoulos, S.; LaMarche, P.

    1996-12-31

    The Tokamak Fusion Test Reactor which is the progenitor for full D-T operating tokamaks has successfully processed > 81 grams of tritium in a safe and efficient fashion. Many of the fundamental operational techniques associated with the safe movement of tritium through the TFTR facility were developed over the course of many years of DOE tritium facilities (LANL, LLNL, SRS, Mound). In the mid 1980`s The Tritium Systems Test Assembly (TSTA) at LANL began reporting operational techniques for the safe handling of tritium, and became a major conduit for the transfer of safe tritium handling technology from DOE weapons laboratories to non-weapon facilities. TFTR has built on many of the TSTA operational techniques and has had the opportunity of performing and enhancing these techniques at America`s first operational D-T fusion reactor. This paper will discuss negative pressure employing `elephant trunks` in the control and mitigation of tritium contamination at the TFTR facility, and the interaction between contaminated line operations and {Delta} pressure control. In addition the strategy employed in managing the movement of tritium through TFTR while maintaining an active tritium inventory of < 50,000 Ci will be discussed. 5 refs.

  7. Atmospheric tritium

    SciTech Connect

    Oestlund, H.G.; Mason, A.S.

    1980-01-01

    Research progress for the year 1979 to 1980 are reported. Concentrations of tritiated water vapor, tritium gas and tritiated hydrocarbons in the atmosphere at selected sampling points are presented. (ACR)

  8. Tritium analysis at TFTR

    SciTech Connect

    Voorhees, D.R.; Rossmassler, R.L.; Zimmer, G.

    1995-04-01

    The tritium analytical system at TFRR is used to determine the purity of tritium bearing gas streams in order to provide inventory and accountability measurements. The system includes a quadrupole mass spectrometer and beta scintillator originally configured at Monsanto Mound Research Laboratory in the late 1970`s and early 1980`s. The system was commissioned and tested between 1991 and 1992 and is used daily for analysis of calibration standards, incoming tritium shipments, gases evolved from uranium storage beds and measurement of gases returned to gas holding tanks. The low resolution mass spectrometer is enhanced by the use of a metal getter pump to aid in resolving the mass 3 and 4 species. The beta scintillator complements the analysis as it detects tritium bearing species that often are not easily detected by mass spectrometry such as condensable species or hydrocarbons containing tritium. The instruments are controlled by a personal computer with customized software written with a graphical programming system designed for data acquisition and control. A discussion of the instrumentation, control systems, system parameters, procedural methods, algorithms, and operational issues will be presented. Measurements of gas holding tanks and tritiated water waste streams using ion chamber instrumentation are discussed elsewhere.

  9. Tritium monitor and collection system

    DOEpatents

    Bourne, Gary L.; Meikrantz, David H.; Ely, Walter E.; Tuggle, Dale G.; Grafwallner, Ervin G.; Wickham, Keith L.; Maltrud, Herman R.; Baker, John D.

    1992-01-01

    This system measures tritium on-line and collects tritium from a flowing inert gas stream. It separates the tritium from other non-hydrogen isotope contaminating gases, whether radioactive or not. The collecting portion of the system is constructed of various zirconium alloys called getters. These alloys adsorb tritium in any of its forms at one temperature and at a higher temperature release it as a gas. The system consists of four on-line getters and heaters, two ion chamber detectors, two collection getters, and two guard getters. When the incoming gas stream is valved through the on-line getters, 99.9% of it is adsorbed and the remainder continues to the guard getter where traces of tritium not collected earlier are adsorbed. The inert gas stream then exits the system to the decay chamber. Once the on-line getter has collected tritium for a predetermined time, it is valved off and the next on-line getter is valved on. Simultaneously, the first getter is heated and a pure helium purge is employed to carry the tritium from the getter. The tritium loaded gas stream is then routed through an ion chamber which measures the tritium activity. The ion chamber effluent passes through a collection getter that readsorbs the tritium and is removable from the system once it is loaded and is then replaced with a clean getter. Prior to removal of the collection getter, the system switches to a parallel collection getter. The effluent from the collection getter passes through a guard getter to remove traces of tritium prior to exiting the system. The tritium loaded collection getter, once removed, is analyzed by liquid scintillation techniques. The entire sequence is under computer control except for the removal and analysis of the collection getter.

  10. Tritium monitor and collection system

    DOEpatents

    Bourne, G.L.; Meikrantz, D.H.; Ely, W.E.; Tuggle, D.G.; Grafwallner, E.G.; Wickham, K.L.; Maltrud, H.R.; Baker, J.D.

    1992-01-14

    This system measures tritium on-line and collects tritium from a flowing inert gas stream. It separates the tritium from other non-hydrogen isotope contaminating gases, whether radioactive or not. The collecting portion of the system is constructed of various zirconium alloys called getters. These alloys adsorb tritium in any of its forms at one temperature and at a higher temperature release it as a gas. The system consists of four on-line getters and heaters, two ion chamber detectors, two collection getters, and two guard getters. When the incoming gas stream is valved through the on-line getters, 99.9% of it is adsorbed and the remainder continues to the guard getter where traces of tritium not collected earlier are adsorbed. The inert gas stream then exits the system to the decay chamber. Once the on-line getter has collected tritium for a predetermined time, it is valved off and the next on-line getter is valved on. Simultaneously, the first getter is heated and a pure helium purge is employed to carry the tritium from the getter. The tritium loaded gas stream is then routed through an ion chamber which measures the tritium activity. The ion chamber effluent passes through a collection getter that readsorbs the tritium and is removable from the system once it is loaded and is then replaced with a clean getter. Prior to removal of the collection getter, the system switches to a parallel collection getter. The effluent from the collection getter passes through a guard getter to remove traces of tritium prior to exiting the system. The tritium loaded collection getter, once removed, is analyzed by liquid scintillation techniques. The entire sequence is under computer control except for the removal and analysis of the collection getter. 7 figs.

  11. Tritium practices past and present

    SciTech Connect

    Gede, V.P.; Gildea, P.D.

    1980-01-01

    History of the production and use of tritium, as well as handling techniques, are reviewed. Handling techniques first used at Lawrence Livermore National Laboratory made use of glass vacuum systems and relatively crude ion chambers for monitoring airborne activity. The first use of inert atmosphere glove boxes demonstrated that uptake through the skin could be a serious personnel exposure problem. Growing environmental concerns in the early 1970's resulted in the implementation by the Atomic Energy Commission of a new criteria to limit atmospheric tritium releases to levels as low as practicable. An important result of the new criteria was the development of containment and recovery systems to capture tritium rather than vent it to the atmosphere. The Sandia National Laboratories, Livermore, Tritium Research Laboratory containment and decontamination systems are presented as a typical example of this technology. The application of computers to control systems is expected to provide the greatest potential for change in future tritium handling practices.

  12. Tritium accountancy in fusion systems

    SciTech Connect

    Klein, J.E.; Clark, E.A.; Harvel, C.D.; Farmer, D.A.; Tovo, L.L.; Poore, A.S.; Moore, M.L.

    2015-03-15

    The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MCA) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MCA requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBA) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material sub-accounts (MSA) are established along with key measurement points (KMP) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSA. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breeding, burn-up, and retention of tritium in the fusion device. The concept of 'net' tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines. (authors)

  13. TRITIUM ACCOUNTANCY IN FUSION SYSTEMS

    SciTech Connect

    Klein, J. E.; Farmer, D. A.; Moore, M. L.; Tovo, L. L.; Poore, A. S.; Clark, E. A.; Harvel, C. D.

    2014-03-06

    The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MC&A) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MC&A requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBAs) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material subaccounts (MSAs) are established along with key measurement points (KMPs) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSAs. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breading, burn-up, and retention of tritium in the fusion device. The concept of “net” tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines.

  14. Tritium handling in vacuum systems

    SciTech Connect

    Gill, J.T.; Coffin, D.O.

    1986-10-01

    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  15. Vanadium hydride deuterium-tritium generator

    DOEpatents

    Christensen, Leslie D.

    1982-01-01

    A pressure controlled vanadium hydride gas generator to provide deuterium-tritium gas in a series of pressure increments. A high pressure chamber filled with vanadium-deuterium-tritium hydride is surrounded by a heater which controls the hydride temperature. The heater is actuated by a power controller which responds to the difference signal between the actual pressure signal and a programmed pressure signal.

  16. Tritium Plasma Experiment Upgrade for Fusion Tritium and Nuclear Sciences

    NASA Astrophysics Data System (ADS)

    Shimada, Masashi; Taylor, Chase N.; Kolasinski, Robert D.; Buchenauer, Dean A.

    2015-11-01

    The Tritium Plasma Experiment (TPE) is a unique high-flux linear plasma device that can handle beryllium, tritium, and neutron-irradiated plasma facing materials, and is the only existing device dedicated to directly study tritium retention and permeation in neutron-irradiated materials [M. Shimada et.al., Rev. Sci. Instru. 82 (2011) 083503 and and M. Shimada, et.al., Nucl. Fusion 55 (2015) 013008]. Recently the TPE has undergone major upgrades in its electrical and control systems. New DC power supplies and a new control center enable remote plasma operations from outside of the contamination area for tritium, minimizing the possible exposure risk with tritium and beryllium. We discuss the electrical upgrade, enhanced operational safety, improved plasma performance, and development of tritium plasma-driven permeation and optical spectrometer system. This upgrade not only improves operational safety of the worker, but also enhances plasma performance to better simulate extreme plasma-material conditions expected in ITER, Fusion Nuclear Science Facility (FNSF), and Demonstration reactor (DEMO). This work was prepared for the U.S. Department of Energy, Office of Fusion Energy Sciences, under the DOE Idaho Field Office contract number DE-AC07-05ID14517.

  17. Controlled chiral electrochromism of polyoxometalates incorporated in supramolecular complexes.

    PubMed

    Zhang, Bin; Guan, Weiming; Zhang, Simin; Li, Bao; Wu, Lixin

    2016-04-01

    A three-component supramolecular system was constructed by combining host-guest recognition and electrostatic interaction for realization of induced circular dichroism of achiral polyanionic clusters in aqueous solution, while the induced chiral heteropoly blue was built and switched off by controlling the redox of the inorganic component via electrochemistry. PMID:27002653

  18. Hybrid FES orthosis incorporating closed loop control and sensory feedback.

    PubMed

    Andrews, B J; Baxendale, R H; Barnett, R; Phillips, G F; Yamazaki, T; Paul, J P; Freeman, P A

    1988-04-01

    A hybrid functional electrical stimulation (FES) orthosis is described, comprising a rigid ankle-foot brace, a multi-channel FES stimulator with surface electrodes, body mounted sensors, a 'rule-based' controller and an electro-cutaneous display for supplementary sensory feedback. The mechanical brace provides stability, without FES activation of muscles, for standing postures normally adopted by patients. This avoids inducing muscle fatigue during prolonged upright activity. However, stability is conditional upon the position of the ground reaction vector (GRV) relative to the knee joint. The finite state FES controller reacts automatically to destabilizing shifts of the GRV by stimulating appropriate anti-gravity musculature to brace the leg. The FES system also features a control mode to initiate and terminate flexion of the leg during forward progression. A simple mode of supplementary sensory feedback was used during the laboratory standing tests to assist the patient in maintaining a set posture. Preliminary results of laboratory tests for two spinal cord injured subjects are presented. PMID:3361878

  19. Preliminary control technology assessment of Mansfield Sanitary, Incorporated, Errysville, Ohio

    SciTech Connect

    Cooper, T.

    1982-03-01

    A visit was made to the Mansfield Sanitary Facility, Perrysville, Ohio to evaluate control methods in place at the site to protect workers from on the job hazards. This facility used a variety of clays, parting compounds, and color additives to blend, form, dry, fire, package, and ship as ceramic plumbing products. Clays used include feldspar, pearless china clay, and nepheline syenite from various suppliers. Other raw materials included Millwood sand, gum, cultozine-fuchsine, industrial plaster, stain, glaze, magnesium aluminum silicate, talc, feldspar, and zirconium silicate. The company made good use of several ventilation techniques at loading stations, transfer points, automatic assembly lines, and the glazing stations. Parting dust became airborne when applied to the molds and while the mold was being dried. Exhaust-ventilation booths used for the spraying of glaze appeared to be very effective. Several areas in which dust-control methods appeared inadequate were noted. The author recommends that some of the work practices and personal protective equipment used as controls should be examined in an in-depth evaluation and documentation.

  20. Continuous aqueous tritium monitor

    DOEpatents

    McManus, Gary J.; Weesner, Forrest J.

    1989-05-30

    An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture and selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration.

  1. Magmatic tritium

    SciTech Connect

    Goff, F.; Aams, A.I.; McMurtry, G.M.; Shevenell, L.; Pettit, D.R.; Stimac, J.A.; Werner, C.

    1997-07-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory. Detailed geochemical sampling of high-temperature fumaroles, background water, and fresh magmatic products from 14 active volcanoes reveal that they do not produce measurable amounts of tritium ({sup 3}H) of deep origin (<0.1 T.U. or <0.32 pCi/kg H{sub 2}O). On the other hand, all volcanoes produce mixtures of meteoric and magmatic fluids that contain measurable {sup 3}H from the meteoric end-member. The results show that cold fusion is probably not a significant deep earth process but the samples and data have wide application to a host of other volcanological topics.

  2. Tritium deformation interactions in FCC austenitic steels

    SciTech Connect

    Chene, J.

    2008-07-15

    Hydrogen deformation interactions are known to control the environmental degradation effects (H and He embrittlement, stress corrosion cracking,...) associated with the presence of H and its isotopes in structural materials. Different types of interaction have been investigated: trapping on stress field and strain-induced defects, enhanced diffusion along dislocation networks, transport by moving dislocation. For several reasons, the quantification of these interactions is a major challenge in nuclear systems involving the presence of tritium: prevention of tritium-induced damage, tritium inventory, management of tritiated waste... This paper reports recent results on the quantitative characterization of tritium deformation interactions in fee materials. (authors)

  3. Continuous Aqueous Tritium Monitoring

    SciTech Connect

    Hofstetter, K.J.

    1995-03-29

    Continuous monitoring for tritium in the aqueous effluents of selected Savannah River Site (SRS) facilities is performed using a custom designed system that includes an automated water purification system and a flow-through radiation detection system optimized for tritium. Beads of plastic scintillators coupled with coincidence electronics provide adequate sensitivity (=25kBz/L) for tritium break-through detection int he aqueous discharge stream from these facilities. The tritium effluent water monitors (TEWMs) at SRS provide early warning (within 30 minutes) of an unanticipated release of tritium, supplement the routine sampling surveillances, and mitigate the impact of aqueous plant discharges of tritium releases to the environment.

  4. Continuous aqueous tritium monitoring

    SciTech Connect

    Hofstetter, K.J.

    1995-10-01

    Continuous monitoring for tritium in the aqueous effluents of selected Savannah River Site (SRS) facilities is performed using a unique system that includes an automated water purification system and a flow-through radiation detection system optimized for tritium. Beads of plastic scintillator coupled with coincidence electronics provide adequate sensitivity (approx.25kBq/L) for tritium breakthrough detection in the aqueous discharge stream from these facilities. The tritium effluent water monitors (TEWMs) at SRS provide early warning (within 30 minutes) of an unanticipated release of tritium, supplement the routine sampling surveillances, and mitigate the impact of aqueous plant discharges of tritium to the environment. 4 refs., 4 figs., 1 tab.

  5. Oxidative Tritium Decontamination System

    SciTech Connect

    Charles A. Gentile; John J. Parker; Gregory L. Guttadora; Lloyd P. Ciebiera

    2002-02-11

    The Princeton Plasma Physics Laboratory, Tritium Systems Group has developed and fabricated an Oxidative Tritium Decontamination System (OTDS), which is designed to reduce tritium surface contamination on various components and items. The system is configured to introduce gaseous ozone into a reaction chamber containing tritiated items that require a reduction in tritium surface contamination. Tritium surface contamination (on components and items in the reaction chamber) is removed by chemically reacting elemental tritium to tritium oxide via oxidation, while purging the reaction chamber effluent to a gas holding tank or negative pressure HVAC system. Implementing specific concentrations of ozone along with catalytic parameters, the system is able to significantly reduce surface tritium contamination on an assortment of expendable and non-expendable items. This paper will present the results of various experimentation involving employment of this system.

  6. Continuous aqueous tritium monitor

    DOEpatents

    McManus, G.J.; Weesner, F.J.

    1987-10-19

    An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture are selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration. 2 figs.

  7. Dietary and taxonomic controls on incorporation of microbial carbon and phosphorus by detritivorous caddisflies.

    PubMed

    Halvorson, Halvor M; White, Grant; Scott, J Thad; Evans-White, Michelle A

    2016-02-01

    Heterotrophic microbes on detritus play critical roles in the nutrition of detritivorous animals, yet few studies have examined factors controlling the acquisition of microbial nutrients toward detritivore growth, which is termed “incorporation". Here, we assessed effects of detrital substrate identity (leaf type), background nutrients, and detritivore species identity on detritivore incorporation of microbial carbon (C) and phosphorus (P) in leaf litter diets. We fed oak and maple litter conditioned under two nutrient concentrations (50 or 500 µg P L(-1)) to the detritivorous caddisfly larvae Ironoquia spp., Lepidostoma spp., and Pycnopsyche lepida and used the radioisotopes 14C as glucose and 33P as phosphate to dually trace incorporation of microbial C and P by caddisflies. Incorporation efficiencies of microbial C (mean ± SE = 12.3 ± 1.3%) were one order of magnitude higher than gross growth efficiencies for bulk detrital C from recent studies (1.05 ± 0.08%). Litter type did not affect incorporation of microbial nutrients; however, caddisflies incorporated microbial P 11 % less efficiently when fed litter from the higher P concentration. Two lower body C:P species (Pycnopsyche and Ironoquia) exhibited 9.9 and 7.1% greater microbial C and 19.0 and 17.7% greater microbial P incorporation efficiencies, respectively, than the higher body C:P species (Lepidostoma). Our findings support ecological stoichiometry theory on post-ingestive regulation that animals fed lower C:P diets should reduce P incorporation efficiency due to excess diet P or alleviation of P-limited growth, and that lower C:P species must incorporate dietary C and P more efficiently to support fast growth of P-rich tissues. PMID:26497125

  8. 1997 evaluation of tritium removal and mitigation technologies for Hanford Site wastewaters

    SciTech Connect

    Jeppson, D.W.; Biyani, R.K.; Duncan, J.B.; Flyckt, D.L.; Mohondro, P.C.; Sinton, G.L.

    1997-07-24

    This report contains results of a biennial assessment of tritium separation technology and tritium nitration techniques for control of tritium bearing wastewaters at the Hanford Site. Tritium in wastewaters at Hanford have resulted from plutonium production, fuel reprocessing, and waste handling operations since 1944. this assessment was conducted in response to the Hanford Federal Facility Agreement and Consent Order.

  9. Vanadium hydride deuterium-tritium generator

    DOEpatents

    Christensen, L.D.

    1980-03-13

    A pressure controlled vanadium hydride gas generator was designed to provide deuterium-tritium gas in a series of pressure increments. A high pressure chamber filled with vanadium-deuterium-tritium hydride is surrounded by a heater which controls the hydride temperature. The heater is actuated by a power controller which responds to the difference signal between the actual pressure signal and a programmed pressure signal.

  10. Sources of tritium

    SciTech Connect

    Phillips, J.E.; Easterly, C.E.

    1980-12-01

    A review of tritium sources is presented. The tritium production and release rates are discussed for light water reactors (LWRs), heavy water reactors (HWRs), high temperature gas cooled reactors (HTGRs), liquid metal fast breeder reactors (LMFBRs), and molten salt breeder reactors (MSBRs). In addition, release rates are discussed for tritium production facilities, fuel reprocessing plants, weapons detonations, and fusion reactors. A discussion of the chemical form of the release is included. The energy producing facilities are ranked in order of increasing tritium production and release. The ranking is: HTGRs, LWRs, LMFBRs, MSBRs, and HWRs. The majority of tritium has been released in the form of tritiated water.

  11. Incorporation of fractional-order dynamics into an existing PI/PID DC motor control loop.

    PubMed

    Tepljakov, Aleksei; Gonzalez, Emmanuel A; Petlenkov, Eduard; Belikov, Juri; Monje, Concepción A; Petráš, Ivo

    2016-01-01

    The problem of changing the dynamics of an existing DC motor control system without the need of making internal changes is considered in the paper. In particular, this paper presents a method for incorporating fractional-order dynamics in an existing DC motor control system with internal PI or PID controller, through the addition of an external controller into the system and by tapping its original input and output signals. Experimental results based on the control of a real test plant from MATLAB/Simulink environment are presented, indicating the validity of the proposed approach. PMID:26639053

  12. The operation of the Tokamak Fusion Test Reactor Tritium Facility

    SciTech Connect

    Gentile, C.A.; LaMarche, P.H.; Anderson, J.L.

    1995-07-01

    The TFTR tritium operations staff has successfully received, stored, handled, and processed over five hundred thousand curies of tritium for the purpose of supporting D-T (Deuterium-Tritium) operations at TFTR. Tritium operations personnel nominally provide continuous round the clock coverage (24 hours/day, 7 days/week) in shift complements consisting of I supervisor and 3 operators. Tritium Shift Supervisors and operators are required to have 5 years of operational experience in either the nuclear or chemical industry and to become certified for their positions. The certification program provides formal instruction, as well as on the job training. The certification process requires 4 to 6 months to complete, which includes an oral board lasting up to 4 hours at which time the candidate is tested on their knowledge of Tritium Technology and TFTR Tritium systems. Once an operator is certified, the training process continues with scheduled training weeks occurring once every 5 weeks. During D-T operations at TFTR the operators must evacuate the tritium area due to direct radiation from TFTR D-T pulses. During `` time operators maintain cognizance over tritium systems via a real time TV camera system. Operators are able to gain access to the Tritium area between TFTR D-T pulses, but have been excluded from die tritium area during D-T pulsing for periods up to 30 minutes. Tritium operators are responsible for delivering tritium gas to TFRR as well as processing plasma exhaust gases which lead to the deposition of tritium oxide on disposable molecular sieve beds (DMSB). Once a DMSB is loaded, the operations staff remove the expended DMSB, and replace it with a new DMSB container. The TFIR tritium system is operated via detailed procedures which require operator sign off for system manipulation. There are >300 procedures controlling the operation of the tritium systems.

  13. Tritium pellet injector results

    SciTech Connect

    Fisher, P.W.; Bauer, M.L.; Baylor, L.R.; Deleanu, L.E.; Fehling, D.T.; Milora, S.L.; Whitson, J.C.

    1988-01-01

    Injection of solid tritium pellets is considered to be the most promising way of fueling fusion reactors. The Tritium Proof-of- Principle (TPOP) experiment has demonstrated the feasibility of forming and accelerating tritium pellets. This injector is based on the pneumatic pipe-gun concept, in which pellets are formed in situ in the barrel and accelerated with high-pressure gas. This injector is ideal for tritium service because there are no moving parts inside the gun and because no excess tritium is required in the pellet production process. Removal of /sup 3/He from tritium to prevent blocking of the cryopumping action by the noncondensible gas has been demonstrated with a cryogenic separator. Pellet velocities of 1280 m/s have been achieved for 4-mm-diam by 4-mm-long cylindrical tritium pellets with hydrogen propellant at 6.96 MPa (1000 psi). 10 refs., 10 figs.

  14. Controllability and Optimal Harvesting of a Prey-Predator Model Incorporating a Prey Refuge

    ERIC Educational Resources Information Center

    Kar, Tapan Kumar

    2006-01-01

    This paper deals with a prey-predator model incorporating a prey refuge and harvesting of the predator species. A mathematical analysis shows that prey refuge plays a crucial role for the survival of the species and that the harvesting effort on the predator may be used as a control to prevent the cyclic behaviour of the system. The optimal…

  15. 77 FR 56911 - Progressive Rail Incorporated-Continuance in Control Exemption-Iowa Traction Railway Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Surface Transportation Board Progressive Rail Incorporated--Continuance in Control Exemption-- Iowa... No. FD 35671, must be filed with the Surface Transportation Board, 395 E Street SW., Washington,...

  16. Radiation protection aspects of repairing a highly contaminated tritium cold box.

    PubMed

    Carmichael, A B; Haynes, M J

    1991-11-01

    Radiation protection aspects of modifying a system exposed to tritium gas are discussed. This paper includes a brief discussion of the tritium gas and tritium surface contamination hazards associated with a facility designed to detritiate heavy water. Also described are the protective equipment, dosimetry, instrumentation, contamination control, and decontamination procedures used during welding of tubes that have been exposed to almost pure tritium gas. Absorption of the tritium gas on materials resulted in exposures to high peak concentrations of tritium oxide and high levels of tritium surface contamination (TSC). PMID:1661277

  17. Fixation of tritium in a highly stable polymer form

    DOEpatents

    Steinberg, Meyer; Colombo, Peter; Pruzansky, Jacob

    1977-01-01

    A method for the fixation of tritium comprising reacting tritiated water with calcium carbide to produce calcium hydroxide and tritiated acetylene, polymerizing the acetylene, and then incorporating the polymer in a solidifying matrix.

