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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 control, October 1984-September 1985

    SciTech Connect

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

    1986-01-28

    This semi-annual report was previously titled ''Tritium Waste Control''. The current title denotes the enlarged scope of the document, which now includes nonwaste related subjects such as tritium monitoring and improved tritium containment systems. Individual projects are indexed separately.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Field Deployable Tritium Assay System Remote Control Software

    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

  9. 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.

  10. Upgrade to the Tritium Remote Control and Monitoring System for TFTR D and D

    SciTech Connect

    P. Sichta; G. Oliaro; S. Sengupta

    2002-01-28

    Since 1988, the Tritium Remote Control and Monitoring System (TRECAMS) has performed crucial functions in support of D-T [deuterium-tritium] operations of the Tokamak Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory (PPPL). Although plasma operations on TFTR were completed in 1997, the need for TRECAMS continued. During this period TRECAMS supported the TFTR tritium systems, the TFTR's Shutdown and Safing phase, and the TFTR Decontamination and Decommissioning (D and D) project. The most critical function of the TRECAMS in the post-TFTR era has been to provide a real-time indication of the airborne tritium levels in the tritium areas and the (HVAC) stacks. TRECAMS is a critical tool in conducting safe TFTR D and D tritium-line breaks and other tritium-related work activities. Beginning in 1998, the failure rate of the system's hardware sharply increased. Furthermore, the specialized knowledge required to maintain the original software and hardware was diminishing. It soon became apparent that a failure of the TRECAMS could significantly impact the TFTR D and D project's cost and schedule. To preclude this, the TRECAMS hardware and software was upgraded in the year 2000 to use modern components. This paper will describe that successful upgrade, including a review of the engineering processes and our operating experiences with the upgraded system.

  11. 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.

  12. 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.

  13. Metal ion blockage of tritium incorporation into gamma-carboxyglutamic acid of prothrombin. Stoichiometry of gamma-carboxyglutamic acid to Gd3+ for the high affinity sites

    SciTech Connect

    Bajaj, S.P.; Saini, R.; Katz, A.; Cai, G.Z.; Maki, S.L.; Brodsky, G.L.

    1988-07-15

    Prothrombin possesses two high affinity and four low affinity gamma-carboxyglutamic acid (Gla)-dependent gadolinium binding sites. Earlier work has shown that tritium can be specifically incorporated at the gamma-carbon of Gla in proteins at pH 5. In the present work we show that inclusion of saturating concentrations of Ca2+ in nondenaturing buffer systems ranging from pH 5.5 to 8.5 prevents the exchange of tritium into all 10 Gla residues of prothrombin. Similarly, saturating concentrations of Gd3+ prevent tritium incorporation into Gla at pH 5.5. Positive cooperativity was observed for the binding of Gd3+ to human prothrombin (at pH 5.5) for the two high affinity sites (Kd congruent to 35 nM). The four low affinity sites bind Gd3+ with a Kd congruent to 5 microM. Incubation of prothrombin ranging in concentrations from 10 to 40 microM with 2 eq of Gd3+ at pH 5.5 prevents 5.7 (average of seven determinations) Gla residues from tritium incorporation. Sedimentation velocity experiments conducted at pH 5.5 indicate that prothrombin in the presence of saturating concentrations of Gd3+ polymerizes, most likely, to a trimer. Further, in the presence of 2 eq of Gd3+, calculated percent weight average concentration of monomer prothrombin is congruent to 100% at 10 microM, approximately equal to 95% at 20 microM, and congruento to 80% at 40 microM protein concentration. Thus, it appears that under conditions in which prothrombin primarily exists as a monomer, occupancy of the initial two metal binding sites by Gd3+ involves six Gla residues.

  14. 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

  15. 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.

  16. 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.

  17. Importance of root HTO uptake in controlling land-surface tritium dynamics after an-acute HT deposition: a numerical experiment.

    PubMed

    Ota, Masakazu; Nagai, Haruyasu; Koarashi, Jun

    2012-07-01

    To investigate the role of belowground root uptake of tritiated water (HTO) in controlling land-surface tritium (T) dynamics, a sophisticated numerical model predicting tritium behavior in an atmosphere-vegetation-soil system was developed, and numerical experiments were conducted using the model. The developed model covered physical tritiated hydrogen (HT) transport in a multilayered atmosphere and soil, as well as microbial oxidation of HT to HTO in the soil, and it was incorporated into a well-established HTO-transfer organically bound tritium (OBT)-formation model. The model performance was tested through the simulation of an existing HT-release experiment. Numerical experiments involving a hypothetical acute HT exposure to a grassland field with a range of rooting depths showed that the HTO release from the leaves to the atmosphere, driven by the root uptake of the deposited HTO, can exceed the HTO evaporation from the ground surface to the atmosphere when root water absorption preferentially occurs beneath the ground surface. Such enhanced soil-leaf-atmosphere HTO transport, caused by the enhanced root HTO uptake, increased HTO concentrations in both the surface atmosphere and in the cellular water of the leaf. Consequently, leaf OBT assimilation calculated for shallow rooting depths increased by nearly an order of magnitude compared to that for large rooting depths. PMID:22390945

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Tritium analysis at TFTR

    SciTech Connect

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

    1995-10-01

    The tritium analytical system at TFTR 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 (QMS) and beta scintillator originally configured at Monsanto Mound Research Laboratory. The system was commissioned and tested in 1992 and is used daily for analysis of calibration standards, incoming tritium shipments, gases evolved from uranium storage beds and effluent gases from the tokamak. 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. 7 refs., 3 figs.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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)

  10. Using thermal evolution profiles to infer tritium speciation in nuclear site metals: an aid to decommissioning.

    PubMed

    Croudace, Ian W; Warwick, Phil E; Kim, Daeji

    2014-09-16

    Understanding the association and retention of tritium in metals has significance in nuclear decommissioning programs and can lead to cost benefits through waste reduction and recycling of materials. To develop insights, a range of metals from two nuclear sites and one non-nuclear site were investigated which had different exposure histories. Tritium speciation in metals was inferred through incremental heating experiments over the range of 20-900 °C using a Raddec Pyrolyser instrument. Systematic differences in thermal desorption profiles were found for nonirradiated and irradiated metals. In nonirradiated metals (e.g., stainless steel and copper), it was found that significant tritium had become incorporated following prolonged exposure to tritiated water vapor (HTO) or tritium/hydrogen gas (HT) in nuclear facilities. This externally derived tritium enters metals by diffusion with a rate controlled by the metal composition and whether the surface of the metal had been sealed or coated prior to exposure. The tritium is normally trapped in hydrated oxides lying along grain boundaries. In irradiated metals, an additional type of tritium can form internally through neutron capture reactions. The amount formed depends on the concentration and distribution of trace lithium and boron in the metal as well as the integrated neutron flux. Liberating this kind of tritium typically requires temperatures above 800 °C. The pattern of tritium evolution derived from simple thermal desorption experiments allows reliable inferences to be drawn on the likely origin, location, and phases that trap tritium. Any weakly bound tritium liberated at temperatures of ~100 °C is indicative of mostly HTO interactions in the metal. Any strongly bound tritium liberated over the range of 600-900 °C is indicative of neutrogenic tritium formed via neutron capture by trace Li and B. Neutron capture by lithium is likely to be more significant than for boron based on lithium's higher trace

  11. 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

  12. 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.

  13. Tritium behavior intentionally released in the room

    SciTech Connect

    Kobayashi, K.; Hayashi, T.; Iwai, Y.; Yamanishi, T.; Willms, R. S.; Carlson, R. V.

    2008-07-15

    To construct a fusion reactor with high safety and acceptability, it is necessary to establish and to ensure tritium safe handling technology. Tritium should be well-controlled not to be released to the environment excessively and to prevent workers from excess exposure. It is especially important to grasp tritium behavior in the final confinement area, such as the room and/or building. In order to obtain data for actual tritium behavior in a room and/or building, a series of intentional Tritium Release Experiments (TREs) were planned and carried out within a radiologically controlled area (main cell) at Tritium System Test Assembly (TSTA) in Los Alamos National Laboratory (LANL) under US-JAPAN collaboration program. These experiments were carried out three times. In these experiments, influence of a difference in the tritium release point and the amount of hydrogen isotope for the initial tritium behavior in the room were suggested. Tritium was released into the main cell at TSTA/LANL. The released tritium reached a uniform concentration about 30 - 40 minutes in all the experiments. The influence of the release point and the amount of hydrogen isotope were not found to be important in these experiments. The experimental results for the initial tritium behavior in the room were also simulated well by the modified three-dimensional eddy flow analysis code FLOW-3D. (authors)

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Tritium labeling of amino acids and peptides with liquid and solid tritium

    SciTech Connect

    Peng, C.T.; Hua, R.L.; Souers, P.C.; Coronado, P.R.

    1988-01-01

    Amino acids and peptides were labeled with liquid and solid tritium at 21 K and 9 K. At these low temperatures radiation degradation is minimal, and tritium incorporation increases with tritium concentration and exposure time. Ring saturation in L-phenyl-alanine does not occur. Peptide linkage in oligopeptides is stable toward tritium. Deiodination in 3-iodotyrosine and 3,5-diiodotyrosine occurs readily and proceeds in steps by losing one iodine atom at a time. Nickel and noble metal supported catalysts when used as supports for dispersion of the substrate promote tritium labeling at 21 K. Our study shows that both liquid and solid tritium are potentially useful agents for labeling peptides and proteins. 11 refs., 1 fig., 3 tabs.