  18. A new glove-box system for a high-pressure tritium pump

    SciTech Connect

    Wilson, S.W.; Borree, R.J.; Chambers, D.I.; Chang, Y.; Merrill, J.T.; Souers, P.C.; Wiggins, R.K.

    1988-05-26

    A new glove-box system that was designed around a high-pressure tritium pump is described. The system incorporates new containment ideas such as ''burpler'' passive pressure controls, valves that can be turned from outside the box, inflatable door seals, ferro-fluidic motor-shaft seals, and rapid box-to-hood conversion during cryostaging. Currently under construction, the system will contain nine separate sections with automatic pressure-balancing and venting systems. 3 refs., 5 figs.

  19. NNSA TRITIUM SUPPLY CHAIN

    SciTech Connect

    Wyrick, Steven; Cordaro, Joseph; Founds, Nanette; Chambellan, Curtis

    2013-08-21

    Savannah River Site plays a critical role in the Tritium Production Supply Chain for the National Nuclear Security Administration (NNSA). The entire process includes: • Production of Tritium Producing Burnable Absorber Rods (TPBARs) at the Westinghouse WesDyne Nuclear Fuels Plant in Columbia, South Carolina • Production of unobligated Low Enriched Uranium (LEU) at the United States Enrichment Corporation (USEC) in Portsmouth, Ohio • Irradiation of TPBARs with the LEU at the Tennessee Valley Authority (TVA) Watts Bar Reactor • Extraction of tritium from the irradiated TPBARs at the Tritium Extraction Facility (TEF) at Savannah River Site • Processing the tritium at the Savannah River Site, which includes removal of nonhydrogen species and separation of the hydrogen isotopes of protium, deuterium and tritium.

  20. Tritium monitoring techniques

    SciTech Connect

    DeVore, J.R.; Buckner, M.A.

    1996-05-01

    As part of their operations, the U.S. Navy is required to store or maintain operational nuclear weapons on ships and at shore facilities. Since these weapons contain tritium, there are safety implications relevant to the exposure of personnel to tritium. This is particularly important for shipboard operations since these types of environments can make low-level tritium detection difficult. Some of these ships have closed systems, which can result in exposure to tritium at levels that are below normally acceptable levels but could still cause radiation doses that are higher than necessary or could hamper ship operations. This report describes the state of the art in commercial tritium detection and monitoring and recommends approaches for low-level tritium monitoring in these environments.

  1. Confinement and Tritium Stripping Systems for APT Tritium Processing

    SciTech Connect

    Hsu, R.H.; Heung, L.K.

    1997-10-20

    This report identifies functions and requirements for the tritium process confinement and clean-up system (PCCS) and provides supporting technical information for the selection and design of tritium confinement, clean-up (stripping) and recovery technologies for new tritium processing facilities in the Accelerator for the Production of Tritium (APT). The results of a survey of tritium confinement and clean-up systems for large-scale tritium handling facilities and recommendations for the APT are also presented.

  2. Incorporation of negative rules and evolution of a fuzzy controller for yeast fermentation process.

    PubMed

    Birle, Stephan; Hussein, Mohamed Ahmed; Becker, Thomas

    2016-08-01

    The control of bioprocesses can be very challenging due to the fact that these kinds of processes are highly affected by various sources of uncertainty like the intrinsic behavior of the used microorganisms. Due to the reason that these kinds of process uncertainties are not directly measureable in most cases, the overall control is either done manually because of the experience of the operator or intelligent expert systems are applied, e.g., on the basis of fuzzy logic theory. In the latter case, however, the control concept is mainly represented by using merely positive rules, e.g., "If A then do B". As this is not straightforward with respect to the semantics of the human decision-making process that also includes negative experience in form of constraints or prohibitions, the incorporation of negative rules for process control based on fuzzy logic is emphasized. In this work, an approach of fuzzy logic control of the yeast propagation process based on a combination of positive and negative rules is presented. The process is guided along a reference trajectory for yeast cell concentration by alternating the process temperature. The incorporation of negative rules leads to a much more stable and accurate control of the process as the root mean squared error of reference trajectory and system response could be reduced by an average of 62.8 % compared to the controller using only positive rules. PMID:27086136

  3. Tritium proof-of-principle injector experiment

    SciTech Connect

    Fisher, P.W.; Milora, S.L.; Combs, S.K.; Carlson, R.V.; Coffin, D.O.

    1988-01-01

    The Tritium Proof-of-Principle (TPOP) pellet injector was designed and built by Oak Ridge National Laboratory (ORNL) to evaluate the production and acceleration of tritium pellets for fueling future fision reactors. The injector uses the pipe-gun concept to form pellets directly in a short liquid-helium-cooled section of the barrel. Pellets are accelerated by using high-pressure hydrogen supplied from a fast solenoid valve. A versatile, tritium-compatible gas-handling system provides all of the functions needed to operate the gun, including feed gas pressure control and flow control, plus helium separation and preparation of mixtures. These systems are contained in a glovebox for secondary containment of tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory (LANL). 18 refs., 3 figs.

  4. Controlled incorporation of mid-to-high Z transition metals in CVD diamond

    SciTech Connect

    Biener, M M; Biener, J; Kucheyev, S O; Wang, Y M; El-Dasher, B; Teslich, N E; Hamza, A V; Obloh, H; Mueller-Sebert, W; Wolfer, M; Fuchs, T; Grimm, M; Kriele, A; Wild, C

    2010-01-08

    We report on a general method to fabricate transition metal related defects in diamond. Controlled incorporation of Mo and W in synthetic CVD diamond was achieved by adding volatile metal precursors to the diamond chemical vapor deposition (CVD) growth process. Effects of deposition temperature, grain structure and precursor exposure on the doping level were systematically studied, and doping levels of up to 0.25 at.% have been achieved. The metal atoms are uniformly distributed throughout the diamond grains without any indication of inclusion formation. These results are discussed in context of the kinetically controlled growth process of CVD diamond.

  5. Tritium release from SS316 under vacuum condition

    SciTech Connect

    Torikai, Y.; Penzhorn, R.D.

    2015-03-15

    The plasma facing surface of the ITER vacuum vessel, partly made of low carbon austenitic stainless steel type 316L, will incorporate tritium during machine operation. In this paper the kinetics of tritium release from stainless steel type 316 into vacuum and into a noble gas stream are compared and modelled. Type 316 stainless steel specimens loaded with tritium either by exposure to 1.2 kPa HT at 573 K or submersion into liquid HTO at 298 K showed characteristic thin surface layers trapping tritium in concentrations far higher than those determined in the bulk. The evolution of the tritium depth profile in the bulk during heating under vacuum was non-discernible from that of tritium liberated into a stream of argon. Only the relative amount of the two released tritium-species, i.e. HT or HTO, was different. Temperature-dependent depth profiles could be predicted with a one-dimensional diffusion model. Diffusion coefficients derived from fitting of the tritium release into an evacuated vessel or a stream of argon were found to be (1.4 ± 1.0)*10{sup -7} and (1.3 ± 0.9)*10{sup -9} cm{sup 2}/s at 573 and 423 K, respectively. Polished surfaces on type SS316 stainless steel inhibit considerably the thermal release rate of tritium.

  6. TRITIUM BARRIER MATERIALS AND SEPARATION SYSTEMS FOR THE NGNP

    SciTech Connect

    Sherman, S; Thad Adams, T

    2008-07-17

    Contamination of downstream hydrogen production plants or other users of high-temperature heat is a concern of the Next Generation Nuclear Plant (NGNP) Project. Due to the high operating temperatures of the NGNP (850-900 C outlet temperature), tritium produced in the nuclear reactor can permeate through heat exchangers to reach the hydrogen production plant, where it can become incorporated into process chemicals or the hydrogen product. The concentration limit for tritium in the hydrogen product has not been established, but it is expected that any future limit on tritium concentration will be no higher than the air and water effluent limits established by the NRC and the EPA. A literature survey of tritium permeation barriers, capture systems, and mitigation measures is presented and technologies are identified that may reduce the movement of tritium to the downstream plant. Among tritium permeation barriers, oxide layers produced in-situ may provide the most suitable barriers, though it may be possible to use aluminized surfaces also. For tritium capture systems, the use of getters is recommended, and high-temperature hydride forming materials such as Ti, Zr, and Y are suggested. Tritium may also be converted to HTO in order to capture it on molecular sieves or getter materials. Counter-flow of hydrogen may reduce the flux of tritium through heat exchangers. Recommendations for research and development work are provided.

  7. Tritium Attenuation by Distillation

    SciTech Connect

    Wittman, N.E.

    2001-07-31

    The objective of this study was to determine how a 100 Area distillation system could be used to reduce to a satisfactory low value the tritium content of the dilute moderator produced in the 100 Area stills, and whether such a tritium attenuator would have sufficient capacity to process all this material before it is sent to the 400 Area for reprocessing.

  8. Radiation quality of tritium.

    PubMed

    Chen, Jing

    2006-01-01

    Tritium occurs from both natural and manufactured processes. In the environment, tritium can exist in the form of tritiated water (HTO) and in an organic form known as organically-bound tritium (OBT). Although, the concentrations of environmental OBT are relatively low, there is concern that current risk factors may underestimate the risk from OBT. Because tritium poses an internal hazard at cellular levels, microdosimetric techniques provide suitable tools for the study of radiation quality of tritium. In this study, microdosimetric simulations are performed for tritium uniformly distributed in a medium, and for tritium bound to biologically critical sites of dimensions from 10 nm to 2 microm. Results of local energy density are different for these two cases in microscopic regions. Based on the spatial distribution of energy deposition, dose mean lineal energies are calculated for tritium in forms of HTO and OBT. The dose mean lineal energies of OBT are about a factor of 1.7 higher than those of HTO in a wide range of target dimensions of biological interest. The results are consistent with radiobiological findings that OBT is about twice as effective as that of HTO. PMID:17132658

  9. Methods for tritium labeling

    DOEpatents

    Andres, Hendrik; Morimoto, Hiromi; Williams, Philip G.

    1993-01-01

    Reagents and processes for reductively introducing deuterium or tritium into organic molecules are described. The reagents are deuterium or tritium analogs of trialkyl boranes, borane or alkali metal aluminum hydrides. The process involves forming these reagents in situ from alkali metal tritides or deuterides.

  10. Radiological training for tritium facilities

    SciTech Connect

    1996-12-01

    This program management guide describes a recommended implementation standard for core training as outlined in the DOE Radiological Control Manual (RCM). The standard is to assist those individuals, both within DOE and Managing and Operating contractors, identified as having responsibility for implementing the core training recommended by the RCM. This training may also be given to radiological workers using tritium to assist in meeting their job specific training requirements of 10 CFR 835.

  11. Oxidative Tritium Decontamination System

    DOEpatents

    Gentile, Charles A. , Guttadora, Gregory L. , Parker, John J.

    2006-02-07

    The Oxidative Tritium Decontamination System, OTDS, provides a method and apparatus for reduction of tritium surface contamination on various items. The OTDS employs ozone gas as oxidizing agent to convert elemental tritium to tritium oxide. Tritium oxide vapor and excess ozone gas is purged from the OTDS, for discharge to atmosphere or transport to further process. An effluent stream is subjected to a catalytic process for the decomposition of excess ozone to diatomic oxygen. One of two configurations of the OTDS is employed: dynamic apparatus equipped with agitation mechanism and large volumetric capacity for decontamination of light items, or static apparatus equipped with pressurization and evacuation capability for decontamination of heavier, delicate, and/or valuable items.

  12. Development of Tritium Permeation Analysis Code (TPAC)

    SciTech Connect

    Eung S. Kim; Chang H. Oh; Mike Patterson

    2010-10-01

    Idaho National Laboratory developed the Tritium Permeation Analysis Code (TPAC) for tritium permeation in the Very High Temperature Gas Cooled Reactor (VHTR). All the component models in the VHTR were developed and were embedded into the MATHLAB SIMULINK package with a Graphic User Interface. The governing equations of the nuclear ternary reaction and thermal neutron capture reactions from impurities in helium and graphite core, reflector, and control rods were implemented. The TPAC code was verified using analytical solutions for the tritium birth rate from the ternary fission, the birth rate from 3He, and the birth rate from 10B. This paper also provides comparisons of the TPAC with the existing other codes. A VHTR reference design was selected for tritium permeation study from the reference design to the nuclear-assisted hydrogen production plant and some sensitivity study results are presented based on the HTGR outlet temperature of 750 degrees C.

  13. Tritium target manufacturing for use in accelerators

    NASA Astrophysics Data System (ADS)

    Bach, P.; Monnin, C.; Van Rompay, M.; Ballanger, A.

    2001-07-01

    As a neutron tube manufacturer, SODERN is now in charge of manufacturing tritium targets for accelerators, in cooperation with CEA/DAM/DTMN in Valduc. Specific deuterium and tritium targets are manufactured on request, according to the requirements of the users, starting from titanium target on copper substrate, and going to more sophisticated devices. A wide range of possible uses is covered, including thin targets for neutron calibration, thick targets with controlled loading of deuterium and tritium, rotating targets for higher lifetimes, or large size rotating targets for accelerators used in boron neutron therapy. Activity of targets lies in the 1 to 1000 Curie, diameter of targets being up to 30 cm. Special targets are also considered, including surface layer targets for lowering tritium desorption under irradiation, or those made from different kinds of occluders such as titanium, zirconium, erbium, scandium, with different substrates. It is then possible to optimize either neutron output, or lifetime and stability, or thermal behavior.

  14. Incorporating residential AC load control into ancillary service markets: Measurement and settlement

    SciTech Connect

    Bode, Josh L.; Sullivan, Michael J.; Berghman, Dries; Eto, Joseph H.

    2013-05-01

    Many pre-existing air conditioner load control programs can provide valuable operational flexibility but have not been incorporated into electricity ancillary service markets or grid operations. Multiple demonstrations have shown that residential air conditioner (AC) response can deliver resources quickly and can provide contingency reserves. A key policy hurdle to be overcome before AC load control can be fully incorporated into markets is how to balance the accuracy, cost, and complexity of methods available for the settlement of load curtailment. Overcoming this hurdle requires a means for assessing the accuracy of shorter-term AC load control demand reduction estimation approaches in an unbiased manner. This paper applies such a method to compare the accuracy of approaches varying in cost and complexity ? including regression analysis, load matching and control group approaches ? using feeder data, household data and AC end-use data. We recommend a practical approach for settlement, relying on an annually updated set of tables, with pre-calculated reduction estimates. These tables allow users to look up the demand reduction per device based on daily maximum temperature, geographic region and hour of day, simplifying settlement and providing a solution to the policy problem presented in this paper.

  15. Considerations for tritium protection at a fusion reactor

    SciTech Connect

    Easterly, C.E.

    1981-01-01

    The purpose of this paper is to indicate the general direction of current fusion reactor concepts regarding tritium, and to indicate some options in tritium control strategies. Certain strategies, in addition to providing reduced potential health hazard, afford the potential for engineering alternatives for in-plant tritium control systems. The overall coupling of containment cleanup systems and health protection must continue to develop with increased knowledge of the health effects of different tritium species and the consequent systems options available subsequent to this understanding.

  16. Tritium calorimeter setup and operation

    SciTech Connect

    Rodgers, David E.

    2002-12-17

    The LBNL tritium calorimeter is a stable instrument capable of measuring tritium with a sensitivity of 25 Ci. Measurement times range from 8-hr to 7-days depending on the thermal conductivity and mass of the material being measured. The instrument allows accurate tritium measurements without requiring that the sample be opened and subsampled, thus reducing personnel exposure and radioactive waste generation. The sensitivity limit is primarily due to response shifts caused by temperature fluctuation in the water bath. The fluctuations are most likely a combination of insufficient insulation from ambient air and precision limitations in the temperature controller. The sensitivity could probably be reduced to below 5 Ci if the following improvements were made: (1) Extend the external insulation to cover the entire bath and increase the top insulation. (2) Improve the seal between the air space above the bath and the outside air to reduce evaporation. This will limit the response drift as the water level drops. (3) Install an improved temperature controller, preferably with a built in chiller, capable of temperature control to {+-}0.001 C.

  17. Accumulative Tritium Transfer from Water into Biosystems

    SciTech Connect

    Baumgaertner, Franz

    2005-07-15

    The energy balance of hydrogen isotopes in H bonds of water and biomolecules results in accumulative tritium transfer from water into biomolecules. Tests of DNA dissolved in tritiated water and of maize or barley hydroponically grown in tritiated water confirm the increase. The primary hydration shell of DNA shows an accumulation factor of {approx}1.4, and the exchangeable hydrogens inside DNA show {approx}2. Logistic growth analyses of maize and barley reveal the intrinsic growth rates of tritium 1.3 and 1.2 times larger than that of hydrogen. The higher rate of tritium than hydrogen incorporation in solid biomatter is caused by the hydration shells, which constitute an intrinsic component of biomolecules.

  18. Method for controlling coolant flow in airfoil, flow control structure and airfoil incorporating the same

    DOEpatents

    Itzel, Gary Michael; Devine, II, Robert Henry; Chopra, Sanjay; Toornman, Thomas Nelson

    2003-07-08

    A coolant flow control structure is provided to channel cooling media flow to the fillet region defined at the transition between the wall of a nozzle vane and a wall of a nozzle segment, for cooling the fillet region. In an exemplary embodiment, the flow control structure defines a gap with the fillet region to achieve the required heat transfer coefficients in this region to meet part life requirements.

  19. TRIO-01 experiment: in-situ tritium recovery results

    SciTech Connect

    Clemmer, R.G.; Finn, P.A.; Billone, M.C.; Misra, B.; Greenwood, L.R.; Dyer, F.F.; Dudley, I.T.; Bate, L.C.; Clemmer, E.D.; Fisher, P.W.

    1983-01-01

    The TRIO-01 experiment was designed to test in-situ tritium recovery and heat transfer performance of a candidate solid breeder, ..gamma..-LiAlO/sub 2/. The results showed that nearly all the tritium generated was recovered. Only < 0.1 wppM tritium remained in the solid after irradiation testing. The heat transfer performance showed that temperature profiles can be effectively controlled.

  20. The Redox State of SECIS Binding Protein 2 Controls Its Localization and Selenocysteine Incorporation Function

    PubMed Central

    Papp, Laura V.; Lu, Jun; Striebel, Frank; Kennedy, Derek; Holmgren, Arne; Khanna, Kum Kum

    2006-01-01

    Selenoproteins are central controllers of cellular redox homeostasis. Incorporation of selenocysteine (Sec) into selenoproteins employs a unique mechanism to decode the UGA stop codon. The process requires the Sec insertion sequence (SECIS) element, tRNASec, and protein factors including the SECIS binding protein 2 (SBP2). Here, we report the characterization of motifs within SBP2 that regulate its subcellular localization and function. We show that SBP2 shuttles between the nucleus and the cytoplasm via intrinsic, functional nuclear localization signal and nuclear export signal motifs and that its nuclear export is dependent on the CRM1 pathway. Oxidative stress induces nuclear accumulation of SBP2 via oxidation of cysteine residues within a redox-sensitive cysteine-rich domain. These modifications are efficiently reversed in vitro by human thioredoxin and glutaredoxin, suggesting that these antioxidant systems might regulate redox status of SBP2 in vivo. Depletion of SBP2 in cell lines using small interfering RNA results in a decrease in Sec incorporation, providing direct evidence for its requirement for selenoprotein synthesis. Furthermore, Sec incorporation is reduced substantially after treatment of cells with agents that cause oxidative stress, suggesting that nuclear sequestration of SBP2 under such conditions may represent a mechanism to regulate the expression of selenoproteins. PMID:16782878

  1. Assessment of geraniol-incorporated polymers to control Aedes albopictus (Diptera: culicidae)

    PubMed Central

    Chuaycharoensuk, T.; Manguin, S.; Duvallet, G.; Chareonviriyaphap, T.

    2012-01-01

    Effective control of mosquito borne diseases has proven extremely difficult with both vector and pathogen remaining entrenched and expanding in many disease endemic areas. When lacking an effective vaccine, vector control methods targeting both larval habitats and adult mosquito populations remain the primary strategy for reducing risk. Aedes albopictus from Thailand was used as a reference baseline for evaluation of natural insecticides incorporated in polymer disks and pellets and tested both in laboratory and field conditions. In laboratory and field tests, the highest larval mortality was obtained with disks or pellets containing IKHC (Insect Killer Highly Concentrate) from Fulltec AG Company. This product is reputed to contain geraniol as an active ingredient. With pellets, high mortality of Ae. albopictus larvae (92%) was observed in presence of 1 g of pellets per 500 ml of water at day 1st, and the mortality was 100% at day 1st for larvae in presence of 5 or 10 g of pellets. Fulltec AG Company has not accepted to give us the exact composition of their IKHC product. Therefore, we cannot recommend it, but the principle of using monoterpenes like geraniol, incorporated into polymer disks or pellets as natural larvicide needs more attention as it could be considered as a powerful alternative in mosquito vector control. PMID:22910616

  2. Internal dosimetry of tritium

    SciTech Connect

    LaBone, T.R.

    1992-01-01

    Tritium is an interesting radionuclide from the perspective of internal dosimetry because of the wide variety of chemical compounds in which it can appear, its unusual routes of entry into the body, and its ability to exchange with stable hydrogen in surrounding material. In this report the internal dosimetry of tritium compounds is reviewed, with emphasis on methods of evaluating bioassay data following chronic and acute intakes. The assumptions and models used in the derivation of Annual Limits on Intake (ALI) and Derived Air Concentrations (DAC) for tritium are also discussed.

  3. Internal dosimetry of tritium

    SciTech Connect

    LaBone, T.R.

    1992-06-01

    Tritium is an interesting radionuclide from the perspective of internal dosimetry because of the wide variety of chemical compounds in which it can appear, its unusual routes of entry into the body, and its ability to exchange with stable hydrogen in surrounding material. In this report the internal dosimetry of tritium compounds is reviewed, with emphasis on methods of evaluating bioassay data following chronic and acute intakes. The assumptions and models used in the derivation of Annual Limits on Intake (ALI) and Derived Air Concentrations (DAC) for tritium are also discussed.

  4. Tritium Issues in Next Step Devices

    SciTech Connect

    C.H. Skinner; G. Federici

    2001-09-05

    Tritium issues will play a central role in the performance and operation of next-step deuterium-tritium (DT) burning plasma tokamaks and the safety aspects associated with tritium will attract intense public scrutiny. The orders-of-magnitude increase in duty cycle and stored energy will be a much larger change than the increase in plasma performance necessary to achieve high fusion gain and ignition. Erosion of plasma-facing components will scale up with the pulse length from being barely measurable on existing machines to centimeter scale. Magnetic Fusion Energy (MFE) devices with carbon plasma-facing components will accumulate tritium by co-deposition with the eroded carbon and this will strongly constrain plasma operations. We report on a novel laser-based method to remove co-deposited tritium from carbon plasma-facing components in tokamaks. A major fraction of the tritium trapped in a co-deposited layer during the deuterium-tritium (DT) campaign on the Tokamak Fusion Test Reactor (TFTR) was released by heating with a scanning laser beam. This technique offers the potential for tritium removal in a next-step DT device without the use of oxidation and the associated deconditioning of the plasma-facing surfaces and expense of processing large quantities of tritium oxide. The operational lifetime of alternative materials such as tungsten has significant uncertainties due to melt layer loss during disruptions. Production of dust and flakes will need careful monitoring and minimization, and control and accountancy of the tritium inventory will be critical issues. Many of the tritium issues in Inertial Fusion Energy (IFE) are similar to MFE, but some, for example those associated with the target factory, are unique to IFE. The plasma-edge region in a tokamak has greater complexity than the core due to lack of poloidal symmetry and nonlinear feedback between the plasma and wall. Sparse diagnostic coverage and low dedicated experimental run time has hampered the

  5. Incorporating family therapy into asthma group intervention: a randomized waitlist-controlled trial.

    PubMed

    Ng, S M; Li, Albert M; Lou, Vivian W Q; Tso, Ivy F; Wan, Pauline Y P; Chan, Dorothy F Y

    2008-03-01

    Asthma psychoeducational programs have been found to be effective in terms of symptom-related outcome. They are mostly illness-focused, and pay minimal attention to systemic/familial factors. This study evaluated a novel asthma psychoeducation program that adopted a parallel group design and incorporated family therapy. A randomized waitlist-controlled crossover clinical trial design was adopted. Children with stable asthma and their parents were recruited from a pediatric chest clinic. Outcome measures included, for the patients: exhaled nitric oxide (eNO), spirometry, and adjustment to asthma; and for the parents: perceived efficacy in asthma management, Hospital Anxiety and Depression Scale anxiety subscale, Body Mind Spirit Well-being Inventory emotion subscale, and Short Form 12 health-related quality of life scale. Forty-six patients participated in the study. Attrition rates were 13.0% and 26.0% for the active and control groups, respectively. Repeated-measures ANOVA revealed a significant decrease in airway inflammation, as indicated by eNO levels, and an increase in patient's adjustment to asthma and parents' perceived efficacy in asthma management. Serial trend analysis revealed that most psychosocial measures continued to progress steadily after intervention. Significant improvements in both symptom-related measures and mental health and relationship measures were observed. The findings supported the value of incorporating family therapy into asthma psychoeducation programs. PMID:18411833

  6. Tunable translational control using site-specific unnatural amino acid incorporation in Escherichia coli

    PubMed Central

    2015-01-01

    Translation of target gene transcripts in Escherichia coli harboring UAG amber stop codons can be switched on by the amber-codon-specific incorporation of an exogenously supplied unnatural amino acid, 3-iodo-L-tyrosine. Here, we report that this translational switch can control the translational efficiency at any intermediate magnitude by adjustment of the 3-iodo-L-tyrosine concentration in the medium, as a tunable translational controller. The translational efficiency of a target gene reached maximum levels with 10−5 M 3-iodo-L-tyrosine, and intermediate levels were observed with suboptimal concentrations (approximately spanning a 2-log10 concentration range, 10−7–10−5 M). Such intermediate-level expression was also confirmed in individual bacteria. PMID:25945307

  7. Autonomous space systems control incorporating automated maneuvers strategies in the presence of parameters uncertainties.

    PubMed

    Mazinan, A H; Shakhesi, S

    2016-05-01

    The research attempts to deal with the autonomous space systems incorporating new automated maneuvers strategies in the presence of parameters uncertainties. The main subject behind the investigation is to realize the high-resolution small amplitude orbital maneuvers via the first control strategy. And subsequently to realize the large amplitude orbital maneuvers via the second control strategy, as well. There is a trajectory optimization to provide the three-axis referenced commends for the aforementioned overactuated autonomous space system to be able to transfer from the initial orbit to its final ones, in finite burn, as long as the uncertainties of key parameters of the system such as the thrust vector, the center of the gravity, the moments of the inertia and so on are taken into real consideration. The strategies performances are finally considered through a series of experiments and a number of benchmarks to be tangibly verified. PMID:26895709

  8. Tritium handling safety and operating experience at the Tritium Systems Test Assembly

    SciTech Connect

    Carlson, R.V.

    1989-01-01

    The Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory is a facility designed to develop and demonstrate, in full scale, technologies necessary for safe and efficient operation of tokamak fusion reactors. TSTA currently consists of systems for pumping DT gas mixtures; for removing impurities; for separating the isotopes of hydrogen; for storage of hydrogen isotopes; for gas analysis; and for assuring safety by the necessary control, monitoring, and detritiation of effluent gaseous streams. TSTA also has several small scale experiments to develop and test new equipment and processes necessary for fusion reactors. Tritium was introduced into TSTA in June 1984. Current inventory is approximately 100 grams. Approximately 10{sup 9} Curies of tritium have been processed in closed loop operation at TSTA. Total tritium releases from the facility stack have been less than 75 Curies. Total operating personnel exposures are less than 500 person-mrem. Exposures to the general public from TSTA tritium releases are extremely small (less than 10{sup {minus}2} mrem). Total tritium buried as waste is less than 36,000 Curies. In this paper, data on component reliability, failure types and rates, and waste quantities are presented. Operational experience under normal, abnormal, and emergency conditions is presented. The DOE requirements for the operation of a tritium facility like TSTA include personnel training, emergency preparedness, radiation protection, safety analysis, and preoperational appraisals. 4 refs., 3 figs., 3 tabs.

  9. Tritium waste package

    DOEpatents

    Rossmassler, Rich; Ciebiera, Lloyd; Tulipano, Francis J.; Vinson, Sylvester; Walters, R. Thomas

    1995-01-01

    A containment and waste package system for processing and shipping tritium xide waste received from a process gas includes an outer drum and an inner drum containing a disposable molecular sieve bed (DMSB) seated within outer drum. The DMSB includes an inlet diffuser assembly, an outlet diffuser assembly, and a hydrogen catalytic recombiner. The DMSB absorbs tritium oxide from the process gas and converts it to a solid form so that the tritium is contained during shipment to a disposal site. The DMSB is filled with type 4A molecular sieve pellets capable of adsorbing up to 1000 curies of tritium. The recombiner contains a sufficient amount of catalyst to cause any hydrogen add oxygen present in the process gas to recombine to form water vapor, which is then adsorbed onto the DMSB.

  10. Tritium catalyzed deuterium tokamaks

    SciTech Connect

    Greenspan, E.; Miley, G.H.; Jung, J.; Gilligan, J.

    1984-04-01

    A preliminary assessment of the promise of the Tritium Catalyzed Deuterium (TCD) tokamak power reactors relative to that of deuterium-tritium (D-T) and catalyzed deuterium (Cat-D) tokamaks is undertaken. The TCD mode of operation is arrived at by converting the /sup 3/He from the D(D,n)/sup 3/He reaction into tritium, by neutron capture in the blanket; the tritium thus produced is fed into the plasma. There are three main parts to the assessment: blanket study, reactor design and economic analysis and an assessment of the prospects for improvements in the performance of TCD reactors (and in the promise of the TCD mode of operation, in general).

  11. Tritium waste package

    DOEpatents

    Rossmassler, R.; Ciebiera, L.; Tulipano, F.J.; Vinson, S.; Walters, R.T.

    1995-11-07

    A containment and waste package system for processing and shipping tritium oxide waste received from a process gas includes an outer drum and an inner drum containing a disposable molecular sieve bed (DMSB) seated within the outer drum. The DMSB includes an inlet diffuser assembly, an outlet diffuser assembly, and a hydrogen catalytic recombiner. The DMSB absorbs tritium oxide from the process gas and converts it to a solid form so that the tritium is contained during shipment to a disposal site. The DMSB is filled with type 4A molecular sieve pellets capable of adsorbing up to 1000 curies of tritium. The recombiner contains a sufficient amount of catalyst to cause any hydrogen and oxygen present in the process gas to recombine to form water vapor, which is then adsorbed onto the DMSB. 1 fig.

  12. PRODUCTION OF TRITIUM

    DOEpatents

    Jenks, G.H.; Shapiro, E.M.; Elliott, N.; Cannon, C.V.

    1963-02-26

    This invention relates to a process for the production of tritium by subjecting comminuted solid lithium fluoride containing the lithium isotope of atomic mass number 6 to neutron radiation in a self-sustaining neutronic reactor. The lithium fiuoride is heated to above 450 deg C. in an evacuated vacuum-tight container during radiation. Gaseous radiation products are withdrawn and passed through a palladium barrier to recover tritium. (AEC)

  13. Thin film tritium dosimetry

    DOEpatents

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  14. Corroborative studies of tritium characterization and depth profiles in concrete

    SciTech Connect

    Hochel, R.C.

    2000-05-05

    This report is the second by the authors on characterizing the tritium content of cement and structural concrete. The first report reviewed the literature and used several new methods to characterize tritium on the surface and through the bulk of contaminated concrete at two facilities at the U.S. Department of Energy Savannah River Site (SRS). In both cases, a relatively constant tritium concentration as a function of depth was observed, which has not been previously reported in the literature. These findings were explained as the relatively rapid transport of tritiated liquid through pores of the hydrated cement, and the exchange of tritium with hydrogen found primarily as free and bound water in the hydrated cement binder. The study reported here extended the measurement of surface and bulk tritium in concrete to three other locations at SRS. The purpose of the current study was to characterize locations whose tritium exposure histories were well documented, and to characterize a location exposed exclusively to gaseous tritium, to confirm and possibly extend the knowledge gained from the earlier study. Results of the current study corroborate the earlier findings, in that the tritium concentration was constant through the bulk when exposed to aqueous tritium, even from a single aqueous tritium exposure. Exposure to gaseous tritium, on the other hand, lead to the well-known diffusion controlled variation of tritium concentration reported in the literature. Sufficient exposure history is available to enable a semi-quantitative explanation of the magnitude and depth dependence of the tritium in both the aqueous- and gas-exposed locations. The penetration of tritium from a liquid can be described by a hydraulic flow model, and gaseous tritium permeates in a diffusive manner. The general correlation of properly measured surface tritium activity to that in the underlying bulk found in the earlier study was confirmed. However, the surface and near surface tritium

  15. The incorporation of activities to control dengue by community health agents

    PubMed Central

    Cazola, Luiza Helena de Oliveira; Tamaki, Edson Mamoru; Pontes, Elenir Rose Jardim Cury; de Andrade, Sonia Maria Oliveira

    2014-01-01

    OBJECTIVE To evaluate the performance of Community Health Agents when dengue control activities were added to their tasks. METHODS Performance was measured comparing the evolution of selected indicators from the Brazilian National Dengue Control Program and the Family Health Strategy for 2002 to 2008 in the municipality of Sao Gabriel do Oeste, MS, Central Western Brazil, with those of Rio Verde de Mato Grosso, neighboring municipality with demographic, socioeconomic and health services similarities. Data were collected from municipal databases of the Information System for Yellow Fever and Dengue and the Information System for Primary Healthcare of the Mato Grosso do Sul State Health Office. The variables selected for the family health strategy activities were: monthly home visits, pregnant women whose antenatal care began in the first trimester, children under one with up-to-date vaccinations and hypertensive patients. Those selected for the Brazilian National Dengue Control Program were: properties inspected with Aedes aegypti and properties not inspected. RESULTS The two municipalities maintained a similar trend in dengue control indicators in the period studied. With regard to the Family Health Strategy, in 2002 Sao Gabriel do Oeste was better off in three of the four indicators studied, however, this situation was reversed at the end of the period when the county was overtaken by Rio Verde de Mato Grosso in three of the four indicators analyzed, including, the monthly average community health worker visits per registered family, the main activity of a Family Health Strategy agent. CONCLUSIONS: Incorporating the National Dengue Control Program into the Family Health Strategy is viable and developed without prejudice to dengue control activities, however, the same did not occur with the activities of family health in Sao Gabriel do Oeste. The additional workload of the community health workers is the most likely hypothesis for the declining performance of these

  16. Total Transfer Capability Assessment Incorporating Corrective Controls for Transient Stability using TSCOPF

    NASA Astrophysics Data System (ADS)

    Hakim, Lukmanul; Kubokawa, Junji; Yorino, Naoto; Zoka, Yoshifumi; Sasaki, Yutaka

    Advancements have been made towards inclusion of both static and dynamic security into transfer capability calculation. However, to the authors' knowledge, work on considering corrective controls into the calculation has not been reported yet. Therefore, we propose a Total Transfer Capability (TTC) assessment considering transient stability corrective controls. The method is based on the Newton interior point method for nonlinear programming and transfer capability is approached as a maximization of power transfer with both static and transient stability constraints are incorporated into our Transient Stability Constrained Optimal Power Flow (TSCOPF) formulation. An interconnected power system is simulated to be subjected to a severe unbalanced 3-phase 4-line to ground fault and following the fault, generator and load are shed in a pre-defined sequence to mimic actual corrective controls. In a deregulated electricity market, both generator companies and large load customers are encouraged to actively participate in maintaining power system stability as corrective controls upon agreement of compensation for being shed following a disturbance. Implementation of this proposal on the actual power system operation should be carried out through combining it with the existing transient stabilization controller system. Utilization of these corrective controls results in increasing TTC as suggested in our numerical simulation. As Lagrange multipliers can also describe sensitivity of both inequality and equality constraints to the objective function, then selection of which generator or load to be shed can be carried out on the basis of values of Lagrange multipliers of its respective generator's rotor angle stability and active power balance equation. Hence, the proposal in this paper can be utilized by system operator to assess the maximum TTC for specific loads and network conditions.

  17. DEVELOPMENT OF THE BULK TRITIUM SHIPPING PACKAGING

    SciTech Connect

    Blanton, P.; Eberl, K.

    2008-09-14

    A new radioactive shipping packaging for transporting bulk quantities of tritium, the Bulk Tritium Shipping Package (BTSP), has been designed for the Department of Energy (DOE) as a replacement for a package designed in the early 1970s. This paper summarizes significant design features and describes how the design satisfies the regulatory safety requirements of the Code of Federal Regulations and the International Atomic Energy Agency. The BTSP design incorporates many improvements over its predecessor by implementing improved testing, handling, and maintenance capabilities, while improving manufacturability and incorporating new engineered materials. This paper also discusses the results from testing of the BTSP to 10 CFR 71 Normal Conditions of Transport and Hypothetical Accident Condition events. The programmatic need of the Department of Energy (DOE) to ship bulk quantities of tritium has been satisfied since the late 1970s by the UC-609 shipping package. The current Certificate of Conformance for the UC-609, USA/9932/B(U) (DOE), will expire in late 2011. Since the UC-609 was not designed to meet current regulatory requirements, it will not be recertified and thereby necessitates a replacement Type B shipping package for continued DOE tritium shipments in the future. A replacement tritium packaging called the Bulk Tritium Shipping Package (BTSP) is currently being designed and tested by Savannah River National Laboratory (SRNL). The BTSP consists of two primary assemblies, an outer Drum Assembly and an inner Containment Vessel Assembly (CV), both designed to mitigate damage and to protect the tritium contents from leaking during the regulatory Hypothetical Accident Condition (HAC) events and during Normal Conditions of Transport (NCT). During transport, the CV rests on a silicone pad within the Drum Liner and is covered with a thermal insulating disk within the insulated Drum Assembly. The BTSP packaging weighs approximately 500 lbs without contents and is 50

  18. An integrative model of the cardiac ventricular myocyte incorporating local control of Ca2+ release.

    PubMed Central

    Greenstein, Joseph L; Winslow, Raimond L

    2002-01-01

    The local control theory of excitation-contraction (EC) coupling in cardiac muscle asserts that L-type Ca(2+) current tightly controls Ca(2+) release from the sarcoplasmic reticulum (SR) via local interaction of closely apposed L-type Ca(2+) channels (LCCs) and ryanodine receptors (RyRs). These local interactions give rise to smoothly graded Ca(2+)-induced Ca(2+) release (CICR), which exhibits high gain. In this study we present a biophysically detailed model of the normal canine ventricular myocyte that conforms to local control theory. The model formulation incorporates details of microscopic EC coupling properties in the form of Ca(2+) release units (CaRUs) in which individual sarcolemmal LCCs interact in a stochastic manner with nearby RyRs in localized regions where junctional SR membrane and transverse-tubular membrane are in close proximity. The CaRUs are embedded within and interact with the global systems of the myocyte describing ionic and membrane pump/exchanger currents, SR Ca(2+) uptake, and time-varying cytosolic ion concentrations to form a model of the cardiac action potential (AP). The model can reproduce both the detailed properties of EC coupling, such as variable gain and graded SR Ca(2+) release, and whole-cell phenomena, such as modulation of AP duration by SR Ca(2+) release. Simulations indicate that the local control paradigm predicts stable APs when the L-type Ca(2+) current is adjusted in accord with the balance between voltage- and Ca(2+)-dependent inactivation processes as measured experimentally, a scenario where common pool models become unstable. The local control myocyte model provides a means for studying the interrelationship between microscopic and macroscopic behaviors in a manner that would not be possible in experiments. PMID:12496068

  19. Treatment of tritiated exhaust gases at the Tritium Laboratory Karlsruhe

    SciTech Connect

    Hutter, E.; Besserer, U.; Jacqmin, G.

    1995-02-01

    The Tritium Laboratory Karlsruhe (TLK) accomplished commissioning; tritium involving activities will start this year. The laboratory is destined mainly to investigating processing of fusion reactor fuel and to developing analytic devices for determination of tritium and tritiated species in view of control and accountancy requirements. The area for experimental work in the laboratory is about 800 m{sup 2}. The tritium infrastructure including systems for tritium storage, transfer within the laboratory and processing by cleanup and isotope separation methods has been installed on an additional 400 m{sup 2} area. All tritium processing systems (=primary systems), either of the tritium infrastructure or of the experiments, are enclosed in secondary containments which consist of gloveboxes, each of them connected to the central depressurization system, a part integrated in the central detritiation system. The atmosphere of each glovebox is cleaned in a closed cycle by local detritiation units controlled by two tritium monitors. Additionally, the TLK is equipped with a central detritiation system in which all gases discharged from the primary systems and the secondary systems are processed. All detritiation units consist of a catalyst for oxidizing gaseous tritium or tritiated hydrocarbons to water, a heat exchanger for cooling the catalyst reactor exhaust gas to room temperature, and a molecular sieve bed for adsorbing the water. Experiments with tracer amounts of tritium have shown that decontamination factors >3000 can be achieved with the TLK detritiation units. The central detritiation system was carefully tested and adjusted under normal and abnormal operation conditions. Test results and the behavior of the tritium barrier preventing tritiated exhaust gases from escaping into the atmosphere will be reported.

  20. Incorporation of methamphetamine and amphetamine in human hair following controlled oral methamphetamine administration

    PubMed Central

    Polettini, Aldo; Cone, Edward J.; Gorelick, David A.; Huestis, Marilyn A.

    2012-01-01

    Background Although hair testing is well established for the assessment of past drug exposure, uncertainties persist about mechanisms of drug incorporation into hair and interpretation of results. The aim of this study was to administer methamphetamine (MAMP) under controlled conditions as a model drug to investigate drug incorporation into human hair. Material and Methods Seven volunteers with a history of stimulant use received 4×10 mg (low) doses of sustained release S-(+)-MAMP HCl within one week, with weekly head hair samples collected by shaving. 3 weeks later, 4 of them received 4×20 mg (high) doses. After extensive isopropanol/phosphate buffer washing of the hair, MAMP and its metabolite amphetamine (AMP) concentrations were determined in all weekly hair samples by LC-MS-MS in selected reaction monitoring mode with the undeca- and deca-deuterated drugs, respectively, as internal standards (LLOQ, 0.005 ng/mg). Results MAMP Tmax occurred from 1 to 2 weeks after both doses, with Cmax ranging from 0.6–3.5 ng/mg after the low and 1.2–5.3 ng/mg after the high MAMP doses. AMP Cmax in hair was 0.1–0.3 ng/mg and 0.2–0.5 ng/mg, respectively, for low and high doses. Highly dose–related concentrations within subjects, but large variability between subjects were observed. MAMP concentrations were above the 0.2 ng/mg cutoff for at least two weeks following administration of both low and high doses. The overall AMP/MAMP ratio ranged from 0.07 to 0.37 with a mean value of 0.15±0.07, and a median of 0.13. The percentage of MAMP and AMP removed with the washing procedure decreased with time after administration. A strong correlation was found between area under the curve of MAMP (r2=0.90, p=0.00) and AMP (r2=0.94, p=0.00) concentrations calculated for the 3-week period following administration and the total melanin concentration in hair. Significant correlations were observed also between Cmax and melanin. Conclusions This study demonstrated that despite large

  1. Tritium confinement, retention, and releases at the tritium laboratory Karlsruhe

    SciTech Connect

    Besserer, U.; Doerr, L.; Glugla, M.

    2008-07-15

    This paper describes the tritium confinement concept and the tritium retention systems at TLK. A description of the AMOR facility for the regeneration of the HTO loaded molecular sieve beds and the operational experience gained from the regeneration of molecular sieve beds (up to 20 times each) is also presented. Finally tritium releases over this period to the environment will also be given. (authors)

  2. Drum bubbler tritium processing system

    DOEpatents

    Rule, Keith; Gettelfinger, Geoff; Kivler, Paul

    1999-01-01

    A method of separating tritium oxide from a gas stream containing tritium oxide. The gas stream containing tritium oxide is fed into a container of water having a head space above the water. Bubbling the gas stream containing tritium oxide through the container of water and removing gas from the container head space above the water. Thereafter, the gas from the head space is dried to remove water vapor from the gas, and the water vapor is recycled to the container of water.

  3. Novel vaginal controlled-delivery systems incorporating coprecipitates of nonoxynol-9.

    PubMed

    Digenis, G A; Nosek, D; Mohammadi, F; Darwazeh, N B; Anwar, H S; Zavos, P M

    1999-08-01

    The purpose of this study was to formulate Nonoxynol-9 (N-9) into a solid coprecipitate form which can be used in preparing pharmaceutically attractive and nonirritating vaginal controlled-release delivery systems (DDSs) such as gelatin capsules (HGC) and tablets. N-9 was coprecipitated with polyvinylpyrrolidone (PVP) with or without iodine to produce solid powders which were incorporated into either (a) bilayer tablet DDSs which possess a fast- (outer) and slow- (inner core) releasing compartment, and (b) HGC DDSs (named Triad HGC) composed of fast- (outer), intermediate- (granules), and slow- (pellets) releasing compartments. The rates of release of iodine and/or [14C]N-9 from the two DDSs were studied in vitro in phosphate buffer at pH 5.0, in human seminal plasma and in vivo after intravaginal administration in rabbits. In all of the above-described release studies, the DDSs were shown to release their N-9 or iodine content rapidly, reaching spermicidal levels within 3 min. This was further substantiated by experiments in which the DDSs were introduced in whole human semen containing live spermatozoa. Complete spermicidal kill was obtained in less than 1 min and in less than 3 min from the bilayer tablet and the Triad HGC, respectively. Furthermore, the release of N-9 from the two DDSs was shown to continue for at least 4 hr in buffers (pH 5.0), human seminal fluid, and after intravaginal administration in rabbits. The resulting powder from the coprecipitation of N-9 and PVP (K-30) can be appropriately formulated into a controlled-released HGC or bilayer tablet to produce vaginal controlled-release DDSs which are nonirritating and have the potential to become effective spermicidal products. PMID:10434288

  4. Are the risks from tritium exposures being underestimated?

    PubMed

    Paquet, F; Métivier, H

    2009-06-01

    Tritium is a radionuclide that will be used and produced in fusion reactors. Tritium toxicity is well known, but its health consequences are more difficult to assess, due to difficulties in assessing doses and to the very few cases of contamination that have occurred since it started being used. The assessment of risks resulting from tritium exposure is based on ICRP models that enable the calculation of doses in tissues, by means of a weighting factor WR, based on the relative biological effectiveness of the various radioactive emissions. Some authors are currently asking for a revision of the weighting factor used for tritium beta-ray emissions, arguing that tritium could be incorporated into DNA. A review of the extensive research conducted on this subject shows that the relative biological effectiveness of tritium is not so different from that of gamma emissions, which are taken as reference radiations. This supports the drive to keep the current weighting factor of 1 for tritium beta emissions, initially proposed and then reaffirmed by the ICRP. PMID:19454789

  5. Monitoring of tritium

    DOEpatents

    Corbett, James A.; Meacham, Sterling A.

    1981-01-01

    The fluid from a breeder nuclear reactor, which may be the sodium cooling fluid or the helium reactor-cover-gas, or the helium coolant of a gas-cooled reactor passes over the portion of the enclosure of a gaseous discharge device which is permeable to hydrogen and its isotopes. The tritium diffused into the discharge device is radioactive producing beta rays which ionize the gas (argon) in the discharge device. The tritium is monitored by measuring the ionization current produced when the sodium phase and the gas phase of the hydrogen isotopes within the enclosure are in equilibrium.

  6. Fabrication of light water reactor tritium targets

    SciTech Connect

    Pilger, J.P.

    1991-11-01

    The mission of the Fabrication Development Task of the Tritium Target Development Project is: to produce a documented technology basis, including specifications and procedures for target rod fabrication; to demonstrate that light water tritium targets can be manufactured at a rate consistent with tritium production requirements; and to develop quality control methods to evaluate target rod components and assemblies, and establish correlations between evaluated characteristics and target rod performance. Many of the target rod components: cladding tubes, end caps, plenum springs, etc., have similar counterparts in LWR fuel rods. High production rate manufacture and inspection of these components has been adequately demonstrated by nuclear fuel rod manufacturers. This summary describes the more non-conventional manufacturing processes and inspection techniques developed to fabricate target rod components whose manufacturability at required production rates had not been previously demonstrated.

  7. Recommendations for Tritium Science and Technology Research and Development in Support of the Tritium Readiness Campaign, TTP-7-084

    SciTech Connect

    Senor, David J.

    2013-10-30

    Between 2006 and 2012 the Tritium Readiness Campaign Development and Testing Program produced significant advances in the understanding of in-reactor TPBAR performance. Incorporating these data into existing TPBAR performance models has improved permeation predictions, and the discrepancy between predicted and observed tritium permeation in the WBN1 coolant has been decreased by about 30%. However, important differences between predicted and observed permeation still remain, and there are significant knowledge gaps that hinder the ability to reliably predict other aspects of TPBAR performance such as tritium distribution, component integrity, and performance margins. Based on recommendations from recent Tritium Readiness Campaign workshops and reviews coupled with technical and programmatic priorities, high-priority activities were identified to address knowledge gaps in the near- (3-5 year), middle- (5-10 year), and long-term (10+ year) time horizons. It is important to note that there are many aspects to a well-integrated research and development program. The intent is not to focus exclusively on one aspect or another, but to approach the program in a holistic fashion. Thus, in addition to small-scale tritium science studies, ex-reactor tritium technology experiments such as TMED, and large-scale in-reactor tritium technology experiments such as TMIST, a well-rounded research and development program must also include continued analysis of WBN1 performance data and post-irradiation examination of TPBARs and lead use assemblies to evaluate model improvements and compare separate-effects and integral component behavior.