  1. Tritium labeling of amino acids and peptides with liquid and solid tritium

    SciTech Connect

    Souers, P.C.; Coronado, P.R.; Peng, C.T.; Hua, R.L.

    1988-01-01

    Amino acids and peptides were labeled with liquid and solid tritium at 21/degree/K and 9/degree/K. At these low temperatures radiation degradation is minimal, and tritium incorporation increases with tritium concentration and exposure time. Ring saturation in L-phenylalanine does not occur. Peptide linkage in oligopeptides is stable toward tritium. Deiodination in 3-iodotyrosine and 3,5-diiodotyrosine occurs readily and proceeds in steps by losing one iodine atom at a time. Nickel and noble metal supported catalysts when used as supports for dispersion of the substrate promote tritium labeling at 21 K. Our study shows that both liquid and solid tritiums are potentially useful agents for labeling peptides and proteins.

  2. Tritium labeling of amino acids and peptides with liquid and solid tritium

    SciTech Connect

    Peng, C.T.; Hua, R.L.; Souers, P.C.; Coronado, P.R.

    1988-09-01

    Amino acids and peptides were labeled with liquid and solid tritium at 21 K and 9 K. At these low temperatures radiation degradation is minimal, and tritium incorporation increases with tritium concentration and exposure time. Ring saturation in L-phenyl-alanine does not occur. Peptide linkage in oligopeptides is stable toward tritium. Deiodination in 3-iodotyrosine and 3,5-diiodotyrosine occurs readily and proceeds in steps by losing one iodine atom at a time. Nickel and noble metal supported catalysts when sued as supports for dispersion of the substrate promote tritium labeling at 21 K. The authors study shows that both liquid and solid tritium are potentially useful agents for labeling peptides and proteins.

  3. 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.

  4. 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.

  5. STAR facility tritium accountancy

    SciTech Connect

    Pawelko, R. J.; Sharpe, J. P.; Denny, B. J.

    2008-07-15

    The Safety and Tritium Applied Research (STAR) facility has been established to provide a laboratory infrastructure for the fusion community to study tritium science associated with the development of safe fusion energy and other technologies. STAR is a radiological facility with an administrative total tritium inventory limit of 1.5 g (14,429 Ci) [1]. Research studies with moderate tritium quantities and various radionuclides are performed in STAR. Successful operation of the STAR facility requires the ability to receive, inventory, store, dispense tritium to experiments, and to dispose of tritiated waste while accurately monitoring the tritium inventory in the facility. This paper describes tritium accountancy in the STAR facility. A primary accountancy instrument is the tritium Storage and Assay System (SAS): a system designed to receive, assay, store, and dispense tritium to experiments. Presented are the methods used to calibrate and operate the SAS. Accountancy processes utilizing the Tritium Cleanup System (TCS), and the Stack Tritium Monitoring System (STMS) are also discussed. Also presented are the equations used to quantify the amount of tritium being received into the facility, transferred to experiments, and removed from the facility. Finally, the STAR tritium accountability database is discussed. (authors)

  6. STAR Facility Tritium Accountancy

    SciTech Connect

    R. J. Pawelko; J. P. Sharpe; B. J. Denny

    2007-09-01

    The Safety and Tritium Applied Research (STAR) facility has been established to provide a laboratory infrastructure for the fusion community to study tritium science associated with the development of safe fusion energy and other technologies. STAR is a radiological facility with an administrative total tritium inventory limit of 1.5g (14,429 Ci) [1]. Research studies with moderate tritium quantities and various radionuclides are performed in STAR. Successful operation of the STAR facility requires the ability to receive, inventory, store, dispense tritium to experiments, and to dispose of tritiated waste while accurately monitoring the tritium inventory in the facility. This paper describes tritium accountancy in the STAR facility. A primary accountancy instrument is the tritium Storage and Assay System (SAS): a system designed to receive, assay, store, and dispense tritium to experiments. Presented are the methods used to calibrate and operate the SAS. Accountancy processes utilizing the Tritium Cleanup System (TCS), and the Stack Tritium Monitoring System (STMS) are also discussed. Also presented are the equations used to quantify the amount of tritium being received into the facility, transferred to experiments, and removed from the facility. Finally, the STAR tritium accountability database is discussed.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Biokinetic aspects of tissue-bound tritium in algae.

    PubMed

    Strack, S; Kistner, G

    1978-01-01

    For the estimate of the radiation exposure of man and for the calculation of the risk of artificial tritium from nuclear power plants, organic tissue-bound tritium is of decisive importance. In model experiments, a tritium incorporation of 61 to 71% was found from tritiated water (HTO) into organic matter of planctonic algae under under reproducible conditions and this was related to the theoretical value. In further experiments the tritium release from these high tritiated algae was of interest. Kept in darkness in tritium-free, non-sterile river water, so that autolytic processes and bacterial decomposition could occur, the concentration of HTO was measured over a period of three weeks. A relatively long half-life of tissue-bound tritium was found under various temperature conditions. Therefore it must be considered that a significant retention of tritium in biological matter has to be taken into account in a natural ecosystem. In streams into which the cooling water of a nuclear reactor is released all conditions are found already for a long turnover and cycling of artificial tritium in living organisms as well as the conditions for a favourable transport of tritium by food chains to man.

  5. 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.

  6. 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.

  7. 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.

  8. Mechanism of tritium diffusion in lithium oxide

    SciTech Connect

    Shah, R.; De Vita, A.; Heine, V.; Payne, M.C.

    1996-04-01

    Lithium oxide is a possible candidate for a breeder blanket material in fusion reactors. Tritium is generated in the material, which can be extracted and fed into the fusion reactor to help sustain the fusion reaction. Experimental studies have shown the extraction rate is controlled by diffusion of tritium in the bulk, but the exact mechanism is not clear. Here we present {ital ab} {ital initio} density functional calculations of the various diffusion pathways which have been suggested, including the diffusion of tritium as an interstitial and various vacancy assisted mechanisms. The activation energy has been calculated for each pathway, and by comparison with experimental results we have deduced which mechanism is most likely. This is shown to be a simple two-stage swapping of a lithium and tritium ion. {copyright} {ital 1996 The American Physical Society.}

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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).

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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…

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Design and construction of the Tritium Systems Test Assembly

    SciTech Connect

    Anderson, J.L.

    1980-01-01

    The objective of TSTA is to develop those aspects of tritium technology related to the fuel cycle for fusion power reactors and to develop the environmental and personnel safety systems required for such a tritium facility. The TSTA schedule calls for construction to be completed and the facility to be operational by the end of FY-1981. The project is now somewhat more than halfway through the design-construction phase and is currently on schedule for the 1981 operational milestone. In this paper the current status of the major subsystems will be discussed. The subsystems to be discussed include the: Vacuum Facility; Fuel Cleanup; Isotope Separation; Transfer Pump; Emergency Tritium Cleanup; Tritium Waste Treatment; Tritium Monitoring; Secondary Containment; and, the Master Data Acquisition and Control System.

  11. 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

  12. 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.

  13. Estimated radiation dose from timepieces containing tritium

    SciTech Connect

    McDowell-Boyer, L M

    1980-01-01

    Luminescent timepieces containing radioactive tritium, either in elemental form or incorporated into paint, are available to the general public. The purpose of this study was to estimate potential radiation dose commitments received by the public annually as a result of exposure to tritium which may escape from the timepieces during their distribution, use, repair, and disposal. Much uncertainty is associated with final dose estimates due to limitations of empirical data from which exposure parameters were derived. Maximum individual dose estimates were generally less than 3 ..mu..Sv/yr, but ranged up to 2 mSv under worst-case conditions postulated. Estimated annual collective (population) doses were less than 5 person/Sv per million timepieces distributed.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Incorporation of a controlled-release glass into a calcium phosphate cement.

    PubMed

    Khairoun, I; Boltong, M G; Gil, F J; Driessens, F C; Planell, J A; Seijas, M M; Martínez, S

    1999-04-01

    A so-called controlled-release glass was synthesized occurring in the system CaO-Na2O-P2O5. A certain sieve fraction of this glass was incorporated in a calcium phosphate cement, of which the powder contained alpha-tricalcium phosphate (alpha-TCP), dicalcium phosphate (DCP) and precipitated hydroxyapatite (HA). The glass appeared to retard the cement setting slightly and it reduced considerably the compressive strength after aging in aqueous solutions which were continuously refreshed. Scanning electron microscope (SEM) pictures and X-ray diffraction (XRD) patterns of the samples after 5 weeks of aging showed that the glass was not dissolved but that large brushite crystals were formed. Thereby, aging in CaCl2 solutions resulted in more brushite formation than aging in NaCl solutions. The brushite crystals did not reinforce the cement. Neither was the aged glass-containing cement weaker than it was before the brushite formation right after complete setting. In conclusion, the incorporation of controlled-release glasses into a calcium phosphate cement and subsequent aging in aqueous solutions did not result in the formation of macropores in the cement structure, but that of brushite crystals. This incorporation reduced the compressive strength of the cement considerably.

  19. 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.

  20. 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)

  1. 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.

  2. High-Resolution CRT Optical Film Recorder Incorporating an Optical Feedback Exposure Control.

    PubMed

    Nix, L A; Ley, G S

    1972-05-01

    A high-resolution CRT optical film recorder incorporating an optical exposure control system is described. The recorder incorporates provisions for a highly nonlinear writing rate of up to 7 to 1 that make it uniquely suited for such applications as side-look radar or sonar. Provisions are made for spot shaping permitting line fill-in between scan lines spaced up to ten spot sizes apart. The recorder achieves a linear gray scale having sixteen equal density steps for a wide range of sweep times by means of a brightness feedback loop that automatically corrects for such problems as phosphor saturation, phosphor noise, nonlinear CRT grid transfer characteristics, variation in cathode emission, and tube aging in conjunction with film gamma correction circuitry.

  3. Tritium Storage Material

    SciTech Connect

    Cowgill, Donald F.; Luo, Weifang; Smugeresky, John E.; Robinson, David B.; Fares, Stephen James; Ong, Markus D.; Arslan, Ilke; Tran, Kim L.; McCarty, Kevin F.; Sartor, George B.; Clift, W. Miles

    2008-09-01

    Nano-structured palladium is examined as a tritium storage material with the potential to release beta-decay-generated helium at the generation rate, thereby mitigating the aging effects produced by enlarging He bubbles. Helium retention in proposed structures is modeled by adapting the Sandia Bubble Evolution model to nano-dimensional material. The model shows that even with ligament dimensions of 6-12 nm, elevated temperatures will be required for low He retention. Two nanomaterial synthesis pathways were explored: de-alloying and surfactant templating. For de-alloying, PdAg alloys with piranha etchants appeared likely to generate the desired morphology with some additional development effort. Nano-structured 50 nm Pd particles with 2-3 mn pores were successfully produced by surfactant templating using PdCl salts and an oligo(ethylene oxide) hexadecyl ether surfactant. Tests were performed on this material to investigate processes for removing residual pore fluids and to examine the thermal stability of pores. A tritium manifold was fabricated to measure the early He release behavior of this and Pd black material and is installed in the Tritium Science Station glove box at LLNL. Pressure-composition isotherms and particle sizes of a comercial Pd black were measured.

  4. 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.

  5. 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.

  6. 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)

  7. Tritium inventory tracking and management

    SciTech Connect

    Eichenberg, T.W.; Klein, A.C.

    1990-09-10

    This investigation has identified a number of useful applications of the analysis of the tracking and management of the tritium inventory in the various subsystems and components in a DT fusion reactor system. Due to the large amounts of tritium that will need to be circulated within such a plant, and the hazards of dealing with the tritium an electricity generating utility may not wish to also be in the tritium production and supply business on a full time basis. Possible scenarios for system operation have been presented, including options with zero net increase in tritium inventory, annual maintenance and blanket replacement, rapid increases in tritium creation for the production of additional tritium supplies for new plant startup, and failures in certain system components. It has been found that the value of the tritium breeding ratio required to stabilize the storage inventory depends strongly on the value and nature of other system characteristics. The real operation of a DT fusion reactor power plant will include maintenance and blanket replacement shutdowns which will affect the operation of the tritium handling system. It was also found that only modest increases in the tritium breeding ratio are needed in order to produce sufficient extra tritium for the startup of new reactors in less than two years. Thus, the continuous operation of a reactor system with a high tritium breeding ratio in order to have sufficient supplies for other plants is not necessary. Lastly, the overall operation and reliability of the power plant is greatly affected by failures in the fuel cleanup and plasma exhaust systems.

  8. Tritium gas transfer pump development

    SciTech Connect

    Sharpe, C.L.

    1985-01-01

    Non-lubricated, hermetically sealed pumps for tritium service have been selected to replace Sprengel pumps in the existing Tritium Facility. These pumps will be the primary gas-transfer pumps in the planned Replacement Tritium Facility. The selected pumps are Metal Bellows Corporation's bellows pumps and Normetex scroll pumps. Pumping range for a Normetex/Metal Bellows system is from 0.01 torr suction to 2300 torr discharge. Performance characteristics of both pumps are presented. 10 figs.

  9. Dose contribution from metabolized organically bound tritium after acute tritiated water intakes in humans.

    PubMed

    Trivedi, A; Galeriu, D; Richardson, R B

    1997-10-01

    Urine samples from eight male radiation workers who had an unplanned acute tritiated water intake were measured for tritium-in-urine up to 300 d post-exposure. During the first month or so post-exposure, these individuals increased their fluid intakes to accelerate the turnover rate of tritium in the body for dose mitigation. Their daily fluid intakes reverted to normal levels in the latter period of the study. A non-linear regressional analysis of the tritium-in-urine data showed that the average biological half-life of tritium in body water, with standard deviation, was 6.3 +/- 1.0 d (range, 5.0-8.1 d) and 8.4 +/- 2.0 d (range, 6.2-12.8 d) during the respective periods of increased fluid intake and the later period of normal fluid intake. A longer term component of tritium excretion was also observed with average biological half-life of 74 +/- 18 d (range, 58-104 d), indicating the incorporation of tritium, and its retention, in the organic fractions of the body. A mathematical model was developed and used to estimate the dose increase from the metabolized organically bound tritium on the basis of the kinetics of tritium-in-urine. The model accounts for a change in the rates of urinary excretion caused by variable fluid intakes. The average dose to the body, for the eight male workers, due to the metabolized organically bound tritium was estimated to be 6.2 +/- 1.3% (range, 3.5% to 8.9%) of the committed effective dose due to tritium in the body water. This value for the dose increase from organically bound tritium is in the range of the current recommendations of the International Commission on Radiological Protection, i.e., organically bound tritium incorporated into the body contributes about 10% of the dose to the body water following tritiated water intakes.

  10. 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.

  11. Drum bubbler tritium processing system

    SciTech Connect

    Rule, Keith; Gettelfinger, Geoff; Kivler, Paul

    1998-12-01

    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. 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.

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

    SciTech Connect

    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.

  13. 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.

  14. 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.

  15. 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

  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. 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.

  18. A novel portable system for detecting and measuring tritium

    NASA Astrophysics Data System (ADS)

    Barillari, Domenico

    2007-06-01

    A novel tritium detector configuration is described based on the anthracene scintillation method. Tritium-bearing samples are applied to a plate-bearing finely sublimed anthracene crystals and viewed in a field-able PMT-based reader against a standard plate. A microprocessor-based control and signal analysis system delivers a reading with a sensitivity of better than 5 nCi 3H in approximately 3 min, and 2.3 nCi in 10 min of counting.

  19. 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.

  20. Tritium Removal System for Airtight Room in High-flux Advanced Neutron Application Reactor (HANARO) - 12110

    SciTech Connect

    Yim, Sung Paal; Lee, Jung Hee; Kim, Hyung-Kyoo; Jung, Hoan Sung; Lee, Cheo Kyung; Yoo, Sun Kyun

    2012-07-01

    An Airtight room was installed to prevent the diffusion of tritium from the instrument room to other areas in HANARO. It was isolated by a robust structure and the inside was closed tightly. A Tritium removal system located outside the instrument room was connected to the airtight room to lower the tritium concentration when the workers enter the room for maintenance of the instruments. The tritium concentration and the dew point in the airtight room were continuously measured during the operation of the tritium removal system. The data were analyzed by using a model. There was a difference between the measured tritium concentration and the one obtained by the model. It is believed that the difference is due to the change of the generation rate of tritium which would increase as the dew point becomes lower. Based on this assumption, the previous equation was revised to better express the performance of the tritium removal system. It was re-estimated that the change of tritium concentration in an airtight room could be predicted well by using a model and equation proposed in the previous study. It was confirmed that there was a definite difference between the measured tritium concentration and the one obtained by equation from the model. It is believed that the difference is due to the change of the generation rate of tritium which would increase as the dew point becomes lower. Based on this assumption, the generation rate of tritium was controlled to have higher value and the change of tritium concentration in airtight room could be more correctly predicted. By using the revised equation, the tritium removal system would be operated more effectively. (authors)

  1. 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.

  2. Covalent incorporation and controlled release of active dexamethasone from injectable polyethylene glycol hydrogels.

    PubMed

    Bezuidenhout, Deon; Oosthuysen, Anel; Davies, Neil; Ahrenstedt, Lage; Dobner, Stephan; Roberts, Peter; Zilla, Peter

    2013-05-01

    Dexamethasone (Dex) is used in a wide range of applications, but may have undesirable systemic side effects. A number of techniques have thus been developed to deliver the substance locally. In this study, dexamethasone was acrylated, pegylated, and tethered to hydrolytically degradable (acrylate based) and nondegradable (vinyl sulfone based) polyethylene glycol hydrogels by nucleophilic addition. Hydrogel swelling, drug elution and drug activity were followed over an extended period in vitro. Nondegradable gels were stable for more than a year, while degradable gels showed increasing swelling ratios due to degradation that resulted in disintegration after ~12 days. Near-linear (zero order) release could be achieved in some cases with the degradable gels, while release from the nondegradable gels approximated first order initial release kinetics. Significantly delayed release was observed in all cases where the Dex was linked to the gels, when compared with controls where the drug was merely physically incorporated. Eluates from the gels containing the tethered drug showed high levels of activity for extended time periods, while the activity of the eluates from gels containing nonbound dexamethasone decreased rapidly within the first few days. Dexamethasone can thus be incorporated using nucleophilic addition chemistry to produce gels that are capable of sustained release of the active drug. The methodology is applicable to a variety of drugs that contain hydroxyl groups.