  8. Controlled Defects of Fluorine-incorporated ZnO Nanorods for Photovoltaic Enhancement

    PubMed Central

    Lee, Hock Beng; Ginting, Riski Titian; Tan, Sin Tee; Tan, Chun Hui; Alshanableh, Abdelelah; Oleiwi, Hind Fadhil; Yap, Chi Chin; Jumali, Mohd Hafizuddin Hj.; Yahaya, Muhammad

    2016-01-01

    Anion passivation effect on metal-oxide nano-architecture offers a highly controllable platform for improving charge selectivity and extraction, with direct relevance to their implementation in hybrid solar cells. In current work, we demonstrated the incorporation of fluorine (F) as an anion dopant to address the defect-rich nature of ZnO nanorods (ZNR) and improve the feasibility of its role as electron acceptor. The detailed morphology evolution and defect engineering on ZNR were studied as a function of F-doping concentration (x). Specifically, the rod-shaped arrays of ZnO were transformed into taper-shaped arrays at high x. A hypsochromic shift was observed in optical energy band gap due to the Burstein-Moss effect. A substantial suppression on intrinsic defects in ZnO lattice directly epitomized the novel role of fluorine as an oxygen defect quencher. The results show that 10-FZNR/P3HT device exhibited two-fold higher power conversion efficiency than the pristine ZNR/P3HT device, primarily due to the reduced Schottky defects and charge transfer barrier. Essentially, the reported findings yielded insights on the functions of fluorine on (i) surface –OH passivation, (ii) oxygen vacancies (Vo) occupation and (iii) lattice oxygen substitution, thereby enhancing the photo-physical processes, carrier mobility and concentration of FZNR based device. PMID:27587295

  9. Controlled Defects of Fluorine-incorporated ZnO Nanorods for Photovoltaic Enhancement.

    PubMed

    Lee, Hock Beng; Ginting, Riski Titian; Tan, Sin Tee; Tan, Chun Hui; Alshanableh, Abdelelah; Oleiwi, Hind Fadhil; Yap, Chi Chin; Jumali, Mohd Hafizuddin Hj; Yahaya, Muhammad

    2016-01-01

    Anion passivation effect on metal-oxide nano-architecture offers a highly controllable platform for improving charge selectivity and extraction, with direct relevance to their implementation in hybrid solar cells. In current work, we demonstrated the incorporation of fluorine (F) as an anion dopant to address the defect-rich nature of ZnO nanorods (ZNR) and improve the feasibility of its role as electron acceptor. The detailed morphology evolution and defect engineering on ZNR were studied as a function of F-doping concentration (x). Specifically, the rod-shaped arrays of ZnO were transformed into taper-shaped arrays at high x. A hypsochromic shift was observed in optical energy band gap due to the Burstein-Moss effect. A substantial suppression on intrinsic defects in ZnO lattice directly epitomized the novel role of fluorine as an oxygen defect quencher. The results show that 10-FZNR/P3HT device exhibited two-fold higher power conversion efficiency than the pristine ZNR/P3HT device, primarily due to the reduced Schottky defects and charge transfer barrier. Essentially, the reported findings yielded insights on the functions of fluorine on (i) surface -OH passivation, (ii) oxygen vacancies (Vo) occupation and (iii) lattice oxygen substitution, thereby enhancing the photo-physical processes, carrier mobility and concentration of FZNR based device. PMID:27587295

  10. Gold nanoparticle incorporated polymer/bioactive glass composite for controlled drug delivery application.

    PubMed

    Jayalekshmi, A C; Sharma, Chandra P

    2015-02-01

    The present study discusses the development of a biodegradable polymer encapsulated-nanogold incorporated-bioactive glass composite (AuPBG) by a low-temperature method. The composite was analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG), fluorescence and dissolution analysis. The composite exhibited aggregation behaviour in solid and solution states and exhibited negative zeta potential (-13.3 ± 1.4 mV). The composite exhibited fast degradation starting from the 5(th) day onwards in phosphate buffered saline (PBS) for a period of 14 days. The composite showed fluorescence quenching effect at pH 7 and the fluorescence recovered at pH 5. The composite has been found to be suitable for the release of doxorubicin at high rates at acidic pH (∼ 5) which is the intracellular pH of tumour cells. The drug loading ratio is also high and it exhibited a controlled release for a period of 8 days in PBS. The system serves as a promising material for targeted drug delivery applications. PMID:25576810

  11. Anti-inflammatory drug incorporation into polymeric nano-hybrids for local controlled release.

    PubMed

    Sammartino, G; Marenzi, G; Tammaro, L; Bolognese, A; Calignano, A; Costantino, U; Califano, L; Mastrangelo, F; Tetè, S; Vittoria, V

    2005-01-01

    In this paper we present the formulation, preparation and characterization of new polymeric composite materials containing a nano-hybrid to be used for the controlled molecular delivery of an anti-inflammatory molecule, Diclofenac. The nano-hybrid consists of a layer of double hydroxide of an Mg-Al hydrotalcite type, in which we replaced the chloride anions present in the host galleries with Diclofenac anions by a simple ion-exchange reaction. Different amounts of the hybrid material were incorporated in polycaprolactone and processed as films of 0.15 mm thickness. The composite materials were analyzed by X-ray diffractometry, thermogravimetry and for their mechanical properties, and showed properties even better than those for the pristine polymer. The release process of the anti-inflammatory molecules was very interesting and promising for tuneable drug delivery. It consists of two stages: a first stage, very rapid as a burst in which a small fraction of the drug is released, and of a second stage that is much slower, extending for longer and longer periods. The parameters influencing the drug release were individuated and discussed. PMID:16848988

  12. Drum bubbler tritium processing system

    DOEpatents

    Rule, K.; Gettelfinger, G.; Kivler, P.

    1999-08-17

    A method is described for separating tritium oxide from a gas stream containing tritium oxide. The gas stream containing tritium oxide is fed into a container of water having a head space above the water. The tritium oxide is separated by bubbling the gas stream containing tritium oxide through the container of water and removing gas from the container head space above the water. Thereafter, the gas from the head space is dried to remove water vapor from the gas, and the water vapor is recycled to the container of water. 2 figs.

  13. ARIES-I tritium system

    SciTech Connect

    Sze, D.K.; Tam, S.W.; Billone, M.C.; Hassanein, A.M. ); Martin, R. )

    1990-09-01

    A key safety concern in a D-T fusion reactor is the tritium inventory. There are three components in a fusion reactor with potentially large inventories, i.e., the blanket, the fuel processing system and the plasma facing components. The ARIES team selected the material combinations, decided the operating conditions and refined the processing systems, with the aiming of minimizing the tritium inventories and leakage. The total tritium inventory for the ARIES-I reactor is only 700 g. This paper discussed the calculations and assumptions we made for the low tritium inventory. We also addressed the uncertainties about the tritium inventory. 13 refs., 2 figs., 3 tabs.

  14. Tritium retention in TFTR

    SciTech Connect

    Dylla, H.F.; Wilson, K.L.

    1988-04-01

    This report discusses the materials physics related to D-T operation in TFTR. Research activities are described pertaining to basic studies of hydrogenic retention in graphite, hydrogen recycling phenomena, first-wall and limiter conditioning, surface analysis of TFTR first-wall components, and estimates of the tritium inventory.

  15. The Callaway Plant's airborne tritium sampling cart

    SciTech Connect

    Graham, C.C.; Roselius, R.R. )

    1986-07-01

    The water vapor condensation method for sampling airborne tritium offers significant advantages over other methods, including minimal sample preparation, high sensitivity, and independence from collection efficiency and sample flow rate. However, it does have disadvantages that must be overcome in the design of a sampler. This article describes a cart-mounted, portable airborne tritium sampler used at the Callaway Nuclear Plant that incorporates the advantages of the condensation technique while minimizing its shortcomings. The key elements in the design of the sampler are the use of a refrigerated bath to cool a series of three water vapor collection traps and the use of an optical condensation dew point hygrometer to measure the moisture content of the sample. Design considerations for the proper operation of dew point hygrometers are presented, and the method used to convert due point readings to water vapor content is described.

  16. Silicon Carbide as a tritium permeation barrier in tungsten plasma-facing components

    NASA Astrophysics Data System (ADS)

    Wright, G. M.; Durrett, M. G.; Hoover, K. W.; Kesler, L. A.; Whyte, D. G.

    2015-03-01

    The control of tritium inventory is of great importance in future fusion reactors, not only from a safety standpoint but also to maximize a reactor's efficiency. Due to the high mobility of hydrogenic species in tungsten (W) one concern is the loss of tritium from the system via permeation through the tungsten plasma-facing components (PFC). This can lead to loss of tritium through the cooling channels of the wall thereby mandating tritium monitoring and recovery methods for the cooling system of the first wall. The permeated tritium is then out of the fuel cycle and cannot contribute to energy production until it is recovered and recycled into the system.

  17. Tritium permeation and related studies on barrier treated 316 stainless steel

    SciTech Connect

    Gilbert, E.R.; Allen, R.P.; Baldwin, D.L.; Bell, R.D.; Brimhall, J.L.; Clemmer, R.G.; Marschman, S.C.; McKinnon, M.A.; Page, R.E.; Powers, H.G.; Chalk, S.G.

    1991-09-01

    To verify the performance of permeation-resistant cladding for tritium targets designed for a New Production Reactor Light Water Reactor, a tritium test facility was designed, developed, and certified. Testing is ongoing to verify the performance of reference designed targets. Accurate measurements were taken of tritium permeating from barrier-coated cladding specimens immersed in high-temperature autoclaves configured to simulate reactor coolant conditions. The tritium test pressure is controlled by heating a zirconium-alloy getter, previously charged with tritium, to a temperature that corresponds to a specified test pressure.

  18. Development of tritium technology for the United States magnetic fusion energy program

    SciTech Connect

    Anderson, J.L.; Wilkes, W.R.

    1980-01-01

    Tritium technology development for the DOE fusion program is taking place principally at three laboratories, Mound Facility, Argonne National Laboratory and the Los Alamos Scientific Laboratory. This paper will review the major aspects of each of the three programs and look at aspects of the tritium technology being developed at other laboratories within the United States. Facilities and experiments to be discussed include the Tritium Effluent Control Laboratory and the Tritium Storage and Delivery System for the Tokamak Fusion Test Reactor at Mound Facility; the Lithium Processing Test Loop and the solid breeder blanket studies at Argonne; and the Tritium Systems Test Assembly at Los Alamos.

  19. TRITIUM RESERVOIR STRUCTURAL PERFORMANCE PREDICTION

    SciTech Connect

    Lam, P.S.; Morgan, M.J

    2005-11-10

    The burst test is used to assess the material performance of tritium reservoirs in the surveillance program in which reservoirs have been in service for extended periods of time. A materials system model and finite element procedure were developed under a Savannah River Site Plant-Directed Research and Development (PDRD) program to predict the structural response under a full range of loading and aged material conditions of the reservoir. The results show that the predicted burst pressure and volume ductility are in good agreement with the actual burst test results for the unexposed units. The material tensile properties used in the calculations were obtained from a curved tensile specimen harvested from a companion reservoir by Electric Discharge Machining (EDM). In the absence of exposed and aged material tensile data, literature data were used for demonstrating the methodology in terms of the helium-3 concentration in the metal and the depth of penetration in the reservoir sidewall. It can be shown that the volume ductility decreases significantly with the presence of tritium and its decay product, helium-3, in the metal, as was observed in the laboratory-controlled burst tests. The model and analytical procedure provides a predictive tool for reservoir structural integrity under aging conditions. It is recommended that benchmark tests and analysis for aged materials be performed. The methodology can be augmented to predict performance for reservoir with flaws.

  20. Suggested methods for determining residual tritium in process beds

    SciTech Connect

    Hoelder, J.S.

    1992-10-29

    This memorandum has been written as a response to an H-Area EH Issue No. 3 milestone (SRTC FY93 Controlled Milestone 15C70) which requires WSRC to {open_quotes}develop methodology for determining residual tritium in process equipment.{close_quotes} An estimate of the tritium residing in process equipment sent for disposal must be reported on a Waste Stream Characterization Form. Currently, these estimates are crude and their technical bases are not well documented. The process equipment addressed in this report may be divided into two categories, routine and non-routine, based on their generation frequency. Magnesium Beds, Uranium Beds, and Gold Traps are regularly sent for disposal depending on the process load; Zeolite Beds and Catalyst Beds are rarely removed from the Tritium Facilities, as they may be regenerated. In general, there are two main sources of residual tritium that which resides in hydroxyl groups on internal surfaces and deposits, and that which has permeated the stainless steel walls and components. The tritiated hydroxyl groups may be exchangeable with gas phase deuterium, and minimized by oxidation at elevated temperatures. The tritium which has diffused into stainless steel is difficult to remove and amounts to a minor portion of the total tritium heel; this value may be calculated by a proven computer program and is on the order of 1--5 Ci per bed. Zeolite Beds are a unique case, as the packing material contains a substantial portion of crystalline hydrate (2% by weight), even after bake out at 500{degrees}C The solid state hydrate will assimilate tritium from adsorbed waters, and calculations show a typical Z-bed may contain 50,000 Ci of residual tritium. It is proposed that a calorimeter be designed and constructed to measure the tritium in Z-beds directly, and that steps be taken to reduce the residual tritium by extraction with deuterated water.

  1. Tritium well depth, tritium well time and sponge mechanism for reducing tritium retention

    NASA Astrophysics Data System (ADS)

    Deng, B. Q.; Li, Z. X.; Li, C. Y.; Feng, K. M.

    2011-07-01

    New simulation results are predicted in a fusion reactor operation process. They are somewhat similar to, but quite different from, the xenon poisoning effects resulting from fission-produced iodine during the restart-up process of a fission reactor. We obtained completely new results of tritium well depth and tritium well time in magnetic confinement fusion energy research area. This study is carried out to investigate the following: what will be the least amount of tritium storage required to start up a fusion reactor and how long the fusion reactor needs to be operated for achieving the tritium break-even during the initial start-up phase due to the finite tritium-breeding time, which is dependent on the tritium breeder, specific structure of the breeding zone, layout of the coolant flow pipes, tritium recovery scheme and applied extraction process, the tritium retention of plasma facing component (PFC) and other reactor components, unrecoverable tritium fraction in the breeder, leakage to the inertial gas container and the natural radioactive decay time constant. We describe these new issues and answer these problems by setting up and solving a set of equations, which are described by a dynamic subsystem model of tritium inventory evolution in a fusion experimental breeder (FEB). Reasonable results are obtained using our simulation model. It is found that the tritium well depth is about 0.319 kg and the tritium well time is approximately 235 full power operation days for the reference case of the designed FEB configuration, and it is also found that after one-year operation the tritium storage reaches 0.767 kg, which is more than the least amount of tritium storage required to start up another FEB-like fusion reactor. The results show that the tritium retention in the PFC is equivalent to 11.9% of tritium well depth that is fairly consistent with the result of 10-20% deduced from the integrated particle balance of European tokamaks. Based on our experimental

  2. Design of a tritium pellet injector for TFTR

    SciTech Connect

    Milora, S.L.; Gouge, M.J.; Fisher, P.W.; Combs, S.K.; Cole, M.J.; Wysor, R.B.; Fehling, D.T.; Foust, C.R.; Baylor, L.R. ); Schmidt, G.L.; Barnes, G.W.; Persing, R.G. . Plasma Physics Lab.)

    1991-01-01

    The TFTR tritium pellet injector (TPI) is designed to provide a tritium pellet fueling capability with pellet speeds in the 1{minus} to 3 km/s-range for the TFTR D-T phase. The existing TFTR deuterium pellet injector is being modified at Oak Ridge National Laboratory to provide a fourshot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns a two -stage light gas gun driver. The pipe gun concept has been qualified for tritium operation by the tritium proof-of-principle injector experiments conducted on the Tritium Systems Test Assembly at Los Alamos National Laboratory. In these experiments, tritium and D-T pellets were accelerated to speeds near 1.5 km/s. The TPI is being designed for pellet sizes in the range from 3.43 to 4.0 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation will be controlled by a programmable logic controller. 7 refs., 4 figs.

  3. Tritium transport vessel using depleted uranium

    SciTech Connect

    Heung, L.K.

    1995-01-01

    A tritium transport vessel using depleted uranium was tested in the laboratory using deuterium and protium. The vessel contains 0.5 kg of depleted uranium and can hold up to 18 grams of tritium. The conditions for activation, tritium loading and tritium unloading were defined. The safety aspects that included air-ingress, tritium diffusion, temperature and pressure potentials were evaluated.

  4. Controlling particle size in the Stöber process and incorporation of calcium.

    PubMed

    Greasley, Sarah L; Page, Samuel J; Sirovica, Slobodan; Chen, Shu; Martin, Richard A; Riveiro, Antonio; Hanna, John V; Porter, Alexandra E; Jones, Julian R

    2016-05-01

    The Stӧber process is commonly used for synthesising spherical silica particles. This article reports the first comprehensive study of how the process variables can be used to obtain monodispersed particles of specific size. The modal particle size could be selected within in the range 20-500nm. There is great therapeutic potential for bioactive glass nanoparticles, as they can be internalised within cells and perform sustained delivery of active ions. Biodegradable bioactive glass nanoparticles are also used in nanocomposites. Modification of the Stӧber process so that the particles can contain cations such as calcium, whilst maintaining monodispersity, is desirable. Here, whilst calcium incorporation is achieved, with a homogenous distribution, careful characterisation shows that much of the calcium is not incorporated. A maximum of 10mol% CaO can be achieved and previous reports are likely to have overestimated the amount of calcium incorporated. PMID:26890387

  5. Polarized tritium target development

    SciTech Connect

    Jones, C.E.; Fedchak, J.A.; Kowalczyk, R.S.

    1995-08-01

    Work began on the development of a completely sealed polarized tritium target for experiments at CEBAF. Because of the similarities between optical pumping of tritium and hydrogen, all prototype work is done with hydrogen. We constructed a test station for filling glassware with hydrogen, where we can dissociate molecular hydrogen and monitor the purity of the gas. A simple two-cell glass system was constructed, consisting of a region in which the molecular hydrogen is dissociated with an RF discharge and a region where the atoms can be optically pumped. So far, a clean discharge was obtained in the glassware. With this system, we plan to investigate ways to eliminate the discharge from the optical pumping region and test the quality of the discharge once the pumping cell is coated with drifilm.

  6. Elemental and Isotopic Incorporation into the Aragonitic Shells of Arctica Islandica: Insights from Temperature Controlled Experiments

    NASA Astrophysics Data System (ADS)

    Wanamaker, A. D.; Gillikin, D. P.

    2014-12-01

    The long-lived ocean quahog, Arctica islandica, is a fairly well developed and tested marine proxy archive, however, the utility of elemental ratios in A. islandica shell material as environmental proxies remains questionable. To further evaluate the influence of seawater temperature on elemental and isotopic incorporation during biomineralization, A. islandica shells were grown at constant temperatures under two regimes during a 16-week period from March 27 to July 21, 2011. Seawater from the Darling Marine Center in Walpole, Maine was pumped into temperature and flow controlled tanks that were exposed to ambient food and salinity conditions. A total of 20 individual juvenile clams with an average shell height of 36 mm were stained with calcein (a commonly used biomarker) and cultured at 10.3 ± 0.3 °C for six weeks. After this, shell heights were measured and the clams were again stained with calcein and cultured at 15.0 ± 0.4 °C for an additional 9.5 weeks. The average shell growth during the first phase of the experiment was 2.4 mm with a linear extension rate of 0.40 mm/week. The average shell growth during the second phase of the experiment was 3.2 mm with an extension rate of 0.34 mm/week. Average salinity values were 30.2 ± 0.7 and 30.7 ±0.7 in the first and second phases of the experiment, respectively. Oxygen isotopes from the cultured seawater were collected throughout the experiment and provide the basis for establishing if shells grew in oxygen isotopic equilibrium. Elemental ratios (primarily Ba/Ca, Mg/Ca, Sr/Ca) in the aragonitic shells were determined via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), while stable oxygen and carbon isotope ratios were measured using continuous flow isotope ratio mass spectrometry. Continuous sampling within and across the temperature conditions (from 10 °C to 15 °C) coupled with the calcein markings provides the ability to place each sample into a precise temporal framework. The

  7. Tritium implantation in the accelerator production of tritium device

    SciTech Connect

    Kidman, R.B.

    1997-11-01

    We briefly describe the methods we have developed to compute the magnitude and spatial distribution of born and implanted tritons and protons in the Accelerator Production of Tritium (AFT) device. The methods are verified against experimental measurements and then used to predict that 16% of the tritium is implanted in the walls of the APT distribution tubes. The methods are also used to estimate the spatial distribution of implanted tritium, which will be required for determining the possible diffusion of tritium out of the walls and back into the gas stream.

  8. Evaluation of tritium release properties of advanced tritium breeders

    SciTech Connect

    Hoshino, T.; Ochiai, K.; Edao, Y.; Kawamura, Y.

    2015-03-15

    Demonstration power plant (DEMO) fusion reactors require advanced tritium breeders with high thermal stability. Lithium titanate (Li{sub 2}TiO{sub 3}) advanced tritium breeders with excess Li (Li{sub 2+x}TiO{sub 3+y}) are stable in a reducing atmosphere at high temperatures. Although the tritium release properties of tritium breeders are documented in databases for DEMO blanket design, no in situ examination under fusion neutron (DT neutron) irradiation has been performed. In this study, a preliminary examination of the tritium release properties of advanced tritium breeders was performed, and DT neutron irradiation experiments were performed at the fusion neutronics source (FNS) facility in JAEA. Considering the tritium release characteristics, the optimum grain size after sintering is <5 μm. From the results of the optimization of granulation conditions, prototype Li{sub 2+x}TiO{sub 3+y} pebbles with optimum grain size (<5 μm) were successfully fabricated. The Li{sub 2+x}TiO{sub 3+y} pebbles exhibited good tritium release properties similar to the Li{sub 2}TiO{sub 3} pebbles. In particular, the released amount of HT gas for easier tritium handling was higher than that of HTO water. (authors)

  9. Constraining the North Atlantic circulation with tritium data

    NASA Technical Reports Server (NTRS)

    Memery, Laurent; Wunsch, Carl

    1990-01-01

    The North Atlantic circulation derived from an inverse calculation by singular-value decomposition is tested against the historical record of tritium. A forward calculation of the tritium transient is performed using the circulation model, published estimates of atmospheric injection rates, and plausible estimates of the tracer history at the open boundaries of the model. The results do not agree with observations of the interior distributions of tritium. Consideration is given to the possibility of improving the agreement by modifying the atmospheric injection rates and the initial estimates of open boundary time histories, treating the boundary conditions as control variables.

  10. A prototype wearable tritium monitor

    SciTech Connect

    Surette, R. A.; Dubeau, J.

    2008-07-15

    Sudden unexpected changes in tritium-in-air concentrations in workplace air can result in significant unplanned exposures. Although fixed area monitors are used to monitor areas where there is a potential for elevated tritium in air concentrations, they do not monitor personnel air space and may require some time for acute tritium releases to be detected. There is a need for a small instrument that will quickly alert staff of changing tritium hazards. A moderately sensitive tritium instrument that workers could wear would bring attention to any rise in tritium levels that were above predetermined limits and help in assessing the potential hazard therefore minimizing absorbed dose. Hand-held instruments currently available can be used but require the assistance of a fellow worker or restrict the user to using only one hand to perform some duties. (authors)

  11. Human factors engineering for the TERF (Tritium Emissions Reduction Facility) project. [Tritium Emissions Reduction Facility

    SciTech Connect

    Hedley, W.H.; Adams, F.S. ); Wells, J.E. )

    1990-12-14

    The Tritium Emissions Reduction Facility (TERF) is being built by EG G Mound Applied Technologies to provide improved control of the tritium emissions from gas streams being processed. Mound handles tritium in connection with production, development, research, disassembly, recovery, and surveillance operations. During these operations, a small fraction of the tritium being processed escapes from its original containment. The objective of this report is to describe the human factors engineering as performed in connection with the design, construction, and testing of the TERF as required in DOE Order 6430.1A, section 1300-12. Human factors engineering has been involved at each step of the process and was considered during the preliminary research on tritium capture before selecting the specific process to be used. Human factors engineering was also considered in determining the requirements for the TERF and when the specific design work was initiated on the facility and the process equipment. Finally, human factors engineering was used to plan the specific acceptance tests that will be made during TERF installation and after its completion. These tests will verify the acceptability of the final system and its components. 16 refs., 8 figs.