  3. 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.

  4. 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.

  5. 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

  6. 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)

  7. Hand-held tools with complex kinematics are efficiently incorporated into movement planning and online control.

    PubMed

    Baugh, Lee A; Hoe, Erica; Flanagan, J Randall

    2012-10-01

    Certain hand-held tools alter the mapping between hand motion and motion of the tool end point that must be controlled in order to perform a task. For example, when using a pool cue, the motion of the cue tip is reversed relative to the hand. Previous studies have shown that the time required to initiate a reaching movement (Fernandez-Ruiz J, Wong W, Armstrong IT, Flanagan JR. Behav Brain Res 219: 8-14, 2011), or correct an ongoing reaching movement (Gritsenko V, Kalaska JF. J Neurophysiol 104: 3084-3104, 2010), is prolonged when the mapping between hand motion and motion of a cursor controlled by the hand is reversed. Here we show that these time costs can be significantly reduced when the reversal is instantiated by a virtual hand-held tool. Participants grasped the near end of a virtual tool, consisting of a rod connecting two circles, and moved the end point to displayed targets. In the reversal condition, the rod translated through, and rotated about, a pivot point such that there was a left-right reversal between hand and end point motion. In the nonreversal control, the tool translated with the hand. As expected, when only the two circles were presented, movement initiation and correction times were much longer in the reversal condition. However, when full vision of the tool was provided, the reaction time cost was almost eliminated. These results indicate that tools with complex kinematics can be efficiently incorporated into sensorimotor control mechanisms used in movement planning and online control.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Improving Area Control Error Diversity Interchange (ADI) Program by Incorporating Congestion Constraints

    SciTech Connect

    Zhou, Ning; Etingov, Pavel V.; Makarov, Yuri V.; Guttromson, Ross T.; McManus, Bart

    2010-04-30

    The area control error (ACE) determines how much a balancing authority (BA) needs to move its regulating units to meet mandatory control performance standard requirements. Regulation is an expensive resource that could cost several hundred million dollars a year for a BA. The amount of regulation needed in a system is increasing with more intermittent generation resources added to the system. The ACE diversity interchange (ADI) program provides a tool for reducing the regulation requirement by combining ACEs from several participating BAs followed by sharing the total ACE among all participating balancing areas. The effect is achieved as a result of the low statistical correlation between the original ACEs of participating BAs. A rule-based ADI approach has already been put into practice in the US Western Interconnection. The degree of actual ACE sharing is artificially limited because of the unknown redistribution of power flows and possible system congestion (these factors are not monitored in the existing ADI). This paper proposes a two-step linear programming (LP) ADI approach that incorporates congestion constraints. In the first step of the proposed LP ADI, the line transmission limits are enforced by setting up corresponding constraints. In the second step, the business fairness is pursued. Simulation is performed to compare the properties of the proposed LP ADI and the existing rule-based ADI. Favorable features, such as avoiding line limit violations and increasing the degree of possible ACE sharing, are observed for the proposed LP ADI.

  20. 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.

  1. 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

  2. Synthesis of the E and Z isomers of the antiestrogen tamoxifen and its metabolite, hydroxytamoxifen, in tritium-labeled form

    SciTech Connect

    Robertson, D.W.; Katzenellenbogen, J.A.

    1982-06-04

    Both isomers of the potent antiestrogen tamoxifen (1,2-diphenyl-1-(4-(2-(dimethylamino)ethoxy)phenyl)-1-butene: E isomer = ICI-47699; Z isomer = ICI-46474, Nolvadex) and its metabolite, hydroxytamoxifen (1-(4-(2-(dimethylamino)ethoxy)phenyl)-1-(4-hydroxyphenyl)-2-phenyl-1-butene), have been synthesized in a high specific activity, tritium-labeled form by catalytic tritium-halogen exchange performed on brominated precursors. The synthesis of another precursor to labeled tamoxifen which would enable the incorporation of three tritium atoms into the molecule by tritium-halogen exchange is reported.

  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. 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.

  5. 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.

  6. 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.

  7. 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

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

    NASA Astrophysics Data System (ADS)

    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

    2016-09-01

    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.

  9. 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

  10. 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.

  11. 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.

  12. 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)

  13. Incorporating Single-Locus Tests into Haplotype Cladistic Analysis in Case-Control Studies

    PubMed Central

    Liu, Jianfeng; Papasian, Chris; Deng, Hong-Wen

    2007-01-01

    In case-control studies, genetic associations for complex diseases may be probed either with single-locus tests or with haplotype-based tests. Although there are different views on the relative merits and preferences of the two test strategies, haplotype-based analyses are generally believed to be more powerful to detect genes with modest effects. However, a main drawback of haplotype-based association tests is the large number of distinct haplotypes, which increases the degrees of freedom for corresponding test statistics and thus reduces the statistical power. To decrease the degrees of freedom and enhance the efficiency and power of haplotype analysis, we propose an improved haplotype clustering method that is based on the haplotype cladistic analysis developed by Durrant et al. In our method, we attempt to combine the strengths of single-locus analysis and haplotype-based analysis into one single test framework. Novel in our method is that we develop a more informative haplotype similarity measurement by using p-values obtained from single-locus association tests to construct a measure of weight, which to some extent incorporates the information of disease outcomes. The weights are then used in computation of similarity measures to construct distance metrics between haplotype pairs in haplotype cladistic analysis. To assess our proposed new method, we performed simulation analyses to compare the relative performances of (1) conventional haplotype-based analysis using original haplotype, (2) single-locus allele-based analysis, (3) original haplotype cladistic analysis (CLADHC) by Durrant et al., and (4) our weighted haplotype cladistic analysis method, under different scenarios. Our weighted cladistic analysis method shows an increased statistical power and robustness, compared with the methods of haplotype cladistic analysis, single-locus test, and the traditional haplotype-based analyses. The real data analyses also show that our proposed method has practical

  14. Incorporating single-locus tests into haplotype cladistic analysis in case-control studies.

    PubMed

    Liu, Jianfeng; Papasian, Chris; Deng, Hong-Wen

    2007-03-23

    In case-control studies, genetic associations for complex diseases may be probed either with single-locus tests or with haplotype-based tests. Although there are different views on the relative merits and preferences of the two test strategies, haplotype-based analyses are generally believed to be more powerful to detect genes with modest effects. However, a main drawback of haplotype-based association tests is the large number of distinct haplotypes, which increases the degrees of freedom for corresponding test statistics and thus reduces the statistical power. To decrease the degrees of freedom and enhance the efficiency and power of haplotype analysis, we propose an improved haplotype clustering method that is based on the haplotype cladistic analysis developed by Durrant et al. In our method, we attempt to combine the strengths of single-locus analysis and haplotype-based analysis into one single test framework. Novel in our method is that we develop a more informative haplotype similarity measurement by using p-values obtained from single-locus association tests to construct a measure of weight, which to some extent incorporates the information of disease outcomes. The weights are then used in computation of similarity measures to construct distance metrics between haplotype pairs in haplotype cladistic analysis. To assess our proposed new method, we performed simulation analyses to compare the relative performances of (1) conventional haplotype-based analysis using original haplotype, (2) single-locus allele-based analysis, (3) original haplotype cladistic analysis (CLADHC) by Durrant et al., and (4) our weighted haplotype cladistic analysis method, under different scenarios. Our weighted cladistic analysis method shows an increased statistical power and robustness, compared with the methods of haplotype cladistic analysis, single-locus test, and the traditional haplotype-based analyses. The real data analyses also show that our proposed method has practical

  15. 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

  16. 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.

  17. Concentration profiles of tritium penetrated into concrete

    SciTech Connect

    Takata, H.; Furuichi, K.; Nishikawa, M.; Fukada, S.; Katayama, K.; Takeishi, T.; Kobayashi, K.; Hayashi, T.; Namba, H.

    2008-07-15

    Concentration profiles of tritium in cement paste, mortar and concrete were measured after exposure to tritiated water vapor for a given time. Tritium penetrated a distance of about 5 cm from the exposed surface during an exposure of 6 months. The model of tritium behavior in concrete materials reported by the present authors was developed in this study with the consideration of the effects of sand and aggregate on both the diffusion coefficient of tritiated water vapor and the isotope exchange capacity. Predictive calculations based on the tritium transport model were also carried out in some situations of tritium leakage. The results of the calculations show that a large amount of tritium will be trapped in the concrete walls, and the trapped tritium will be gradually released back to the tritium handling room over the time of months to years even after the decontamination of the room is completed. (authors)

  18. 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.

  19. 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.

  20. Tritium Migration Analysis Program Version 4

    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

  1. 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

  2. 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.