  12. Welding tritium exposed stainless steel

    SciTech Connect

    Kanne, W.R. Jr.

    1994-11-01

    Stainless steels that are exposed to tritium become unweldable by conventional methods due to buildup of decay helium within the metal matrix. With longer service lives expected for tritium containment systems, methods for welding on tritium exposed material will become important for repair or modification of the systems. Solid-state resistance welding and low-penetration overlay welding have been shown to mitigate helium embrittlement cracking in tritium exposed 304 stainless steel. These processes can also be used on stainless steel containing helium from neutron irradiation, such as occurs in nuclear reactors.

  13. Recovery of tritium from water

    SciTech Connect

    Sienkiewicz, C.J.; Lentz, J.E. . Mound)

    1988-09-01

    The pilot-scale Combined Electrolysis Catalytic Exchange (CECE) system developed at the U.S. Department of Energy's Mound facility has evolved into a fully operational tritium recovery system. This has resulted from the evaluation of recent developments in AECL/CRNL hydrophobic exchange catalyst in the CECE system. Data obtained during recent tests led to the design and installation of an aqueous tritium recovery facility. Operation of the Tritium Aqueous Waste Recovery System makes possible the recovery of tritium from low-level tritiated aqueous waste streams.

  14. Recovery of tritium from water

    SciTech Connect

    Sienkiewicz, C.J.; Lentz, J.E.

    1988-01-01

    The pilot-scale Combined Electrolysis Catalytic Exchange (CECE) system developed at the US Department of Energy's Mound facility has evolved into a fully operational tritium recovery system. This has resulted from the evaluation of recent developments in AECL/ORNL hydrophobic exchange catalyst in the CECE system. Data obtained during recent tests led to the design and installation of an aqueous tritium recovery facility. Operation of the Tritium Aqueous Waste Recovery System makes possible the recovery of tritium from low-level tritiated aqueous waste streams. 14 refs., 4 figs.

  15. Producing tritium in a homogenous reactor

    DOEpatents

    Cawley, William E.

    1985-01-01

    A method and apparatus are described for the joint production and separation of tritium. Tritium is produced in an aqueous homogenous reactor and heat from the nuclear reaction is used to distill tritium from the lower isotopes of hydrogen.

  16. 2009 EVALUATION OF TRITIUM REMOVAL AND MITIGATION TECHNOLOGIES FOR WASTEWATER TREATMENT

    SciTech Connect

    LUECK KJ; GENESSE DJ; STEGEN GE

    2009-02-26

    Since 1995, a state-approved land disposal site (SALDS) has received tritium contaminated effluents from the Hanford Site Effluent Treatment Facility (ETF). Tritium in this effluent is mitigated by storage in slow moving groundwater to allow extended time for decay before the water reaches the site boundary. By this method, tritium in the SALDS is isolated from the general environment and human contact until it has decayed to acceptable levels. This report contains the 2009 update evaluation of alternative tritium mitigation techniques to control tritium in liquid effluents and groundwater at the Hanford site. A thorough literature review was completed and updated information is provided on state-of-the-art technologies for control of tritium in wastewaters. This report was prepared to satisfy the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-026-07B (Ecology, EPA, and DOE 2007). Tritium separation and isolation technologies are evaluated periodically to determine their feasibility for implementation to control Hanford site liquid effluents and groundwaters to meet the Us. Code of Federal Regulations (CFR), Title 40 CFR 141.16, drinking water maximum contaminant level (MCL) for tritium of 20,000 pOll and/or DOE Order 5400.5 as low as reasonably achievable (ALARA) policy. Since the 2004 evaluation, there have been a number of developments related to tritium separation and control with potential application in mitigating tritium contaminated wastewater. These are primarily focused in the areas of: (1) tritium recycling at a commercial facility in Cardiff, UK using integrated tritium separation technologies (water distillation, palladium membrane reactor, liquid phase catalytic exchange, thermal diffusion), (2) development and demonstration of Combined Electrolysis Catalytic Exchange (CECE) using hydrogen/water exchange to separate tritium from water, (3) evaporation of tritium contaminated water for dispersion in the

  17. On Optimizing H. 264/AVC Rate Control by Improving R-D Model and Incorporating HVS Characteristics

    NASA Astrophysics Data System (ADS)

    Zhu, Zhongjie; Wang, Yuer; Bai, Yongqiang; Jiang, Gangyi

    2010-12-01

    The state-of-the-art JVT-G012 rate control algorithm of H.264 is improved from two aspects. First, the quadratic rate-distortion (R-D) model is modified based on both empirical observations and theoretical analysis. Second, based on the existing physiological and psychological research findings of human vision, the rate control algorithm is optimized by incorporating the main characteristics of the human visual system (HVS) such as contrast sensitivity, multichannel theory, and masking effect. Experiments are conducted, and experimental results show that the improved algorithm can simultaneously enhance the overall subjective visual quality and improve the rate control precision effectively.

  18. Controlling Mechanical Properties of Cell-Laden Hydrogels by Covalent Incorporation of Graphene Oxide

    PubMed Central

    Cha, Chaenyung; Shin, Su Ryon; Gao, Xiguang; Annabi, Nasim; Dokmeci, Mehmet R.; Tang, Xiaowu (Shirley); Khademhosseini, Ali

    2013-01-01

    Graphene-based materials are useful reinforcing agents to modify the mechanical properties of hydrogels. Here, we present an approach to covalently incorporate graphene oxide (GO) into hydrogels via radical copolymerization to enhance the dispersion and conjugation of GO sheets within the hydrogels. GO is chemically modified to present surface-grafted methacrylate groups (MeGO). In comparison to GO, higher concentrations of MeGO can be stably dispersed in a pre-gel solution containing methacrylated gelatin (GelMA) without aggregation or significant increase in viscosity. In addition, the resulting MeGO-GelMA hydrogels demonstrate a significant increase in fracture strength with increasing MeGO concentration. Interestingly, the rigidity of the hydrogels is not significantly affected by the covalently incorporated GO. Therefore, our approach can be used to enhance the structural integrity and resistance to fracture of the hydrogels without inadvertently affecting their rigidity, which is known to affect the behavior of encapsulated cells. The biocompatibility of MeGO-GelMA hydrogels is confirmed by measuring the viability and proliferation of the encapsulated fibroblasts. Overall, this study highlights the advantage of covalently incorporating GO into a hydrogel system, and improves the quality of cell-laden hydrogels. PMID:24127350

  19. Controlling mechanical properties of cell-laden hydrogels by covalent incorporation of graphene oxide.

    PubMed

    Cha, Chaenyung; Shin, Su Ryon; Gao, Xiguang; Annabi, Nasim; Dokmeci, Mehmet R; Tang, Xiaowu Shirley; Khademhosseini, Ali

    2014-02-12

    Graphene-based materials are useful reinforcing agents to modify the mechanical properties of hydrogels. Here, an approach is presented to covalently incorporate graphene oxide (GO) into hydrogels via radical copolymerization to enhance the dispersion and conjugation of GO sheets within the hydrogels. GO is chemically modified to present surface-grafted methacrylate groups (MeGO). In comparison to GO, higher concentrations of MeGO can be stably dispersed in a pre-gel solution containing methacrylated gelatin (GelMA) without aggregation or significant increase in viscosity. In addition, the resulting MeGO-GelMA hydrogels demonstrate a significant increase in fracture strength with increasing MeGO concentration. Interestingly, the rigidity of the hydrogels is not significantly affected by the covalently incorporated GO. Therefore, this approach can be used to enhance the structural integrity and resistance to fracture of the hydrogels without inadvertently affecting their rigidity, which is known to affect the behavior of encapsulated cells. The biocompatibility of MeGO-GelMA hydrogels is confirmed by measuring the viability and proliferation of the encapsulated fibroblasts. Overall, this study highlights the advantage of covalently incorporating GO into a hydrogel system, and improves the quality of cell-laden hydrogels. PMID:24127350

  20. A Theory and Model of Conflict Detection in Air Traffic Control: Incorporating Environmental Constraints

    ERIC Educational Resources Information Center

    Loft, Shayne; Bolland, Scott; Humphreys, Michael S.; Neal, Andrew

    2009-01-01

    A performance theory for conflict detection in air traffic control is presented that specifies how controllers adapt decisions to compensate for environmental constraints. This theory is then used as a framework for a model that can fit controller intervention decisions. The performance theory proposes that controllers apply safety margins to…

  1. Tritium recycling (processing) facility design

    SciTech Connect

    Metzler, J.; Le, T.

    1995-10-01

    The maintenance of a nuclear weapons capability requires the periodic replacement of tritium contained in each of the weapons in the nuclear weapons stockpile because the radioactive decay of tritium reduces its quantity by about 5.5 percent per year. The Tritium Recycling Plant (TRP) performs the activities necessary to recover, purify, and recycle tritium returned from the field. Tritium is contained in vessels called reservoirs. The TRP also has the capability to conduct environmental tests to ensure the reliability and quality of the reservoirs. Currently, the U.S. has no source of new tritium. The proposed new TRP is an option the U.S. Department of Energy (U.S. DOE) is considering that could be collocated with the new Tritium Supply Plant if it is built at Oak Ridge, Pantex, Nevada Test Site, or Idaho National Engineering Laboratory. It will comply with applicable environment, safety and health, (ES&H) regulations and orders. If the new Tritium Supply Plant is built at the Savannah River Site, the existing TRP would be upgraded, as necessary. 3 refs., 4 figs.

  2. Microbial Control of Insect Pests in Temperate Orchard Systems: Potential for Incorporation into IPM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to their selectivity and safety, microbial control agents appear to be ready made components of IPM systems that will not pose a threat to applicators or the environment and will allow other natural enemies to function. Control of several orchard pest insects using microbial control agents, incl...

  3. Tritium activities in the United States

    SciTech Connect

    Anderson, J.L.; LaMarche, P.

    1995-07-01

    There have been many significant changes in the status of tritium activities in the US since the 4th Tritium Conference in October, 1991. The replacement Tritium Facility (RTF) at Savannah River Site and the Weapons Engineering Tritium Facility (WETF) at the Los Alamos National Laboratory are now operational with tritium. The Tokamak Fusion Test Reactor (TFTR) has initiated a highly successful experimental campaign studying DT plasmas, and has produced more than 10 Megawatts (MW) of fusion power in a D-T plasma. Sandia National Laboratory has ceased tritium operations at the Tritium Research Laboratory (TRL) and many of the activities previously performed there have been transferred to Los Alamos and Savannah River. The tritium laboratory at Lawrence Livermore National Laboratory has reduced the tritium inventory to <5 grams. The Tritium Systems Test Assembly (TSTA) at Los Alamos continues to be at the forefront of tritium technology and safety development for the fusion energy program.

  4. Aqueous effluent tritium monitor development

    SciTech Connect

    Hofstetter, K.J.; Wilson, H.T. )

    1992-03-01

    This paper discusses the development of a low-level tritium monitor for aqueous effluent which has explored several potential techniques. In one method, a water-immiscible liquid scintillation cocktail was ultrasonically mixed with an aqueous sample to form a water-cocktail dispersion for analysis by liquid scintillation spectrometry. The organic cocktail could then be reused after phase separation. Of the cocktails tested, a toluene-based cocktail showed the highest tritium detection efficiency (7%). In another technique, the sensitivity of various solid scintillators (plastic beads, crushed inorganic salts, etc.) to tritium in aqueous solutions was measured. The most efficient solid scintillator had a 2% tritium detection efficiency. In a third method, a large surface area detector was constructed from thin fibers of plastic scintillator. This detector had a 0.1% intrinsic tritium detection efficiency.

  5. Tritium Production from Palladium Alloys

    SciTech Connect

    Claytor, T.N.; Schwab, M.J.; Thoma, D.J.; Teter, D.F.; Tuggle, D.G.

    1998-04-19

    A number of palladium alloys have been loaded with deuterium or hydrogen under low energy bombardment in a system that allows the continuous measurement of tritium. Long run times (up to 200 h) result in an integration of the tritium and this, coupled with the high intrinsic sensitivity of the system ({approximately}0.1 nCi/l), enables the significance of the tritium measurement to be many sigma (>10). We will show the difference in tritium generation rates between batches of palladium alloys (Rh, Co, Cu, Cr, Ni, Be, B, Li, Hf, Hg and Fe) of various concentrations to illustrate that tritium generation rate is dependent on alloy type as well as within a specific alloy, dependent on concentration.

  6. Removal of tritium from TFTR

    SciTech Connect

    Mueller, D.; Blanchard, W.; Collins, J.; Hosea, J.; Kamperschroer, J.; Nagy, A.; Owens, D.K.; Raftopoulos, S.; Skinner, C.H.

    1996-12-31

    Operation of the Tokamak Fusion Test Reactor (TFTR) with a mixture of deuterium and tritium fueling has permitted the opportunity to measure the retention of tritium in the graphite limiter and other internal hardware. The use of discharge cleaning techniques and venting to remove the tritium was investigated. The tritium was introduced into TFTR by neutral beam injection and by gas puffing. The graphite limiter is subject to erosion and codeposition. While short term retention was high, the retention averaged over the 1993-1995 D-T campaign was 52% {+-} 15%. The tritium removal techniques resulted in lowering the in-vessel inventory from 16.4 kCi at the end of 1995 operation to 7.2 kCi at the start of the 1996 experimental program. 14 refs., 3 figs., 1 tab.

  7. Microstructural control of calcite via incorporation of intracrystalline organic molecules in shells

    NASA Astrophysics Data System (ADS)

    Okumura, Taiga; Suzuki, Michio; Nagasawa, Hiromichi; Kogure, Toshihiro

    2013-10-01

    It is widely accepted that organic substances regulate or influence the structure of biominerals, but its direct evidences are not plenty. Here we show that the crystallographic microstructures in biotic calcites arise from incorporated intracrystalline organic molecules (IOMs), through a comparison between biotic calcites in shells and synthetic ones with the IOMs extracted from the shells. Although the prismatic layers of a pearl oyster (Pinctada fucata) and a pen shell (Atrina pectinata) morphologically resemble each other, the crystallographic features of constituent calcites are considerably different; in Pinctada, the IOMs are distributed inhomogeneously to form small-angle grain boundaries and associated crystal defects, whereas in Atrina, the IOMs are distributed almost homogeneously and defects are rare in the calcite crystals. We conducted in vitro calcite syntheses in the presence of the IOMs in EDTA-soluble extracts from the prisms. The IOMs in the extracts from Pinctada and Atrina were incorporated into synthetic calcites in a different manner, exhibiting defect-rich/free features as observed in the natural shells. With regard to amino acid compositions of the IOMs, the extract from Atrina has a higher proportion of acidic amino acids than that from Pinctada, implying that acidic proteins do not correlate directly to their affinity for calcium carbonate crystals.

  8. Sodium-Doped Molybdenum Targets for Controllable Sodium Incorporation in CIGS Solar Cells: Preprint

    SciTech Connect

    Mansfield, L. M.; Repins, I. L.; Glynn, S.; Carducci, M. D.; Honecker, D. M.; Pankow, J.; Young, M.; DeHart, C.; Sundaramoorthy, R.; Beall, C. L.; To, B.

    2011-07-01

    The efficiency of Cu(In,Ga)Se2 (CIGS) solar cells is enhanced when Na is incorporated in the CIGS absorber layer. This work examines Na incorporation in CIGS utilizing Na-doped Mo sputtered from targets made with sodium molybdate-doped (MONA) powder. Mo:Na films with varying thicknesses were sputtered onto Mo-coated borosilicate glass (BSG) or stainless steel substrates for CIGS solar cells. By use of this technique, the Na content of CIGS can be varied from near-zero to higher than that obtained from a soda-lime glass (SLG) substrate. Targets and deposition conditions are described. The doped Mo films are analyzed, and the resulting devices are compared to devices fabricated on Mo-coated SLG as well as Mo-coated BSG with NaF. Completed devices utilizing MONA exceeded 15.7% efficiency without anti-reflective coating, which was consistently higher than devices prepared with the NaF precursor. Strategies for minimizing adhesion difficulties are presented.

  9. Plasma Fueling, Pumping, and Tritium Handling Considerations for FIRE

    SciTech Connect

    Fisher, P.W.; Foster, C.A.; Gentile, C.A.; Gouge, M.J.; Nelson, B.E.

    1999-11-13

    Tritium pellet injection will be utilized on the Fusion Ignition Research Experiment (FIRE) for efficient tritium fueling and to optimize the density profile for high fusion power. Conventional pneumatic pellet injectors, coupled with a guidetube system to launch pellets into the plasma from the high, field side, low field side, and vertically, will be provided for fueling along with gas puffing for plasma edge density control. About 0.1 g of tritium must be injected during each 10-s pulse. The tritium and deuterium will be exhausted into the divertor. The double null divertor will have 16 cryogenic pumps located near the divertor chamber to provide the required high pumping speed of 200 torr-L/s.

  10. Tritium-field betacells

    SciTech Connect

    Walko, R.J.; Lincoln, R.C.; Baca, W.E. ); Goods, S.H. ); Negley, G.H. )

    1991-01-01

    Betavoltaic power sources operate by converting the nuclear decay energy of beta-emitting radioisotopes into electricity. Since they are not chemically driven, they could operate at temperatures which would either be to hot or too cold for typical chemical batteries. Further, for long lived isotopes, they offer the possibility of multi-decade active lifetimes. Two approaches are being investigated: direct and indirect conversion. Direct conversion cells consist of semiconductor diodes similar to photovoltaic cells. Beta particle directly bombard these cells, generating electron-hole pairs in the semiconductor which are converted to useful power. Many using low power flux beta emitters, wide bandgap semiconductors are required to achieve useful conversion efficiencies. The combination of tritium, as the beta emitter, and gallium phosphide (GaP), as the semiconductor converter, was evaluated. Indirect conversion betacells first convert the beta energy to light with a phosphor, and then to electricity with photovoltaic cells. An indirect conversion power source using a tritium radioluminescent (RL) light is being investigated. Our analysis indicates that this approach has the potential for significant volume and cost savings over the direct conversion method. 7 refs., 11 figs.

  11. Control technology for integrated circuit fabrication at Micro-Circuit Engineering, Incorporated, West Palm Beach, Florida

    NASA Astrophysics Data System (ADS)

    Mihlan, G. I.; Mitchell, R. I.; Smith, R. K.

    1984-07-01

    A survey to assess control technology for integrated circuit fabrication was conducted. Engineering controls included local and general exhaust ventilation, shielding, and personal protective equipment. Devices or work stations that contained toxic materials that were potentially dangerous were controlled by local exhaust ventilation. Less hazardous areas were controlled by general exhaust ventilation. Process isolation was used in the plasma etching, low pressure chemical vapor deposition, and metallization operations. Shielding was used in ion implantation units to control X-ray emissions, in contact mask alignes to limit ultraviolet (UV) emissions, and in plasma etching units to control radiofrequency and UV emissions. Most operations were automated. Use of personal protective equipment varied by job function.

  12. Determination of tritiated formaldehyde in effluents from tritium facilities

    SciTech Connect

    Belot, Y.; Camus, H.; Marini, T. )

    1992-03-01

    Recent observations suggested that formal-dehyde can be incorporated in vegetation at a very high rate. In this paper, the authors develop a methodology for determining tritiated formaldehyde (CHTO) in gaseous effluent containing HTO and HT as dominant species. CHTO being very soluble in water is collected in a solution of carrier formaldehyde. This carrier is necessary for precipitating for formaldehyde derivative of dimedone and collecting it by filtration. The precipitate, which contains the formaldehyde hydrogens, is freed from exchangeable tritium, dried in oven, and combusted to water for tritium determination. CHTO can thus be separated from HTO with a high efficiency, leading to the possibility of determining accurately 1 Bq of CHTO in as much as 5 {times} 10{sup 4} Bq of HTO. The methodology has been applied in preliminary experiments to determine the ratio of CHTO to HTO in effluent from a tritium-handling facility and effluent released from solid miscellaneous wastes.

  13. 40 CFR 82.116 - Compliance by manufacturers or importers incorporating products manufactured with controlled...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reasonable belief. The importer of a product purchased or obtained from a foreign manufacturer or supplier, which product may have been manufactured with a controlled substance, may rely on the information that... subpart, any products manufactured with a controlled substance that are supplied to the importer, or...

  14. 40 CFR 82.116 - Compliance by manufacturers or importers incorporating products manufactured with controlled...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reasonable belief. The importer of a product purchased or obtained from a foreign manufacturer or supplier, which product may have been manufactured with a controlled substance, may rely on the information that... subpart, any products manufactured with a controlled substance that are supplied to the importer, or...

  15. 40 CFR 82.116 - Compliance by manufacturers or importers incorporating products manufactured with controlled...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reasonable belief. The importer of a product purchased or obtained from a foreign manufacturer or supplier, which product may have been manufactured with a controlled substance, may rely on the information that... subpart, any products manufactured with a controlled substance that are supplied to the importer, or...

  16. 40 CFR 82.116 - Compliance by manufacturers or importers incorporating products manufactured with controlled...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reasonable belief. The importer of a product purchased or obtained from a foreign manufacturer or supplier, which product may have been manufactured with a controlled substance, may rely on the information that... subpart, any products manufactured with a controlled substance that are supplied to the importer, or...

  17. 40 CFR 82.116 - Compliance by manufacturers or importers incorporating products manufactured with controlled...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reasonable belief. The importer of a product purchased or obtained from a foreign manufacturer or supplier, which product may have been manufactured with a controlled substance, may rely on the information that... subpart, any products manufactured with a controlled substance that are supplied to the importer, or...

  18. Incorporating a disturbance observer with direct velocity feedback for control of human-induced vibrations

    NASA Astrophysics Data System (ADS)

    Nyawako, Donald; Reynolds, Paul; Hudson, Emma

    2016-04-01

    Feedback control strategies are desirable for disturbance rejection of human-induced vibrations in civil engineering structures as human walking forces cannot easily be measured. In relation to human-induced vibration control studies, most past researches have focused on floors and footbridges and the widely used linear controller implemented in the trials has been the direct velocity feedback (DVF) scheme. With appropriate compensation to enhance its robustness, it has been shown to be effective at damping out the problematic modes of vibration of the structures in which the active vibration control systems have been implemented. The work presented here introduces a disturbance observer (DOB) that is used with an outer-loop DVF controller. Results of analytical studies presented in this work based on the dynamic properties of a walkway bridge structure demonstrate the potential of this approach for enhancing the vibration mitigation performance offered by a purely DVF controller. For example, estimates of controlled frequency response functions indicate improved attenuation of vibration around the dominant frequency of the walkway bridge structure as well as at higher resonant frequencies. Controlled responses from three synthesized walking excitation forces on a walkway bridge structure model show that the inclusion of the disturbance observer with an outer loop DVF has potential to improve on the vibration mitigation performance by about 3.5% at resonance and 6-10% off-resonance. These are realised with hard constraints being imposed on the low frequency actuator displacements.

  19. The Plasmodium falciparum Translationally Controlled Tumor Protein (TCTP) Is Incorporated More Efficiently into B Cells than Its Human Homologue

    PubMed Central

    Calderón-Pérez, Berenice; Xoconostle-Cázares, Beatriz; Lira-Carmona, Rosalía; Hernández-Rivas, Rosaura; Ortega-López, Jaime; Ruiz-Medrano, Roberto

    2014-01-01

    Plasmodium falciparum secretes a homologue of the translationally controlled tumor protein (TCTP) into serum of infected individuals, although its role in pathogenesis or virulence is unknown. To determine the effect of P. falciparum TCTP on B cells as compared to human TCTP, fluorescently labeled proteins were incubated on primary cultures of mouse splenic B cells and analyzed by flow cytometry and confocal microscopy. Our results indicate that both recombinant proteins are incorporated into B cells, but differ significantly in their rate and percentage of incorporation, being significantly higher for P. falciparum TCTP. Furthermore, P. falciparum TCTP showed a lower B cell proliferative effect than human TCTP, suggesting a mechanism through which the former could interfere in the host's immune response. PMID:24465583

  20. Using the Tritium Plasma Experiment to evaluate ITER PFC safety. [Plasma-Facing Components

    SciTech Connect

    Longhurst, G.R.; Anderl, R.A. ); Bartlit, J.R. ); Causey, R.A. ); Haines, J.R. )

    1993-01-01

    The Tritium Plasma Experiment was assembled at Sandia National Laboratories, Livermore to investigate interactions between dense plasmas at low energies and plasma-facing component materials. This apparatus has the unique capability of replicating plasma conditions in a tokamak divertor with particle flux densities of 2 [times] 10[sup 19] ions/cm[sup 2] [center dot] s and a plasma temperature of about 15 eV using a plasma that includes tritium. With the closure of the Tritium Research Laboratory at Livermore, the experiment was moved to the Tritium Systems Test Assembly facility at Los Alamos National Laboratory. An experimental program has been initiated there using the Tritium Plasma Experiment to examine safety issues related to tritium in plasma-facing components, particularly the ITER divertor. Those issues include tritium retention and release characteristics, tritium permeation rates and transient times to coolant streams, surface modification and erosion by the plasma, the effects of thermal loads and cycling, and particulate production. A considerable lack of data exists in these areas for many of the materials, especially beryllium, being considered for use in ITER. Not only will basic material behavior with respect to safety issues in the divertor environment be examined, but innovative techniques for optimizing performance with respect to tritium safety by material modification and process control will be investigated. Supplementary experiments will be carried out at the Idaho National Engineering Laboratory and Sandia National Laboratory to expand and clarify results obtained on the Tritium Plasma Experiment.