  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 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

  5. Tritium systems test assembly stabilization

    SciTech Connect

    Jasen, W. G.; Michelotti, R. A.; Anast, K. R.; Tesch, Charles

    2004-01-01

    The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium technology Research and Development (R&D) primarily for future fusion power reactors. The facility was conceived in mid 1970's, operations commenced in early 1980's, stabilization and deactivation began in 2000 and were completed in 2003. The facility will remain in a Surveillance and Maintenance (S&M) mode until the Department of Energy (DOE) funds demolition of the facility, tentatively in 2009. A safe and stable end state was achieved by the TSTA Facility Stabilization Project (TFSP) in anticipation of long term S&M. At the start of the stabilization project, with an inventory of approximately 140 grams of tritium, the facility was designated a Hazard Category (HC) 2 Non-Reactor Nuclear facility as defined by US Department of Energy standard DOE-STD-1027-92 (1997). The TSTA facility comprises a laboratory area, supporting rooms, offices and associated laboratory space that included more than 20 major tritium handling systems. The project's focus was to reduce the tritium inventory by removing bulk tritium, tritiated water wastes, and tritium-contaminated high-inventory components. Any equipment that remained in the facility was stabilized in place. All of the gloveboxes and piping were rendered inoperative and vented to atmosphere. All equipment, and inventoried tritium contamination, remaining in the facility was left in a safe-and-stable state. The project used the End Points process as defined by the DOE Office of Environmental Management (web page http://www.em.doe.- gov/deact/epman.htmtlo) document and define the end state required for the stabilization of TSTA Facility. The End Points process added structure that was beneficial through virtually all phases of the project. At completion of the facility stabilization project the residual tritium inventory was approximately 3,000 curies, considerably less than the 1.6-gram threshold for a HC 3 facility. TSTA is now designated as a

  6. 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

  7. 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.

  8. Measurement assurance program for LSC analyses of tritium samples

    SciTech Connect

    Levi, G.D. Jr.; Clark, J.P.

    1997-05-01

    Liquid Scintillation Counting (LSC) for Tritium is done on 600 to 800 samples daily as part of a contamination control program at the Savannah River Site`s Tritium Facilities. The tritium results from the LSCs are used: to release items as radiologically clean; to establish radiological control measures for workers; and to characterize waste. The following is a list of the sample matrices that are analyzed for tritium: filter paper smears, aqueous, oil, oily rags, ethylene glycol, ethyl alcohol, freon and mercury. Routine and special causes of variation in standards, counting equipment, environment, operators, counting times, samples, activity levels, etc. produce uncertainty in the LSC measurements. A comprehensive analytical process measurement assurance program such as JTIPMAP{trademark} has been implemented. The process measurement assurance program is being used to quantify and control many of the sources of variation and provide accurate estimates of the overall measurement uncertainty associated with the LSC measurements. The paper will describe LSC operations, process improvements, quality control and quality assurance programs along with future improvements associated with the implementation of the process measurement assurance program.

  9. Storage and Assay of Tritium in STAR

    SciTech Connect

    Longhurst, Glen R.; Anderl, Robert A.; Pawelko, Robert J.; Stoots, Carl J.

    2005-07-15

    The Safety and Tritium Applied Research (STAR) facility at the Idaho National Engineering and Environmental Laboratory (INEEL) is currently being commissioned to investigate tritium-related safety questions for fusion and other technologies. The tritium inventory for the STAR facility will be maintained below 1.5 g to avoid the need for STAR to be classified as a Category 3 nuclear facility. A key capability in successful operation of the STAR facility is the ability to receive, inventory, and dispense tritium to the various experiments underway there. The system central to that function is the Tritium Storage and Assay System (SAS).The SAS has four major functions: (1) receiving and holding tritium, (2) assaying, (3) dispensing, and (4) purifying hydrogen isotopes from non-hydrogen species.This paper describes the design and operation of the STAR SAS and the procedures used for tritium accountancy in the STAR facility.

  10. Tritium issues in plasma wall interactions

    NASA Astrophysics Data System (ADS)

    Tanabe, Tetsuo

    2010-05-01

    Since tritium resources are very limited, not only for safety reason but also for tritium economy, tritium inventory in a reactor must be kept as small as possible. In the present tokamaks, however, hydrogen retention rate in their vacuum vessel is significantly large, i.e. more than 20% of fueled hydrogen is continuously piled up, which must not be allowed in a reactor. After the introduction of tritium as a hydrogen radioisotope, the paper summarizes present tritium issues in plasma wall interactions, in particular, fueling, retention and recovering, considering the handling of large amounts of tritium, i.e. confinement, leakage, contamination, permeation, regulations and tritium accountancy. Progress in overcoming such problems will be also presented.

  11. 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.

  12. 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.

  13. 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)

  14. 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…

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Sodium-Doped Molybdenum Targets for Controllable Sodium Incorporation in CIGS Solar Cells

    SciTech Connect

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

    2011-01-01

    The efficiency of Cu(In, Ga)Se{sub 2} (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.

  20. 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.

  1. Tritium retention in jet cryopanel samples

    SciTech Connect

    Walthers, C.R.; Jenkins, E.M. ); Mayaux, C.; Obert, W. )

    1991-01-01

    The possibility that tritium might exchange with water trapped in aluminum anodize cryopanels in JET prompted a test program at the Tritium Systems Test Assembly, TSTA, Los Alamos, New Mexico. JET furnished two test pieces of cryopanel which were exposed to tritium at approximately liquid nitrogen temperature and 25 torr pressure for nearly two weeks. One specimen was removed and the retained tritium was measured. The second specimen was subjected to several increasing temperature vacuum bakeouts and the effectiveness of the bakeouts were inferred from the pressure history of the chamber. When the retained tritium in the second specimen was measured it was found that nearly 95% of the tritium, as measured in the first specimen, had been removed during the vacuum bakeouts. If the tritium retained in the cryopanel without bakeout were scaled to JET conditions according to a linear pressure time relationship, the tritium expected to become trapped in the JET cryopanels would be approximately 0.6 gram. Testing is currently underway at TSTA which will determine the tritium retention to be expected under more realistic JET operating conditions and which will assess the effectiveness of various bake or purge schemes in removing the trapped tritium. 2 refs., 2 figs.

  2. Titanium for long-term tritium storage

    SciTech Connect

    Heung, L.K.

    1994-12-01

    Due to the reduction of nuclear weapon stockpile, there will be an excess of tritium returned from the field. The excess tritium needs to be stored for future use, which might be several years away. A safe and cost effective means for long term storage of tritium is needed. Storing tritium in a solid metal tritide is preferred to storing tritium as a gas, because a metal tritide can store tritium in a compact form and the stored tritium will not be released until heat is applied to increase its temperature to several hundred degrees centigrade. Storing tritium as a tritide is safer and more cost effective than as a gas. Several candidate metal hydride materials have been evaluated for long term tritium storage. They include uranium, La-Ni-Al alloys, zirconium and titanium. The criteria used include material cost, radioactivity, stability to air, storage capacity, storage pressure, loading and unloading conditions, and helium retention. Titanium has the best combination of properties and is recommended for long term tritium storage.

  3. Normalized Tritium Quantification Approach (NoTQA) a Method for Quantifying Tritium Contaminated Trash and Debris at LLNL

    SciTech Connect

    Dominick, J L; Rasmussen, C L

    2008-07-23

    Several facilities and many projects at LLNL work exclusively with tritium. These operations have the potential to generate large quantities of Low-Level Radioactive Waste (LLW) with the same or similar radiological characteristics. A standardized documented approach to characterizing these waste materials for disposal as radioactive waste will enhance the ability of the Laboratory to manage them in an efficient and timely manner while ensuring compliance with all applicable regulatory requirements. This standardized characterization approach couples documented process knowledge with analytical verification and is very conservative, overestimating the radioactivity concentration of the waste. The characterization approach documented here is the Normalized Tritium Quantification Approach (NoTQA). This document will serve as a Technical Basis Document which can be referenced in radioactive waste characterization documentation packages such as the Information Gathering Document. In general, radiological characterization of waste consists of both developing an isotopic breakdown (distribution) of radionuclides contaminating the waste and using an appropriate method to quantify the radionuclides in the waste. Characterization approaches require varying degrees of rigor depending upon the radionuclides contaminating the waste and the concentration of the radionuclide contaminants as related to regulatory thresholds. Generally, as activity levels in the waste approach a regulatory or disposal facility threshold the degree of required precision and accuracy, and therefore the level of rigor, increases. In the case of tritium, thresholds of concern for control, contamination, transportation, and waste acceptance are relatively high. Due to the benign nature of tritium and the resulting higher regulatory thresholds, this less rigorous yet conservative characterization approach is appropriate. The scope of this document is to define an appropriate and acceptable

  4. 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.

  5. Control of gene transfer on a DNA-fibronectin-apatite composite layer by the incorporation of carbonate and fluoride ions.

    PubMed

    Yazaki, Yushin; Oyane, Ayako; Sogo, Yu; Ito, Atsuo; Yamazaki, Atsushi; Tsurushima, Hideo

    2011-07-01

    Gene transfer techniques are useful tools for controlling cell behavior, such as proliferation and differentiation. We have recently developed an efficient area-specific gene transfer system using a DNA-fibronectin-apatite composite layer (DF-Ap layer). In this system, partial dissolution of the composite layer is likely to be a crucial step for gene transfer. In the present study, layer solubility was adjusted by incorporating various contents of carbonate or fluoride ions into the DF-Ap layer via ionic substitution for the apatite crystals. Carbonate ion incorporation increased the solubility of the DF-Ap layer, thereby increasing the efficiency of gene transfer on the layer. In contrast, the incorporation of fluoride ions decreased the solubility of the DF-Ap layer, thereby decreasing the efficiency and delaying the timing of gene transfer on the layer dose-dependently. The present gene transfer system with controllable efficiency and timing would be useful in tissue engineering applications because cell differentiation can be induced effectively by regulating appropriate gene expression with suitable timing.