  1. Behaviour of tritium in the vacuum vessel of JT-60U

    SciTech Connect

    Kobayashi, K.; Miya, N.; Ikeda, Y.; Torikai, Y.; Saito, M.; Alimov, V.

    2015-03-15

    The disassembly of the JT-60U torus started in 2010 after 18 years of deuterium plasma operations. The vessel is made of Inconel 625. Therefore, it was very important to study the hydrogen isotope (particularly tritium) behavior in Inconel 625 from the viewpoint of the clearance procedure. Inconel 625 specimen was exposed to the D{sub 2} (92.8 %) - T{sub 2} (7.2 %) gas mixture at 573 K for 5 hours. The tritium release from the specimen at 298 K was controlled for about 1 year. After that a part of tritium remaining in the specimen was released by heating up to 1073 K. Other part of tritium trapped in the specimen was measured by chemical etching method. Most of the chemical form of the released tritium was HTO. The contaminated specimen by tritium was released continuously the diffusible tritium under the ambient condition. In the tritium release experiment, the amount of desorbed tritium was about 99% during 1 year. It was considered that the tritium in Inconel 625 was released easily.

  2. Tritium permeation characterization of Al2O3/FeAl coatings as tritium permeation barriers on 321 type stainless steel containers

    NASA Astrophysics Data System (ADS)

    Yang, Feilong; Xiang, Xin; Lu, Guangda; Zhang, Guikai; Tang, Tao; Shi, Yan; Wang, Xiaolin

    2016-09-01

    Accurate tritium transport properties of prospective tritium permeation barriers (TPBs) are essential to tritium systems in fusion reactors. By passing a temperature and rate-controlled sweeping gas over specimen surfaces to carry the permeated tritium to an ion chamber, the gas-driven permeation of tritium has been performed on 321 type stainless steel containers with Al2O3/FeAl barriers, to determine the T-permeation resistant performance and mechanism of the barrier. The tritium permeability of the Al2O3/FeAl coated container was reduced by 3 orders of magnitude at 500-700 °C by contrast with that of the bare one, which meets the requirement of the tritium permeation reduction factor (PRF) of TPBs for tritium operating components in the CN-HCCB TBM. The Al2O3/FeAl barrier resists the tritium permeation by the diffusion in the bulk substrate at a limited number of defect sites with an effective area and thickness, suggesting that the TPB quality is a very important factor for efficient T-permeation resistance.

  3. A decade of tritium technology development and operation at the tritium laboratory Karlsruhe

    SciTech Connect

    Doerr, L.; Besserer, U.; Bekris, N.; Bornschein, B.; Caldwell-Nichols, C.; Demange, D.; Cristescu, I.; Cristescu, I. R.; Glugla, M.; Hellriegel, G.; Schaefer, P.; Weite, S.; Wendel, J.

    2008-07-15

    The Tritium Laboratory Karlsruhe (TLK) has been designed to handle relevant amounts of tritium for the development of tritium technology for fusion reactors. This paper describes the tritium technology development and experience gained during the upgrade of facilities, interventions, replacement of failed components and operation of the TLK since its commissioning with tritium in 1994. (authors)

  4. Interlaboratory Comparison of Organically Bound Tritium Measurements in Environmental Samples

    SciTech Connect

    Workman, W.J.G.; Kim, S.B.; Kotzer, T.G.

    2005-07-15

    The measurement of organically bound tritium in environmental samples is essential for assessing the impact of tritium releases in terms of doses to the general public and a growing number of laboratories are now required to make them. Interlaboratory comparisons provide one way for laboratories to practice and check their analytical methods and procedures. At AECL's Chalk River Laboratories, two organic matrices with tritium concentrations less than 1.5 kBq/g were developed and distributed to seven laboratories in Canada, Europe and Russia for measurement. Some participants experienced difficulties in analysing the samples, especially with the lower concentrations, where results varied by more than an order of magnitude. Laboratories incorporating procedures such as rinsing to remove tritium from exchangeable sites, using standardized combustion methods and purifying the combustion water obtained more reliable, consistent results. The preparation of the standard reference material must be carefully executed in order to produce a homogeneous sample of uniform size. The tritium measurement community would benefit if standard reference materials in the environmental concentration range were available.

  5. Study of Traces of Tritium at the World Trade Center

    SciTech Connect

    Semkow, T M; Hafner, S R; Parekh, P P; Wozniak, G J; Haines, D K; Husain, L; Rabun, R L; Williams, P G

    2002-10-01

    Traces of tritiated water (HTO) were detected at the World Trade Center (WTC) ground zero after the 9/11/01 terrorist attack. A water sample from the WTC sewer, collected on 9/13/01, contained 0.164 {+-} 0.074 (2 {sigma}) nCi/L of HTO. A split water sample, collected on 9/21/01 from the basement of WTC Building 6, contained 3.53 {+-} 0.17 and 2.83 {+-} 0.15 nCi/L, respectively. These results are well below the levels of concern to human exposure. Several water and vegetation samples were analyzed from sites outside ground zero, located in Manhattan, Brooklyn, Queens, and the Kensico and Croton Reservoirs. No HTO above the background was found in those samples. Tritium radioluminescent (RL) devices were investigated as possible sources of the traces of tritium at ground zero. It was determined that the two Boeing 767 aircraft that hit the Twin Towers contained a combined 34 Ci of tritium at the time of impact in their emergency exit signs. There is also evidence that many weapons from law enforcement were present and destroyed at WTC. Such weaponry contains by design tritium sights. The fate and removal of tritium from ground zero were investigated, taking into consideration tritium chemistry and water flow originating from the fire fighting, rain, as well as leaks from the Hudson River and broken mains. A box model was developed to describe the above scenario. The model is consistent with instantaneous oxidation of the airplane tritium in the jet-fuel explosion, deposition of a small fraction of HTO at ground zero, and water-flow controlled removal of HTO from the debris. The model also suggests that tritium from the weapons would be released and oxidized to HTO at a much slower rate in the lingering fires at ground zero.

  6. Tritium Elimination System Using Tritium Gas Oxidizing Bacteria

    SciTech Connect

    Ichimasa, Michiko; Awagakubo, Sayuri; Takahashi, Miho; Tauchi, Hiroshi; Hayashi, Takumi; Kobayashi, Kazuhiro; Nishi, Masataka; Ichimasa, Yusuke

    2005-07-15

    In order to eliminate atmospheric tritium gas (HT) released from tritium handling apparatus, we proposed to use the HT oxidizing ability (hydrogenase enzyme) of bacterial strains isolated from surface soils instead of a high temperature precious metal catalyst. Among the isolated strains with high HT oxidation activity, several strains were selected to develop a tritium elimination (detritiation) system. Bioreactors were made of bacterial cells grown on agar medium on a cartridge filter and stored in a refrigerator until use. The detritiation ability of these bioreactors at room temperature was investigated during the intentional HT release experiments carried out in the Cassion Assembly for Tritium Safety Study (CATS) in TPL/JAERI. When HT contaminated air from the CATS was introduced into the biological detritiation system, in which three bioreactors were connected in series, 86% of HT in air was removed as tritiated water in these bioreactors at a flow rate of 100 cm{sup 3}/min for 2 hours.

  7. Effect of Control-released Basic Fibroblast Growth Factor Incorporated in β-Tricalcium Phosphate for Murine Cranial Model

    PubMed Central

    Shimizu, Azusa; Tajima, Satoshi; Tobita, Morikuni; Tanaka, Rica; Tabata, Yasuhiko

    2014-01-01

    Background: β-Tricalcium phosphate (β-TCP) is used clinically as a bone substitute, but complete osteoinduction is slow. Basic fibroblast growth factor (bFGF) is important in bone regeneration, but the biological effects are very limited because of the short half-life of the free form. Incorporation in gelatin allows slow release of growth factors during degradation. The present study evaluated whether control-released bFGF incorporated in β-TCP can promote bone regeneration in a murine cranial defect model. Methods: Bilateral cranial defects of 4 mm in diameter were made in 10-week-old male Sprague-Dawley rats treated as follows: group 1, 20 μl saline as control; group 2, β-TCP disk in 20 μl saline; group 3, β-TCP disk in 50 μg bFGF solution; and group 4, β-TCP disk in 50 μg bFGF-containing gelatin hydrogel (n = 6 each). Histological and imaging analyses were performed at 1, 2, and 4 weeks after surgery. Results: The computed tomography value was lower in groups 3 and 4, whereas the rate of osteogenesis was higher histologically in group 4 than in the other groups. The appearance of tartrate-resistant acid phosphate–positive cells and osteocalcin-positive cells and disappearance of osteopontin-positive cells occurred earlier in group 4 than in the other groups. Conclusions: These findings suggest that control-released bFGF incorporated in β-TCP can accelerate bone regeneration in the murine cranial defect model and may be promising for the clinical treatment of cranial defects. PMID:25289319

  8. Differential atmospheric tritium sampler

    DOEpatents

    Griesbach, O.A.; Stencel, J.R.

    1987-10-02

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The moisture then passes through a combustion chamber where hydrogen gas in the form of H/sub 2/ or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  9. Differential atmospheric tritium sampler

    DOEpatents

    Griesbach, Otto A.; Stencel, Joseph R.

    1990-01-01

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The mixture then passes through a combustion chamber where hydrogen gas in the form of H.sub.2 or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  10. SOLERAS - Solar Controlled Environment Agriculture Project. Final report, Volume 6. Science Applications, Incorporated system analysis

    SciTech Connect

    Not Available

    1985-01-01

    This report summarizes the results of the systems analysis task for the conceptual design of a commercial size, solar powered, controlled environment agriculture system. The baseline greenhouse system consists of a 5-hectare growing facility utilizing an innovative fluid roof filter concept to provide temperature and humidity control. Fresh water for the system is produced by means of a reverse osmosis desalination unit and energy is provided by means of a solar photovoltaic array in conjunction with storage batteries and a power conditioning unit. The greenhouse environment is controlled via circulation of brackish groundwater in a closed system, which permits water recovery during dehumidification as well as CO/sub 2/ enrichment for increased crop productivity.

  11. Physical Activity Capture Technology With Potential for Incorporation Into Closed-Loop Control for Type 1 Diabetes.

    PubMed

    Dadlani, Vikash; Levine, James A; McCrady-Spitzer, Shelly K; Dassau, Eyal; Kudva, Yogish C

    2015-11-01

    Physical activity is an important determinant of glucose variability in type 1 diabetes (T1D). It has been incorporated as a nonglucose input into closed-loop control (CLC) protocols for T1D during the last 4 years mainly by 3 research groups in single center based controlled clinical trials involving a maximum of 18 subjects in any 1 study. Although physical activity data capture may have clinical benefit in patients with T1D by impacting cardiovascular fitness and optimal body weight achievement and maintenance, limited number of such studies have been conducted to date. Clinical trial registries provide information about a single small sample size 2 center prospective study incorporating physical activity data input to modulate closed-loop control in T1D that are seeking to build on prior studies. We expect an increase in such studies especially since the NIH has expanded support of this type of research with additional grants starting in the second half of 2015. Studies (1) involving patients with other disorders that have lasted 12 weeks or longer and tracked physical activity and (2) including both aerobic and resistance activity may offer insights about the user experience and device optimization even as single input CLC heads into real-world clinical trials over the next few years and nonglucose input is introduced as the next advance. PMID:26481641

  12. Preparation and properties of calcium phosphate cements incorporated gelatin microspheres and calcium sulfate dihydrate as controlled local drug delivery system.

    PubMed

    Cai, Shu; Zhai, Yujia; Xu, Guohua; Lu, Shanshan; Zhou, Wei; Ye, Xiaojian

    2011-11-01

    To develop high macroporous and degradable bone cements which can be used as the substitute of bone repairing and drug carriers, cross-linked gelatin microspheres (GMs) and calcium sulfate dihydrate (CSD) powder were incorporated into calcium phosphate bone cement (CPC) to induce macropores, adjust drug release and control setting time of α-TCP-liquid mixtures after degradation of GMs and dissolution of CSD. In this study, CSD was introduced into CPC/10GMs composites to offset the prolonged setting time caused by the incorporation of GMs, and gentamicin sulphate (GS) was chosen as the model drug entrapped within the GMs. The effects of CSD amount on the cement properties, drug release ability and final macroporosity after GMs degradation were studied in comparison with CPC/GMs cements. The resulting cements presented reduced setting time and increased compressive strength as the content of CSD below 5 wt%. Sustained release of GS was obtained on at least 21 days, and release rates were found to be chiefly controlled by the GMs degradation rate. After 4 weeks of degradation study, the resulting composite cements appeared macroporous, degradable and suitable compressive strength, suggesting that they have potential as controlled local drug delivery system and for cancellous bone applications. PMID:21894539

  13. Composition containing aerogel substrate loaded with tritium

    DOEpatents

    Ashley, Carol S.; Brinker, C. Jeffrey; Ellefson, Robert E.; Gill, John T.; Reed, Scott; Walko, Robert J.

    1992-01-01

    The invention provides a process for loading an aerogel substrate with tritium and the resultant compositions. According to the process, an aerogel substrate is hydrolyzed so that surface OH groups are formed. The hydrolyzed aerogel is then subjected to tritium exchange employing, for example, a tritium-containing gas, whereby tritium atoms replace H atoms of surface OH groups. OH and/or CH groups of residual alcohol present in the aerogel may also undergo tritium exchange.

  14. Tritium Facilities Modernization and Consolidation Project Process Waste Assessment (Project S-7726)

    SciTech Connect

    Hsu, R.H.; Oji, L.N.

    1997-11-14

    Under the Tritium Facility Modernization {ampersand} Consolidation (TFM{ampersand}C) Project (S-7726) at the Savannah River Site (SS), all tritium processing operations in Building 232-H, with the exception of extraction and obsolete/abandoned systems, will be reestablished in Building 233-H. These operations include hydrogen isotopic separation, loading and unloading of tritium shipping and storage containers, tritium recovery from zeolite beds, and stripping of nitrogen flush gas to remove tritium prior to stack discharge. The scope of the TFM{ampersand}C Project also provides for a new replacement R&D tritium test manifold in 233-H, upgrading of the 233- H Purge Stripper and 233-H/234-H building HVAC, a new 234-H motor control center equipment building and relocating 232-H Materials Test Facility metallurgical laboratories (met labs), flow tester and life storage program environment chambers to 234-H.

  15. Incorporating Artificial Neural Networks in the dynamic thermal-hydraulic model of a controlled cryogenic circuit

    NASA Astrophysics Data System (ADS)

    Carli, S.; Bonifetto, R.; Savoldi, L.; Zanino, R.

    2015-09-01

    A model based on Artificial Neural Networks (ANNs) is developed for the heated line portion of a cryogenic circuit, where supercritical helium (SHe) flows and that also includes a cold circulator, valves, pipes/cryolines and heat exchangers between the main loop and a saturated liquid helium (LHe) bath. The heated line mimics the heat load coming from the superconducting magnets to their cryogenic cooling circuits during the operation of a tokamak fusion reactor. An ANN is trained, using the output from simulations of the circuit performed with the 4C thermal-hydraulic (TH) code, to reproduce the dynamic behavior of the heated line, including for the first time also scenarios where different types of controls act on the circuit. The ANN is then implemented in the 4C circuit model as a new component, which substitutes the original 4C heated line model. For different operational scenarios and control strategies, a good agreement is shown between the simplified ANN model results and the original 4C results, as well as with experimental data from the HELIOS facility confirming the suitability of this new approach which, extended to an entire magnet systems, can lead to real-time control of the cooling loops and fast assessment of control strategies for heat load smoothing to the cryoplant.

  16. siRNA knockdown validation 101: Incorporating negative controls in antibody research

    PubMed Central

    Olds, Will; Li, Jason

    2016-01-01

    More antibody validation protocols would identify non-specific reagents – a major source of irreproducible research – with the inclusion of negative controls. This article presents an overview of one such method: siRNA knockdown. The authors outline a general protocol, the knockdown mechanism, and tips for evaluating knockdown experiments. PMID:26998240

  17. Marginal abatement cost curve for NOx incorporating controls, renewable electricity, energy efficiency and fuel switching

    EPA Science Inventory

    A marginal abatement cost curve (MACC) traces out the relationship between the quantity of pollution abated and the marginal cost of abating each additional unit. In the context of air quality management, MACCs typically are developed by sorting end-of-pipe controls by their resp...

  18. Incorporating Daily Flood Control Objectives Into a Monthly Stochastic Dynamic Programing Model for a Hydroelectric Complex

    NASA Astrophysics Data System (ADS)

    Druce, Donald J.

    1990-01-01

    A monthly stochastic dynamic programing model was recently developed and implemented at British Columbia (B.C.) Hydro to provide decision support for short-term energy exports and, if necessary, for flood control on the Peace River in northern British Columbia. The model establishes the marginal cost of supplying energy from the B.C. Hydro system, as well as a monthly operating policy for the G.M. Shrum and Peace Canyon hydroelectric plants and the Williston Lake storage reservoir. A simulation model capable of following the operating policy then determines the probability of refilling Williston Lake and possible spill rates and volumes. Reservoir inflows are input to both models in daily and monthly formats. The results indicate that flood control can be accommodated without sacrificing significant export revenue.

  19. Study for incorporating time-synchronized approach control into the CH-47/VALT digital navigation system

    NASA Technical Reports Server (NTRS)

    Mcconnell, W. J., Jr.

    1979-01-01

    Techniques for obtaining time synchronized (4D) approach control in the VALT research helicopter is described. Various 4D concepts and their compatibility with the existing VALT digital computer navigation and guidance system hardware and software are examined. Modifications to various techniques were investigated in order to take advantage of the unique operating characteristics of the helicopter in the terminal area. A 4D system is proposed, combining the direct to maneuver with the existing VALT curved path generation capability.

  20. Incorporating real time velocity map image reconstruction into closed-loop coherent control

    NASA Astrophysics Data System (ADS)

    Rallis, C. E.; Burwitz, T. G.; Andrews, P. R.; Zohrabi, M.; Averin, R.; De, S.; Bergues, B.; Jochim, Bethany; Voznyuk, A. V.; Gregerson, Neal; Gaire, B.; Znakovskaya, I.; McKenna, J.; Carnes, K. D.; Kling, M. F.; Ben-Itzhak, I.; Wells, E.

    2014-11-01

    We report techniques developed to utilize three-dimensional momentum information as feedback in adaptive femtosecond control of molecular dynamics. Velocity map imaging is used to obtain the three-dimensional momentum map of the dissociating ions following interaction with a shaped intense ultrafast laser pulse. In order to recover robust feedback information, however, the two-dimensional momentum projection from the detector must be inverted to reconstruct the full three-dimensional momentum of the photofragments. These methods are typically slow or require manual inputs and are therefore accomplished offline after the images have been obtained. Using an algorithm based upon an "onion-peeling" (also known as "back projection") method, we are able to invert 1040 × 1054 pixel images in under 1 s. This rapid inversion allows the full photofragment momentum to be used as feedback in a closed-loop adaptive control scheme, in which a genetic algorithm tailors an ultrafast laser pulse to optimize a specific outcome. Examples of three-dimensional velocity map image based control applied to strong-field dissociation of CO and O2 are presented.

  1. Incorporation of nisin in natural casing for the control of spoilage microorganisms in vacuum packaged sausage

    PubMed Central

    de Barros, Joyce Regina; Kunigk, Leo; Jurkiewicz, Cynthia Hyppolito

    2010-01-01

    This study aimed to evaluate the effectiveness of natural casing treatment with nisin and phosphoric acid on control of spoilage microorganisms in vacuum packaged sausages. Ovine casings were dipped in the following baths: 1) 0.1% food grade phosphoric acid; 2) 5.0 mg/L nisin; 3) 0.1% phosphoric acid and 5.0 mg/L nisin; and 4) sterile water (control). The sausages were produced in a pilot plant, stuffed into the pretreated natural casings, vacuum packaged and stored at 4 and 10 °C for 56 days. The experiments were performed according to a full factorial design 23, totalizing 8 treatments that were repeated in 3 blocks. Aerobic plate counts and lactic acid bacteria analysis were conducted at 1, 14, 28, 42 and 56 days of storage. Treatment of casings with phosphoric acid 0.1% alone did not inhibit the growth of lactic acid bacteria and reduced the aerobic plate count by 1 log. The activity of nisin against lactic acid bacteria was enhanced by the addition of phosphoric acid, demonstrating a synergistic effect. Furthermore nisin activity was more evident at lower storage temperature (4 ºC). Therefore treatment of the natural casings with nisin and phosphoric acid, combined with low storage temperature, are obstacles that present a potential for controlling the growth of lactic acid bacteria in vacuum packaged sausage. PMID:24031580

  2. Modeling tritium behavior in Li{sub 2}ZrO{sub 3}.

    SciTech Connect

    Billone, M. C.

    1998-01-13

    Lithium metazirconate (Li{sub 2}ZrO{sub 3}) is a promising tritium breeder material for fusion reactors because of its excellent tritium release characteristics. In particular, for water-cooled breeding blankets (e.g., ITER), Li{sub 2}ZrO{sub 3} is appealing from a design perspective because of its good tritium release at low operating temperatures. The steady-state and transient tritium release/retention database for Li{sub 2}ZrO{sub 3} is reviewed, along with conventional diffusion and first-order surface resorption models which have been used to match the database. A first-order surface resorption model is recommended in the current work both for best-estimate and conservative (i.e., inventory upper-bound) predictions. Model parameters we determined and validated for both types of predictions, although emphasis is placed on conservative design predictions. The effects on tritium retention of ceramic microstructure, protium partial pressure in the purge gas and purge gas flow rate are discussed, along with other mechanisms for tritium retention which may not be dominant in the experiments, but may be important in blanket design analyses. The proposed tritium retention/release model can be incorporated into a transient thermal performance code to enable whole-blanket predictions of tritium retention/release during cyclic reactor operation. Parameters for the ITER driver breeding blanket are used to generate a numerical set of model predictions for steady-state operation.

  3. Real-time tritium imaging

    SciTech Connect

    Malinowski, M.E.

    1981-09-15

    A real-time image of a tritium-containing titanium film has been made by detecting the secondary electrons produced by tritium ..beta.. decay with a simple two-element electrostatic lens and microchannel plate image intensifier. The obtained image indicates that a resolution of better than 100 ..mu..m is currently obtainable and suggests that image magnification to enhance resolution should be possible.

  4. [Incorporation of the Hazard Analysis and Critical Control Point system (HACCP) in food legislation].

    PubMed

    Castellanos Rey, Liliana C; Villamil Jiménez, Luis C; Romero Prada, Jaime R

    2004-01-01

    The Hazard Analysis and Critical Control Point system (HACCP), recommended by different international organizations as the Codex Alimentarius Commission, the World Trade Organization (WTO), the International Office of Epizootics (OIE) and the International Convention for Vegetables Protection (ICPV) amongst others, contributes to ensuring the innocuity of food along the agro-alimentary chain and requires of Good Manufacturing Practices (GMP) for its implementation, GMP's which are legislated in most countries. Since 1997, Colombia has set rules and legislation for application of HACCP system in agreement with international standards. This paper discusses the potential and difficulties of the legislation enforcement and suggests some policy implications towards food safety. PMID:15656068

  5. Separation of Tritium from Wastewater

    SciTech Connect

    JEPPSON, D.W.

    2000-01-25

    A proprietary tritium loading bed developed by Molecular Separations, Inc (MSI) has been shown to selectively load tritiated water as waters of hydration at near ambient temperatures. Tests conducted with a 126 {micro}C{sub 1} tritium/liter water standard mixture showed reductions to 25 {micro}C{sub 1}/L utilizing two, 2-meter long columns in series. Demonstration tests with Hanford Site wastewater samples indicate an approximate tritium concentration reduction from 0.3 {micro}C{sub 1}/L to 0.07 {micro}C{sub 1}/L for a series of two, 2-meter long stationary column beds Further reduction to less than 0.02 {micro}C{sub 1}/L, the current drinking water maximum contaminant level (MCL), is projected with additional bed media in series. Tritium can be removed from the loaded beds with a modest temperature increase and the beds can be reused Results of initial tests are presented and a moving bed process for treating large quantities of wastewaters is proposed. The moving bed separation process appears promising to treat existing large quantities of wastewater at various US Department of Energy (DOE) sites. The enriched tritium stream can be grouted for waste disposition. The separations system has also been shown to reduce tritium concentrations in nuclear reactor cooling water to levels that allow reuse. Energy requirements to reconstitute the loading beds and waste disposal costs for this process appear modest.