  6. EFFECTS OF TRITIUM EXPOSURE ON UHMW-PE, PTFE, AND VESPEL

    SciTech Connect

    Clark, E; Kirk Shanahan, K

    2006-05-31

    Samples of three polymers, Ultra-High Molecular Weight Polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, also known as Teflon{reg_sign}), and Vespel{reg_sign} polyimide were exposed to 1 atmosphere of tritium gas at ambient temperature for varying times up to 2.3 years in closed containers. Sample mass and size measurements (to calculate density), spectra-colorimetry, dynamic mechanical analysis (DMA), and Fourier-transform infrared spectroscopy (FT-IR) were employed to characterize the effects of tritium exposure on these samples. Changes of the tritium exposure gas itself were characterized at the end of exposure by measuring total pressure and by mass spectroscopic analysis of the gas composition. None of the polymers exhibited significant changes of density. The color of initially white UHMW-PE and PTFE dramatically darkened to the eye and the color also significantly changed as measured by colorimetry. The bulk of UHMW-PE darkened just like the external surfaces, however the fracture surface of PTFE appeared white compared to the PTFE external surfaces. The white interior could have been formed while the sample was breaking or could reflect the extra tritium dose at the surface directly from the gas. The dynamic mechanical response of UHMW-PE was typical of radiation effects on polymers- an initial stiffening (increased storage modulus) and reduction of viscous behavior after three months exposure, followed by lowering of the storage modulus after one year exposure and longer. The storage modulus of PTFE increased through about nine months tritium exposure, then the samples became too weak to handle or test using DMA. Characterization of Vespel{reg_sign} using DMA was problematic--sample-to-sample variations were significant and no systematic change with tritium exposure could be discerned. Isotopic exchange and incorporation of tritium into UHMW-PE (exchanging for protium) and into PTFE (exchanging for fluorine) was observed by FT-IR using an attenuated

  7. 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.

  8. Development of a tritium monitor combined with an electrochemical tritium pump using a proton conducting oxide

    SciTech Connect

    Tanaka, M.; Sugiyama, T.

    2015-03-15

    The detection of low level tritium is one of the key issues for tritium management in tritium handling facilities. Such a detection can be performed by tritium monitors based on proton conducting oxide technique. We tested a tritium monitoring system composed of a commercial proportional counter combined with an electrochemical hydrogen pump equipped with CaZr{sub 0.9}In{sub 0.1}O{sub 3-α} as proton conducting oxide. The hydrogen pump operated at 973 K under electrolysis conditions using tritiated water vapor (HTO). The proton conducting oxide extracts tritium molecules (HT) from HTO and tritium concentration is measured by the proportional counter. The advantage of the proposed tritium monitoring system is that it is able to convert HTO into molecular hydrogen.

  9. Comparison of Tritium Component Failure Rate Data

    SciTech Connect

    Lee C. Cadwallader

    2004-09-01

    Published failure rate values from the US Tritium Systems Test Assembly, the Japanese Tritium Process Laboratory, the German Tritium Laboratory Karlsruhe, and the Joint European Torus Active Gas Handling System have been compared. This comparison is on a limited set of components, but there is a good variety of data sets in the comparison. The data compared reasonably well. The most reasonable failure rate values are recommended for use on next generation tritium handling system components, such as those in the tritium plant systems for the International Thermonuclear Experimental Reactor and the tritium fuel systems of inertial fusion facilities, such as the US National Ignition Facility. These data and the comparison results are also shared with the International Energy Agency cooperative task on fusion component failure rate data.

  10. Tritium Retention and Removal in Tokamaks

    SciTech Connect

    Skinner, Charles H.

    2009-02-19

    Management of tritium inventory remains one of the grand challenges in the development of fusion energy. Tritium is an important source term in safety assessments, it is expensive and in short supply. Tritium can be continuously retained in a tokamak by codeposition with eroded carbon or beryllium and JET and TFTR with carbon plasma facing components showed a tritium retention level that would be unacceptable in ITER or future fusion reactors. Asdex-U and Alcator C-mod have shown reduced hydrogenic retention with tungsten clad and molybdenum plasma facing components. Once the tritium inventory approaches the administrative limit, tritium must be removed to permit continued D-T plasma operations. Several candidate techniques are being considered and need to be proven at a relevant speed and efficiency in contemporary tokamaks. Projections for ITER are discussed.

  11. Tritium retention and removal on TFTR

    SciTech Connect

    Mueller, D.; Blanchard, W.; Doyle, B.L.

    1997-11-01

    Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the injected fuel in the torus. Tritium has been successfully removed from TFTR by glow discharge cleaning and by air purges. The in-vessel inventory was reduced by a factor of 2, facilitating machine maintenance. In TFTR, the amount of dust recovered from the TFTR vacuum vessel has varied from several grams to a few kilograms.

  12. Tritium retention and removal on TFTR

    SciTech Connect

    Mueller, D.; Blanchard, W.; Doyle, B.L.

    1997-10-01

    Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the injected fuel in the torus. Tritium has been successfully removed from TFTR by glow discharge cleaning and by air purges. The in-vessel inventory was reduced by a factor of 2, facilitating machine maintenance. In TFTR, the amount of dust recovered from the TFTR vacuum vessel has varied from several grams to a few kilograms.

  13. Tritium Removal from Carbon Plasma Facing Components

    SciTech Connect

    C.H. Skinner; J.P. Coad; G. Federici

    2003-11-24

    Tritium removal is a major unsolved development task for next-step devices with carbon plasma-facing components. The 2-3 order of magnitude increase in duty cycle and associated tritium accumulation rate in a next-step tokamak will place unprecedented demands on tritium removal technology. The associated technical risk can be mitigated only if suitable removal techniques are demonstrated on tokamaks before the construction of a next-step device. This article reviews the history of codeposition, the tritium experience of TFTR (Tokamak Fusion Test Reactor) and JET (Joint European Torus) and the tritium removal rate required to support ITER's planned operational schedule. The merits and shortcomings of various tritium removal techniques are discussed with particular emphasis on oxidation and laser surface heating.

  14. DEPLOYMENT OF THE BULK TRITIUM SHIPPING PACKAGE

    SciTech Connect

    Blanton, P.

    2013-10-10

    A new Bulk Tritium Shipping Package (BTSP) was designed by the Savannah River National Laboratory to be a replacement for a package that has been used to ship tritium in a variety of content configurations and forms since the early 1970s. The BTSP was certified by the National Nuclear Safety Administration in 2011 for shipments of up to 150 grams of Tritium. Thirty packages were procured and are being delivered to various DOE sites for operational use. This paper summarizes the design features of the BTSP, as well as associated engineered material improvements. Fabrication challenges encountered during production are discussed as well as fielding requirements. Current approved tritium content forms (gas and tritium hydrides), are reviewed, as well as, a new content, tritium contaminated water on molecular sieves. Issues associated with gas generation will also be discussed.

  15. HiPER Tritium factory elements

    NASA Astrophysics Data System (ADS)

    Guillaume, Didier

    2011-06-01

    HiPER will include a Tritium target factory. This presentation is an overview. We start from process ideas to go to first sketch passing through safety principles. We will follow the Tritium management process. We need first a gas factory producing the right gas mixture from hydrogen, Deuterium and Tritium storage. Then we could pass through the target factory. It is based on our LMJ single shot experiment and some new development like the injector. Then comes pellet burst and vapour recovery. The Tritium factory has to include the waste recovery, recycling process with gas purification before storage. At least, a nuclear plant is not a classical building. Tritium is also very special... All the design ideas have to be adapted. Many facilities are necessary, some with redundancy. We all have to well known these constraints. Tritium budget will be a major contributor for a material point of view as for a financial one.

  16. Subwog 12-D tritium technology meeting

    SciTech Connect

    Parker, M.J.; Addis, R.P.

    1991-01-01

    The first Subwog 12-D Tritium Technology Meeting was held at the Westinghouse Savannah River Site during the week of May 21, 1990. Subwog 12-D was created as a subwog of JOWOG 12 to address the need to understand tritium applications throughout the entire weapons complex. This includes weapons related concerns, but is primarily intended to cover tritium production and handling, environmental, safety and health issues, compatibility with materials in general; and facility design, commissioning and decommissioning activities. Tritium technology issues discussed included the physical and chemical properties, kinetics, storage, reservoir loading techniques, isotope exchange, radiolysis/aging, process and handling technology, compatibility, purification and filtering, analysis, monitoring methods, function testing, packaging and shipping, environmental and operational safety, facility design and safety, glovebox atmosphere clean-up systems, glovebox/facility decommissioning, tritium production target materials, and tritium recovery. This document provides a collection of most of the unclassified extended abstracts and abstracts presented at Subwog 12-D.

  17. Subwog 12-D tritium technology meeting. Abstracts

    SciTech Connect

    Parker, M.J.; Addis, R.P.