  6. Aqueous effluent tritium monitor development

    SciTech Connect

    Hofstetter, K.J.; Wilson, H.T.

    1991-12-31

    The development of a low-level tritium monitor for aqueous effluents has explored several potential techniques. In one method, a water-immiscible liquid scintillation cocktail was ultrasonically mixed with an aqueous sample to form a water-cocktail dispersion which was analyzed by liquid scintillation spectrometry. The organic cocktail could then be reused after phase separation. Of the cocktails tested, the highest tritium detection efficiency (7%) was determined for a toluene-based cocktail. In another technique, the response of various solid scintillators (plastic beads, crushed inorganic salts, etc.) to tritium solutions was measured. A 2% tritium detection efficiency was observed for the most efficient solid scintillators tested. In a third method, a large surface area detector was constructed from thin fibers of plastic scintillator. This detector had a 0.1% intrinsic tritium detection efficiency. While sensitivities of {approximately}25 kBg/L of tritium for a short count have been attained using several of these techniques, non can reach the environmental level of <1 kBg/L in aqueous solutions.

  7. Aqueous effluent tritium monitor development

    SciTech Connect

    Hofstetter, K.J.; Wilson, H.T.

    1991-01-01

    The development of a low-level tritium monitor for aqueous effluents has explored several potential techniques. In one method, a water-immiscible liquid scintillation cocktail was ultrasonically mixed with an aqueous sample to form a water-cocktail dispersion which was analyzed by liquid scintillation spectrometry. The organic cocktail could then be reused after phase separation. Of the cocktails tested, the highest tritium detection efficiency (7%) was determined for a toluene-based cocktail. In another technique, the response of various solid scintillators (plastic beads, crushed inorganic salts, etc.) to tritium solutions was measured. A 2% tritium detection efficiency was observed for the most efficient solid scintillators tested. In a third method, a large surface area detector was constructed from thin fibers of plastic scintillator. This detector had a 0.1% intrinsic tritium detection efficiency. While sensitivities of {approximately}25 kBg/L of tritium for a short count have been attained using several of these techniques, non can reach the environmental level of <1 kBg/L in aqueous solutions.

  8. MEMS closed-loop control incorporating a memristor as feedback sensing element

    SciTech Connect

    Garcia, Ernest J.; Almeida, Sergio F.; Mireles, Jr., Jose; Zubia, David

    2015-12-01

    In this work the integration of a memristor with a MEMS parallel plate capacitor coupled by an amplification stage is simulated. It is shown that the MEMS upper plate position can be controlled up to 95% of the total gap. Due to its common operation principle, the change in the MEMS plate position can be interpreted by the change in the memristor resistance, or memristance. A memristance modulation of ~1 KΩ was observed. A polynomial expression representing the MEMS upper plate displacement as a function of the memristance is presented. Thereafter a simple design for a voltage closed-loop control is presented showing that the MEMS upper plate can be stabilized up to 95% of the total gap using the memristor as a feedback sensing element. As a result, the memristor can play important dual roles in overcoming the limited operation range of MEMS parallel plate capacitors and in simplifying read-out circuits of those devices by representing the motion of the upper plate in the form of resistance change instead of capacitance change.

  9. MEMS closed-loop control incorporating a memristor as feedback sensing element

    DOE PAGESBeta

    Garcia, Ernest J.; Almeida, Sergio F.; Mireles, Jr., Jose; Zubia, David

    2015-12-01

    In this work the integration of a memristor with a MEMS parallel plate capacitor coupled by an amplification stage is simulated. It is shown that the MEMS upper plate position can be controlled up to 95% of the total gap. Due to its common operation principle, the change in the MEMS plate position can be interpreted by the change in the memristor resistance, or memristance. A memristance modulation of ~1 KΩ was observed. A polynomial expression representing the MEMS upper plate displacement as a function of the memristance is presented. Thereafter a simple design for a voltage closed-loop control ismore » presented showing that the MEMS upper plate can be stabilized up to 95% of the total gap using the memristor as a feedback sensing element. As a result, the memristor can play important dual roles in overcoming the limited operation range of MEMS parallel plate capacitors and in simplifying read-out circuits of those devices by representing the motion of the upper plate in the form of resistance change instead of capacitance change.« less

  10. Control of soilborne plant pathogens by incorporating fresh organic amendments followed by tarping.

    PubMed

    Blok, W J; Lamers, J G; Termorshuizen, A J; Bollen, G J

    2000-03-01

    ABSTRACT A new method for the control of soilborne plant pathogens was tested for its efficacy in two field experiments during two years. Plots were amended with fresh broccoli or grass (3.4 to 4.0 kg fresh weight m(-2)) or left nonamended, and covered with an airtight plastic cover (0.135 mm thick) or left noncovered. In plots amended with broccoli or grass and covered with plastic sheeting, anaerobic and strongly reducing soil conditions developed quickly, as indicated by rapid depletion of oxygen and a decrease in redox potential values to as low as -200 mV. After 15 weeks, survival of Fusarium oxysporum f. sp. asparagi, Rhizoctonia solani, and Verticillium dahliae in inoculum samples buried 15 cm deep was strongly reduced in amended, covered plots in both experiments. The pathogens were not or hardly inactivated in amended, noncovered soil or nonamended, covered soil. The latter indicates that thermal inactivation due to increased soil temperatures under the plastic cover was not involved in pathogen inactivation. The results show the potential for this approach to control various soilborne pathogens and that it may serve as an alternative to chemical soil disinfestation for high-value crops under conditions where other alternatives, such as solarization or soil flooding, are not effective or not feasible. PMID:18944617

  11. SOLERAS - Solar Controlled Environment Agriculture Project. Final report, Volume 5. Science Applications, Incorporated system requirements definition

    SciTech Connect

    Not Available

    1985-01-01

    This report sets forth the system requirements for a Solar Controlled-Environment Agriculture System (SCEAS) Project. In the report a conceptual baseline system description for an engineering test facility is given. This baseline system employs a fluid roof/roof filter in combination with a large storage tank and a ground water heat exchanger in order to provide cooling and heating as needed. Desalination is accomplished by pretreatment followed by reverse osmosis. Energy is provided by means of photovoltaics and wind machines in conjunction with storage batteries. Site and climatic data needed in the design process are given. System performance specifications and integrated system design criteria are set forth. Detailed subsystem design criteria are presented and appropriate references documented.

  12. Primer on tritium safe handling practices

    SciTech Connect

    Not Available

    1994-12-01

    This Primer is designed for use by operations and maintenance personnel to improve their knowledge of tritium safe handling practices. It is applicable to many job classifications and can be used as a reference for classroom work or for self-study. It is presented in general terms for use throughout the DOE Complex. After reading it, one should be able to: describe methods of measuring airborne tritium concentration; list types of protective clothing effective against tritium uptake from surface and airborne contamination; name two methods of reducing the body dose after a tritium uptake; describe the most common method for determining amount of tritium uptake in the body; describe steps to take following an accidental release of airborne tritium; describe the damage to metals that results from absorption of tritium; explain how washing hands or showering in cold water helps reduce tritium uptake; and describe how tritium exchanges with normal hydrogen in water and hydrocarbons.

  13. Controlled Nitrogen Atom Incorporation at Silicon - Dioxide Interfaces by a New, Low-Temperature Remote Plasma Process

    NASA Astrophysics Data System (ADS)

    Lee, David Roger

    1995-01-01

    A new, low-temperature (300^circ C), remote plasma process has been developed for incorporating controlled amounts of N-atoms at Si-SiO _2 interfaces and has been shown to improve the quality and reliability of Metal-Oxide-Semiconductor (MOS) devices. The process involves exposing an ex-situ cleaned wafer to species from a remote N_2 O plasma as a prelude to Remote Plasma Enhanced Chemical Vapor Deposition (Remote PECVD) of gate-quality SiO_2 films. Auger Electron Spectroscopy (AES) studies and Secondary Ion Mass Spectrometry (SIMS) depth profiles have been used to investigate the chemical nature of the Si-SiO_2 interface formed by this new technique. The results indicate that this pre-deposition process (1) removed residual carbon to ~10^{12 } C-atoms/cm^2, (2) resulted in the remote plasma-assisted growth of ~0.5 nm of SiO_2, and (3) incorporated controllably between 10^ {14}-10^{15} N-atoms/cm^2 at the Si-SiO _2 interface. Optical Second Harmonic Generation (SHG) spectroscopy has shown that the N-atoms are bonded to Si-atoms at the Si-SiO_2 interface and relieve chemical strain in adjacent Si-Si bonds relative to the case where only O-atoms are bonded at the interface. This N_2O remote plasma, predeposition oxidation process was used in a cluster tool manufacturing test bed for the fabrication of MOS capacitors and Field-Effect Transistors (FETs). Remote PECVD oxides with and without nitrided interfaces were compared, and N-atom incorporation by this technique was found to improve the drive current and high-field electron mobility of n -MOSFETs while not adversely affecting the threshold voltage, V_{rm t}, or peak channel transconductance, g_{rm m}, of the devices. N-atom incorporation also suppressed hot-carrier damage in the gate dielectric of sub-micron (effective channel length ~ 0.64 μm) n-MOSFETs. In particular, peak g_{rm m}, V _{rm t}, and the slope of the subthreshold current are all degraded less with increasing N-atom concentrations at the Si-SiO _2

  14. Incorporation of essential oils and nanoparticles in pullulan films to control foodborne pathogens on meat and poultry products.

    PubMed

    Morsy, Mohamed K; Khalaf, Hassan H; Sharoba, Ashraf M; El-Tanahi, Hassan H; Cutter, Catherine N

    2014-04-01

    The incorporation of essential oils and nanotechnology into edible films has the potential to improve the microbiological safety of foods. The aim of this study was to evaluate the effectiveness of pullulan films containing essential oils and nanoparticles against 4 foodborne pathogens. Initial experiments using plate overlay assays demonstrated that 2% oregano essential oil was active against Staphylococcus aureus and Salmonella Typhimurium, whereas Listeria monocytogenes and Escherichia coli O157:H7 were not inhibited. Two percent rosemary essential oil was active against S. aureus, L. monocytogenes, E. coli O157:H7, and S. Typhimurium, when compared with 1%. Zinc oxide nanoparticles at 110 nm were active against S. aureus, L. monocytogenes, E. coli O157:H7, and S. Typhimurium, when compared with 100 or 130 nm. Conversely, 100 nm silver (Ag) nanoparticles were more active against S. aureus than L. monocytogenes. Using the results from these experiments, the compounds exhibiting the greatest activity were incorporated into pullulan films and found to inhibit all or some of the 4 pathogens in plate overlay assays. In challenge studies, pullulan films containing the compounds effectively inhibited the pathogens associated with vacuum packaged meat and poultry products stored at 4 °C for up to 3 wk, as compared to control films. Additionally, the structure and cross-section of the films were evaluated using electron microscopy. The results from this study demonstrate that edible films made from pullulan and incorporated with essential oils or nanoparticles may improve the safety of refrigerated, fresh or further processed meat and poultry products. PMID:24621108

  15. Laser-assisted isotope separation of tritium

    DOEpatents

    Herman, Irving P.; Marling, Jack B.

    1983-01-01

    Methods for laser-assisted isotope separation of tritium, using infrared multiple photon dissociation of tritium-bearing products in the gas phase. One such process involves the steps of (1) catalytic exchange of a deuterium-bearing molecule XYD with tritiated water DTO from sources such as a heavy water fission reactor, to produce the tritium-bearing working molecules XYT and (2) photoselective dissociation of XYT to form a tritium-rich product. By an analogous procedure, tritium is separated from tritium-bearing materials that contain predominately hydrogen such as a light water coolant from fission or fusion reactors.

  16. Recent progresses in tritium radioecology and dosimetry

    SciTech Connect

    Galeriu, D.; Davis, P.; Raskob, W.; Melintescu, A.

    2008-07-15

    In this paper, some aspects of recent progress in tritium radioecology and dosimetry are presented, with emphasis on atmospheric releases to terrestrial ecosystems. The processes involved in tritium transfer through the environment are discussed, together with the current status of environmental tritium models. Topics include the deposition and reemission of HT and HTO, models for the assessment of routine and accidental HTO emissions, a new approach to modeling the dynamics of tritium in mammals, the dose consequences of tritium releases and aspects of human dosimetry. The need for additional experimental data is identified, together with the attributes that would be desirable in the next generation of tritium codes. (authors)

  17. A Computationally Efficient, Exploratory Approach to Brain Connectivity Incorporating False Discovery Rate Control, A Priori Knowledge, and Group Inference

    PubMed Central

    Liu, Aiping; Li, Junning; Wang, Z. Jane; McKeown, Martin J.

    2012-01-01

    Graphical models appear well suited for inferring brain connectivity from fMRI data, as they can distinguish between direct and indirect brain connectivity. Nevertheless, biological interpretation requires not only that the multivariate time series are adequately modeled, but also that there is accurate error-control of the inferred edges. The PCfdr algorithm, which was developed by Li and Wang, was to provide a computationally efficient means to control the false discovery rate (FDR) of computed edges asymptotically. The original PCfdr algorithm was unable to accommodate a priori information about connectivity and was designed to infer connectivity from a single subject rather than a group of subjects. Here we extend the original PCfdr algorithm and propose a multisubject, error-rate-controlled brain connectivity modeling approach that allows incorporation of prior knowledge of connectivity. In simulations, we show that the two proposed extensions can still control the FDR around or below a specified threshold. When the proposed approach is applied to fMRI data in a Parkinson's disease study, we find robust group evidence of the disease-related changes, the compensatory changes, and the normalizing effect of L-dopa medication. The proposed method provides a robust, accurate, and practical method for the assessment of brain connectivity patterns from functional neuroimaging data. PMID:23251232

  18. Controllable photoluminescence enhancement of CdTe/CdS quantum dots thin films incorporation with Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Wang, Hongyu; Xu, Ling; Zhang, Renqi; Ge, Zhaoyun; Zhang, Wenping; Xu, Jun; Ma, Zhongyuan; Chen, Kunji

    2015-03-01

    Au nanoparticles (Au NPs)/CdTe/CdS QDs nanocomposite films were fabricated by deposition of Au NPs and layer-by-layer self-assembly of colloidal CdTe/CdS QDs. Photoluminescence (PL) spectra showed that Au NPs incorporation resulted in an increase of PL intensity about 16-fold compared with that of the samples without Au NPs. PL enhancement of Au NPs/CdTe/CdS QDs nanocomposite films can be controlled by tuning the thickness of spacer layer between the metal nanoparticles (MNPs) and QDs. Optical absorption spectra exhibited the incorporation of Au NPs boosted the absorption of Au NPs/CdTe/CdS QDs nanocomposite films. The results of finite-difference time-domain (FDTD) simulation indicated that the increased sizes of Au NPs resulted in stronger localization of electric field, which boosted the PL intensity of QDs in the vicinity of Au NPs. We thought that these were mainly attributed to localized SP enhancement effects of the Au NPs. Our experiment results demonstrated that Au NPs/QDs nanocomposite films would be a promising candidate for optoelectronic devices application.

  19. Tritium permeation through steam generator tubing of helium-cooled ceramic breeder blankets

    SciTech Connect

    Fuetterer, M.; Raepsaet, X.; Proust, E.

    1994-12-31

    The potential sources of tritium contamination of the helium-coolant of ceramic breeder blankets have been evaluated in a previous paper for the specific case of the European BIT DEMO blanket. This evaluation associated with a rough assessment of the permeability to tritium of the tubing of helium-heated steam generators confirmed that the control of tritium losses to the steam circuit is a critical issue for this class of blanket requiring developments in three areas: (1) permeation barriers, (2) tritium recovery processes maintaining a very low concentration in tritiated species in the coolant, and (3) methods for controlling the chemistry of the coolant. Consequently, in order to define the specifications of these developments, a detailed evaluation of the permeability to tritium of helium-heated steam generators (SGs) was performed, which will be reported in this paper. This study includes the definition of the thermal-hydraulic operating conditions of the SGs through thermodynamic cycle calculations, and its thermal-hydraulic design. The obtained geometry, area and temperature profiles along the tubes are then used to estimate, based on relevant permeability data, the tritium permeation through the SG as a function of the composition in tritiated species of the coolant. The implications of these results, in terms of requirements for the considered tritium control methods, will also be discussed on the basis of expected limits in tritium release to the steam circuit.

  20. How tritium illuminates catchment structure

    NASA Astrophysics Data System (ADS)

    Stewart, M.; Morgenstern, U.; McDonnell, J.

    2012-04-01

    Streams contain water which has taken widely-varying times to pass through catchments, and the distribution of ages is likely to change with the flow. Part of the water has 'runoff' straight to the stream with little delay, other parts are more delayed and some has taken years (in some cases decades) to traverse the deeper regolith or bedrock of the catchment. This work aims to establish the significance of the last component, which is important because it can cause catchments to have long memories of contaminant inputs (e.g. nitrate). Results of tritium studies on streams world-wide were accessed from the scientific literature. Most of the studies assumed that there were just two age-components present in the streams (i.e. young and old). The mean ages and proportions of the components were found by fitting simulations to tritium data. It was found that the old component in streams was substantial (average was 50% of the annual runoff) and had considerable age (average mean age was 10 years) (Stewart et al., 2010). Use of oxygen-18 or chloride variations to estimate streamflow mean age usually does not reveal the age or size of this old component, because these methods cannot detect water older than about four years. Consequently, the use of tritium has shown that substantial parts of streamflow in headwater catchments are older than expected, and that deep groundwater plays an active and sometimes even a dominant role in runoff generation. Difficulties with interpretation of tritium in streams in recent years due to interference from tritium due to nuclear weapons testing are becoming less serious, because very accurate tritium measurements can be made and there is now little bomb-tritium remaining in the atmosphere. Mean ages can often be estimated from single tritium measurements in the Southern Hemisphere, because there was much less bomb-tritium in the atmosphere. This may also be possible for some locations in the Northern Hemisphere. Age determination on

  1. Controls on the production, incorporation and decomposition of glomalin - a novel fungal soil protein important to soil carbon

    SciTech Connect

    Matthias C. Rillig

    2003-11-20

    OAK B263 Glomalin is an operationally defined soil protein, produced by arbuscular mycorrhizal fungi (AMF), with importance in soil carbon sequestration through its relationship with soil aggregation. The goal of the project was to further explore the natural history of glomalin and to address several questions regarding basic behavior of this compound in soil (production, incorporation, decomposition). We have obtained a significant amount of novel information on the arbuscular mycorrhizal fungal soil protein, concerning factors controlling its production to mechanisms of incorporation and decomposition. These findings have resulted in 10 publications in peer-reviewed journals, with several more submitted or in preparation, and 16 contributed presentations at meetings. I have sought collaborative opportunities whenever they fit within the research proposed to enhance our productivity. Additionally, although not part of the original proposed work, we have made a significant effort to elucidate the molecular biology of glomalin (in response to Program Officer suggestions). In addition to peer-reviewed publications there have also been a number of invited presentations, including a keynote address delivered by the PI at the International Conference on Mycorrhizae (ICOM4) in Montreal, summer 2003. Two Master's students have been trained (and graduated), and a postdoctoral associate has been mentored, as well as numerous undergraduate researchers at UM. In this report I summarize the major findings of the project in the areas of glomalin production control (host factors, elevated CO2), incorporation, and decomposition. Section D is newly added and describes recent progress in molecular biology. Briefly, we found that glomalin production is influenced by the host, as shown by host species effects and responses to elevated CO2. We have recently made a significant breakthrough in understanding how glomalin may become deposited into soil; apparently the dominant pathway is

  2. Static Performance of a Fixed-Geometry Exhaust Nozzle Incorporating Porous Cavities for Shock-Boundary Layer Interaction Control

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Hunter, Craig A.

    1999-01-01

    An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to determine the internal performance of a fixed-geometry exhaust nozzle incorporating porous cavities for shock-boundary layer interaction control. Testing was conducted at static conditions using a sub-scale nozzle model with one baseline and 27 porous configurations. For the porous configurations, the effects of percent open porosity, hole diameter, and cavity depth were determined. All tests were conducted with no external flow at nozzle pressure ratios from 1.25 to approximately 9.50. Results indicate that baseline nozzle performance was dominated by unstable, shock-induced, boundary-layer separation at over-expanded conditions. Porous configurations were capable of controlling off-design separation in the nozzle by either alleviating separation or encouraging stable separation of the exhaust flow. The ability of the porous nozzle concept to alternately alleviate separation or encourage stable separation of exhaust flow through shock-boundary layer interaction control offers tremendous off-design performance benefits for fixed-geometry nozzle installations. In addition, the ability to encourage separation on one divergent flap while alleviating it on the other makes it possible to generate thrust vectoring using a fixed-geometry nozzle.

  3. Tritium Migration Analysis Program Version 4

    Energy Science and Technology Software Center (ESTSC)

    1991-06-12

    TMAP4 was developed as a safety analysis code, mainly to analyze tritium retention and loss in fusion reactor structures and systems during normal operational and accident conditions. It incorporates one-dimensional thermal and mass-diffusive transport and trapping calculations through structures and zero dimensional fluid transport between enclosures and across the interface between enclosures and structures. Diffusion structures may be linked together with other structures, and multiple structures may interact with an enclosure. A key feature ismore » the ability to input problem definition parameters as constants, interpolation tables, or FORTRAN equations. The code is specifically intended for use under a DOS operating system on PC type minicomputers, but it has also been run successfully on workstations and mainframe computer systems. Use of the equation-input feature requires access to a FORTRAN-77 compiler, and a linker program is required.« less

  4. Safety assessment of the tritium recovery system

    SciTech Connect

    Not Available

    1994-09-01

    This Safety Assessment (SA) contains descriptions and evaluations of the environmental, health, and safety issues associated with the Tritium Recovery System (TRS) at the Pinellas Plant. It provides: 1. site and facility descriptions, 2. an overall description of the TRS and its operations, 3. an evaluation of the hazards associated with TRS operations, 4. descriptions and analyses of the adequacy of measures taken to eliminate, control, or mitigate identified hazards, and 5. assessment of potential accidents and their associated risks. This SA contains the results of safety evaluations of TRS operations, equipment, and supplied systems. The evaluations include, as appropriate, preliminary hazards listings, qualitative risk assessments, and quantitative risk assessments.

  5. Overview of Recent Tritium Experiments in TPE

    SciTech Connect

    Masashi Shimada; T. Otsuka; R. J. Pawelko; P. Calderoni; J. P. Sharpe

    2010-10-01

    Tritium retention in plasma-facing components influences the design, operation, and lifetime of fusion devices such as ITER. Most of the retention studies were carried out with the use of either hydrogen or deuterium. Tritium Plasma Experiment is a unique linear plasma device that can handle radioactive fusion fuel of tritium, toxic material of beryllium, and neutron-irradiated material. A tritium depth profiling method up to mm range was developed using a tritium imaging plate and a diamond wire saw. A series of tritium experiments (T2/D2 ratio: 0.2 and 0.5 %) was performed to investigate tritium depth profiling in bulk tungsten, and the results shows that tritium is migrated into bulk tungsten up to mm range.

  6. Longitudinal Stability and Control Characteristics of a B-29 Airplane with a Booster Incorporated in the Elevator Control System to Provide Various Stick-Force and Control-Rate Characteristics

    NASA Technical Reports Server (NTRS)

    Mathews, Charles W.; Talmage, Donald B.; Whitten, James B.

    1948-01-01

    The longitudinal stability and control characteristics of a B-29 airplane have been measured with a booster incorporated in the elevator control system. Tests were made to determine the effects on the handling qualities of the test airplane of variations in pilots control-force gradients as well as the effects of variations in the maximum rate of control motion supplied by the booster system.

  7. Multi-purpose droop controllers incorporating a passivity-based stabilizer for unified control of electronically interfaced distributed generators including primary source dynamics.

    PubMed

    Azimi, Seyed Mohammad; Afsharnia, Saeed

    2016-07-01

    This paper presents multi-purpose droop controllers for electronically-interfaced distributed generators (EI-DGs). These controllers allow the micro-grids to operate in grid-connected mode, islanded mode and mode transition transients with a unique control configuration. The active and reactive-power sharing among EI-DGs are satisfied by the proposed droop controllers in islanded mode. On the other hand, in the grid-connected mode, the droop controllers adjust the output active and reactive-powers of EI-DGs at the pre-programmed constant levels. The provision of sufficient damping capability and maintenance of the transient stability in all operational modes of EI-DGs are warranted by the suggested stabilizer. This stabilizer, which is designed using the passivity-based control (PBC) approach, is incorporated in the droop controllers to dampen power-angle, frequency and voltage deviations during large transients using solely local information. The primary source dynamics of EI-DGs are also considered. It is analytically proven that the presence of the primary source dynamics leads to attenuation of the damping capability of EI-DGs in transients. To compensate the adverse effect of the primary source dynamics during transients a novel compensator is inserted in the frequency-droop loop. Finally, time-domain simulations are performed on a multi-resources MG to verify the analytical results compared to those obtained, based on a recently-developed strategy. PMID:27085670

  8. Linear accelerator for tritium production

    SciTech Connect

    Garnett, R.W.; Billen, J.H.; Chan, K.C.; Genzlinger, R.; Gray, E.R.; Nath, S.; Rusnak, B.; Schrage, D.L.; Stovall, J.E.; Takeda, H.; Wood, R.; Wangler, T.P.; Young, L.M.

    1996-06-01

    For many years now, Los Alamos National Laboratory has been working to develop a conceptual design of a facility for accelerator production of tritium (APT). The APT accelerator will produce high energy protons which will bombard a heavy metal target, resulting in the production of large numbers of spallation neutrons. These neutrons will be captured by a low-{ital Z} target to produce tritium. This paper describes the latest design of a room-temperature, 1.0 GeV, 100 mA, cw proton accelerator for tritium production. The potential advantages of using superconducting cavities in the high-energy section of the linac are also discussed and a comparison is made with the baseline room-temperature accelerator. {copyright} {ital 1996 American Institute of Physics.}

  9. Modeling Tritium Life cycle in Nuclear Plants

    SciTech Connect

    Hussey, D.; Saunders, P.; Morey, D.; Pitt, N.; Wilson, J.; Claes, B.

    2006-07-01

    The mathematical development of a tritium model for nuclear power plants is presented. The model requires that the water and tritium material balance be satisfied throughout normal operations and shutdown. The model results obtained at the time of publishing include the system definitions and comparison of the model predictions of tritium generations compared to the observed plant data of the Braidwood station. A scenario that models using ion exchange resin to remove coolant boron demonstrates the tritium concentration levels are manageable. (authors)

  10. Design of the Target Fabrication Tritium Laboratory

    SciTech Connect

    Sherohman, J.W.; Roberts, D.H.; Levine, B.H.

    1982-05-05

    The design of the Target Fabrication Tritium Laboratory for deuterium-tritium fuel processing for laser fusion targets has been accomplished with the intent of providing redundant safeguard systems. The design of the tritium laboratory is based on a combination of tritium handling techniques that are currently used by experienced laboratories. A description of the laboratory in terms of its interrelated processing systems is presented to provide an understanding of the design features for safe operation.

  11. Effects of tritium on material properties

    SciTech Connect

    Caskey, G.R. Jr.

    1985-01-01

    The effecs of tritium on deformation and fracture of metals are reviewed with emphasis on similarities and differences between tritium and the other hydrogen isotopes. Helium generated by radioactive decay of tritium introduces time dependent property changes not observed with protium or deuterium. On-going studies and topics for further investigations are identified. 17 refs., 6 figs., 9 tabs.

  12. Secondary Prevention following CABG: Findings of a National Randomized Controlled Trial and Sustained Society-Led Incorporation into Practice

    PubMed Central

    Williams, Judson B.; DeLong, Elizabeth R.; Peterson, Eric D.; Dokholyan, Rachel S.; Ou, Fang-Shu; Ferguson, T. Bruce

    2013-01-01

    Background Despite evidence supporting the use of aspirin, B-blockers, ACE inhibitors, and lipid-lowering therapies in eligible patients, adoption of these secondary prevention measures following coronary artery bypass grafting (CABG) has been inconsistent. We sought to rigorously test on a national scale whether low-intensity continuous quality improvement (CQI) interventions can be used to speed secondary prevention adherence following CABG. Methods and Results A total of 458 hospitals participating in the Society of Thoracic Surgeons National Cardiac Database and treating 361,328 patients undergoing isolated CABG were randomized to either a control or an intervention group. The intervention group received CQI materials designed to influence the prescription of the secondary prevention medications at discharge. The primary outcome measure was discharge prescription rates of the targeted secondary prevention medications at intervention vs. control sites, assessed by measuring pre-intervention and post-intervention site differences. Pre-randomization treatment patterns and baseline data were similar in the control (N=234) and treatment (N=224) groups. Individual medication use as well as composite adherence increased over 24 months in both groups, with a markedly more rapid rate of adherence uptake among the intervention hospitals and a statistically significant therapy hazard ratio in the intervention vs. control group for all 4 secondary prevention medications. Conclusions Provider-led, low-intensity CQI efforts can improve the adoption of care processes into national practice within the context of a medical specialty society infrastructure. The findings of the present trial have led to the incorporation of study outcome metrics into a medical society rating system for ongoing quality improvement. PMID:21173357

  13. Incorporating linked healthcare claims to improve confounding control in a study of in-hospital medication use

    PubMed Central

    Franklin, Jessica M; Eddings, Wesley; Schneeweiss, Sebastian; Rassen, Jeremy A

    2015-01-01

    Introduction The Premier Perspective hospital billing database provides a promising data source for studies of inpatient medication use. However, in-hospital recording of confounders is limited, and incorporating linked healthcare claims data available for a subset of the cohort may improve confounding control. We investigated methods capable of adjusting for confounders measured in a subset, including complete case analysis, multiple imputation of missing data, and propensity score (PS) calibration. Methods Methods were implemented in an example study of adults in Premier undergoing percutaneous coronary intervention (PCI) in 2004-2008 and exposed to either bivalirudin or heparin. In a subset of patients enrolled in UnitedHealth for at least 90 days before hospitalization, additional confounders were assessed from healthcare claims, including comorbidities, prior medication use, and service use intensity. Diagnostics for each method were evaluated, and methods were compared with respect to the estimates and confidence intervals of treatment effects on repeat PCI, bleeding, and in-hospital death. Results Of 210,268 patients in the hospital-based cohort, 3,240 (1.5%) had linked healthcare claims. This subset was younger and healthier than the overall study population. The linked subset was too small for complete case evaluation of 2 of the 3 outcomes of interest. Multiple imputation and PS calibration did not meaningfully impact treatment effect estimates and associated confidence intervals. Conclusions Despite more than 98% missingness on 24 variables, PS calibration and multiple imputation incorporated confounders from healthcare claims without major increases in estimate uncertainty. Additional research is needed to determine the relative bias of these methods. PMID:25935198

  14. Evaluation of drug incorporation into hair segments and nails by enantiomeric analysis following controlled single MDMA intakes.

    PubMed

    Madry, Milena M; Steuer, Andrea E; Hysek, Cédric M; Liechti, Matthias E; Baumgartner, Markus R; Kraemer, Thomas

    2016-01-01

    Incorporation rates of the enantiomers of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolite 3,4-methylenedioxyamphetamine (MDA) into hair and nails were investigated after controlled administration. Fifteen subjects without MDMA use received two doses of 125 mg of MDMA. Hair, nail scrapings, and nail clippings were collected 9-77 days after the last administration (median 20 days). Hair samples were analyzed in segments of 1- to 2-cm length. After chiral derivatization with N-(2,4-dinitro-5-fluorophenyl)-L-valinamide, MDMA and MDA diastereomers were analyzed by liquid chromatography-tandem mass spectrometry. Highest concentrations in hair segments corresponded to the time of MDMA intake. They ranged from 101 to 3200 pg/mg and 71 to 860 pg/mg for R- and S-MDMA, and from 3.2 to 116 pg/mg and 4.4 to 108 pg/mg for R- and S-MDA, respectively. MDMA and MDA concentrations in nail scrapings and clippings were significantly lower than in hair samples. There was no significant difference between enantiomeric ratios of R/S-MDMA and R/S-MDA in hair and nail samples (medians 2.2-2.4 for MDMA and 0.85-0.95 for MDA). Metabolite ratios of MDA to MDMA were in the same range in hair and nail samples (medians 0.044-0.055). Our study demonstrates that administration of two representative doses of MDMA was detected in the hair segments corresponding to the time of intake based on average hair growth rates. MDMA was detected in all nail samples regardless of time passed after intake. Comparable R/S ratios in hair and nail samples may indicate that incorporation mechanisms into both matrices are comparable. PMID:26521178

  15. Fuzzy integral-based gaze control architecture incorporated with modified-univector field-based navigation for humanoid robots.

    PubMed

    Yoo, Jeong-Ki; Kim, Jong-Hwan

    2012-02-01

    When a humanoid robot moves in a dynamic environment, a simple process of planning and following a path may not guarantee competent performance for dynamic obstacle avoidance because the robot acquires limited information from the environment using a local vision sensor. Thus, it is essential to update its local map as frequently as possible to obtain more information through gaze control while walking. This paper proposes a fuzzy integral-based gaze control architecture incorporated with the modified-univector field-based navigation for humanoid robots. To determine the gaze direction, four criteria based on local map confidence, waypoint, self-localization, and obstacles, are defined along with their corresponding partial evaluation functions. Using the partial evaluation values and the degree of consideration for criteria, fuzzy integral is applied to each candidate gaze direction for global evaluation. For the effective dynamic obstacle avoidance, partial evaluation functions about self-localization error and surrounding obstacles are also used for generating virtual dynamic obstacle for the modified-univector field method which generates the path and velocity of robot toward the next waypoint. The proposed architecture is verified through the comparison with the conventional weighted sum-based approach with the simulations using a developed simulator for HanSaRam-IX (HSR-IX). PMID:21878418

  16. Tritium release from Ti-T layers in air, in aqueous media and in animal experiments.

    PubMed

    Bíró, J; Fehér, I; Máté, L; Varga, L

    1978-01-01

    In connection with Ti-T incorporation hazard to which operators of neutron generators are exposed the release of tritium from Ti-T preparations of different ages was studied in experiments carried out in air, in aqueous media and in living animals. Samples were prepared with activities from 10 to 30 mCi and the effect of storage on the tritium release rate was also observed. In 250 days a fraction of 10(-3) of the tritium activity was absorbed by aqueous liquids. In air the release varied from 10(-6) to 10(-7) per hour. The Ti-T samples of different ages, introduced surgically into the abdominal cavity of rats, showed the tritium release rate to decrease with time. The tritium activity observable in the circulation was 5 to 6 orders of magnitude smaller compared with the introduced value. The observations permit the inference that in the case of Ti-T incorporation only a minor fraction of the tritium burden can be assessed from the activity measured in the urine. PMID:754442

  17. Physical inventory by use of modeling for the tritium aqueous waste recovery system

    SciTech Connect

    Sienkiewicz, C.J.; Lentz, J.E.; Wiggins, D.V.

    1988-09-01

    Physical inventory requirements for the Tritium Aqueous Waste Recovery System (TAWRS) present constraints that required unique solutions. Available analytical techniques for which sound measurement control practices existed could not be readily adapted to the system without significant modifications and expense. A mathematical model was developed that accurately estimates total system inventory, given a few key measurements. Tritium concentrations in two streams, the tritiated feed stream to the process and the tritiated hydrogen stream generated by the electrolysis cells, provides the key values to the model. The model relates the tritium concentration throughout the system to the tritium concentration in these two streams. Testing of the system using low-level tritiated feed water was conducted to characterize tritium distribution in the system and to relate key values to total inventory.

  18. Physical inventory by use of modeling for the tritium aqueous waste recovery system

    SciTech Connect

    Sienkiewicz, C.J.; Lentz, J.E.; Wiggins, D.V.

    1988-01-01

    Physical inventory requirements for the Tritium Aqueous Waste Recovery System (TAWRS) presented constraints that required unique solutions. Available analytical techniques for which sound measurement control practices existed could not be readily adapted to the system without significant modifications and expense. Based on the assumption that would accurately estimate total system inventory given a few key measurements, a model was developed for TAWRS. Tritium concentrations in two streams, the tritiated feed stream to the process and the tritiated hydrogen stream generated by the electrolysis cells, provided the key values to the model. The proposed mathematical model relates the tritium concentration throughout the system to the tritium concentration in these two streams. Testing of the system using low-level tritiated feed water was conducted to characterize tritium distribution in the system and to relate key values to total inventory. 4 refs., 2 figs.,

  19. EFFECTS OF TRITIUM GAS EXPOSURE ON POLYMERS

    SciTech Connect

    Clark, E.; Fox, E.; Kane, M.; Staack, G.

    2011-01-07

    Effects of tritium gas exposure on various polymers have been studied over the last several years. Despite the deleterious effects of beta exposure on many material properties, structural polymers continued to be used in tritium systems. Improved understanding of the tritium effects will allow more resistant materials to be selected. Currently polymers find use mainly in tritium gas sealing applications (eg. valve stem tips, O-rings). Future uses being evaluated including polymeric based cracking of tritiated water, and polymer-based sensors of tritium.

  20. Tritium hazard via the ingestion pathway

    SciTech Connect

    Travis, C.C.

    1985-01-01

    The classic methodology for estimating dose to man from environmental tritium ignores the fact that organically bound tritium in foodstuffs may be directly assimilated in the bound compartment of tissues without previous oxidation. We propose a four-compartment model that allows for the ability to input organically bound tritium in foodstuffs directly into the organic compartments of the model. We found that organically bound tritium in foodstuffs can increase the total body dose by a factor of 1.7 to 4.5 times the free body water dose alone, depending on the bound to loose ratio of tritium in the diet. 10 refs., 1 fig., 1 tab.

  1. Tritium migration from a low-level radioactive-waste disposal site near Chicago, Illinois

    USGS Publications Warehouse

    Nicholas, J.R.; Healy, R.W.

    1988-01-01

    This paper describes the results of a study to determine the geologic and hydrologic factors that control migration of tritium from a closed, low-level radioactive-waste disposal site. The disposal site, which operated from 1943 to mid1949, contains waste generated by research activities at the world's first nuclear reactors. Tritium has migrated horizontally at least 1,300 feet northward in glacial drift and more than 650 feet in the underlying dolomite. Thin, gently sloping sand layers in an otherwise clayey glacial drift are major conduits for ground-water flow and tritium migration in a perched zone beneath the disposal site. Tritium concentrations in the drift beneath the disposal site exceed 100,000 nanocuries per liter. Regional horizontal joints in the dolomite are enlarged by solution and are the major conduits for ground-water flow and tritium migration in the dolomite. A weathered zone at the top of the dolomite also is a pathway for tritium migration. The maximum measured tritium concentration in the dolomite is 29.4 nanocuries per liter. Fluctuations of tritium concentration in the dolomite are the result of dilution by seasonal recharge from the drift.

  2. Current status of tritium calorimetry at TLK

    SciTech Connect

    Buekki-Deme, A.; Alecu, C.G.; Kloppe, B.; Bornschein, B.

    2015-03-15

    Inside a tritium facility, calorimetry is an important analytical method as it is the only reference method for accountancy (it is based on the measurement of the heat generated by the radioactive decay). Presently, at Tritium Laboratory Karlsruhe (TLK), 4 calorimeters are in operation, one of isothermal type and three of inertial guidance control type (IGC). The volume of the calorimeters varies between 0.5 and 20.6 liters. About two years ago we started an extensive work to improve our calorimeters with regard to reliability and precision. We were forced to upgrade 3 of our 4 calorimeters due to the outdated interfaces and software. This work involved creating new LabView programs driving the devices, re-tuning control loops and replacing obsolete hardware components. In this paper we give a review on the current performance of our calorimeters, comparing it to recently available devices from the market and in the literature. We also show some ideas for a next generation calorimeter based on experiences with our IGC calorimeters and other devices reported in the literature. (authors)

  3. Weapons engineering tritium facility overview

    SciTech Connect

    Najera, Larry

    2011-01-20

    Materials provide an overview of the Weapons Engineering Tritium Facility (WETF) as introductory material for January 2011 visit to SRS. Purpose of the visit is to discuss Safety Basis, Conduct of Engineering, and Conduct of Operations. WETF general description and general GTS program capabilities are presented in an unclassified format.

  4. Tritium pellet injection sequences for TFTR

    SciTech Connect

    Houlberg, W.A.; Milora, S.L.; Attenberger, S.E.; Singer, C.E.; Schmidt, G.L.

    1983-01-01

    Tritium pellet injection into neutral deuterium, beam heated deuterium plasmas in the Tokamak Fusion Test Reactor (TFTR) is shown to be an attractive means of (1) minimizing tritium use per tritium discharge and over a sequence of tritium discharges; (2) greatly reducing the tritium load in the walls, limiters, getters, and cryopanels; (3) maintaining or improving instantaneous neutron production (Q); (4) reducing or eliminating deuterium-tritium (D-T) neutron production in non-optimized discharges; and (5) generally adding flexibility to the experimental sequences leading to optimal Q operation. Transport analyses of both compression and full-bore TFTR plasmas are used to support the above observations and to provide the basis for a proposed eight-pellet gas gun injector for the 1986 tritium experiments.

  5. Tritium dynamics in soils and plants grown under three irrigation regimes at a tritium processing facility in Canada.

    PubMed

    Mihok, S; Wilk, M; Lapp, A; St-Amant, N; Kwamena, N-O A; Clark, I D

    2016-03-01

    The dynamics of tritium released from nuclear facilities as tritiated water (HTO) have been studied extensively with results incorporated into regulatory assessment models. These models typically estimate organically bound tritium (OBT) for calculating public dose as OBT itself is rarely measured. Higher than expected OBT/HTO ratios in plants and soils are an emerging issue that is not well understood. To support the improvement of models, an experimental garden was set up in 2012 at a tritium processing facility in Pembroke, Ontario to characterize the circumstances under which high OBT/HTO ratios may arise. Soils and plants were sampled weekly to coincide with detailed air and stack monitoring. The design included a plot of native grass/soil, contrasted with sod and vegetables grown in barrels with commercial topsoil under natural rain and either low or high tritium irrigation water. Air monitoring indicated that the plume was present infrequently at concentrations of up to about 100 Bq/m(3) (the garden was not in a major wind sector). Mean air concentrations during the day on workdays (HTO 10.3 Bq/m(3), HT 5.8 Bq/m(3)) were higher than at other times (0.7-2.6 Bq/m(3)). Mean Tissue Free Water Tritium (TFWT) in plants and soils and OBT/HTO ratios were only very weakly or not at all correlated with releases on a weekly basis. TFWT was equal in soils and plants and in above and below ground parts of vegetables. OBT/HTO ratios in above ground parts of vegetables were above one when the main source of tritium was from high tritium irrigation water (1.5-1.8). Ratios were below one in below ground parts of vegetables when irrigated with high tritium water (0.4-0.6) and above one in vegetables rain-fed or irrigated with low tritium water (1.3-2.8). In contrast, OBT/HTO ratios were very high (9.0-13.5) when the source of tritium was mainly from the atmosphere. TFWT varied considerably through time as a result of SRBT's operations; OBT/HTO ratios showed no clear temporal

  6. Production of highly tritiated water for tritium exposure studies

    SciTech Connect

    Muirhead, C.; Pilatzke, K.; Tripple, A.; Philippi, N.; McCrimmon, K.; Castillo, I.; Boniface, H.; Suppiah, S.

    2015-03-15

    Tritium Facility staff at Chalk River Laboratories (CRL) have successfully prepared highly tritiated water for use in radiation resistance of PEM (Proton Exchange Membrane-based)electrolyser membrane. The goal of System A was to convert a known amount of elemental tritium (HT) into tritiated water vapour using a copper(II) oxide bed, and to condense the tritiated water vapour into a known amount of chilled heavy water (D{sub 2}O). The conversion and capture of tritium using this system is close to 100%. The goal of System B was to transfer tritiated water from the containment vessel to an exposure vessel (experiment) in a controlled and safe manner. System B is based on the pushing of D{sub 2}0 with low-pressure argon carrier gas to a calibrated volume and then to the exposure vessel. A method for delivering a known and controlled amount of tritiated water has been successfully demonstrated at CRL. Using both systems Tritium Facility staff have made and distributed highly tritiated water in a safe and controlled manner. This paper focuses on how the tritiated water was produced and dispensed to the experiment.

  7. Observation of tritium distribution in iron oxide with tritium micro autoradiography

    SciTech Connect

    Isobe, K.; Hayashi, T.; Nakamura, H.; Kobayashi, K.; Yamanishi, T.; Okuno, K.

    2008-07-15

    To clarify the tritium permeation behavior, tritium distribution in iron oxidized in high temperature water was observed with tritium micro autoradiography. It was found that tritium was distributed homogeneously in the iron metal. However the oxide surface (magnetite) was found to contain a very low concentration of tritium. The inner layer of oxide could strongly effect the tritium permeation. From a comparison with the permeation experiment that had been reported in Ref. 1, it was suggested that tritium would mainly diffuse other path except the oxide lattice. According to the chemical form of tritium, which was released from iron surface into water, two assumptions were suggested. One is based on the different combination of tritium on the water-surface interface. The other is based on the oxidation mechanism. (authors)

  8. Tritium Burn-up Depth and Tritium Break-Even Time

    NASA Astrophysics Data System (ADS)

    Li, Cheng-Yue; Deng, Bai-Quan; Huang, Jin-Hua; Yan, Jian-Cheng

    2006-08-01

    Similarly to but quite different from the xenon poisoning effects resulting from fission-produced iodine during the restart-up process of a fission reactor, we introduce a completely new concept of the tritium burn-up depth and tritium break-even time in the fusion energy research area. To show what the least required amount of tritium storage is used to start up a fusion reactor and how long a time the fusion reactor needs to be operated for achieving the tritium break-even during the initial start-up phase due to the finite tritium breeding time that is dependent on the tritium breeder, specific structure of breeding zone, layout of coolant flow pipe, tritium recovery scheme, extraction process, the tritium retention of reactor components, unrecoverable tritium fraction in breeder, leakage to the inertial gas container, and the natural decay etc., we describe this new phenomenon and answer this problem by setting up and by solving a set of equations, which express a dynamic subsystem model of the tritium inventory evolution in a fusion experimental breeder (FEB). It is found that the tritium burn-up depth is 317 g and the tritium break-even time is approximately 240 full power days for FEB designed detail configuration and it is also found that after one-year operation, the tritium storage reaches 1.18 kg that is more than the least required amount of tritium storage to start up three of FEB-like fusion reactors.

  9. DEVELOPMENT AND USE OF A BULK TRITIUM SHIPPING PACKAGE

    SciTech Connect

    Blanton, P.

    2010-09-30

    A shipping package for transporting tritium has been developed for use by the National Nuclear Safety Administration as a replacement for the DOE Model UC-609, a tritium package developed and used by the DOE and NRC since the early 1970s. This paper presents the major design features and highlights the improvements made over its predecessor by incorporating new engineered materials and implementing improved testing, handling, and maintenance capabilities, while improving manufacturability. A discussion will be provided demonstrating how the BTSP complies with the regulatory safety requirements of the Nuclear Regulatory Commission. The paper further summarizes the results of testing to 10 CFR 71 Normal Conditions of Transport and Hypothetical Accident Conditions events. Planned and possible future missions for this packaging will be addressed.

  10. Enhanced control of in vivo bone formation with surface functionalized alginate microbeads incorporating heparin and human bone morphogenetic protein-2.

    PubMed

    Abbah, Sunny Akogwu; Liu, Jing; Goh, James Cho Hong; Wong, Hee-Kit

    2013-02-01

    In this study, we tested the hypothesis that a surface functionalization delivery platform incorporating heparin onto strontium alginate microbeads surfaces would convert this "naive carriers" into "mini-reservoirs" for localized in vivo delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2) that will induce functional bone regeneration. In vitro evaluation confirmed that (1) heparin incorporation could immobilize and prolong rhBMP-2 release for approximately 3 weeks; (2) a significant decrease (p<0.01) in rhBMP-2 burst release is attainable depending on initial protein load; and (3) rhBMP-2 released from surface functionalized microbeads retained bioactivity and stimulated higher alkaline phosphatase activity in cultured C(2)C(12) cells when compared with daily administration of fresh bolus rhBMP-2. Subsequently, surface functionalized microbeads were used for in vivo delivery of rhBMP-2 at local sites of posterolateral spinal fusion surgery in rats. The microbeads were loaded into the pores of medical-grade polyepsilone caprolactone-tricalcium phosphate scaffolds before implantation. Results revealed robust bone formation and a biomechanically solid fusion after 6 weeks. When compared with a control group consisting of an equivalent amount of rhBMP-2 that was directly adsorbed onto bare-surfaced microbeads with no heparin, a 5.3-fold increase in bone volume fraction and a 2.6-fold increase in bending stiffness (flexion/extension) were observed. When compared with collagen sponge carriers of rhBMP-2, a 1.5-fold and a 1.3-fold increase in bone volume fraction and bending stiffness were observed, respectively. More importantly, 3D micro-computed tomography images enabled the visualization of a well-contained newly formed bone at ipsilateral implant sites with surface functionalized rhBMP-2 delivery. This was absent with collagen sponge carriers where newly formed bone tissue was poorly contained and crossed over the posterior midline to contralateral