    1991-12-31

    The first Subwog 12-D Tritium Technology Meeting was held at the Westinghouse Savannah River Site during the week of May 21, 1990. Subwog 12-D was created as a subwog of JOWOG 12 to address the need to understand tritium applications throughout the entire weapons complex. This includes weapons related concerns, but is primarily intended to cover tritium production and handling, environmental, safety and health issues, compatibility with materials in general; and facility design, commissioning and decommissioning activities. Tritium technology issues discussed included the physical and chemical properties, kinetics, storage, reservoir loading techniques, isotope exchange, radiolysis/aging, process and handling technology, compatibility, purification and filtering, analysis, monitoring methods, function testing, packaging and shipping, environmental and operational safety, facility design and safety, glovebox atmosphere clean-up systems, glovebox/facility decommissioning, tritium production target materials, and tritium recovery. This document provides a collection of most of the unclassified extended abstracts and abstracts presented at Subwog 12-D.

  18. Recovery of tritium from tritiated molecules

    DOEpatents

    Swansiger, W.A.

    1984-10-17

    This invention relates to the recovery of tritium from various tritiated molecules by reaction with uranium. More particularly, the invention relates to the recovery of tritium from tritiated molecules by reaction with uranium wherein the reaction is conducted in a reactor which permits the reaction to occur as a moving front reaction from the point where the tritium enters the reactor charged with uranium down the reactor until the uranium is exhausted.

  19. Tritium radioluminescent devices, Health and Safety Manual

    SciTech Connect

    Traub, R.J.; Jensen, G.A.

    1995-06-01

    This document consolidates available information on the properties of tritium, including its environmental chemistry, its health physics, and safe practices in using tritium-activated RL lighting. It also summarizes relevant government regulations on RL lighting. Chapters are divided into a single-column part, which provides an overview of the topic for readers simply requiring guidance on the safety of tritium RL lighting, and a dual-column part for readers requiring more technical and detailed information.

  20. Tritium in precipitation of Vostok (Antarctica): conclusions on the tritium latitude effect.

    PubMed

    Hebert, Detlef

    2011-09-01

    During the Antarctic summer of 1985 near the Soviet Antarctic station Vostok, firn samples for tritium measurements were obtained down to a depth of 2.40 m. The results of the tritium measurements are presented and discussed. Based on this and other data, conclusions regarding the tritium latitude effect are derived.

  1. Storage and Assay of Tritium in STAR

    SciTech Connect

    Glen R. Longhurst; Robert A. Anderl; Robert J. Pawelko

    2004-09-01

    The Safety and Tritium Applied Research (STAR) facility has recently been commissioned to investigate tritium-related safety questions for fusion and other technologies. The authorized inventory of tritium is 1.6 grams, the threshold quantity for nuclear facility classification. A key capability in successful operation of the STAR facility is the ability to receive, inventory, and dispense tritium to the various experiments underway there. The system central to that function is the Tritium Storage and Assay System (SAS). The SAS has four major functions: (1) receiving and holding tritium from shipping containers brought into the STAR facility, (2) assaying the amount of tritium in the SAS, (3) dispensing tritium to secondary beds or containers used for transferring it to the experimental systems in the STAR facility, and (4) purifying hydrogen isotopes from non-hydrogen species. To that may be added a fifth, optional function, isotopic separation of hydrogen isotopes using bed-to-bed transfer techniques. This paper documents the design and operation of the STAR SAS and the procedures used for tritium accountancy in the STAR facility.

  2. Tritium proof-of-principle pellet injector

    SciTech Connect

    Fisher, P.W.

    1991-07-01

    The tritium proof-of-principle (TPOP) experiment was designed and built by Oak Ridge National Laboratory (ORNL) to demonstrate the formation and acceleration of the world's first tritium pellets for fueling of future fusion reactors. The experiment was first used to produce hydrogen and deuterium pellets at ORNL. It was then moved to the Tritium Systems Test Assembly at Los Alamos National Laboratory for the production of tritium pellets. The injector used in situ condensation to produce cylindrical pellets in a 1-m-long, 4-mm-ID barrel. A cryogenic {sup 3}He separator, which was an integral part of the gun assembly, was capable of lowering {sup 3}He levels in the feed gas to <0.005%. The experiment was housed to a glovebox for tritium containment. Nearly 1500 pellets were produced during the course of the experiment, and about a third of these were pure tritium or mixtures of deuterium and tritium. Over 100 kCi of tritium was processed through the experiment without incident. Tritium pellet velocities of 1400 m/s were achieved with high-pressure hydrogen propellant. The design, operation, and results of this experiment are summarized. 34 refs., 44 figs., 3 tabs.

  3. Tritium proof-of-principle pellet injector

    NASA Astrophysics Data System (ADS)

    Fisher, P. W.

    1991-07-01

    The tritium proof-of-principle (TPOP) experiment was designed and built by Oak Ridge National Laboratory (ORNL) to demonstrate the formation and acceleration of the world's first tritium pellets for fueling of future fusion reactors. The experiment was first used to produce hydrogen and deuterium pellets at ORNL. It was then moved to the Tritium Systems Test Assembly at Los Alamos National Laboratory for the production of tritium pellets. The injector used in situ condensation to produce cylindrical pellets in a 1-m-long, 4-mm-ID barrel. A cryogenic He-3 separator, which was an integral part of the gun assembly, was capable of lowering He-3 levels in the feed gas to less than 0.005 percent. The experiment was housed to a glovebox for tritium containment. Nearly 1500 pellets were produced during the course of the experiment, and about a third of these were pure tritium or mixtures of deuterium and tritium. Over 100 kCi of tritium was processed through the experiment without incident. Tritium pellet velocities of 1400 m/s were achieved with high-pressure hydrogen propellant. The design, operation, and results of this experiment are summarized.

  4. Tritium removal and separation technology developments

    SciTech Connect

    Bonnett, I.; Busigin, A.; Shapiro, A.

    2008-07-15

    Recent increased interest from regulators and the public has led more organizations to consider the environmental impact and safety considerations of tritium handling. Examples include the significance of the tritium isotope separation system on ITER licensing, remediation of ground water from power utilities and government facilities and concerns of high tritium concentrations within operational CANDU reactors. GE Healthcare, formerly Amersham pic, has been producing tritium-labelled chemicals since the late 1940's. GE's manufacturing site located near Cardiff, UK has installed a tritium waste treatment and enrichment facility to radically reduce tritium discharges to the environment. This facility employs a continuous processing plant that recovers tritium from a complex mixture of tritiated organic and aqueous waste compounds. Two isotope separation techniques are used to achieve a final pure tritium product, which is used in the manufacturing of labelled compounds. Building upon this experience, together with Special Separations Applications Inc. (SSAI), GE has developed a large-scale diffusion-based isotope separation process as an alternative to conventional cryogenic distillation. Having a tritium inventory an order of magnitude lower than conventional cryogenic distillation, this process is attractive for heavy water detritiation, applicable to single and multi-unit CANDU reactors and research reactors as well as fusion applications. Additionally, the new process has advantages of being cryogen-free, less complex, simple to operate and having improved conventional and radiological safety. (authors)

  5. Distribution of bomb tritium in the ocean

    SciTech Connect

    Broecker, W.S.; Peng, T.H.; Ostlund, G.

    1986-12-15

    A global picture of the water column inventories of bomb-produced tritium is constructed from the GEOSECS data set. This picture is compared with that obtained by combining the bomb tritium input function of Weiss and Roether (1980) with the bomb radiocarbon calibrate lateral redistribution model of Broecker et al. (1985). While differences between the calculated and observed distribution exist, they are surprisingly small. Tritium distributions calculated using the lateral redistribution model provide predictions of the changes to be expected in the next few decades. Such predictions are essential to the design of sound strategies for continued monitoring of the tritium transient.

  6. Microbial control of insect pests in temperate orchard systems: potential for incorporation into IPM.

    PubMed

    Lacey, Lawrence A; Shapiro-Ilan, David I

    2008-01-01

    Because of their selectivity and safety, microbial control agents (MCAs) appear to be ready-made components of integrated pest management (IPM) systems that do not pose a threat to applicators or the environment and allow other natural enemies to function. Control of several orchard pest insects using MCAs, including viruses, Bacillus thuringiensis, fungi, and entomopathogenic nematodes (EPNs), have been demonstrated in apple, pear, stone fruits, citrus, and several nut crops. B. thuringiensis is the most used MCA for control of lepidopteran orchard pests. Significant use of EPNs in citrus for control of root weevils is also reported. The granulovirus of codling moth is used increasingly in apple and pear by organic growers, with interest also shown by conventional growers. Although some success has been achieved, in most orchard systems MCAs account for a relatively small proportion of the pest control tactics employed, and in some systems they are not used at all. Research toward improving MCA efficacy and economic competitiveness is required to enhance the role of MCAs in IPM.

  7. The effects of tritium and decay helium on the fracture toughness properties of stainless steels

    SciTech Connect

    Morgan, M.J.

    1991-01-01

    J-integral fracture mechanics techniques and scanning electron microscopy observations were used to investigate the effects of tritium and its decay product, helium-3, on Types 304L, 316L, 21-6-9, A286, and JBK-75 (Modified A286) stainless steels. Tritium-exposed samples of each steel had lower fracture toughness values and less resistance to stable crack growth than control samples. Type 316L stainless steel was more resistant to the embrittling effects of tritium and decay helium than the other steels.

  8. The effects of tritium and decay helium on the fracture toughness properties of stainless steels

    SciTech Connect

    Morgan, M.J.

    1991-12-31

    J-integral fracture mechanics techniques and scanning electron microscopy observations were used to investigate the effects of tritium and its decay product, helium-3, on Types 304L, 316L, 21-6-9, A286, and JBK-75 (Modified A286) stainless steels. Tritium-exposed samples of each steel had lower fracture toughness values and less resistance to stable crack growth than control samples. Type 316L stainless steel was more resistant to the embrittling effects of tritium and decay helium than the other steels.

  9. Computer controlled [ital in] [ital situ] radiolysis electron spin resonance spectrometer incorporating magnetic field-microwave frequency locking

    SciTech Connect

    Madden, K.P.; McManus, H.J.D.; Fessenden, R.W. )

    1994-01-01

    A lab-built personal computer-based electron spin resonance (ESR) spectrometer is described which incorporates a wide range magnetic field/microwave frequency lock as part of its magnetic field control subsystem. Instrument operation is accomplished by keyboard commands, with important experimental variables logged automatically for reference during subsequent data analysis. The spectrometer features both narrowband field modulation and direct-detection time-resolved ESR modes. The data acquisition system and field/frequency lock operate such that spectrum recordings consisting of multiple magnetic field sweeps are undistorted by long-term klystron frequency drift. The spectrometer features low noise microwave preamplification, balanced mixer detection, automatic reference arm phase control, and a fast automatic frequency control system requiring no klystron frequency modulation. Natural abundance [sup 13]C and [sup 33]S studies of the terephthalic acid radical trianion and sulfite radical anion are presented as proof of spectrometer performance.

  10. 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

  11. 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.

  12. Tritium storage/delivery and associated cleanup systems for TFTR

    SciTech Connect

    Gill, J.T.; Anderson, B.E.; Watkins, R.A.; Pierce, C.W.

    1982-01-01

    The Tritium Storage and Delivery System (TSDS) will provide the tritium for high power plasmas in TFTR. TSDS will store tritium as solid uranium tritide at room temperature. At greater than or equal to 400/sup 0/C gas may be released from uranium and pumped through a metal bellows pump to a holding volume. Acceptably pure T/sub 2/ will be passed along a 40 m manifold into the storage volumes of three piezoelectric gas injection valves above the torus. Tests on several above components are described. Process components are contained within evacuable housings and three seismically qualified gloveboxes. Two of these boxes are serviced by catalytic oxidation/dessicant adsorption-based T/sub 2/ cleanup systems, one of which is dedicated and the other also detritiating torus and neutral beam exhaust gases. TSDS is located in a sealable vault, its air purifiable by a third such system. Emergency dehumidification of the torus test cell and its basement is also provided. TSDS and the cleanup systems will operate remotely under hardwired interlocks and operator-interactive computer control. Interlocks are safety-oriented and, e.g., prevent overheating of uranium, overpressurization of bellows pumps, and large glovebox pressure excursions. Tritium monitors are important to cleanup interlocks.

  13. Tritium storage/delivery and associated cleanup systems for TFTR

    SciTech Connect

    Gill, J.T.; Anderson, B.E.; Watkins, R.A.; Pierce, C.W.

    1983-04-01

    The tritium storage and delivery system (TSDS) will provide the tritium for high power plasmas in TFTR. TSDS will store tritium as solid uranium tritide at room temperature. At > or approx. =400 /sup 0/C gas may be released from uranium and pumped through a metal bellows pump to a holding volume. Acceptably pure T/sub 2/ will be passed along a approx.100-ft manifold into the storage volumes of three piezoelectric gas injection valves above the torus. Tests on several above components are described. Process components are contained within evacuable housings and three seismically qualified gloveboxes. Two of these boxes are serviced by catalytic oxidation/dessicant adsorption-based T/sub 2/ cleanup systems, one of which is dedicated and the other also detritiating torus and neutral beam exhaust gases. TSDS is located in a sealable vault, it is air purifiable by a third such system. Emergency dehumidification of the torus test cell and its basement is also provided. TSDS and the cleanup systems will operate remotely under hardwired interlocks and operator--interactive computer control. Interlocks are safety-oriented and, e.g., prevent overheating of uranium, overpressurization of bellows pumps, and large glovebox pressure excursions. Tritium monitors are important to cleanup interlocks.

  14. 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

    2015-10-18

    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.

  15. 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

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

    PubMed Central

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

    2015-01-01

    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

  17. Passive transdermal systems whitepaper incorporating current chemistry, manufacturing and controls (CMC) development principles.

    PubMed

    Van Buskirk, Glenn A; Arsulowicz, Daniel; Basu, Prabir; Block, Lawrence; Cai, Bing; Cleary, Gary W; Ghosh, Tapash; González, Mario A; Kanios, David; Marques, Margareth; Noonan, Patrick K; Ocheltree, Terrance; Schwarz, Peter; Shah, Vinod; Spencer, Thomas S; Tavares, Lino; Ulman, Katherine; Uppoor, Rajendra; Yeoh, Thean

    2012-03-01

    In this whitepaper, the Manufacturing Technical Committee (MTC) of the Product Quality Research Institute has updated the 1997 Transdermal Drug Delivery Systems Scale-Up and Post Approval Change workshop report findings to add important new product development and control principles. Important topics reviewed include ICH harmonization, quality by design, process analytical technologies, product and process validation, improvements to control of critical excipients, and discussion of Food and Drug Administration's Guidance on Residual Drug in Transdermal and Related Drug Delivery Systems as well as current thinking and trends on in vitro-in vivo correlation considerations for transdermal systems. PMID:22215291

  18. 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.

  19. 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...

  20. Tritium percolation, convection, and permeation in fusion solid breeder blankets

    SciTech Connect

    Billone, M.C.; Liu, Y.Y.

    1985-01-01

    Models are developed to describe the percolation of released tritium through the breeder interconnected porosity to the purge stream, convection of tritium by the helium purge stream, and leakage or permeation of tritium through the structural material to the primary coolant system. Important parameters in the models are tritium generation rate, breeder microstructure, tritium species in the gas phase, temperatures, tritium diffusivities and permeabilities, and effectiveness of oxide barriers.

  1. A remotely operated, field deployable tritium analysis system for surface and groundwater measurement

    SciTech Connect

    Cable, P.R.; Hofstetter, K.J.; Beals, D.M.; Jones, J.D.; Collins, S.L.; Noakes, J.E.; Spaulding, J.D.; Neary, M.P.; Peterson, R.

    1996-12-31

    A prototype system for the remote, in situ analysis of tritium in surface and ground waters has been developed at the Savannah River Site through the combined efforts of university, private industry, and government laboratory personnel under a project funded by the DOE/OTD. Using automated liquid scintillation counting techniques, the Field Deployable Tritium Analysis System (FDTAS) has been shown in laboratory and limited field tests to have sufficient sensitivity to measure tritium in water samples at environmental levels (10 Bq/L [{approximately}300 pCi/L] for a 100-minute count) on a near-real time basis. These limits are well below the EPA drinking water standard for tritium at 740 Bq/L (1) and lower than the normal upstream Savannah River tritium concentration of {approximately}40 Bq/L (2). The FDTAS consists of a fixed volume sampler (50 mL), an on-line water purification system, and a stop-flow liquid scintillation counter for detecting tritium in the purified sample. All operations are controlled and monitored by a remote computer using standard telephone line modem communications. The FDTAS offers a cost-effective alternative to the expensive and time-consuming methods of field sample collection and laboratory analyses for tritium in contaminated groundwater.

  2. 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.

  3. Process control through the incorporation of PLC networks in service radiation facilities

    NASA Astrophysics Data System (ADS)

    Möhlmann, J. H. F.

    In order to ensure the smooth and safe running and operation of an irradiation facility, several regulations must be complied with, most of which are prescribed by the authorities. However, internal working regulations, based on years of practical experience, are of equal importance. The application of computers, micro-processors and PLCs, in combination with semi-conductor electronics, has improved process control considerably. Not only can every step in the process and even each detailed function be controlled, but also the combination of the different functions. By using PLC-systems in combination with computers, important data can be stored, recorded and presented in such a way that the technical staff can be warned in advance of breakdowns or undesirable deviations in the process parameters. Keeping a log of these data will help guarantee the correct functioning of the irradiation facility. It is even possible with these modern PLC techniques to monitor the control-console, so that each operation is recorded and accessible.

  4. 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

  5. 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.

  6. Tritium-powered radiation sensor network

    NASA Astrophysics Data System (ADS)

    Litz, Marc S.; Russo, Johnny A.; Katsis, Dimos

    2016-05-01

    Isotope power supplies offer long-lived (100 years using 63Ni), low-power energy sources, enabling sensors or communications nodes for the lifetime of infrastructure. A tritium beta-source (12.5-year half-life) encapsulated in a phosphor-lined vial couples directly to a photovoltaic (PV) to generate a trickle current into an electrical load. An inexpensive design is described using commercial-of-the-shelf (COTS) components that generate 100 μWe for nextgeneration compact electronics/sensors. A matched radiation sensor has been built for long-duration missions utilizing microprocessor-controlled sleep modes, low-power electronic components, and a passive interrupt driven environmental wake-up. The low-power early-warning radiation detector network and isotope power source enables no-maintenance mission lifetimes.

  7. [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.

  8. 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

  9. 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.

  10. Correlation of rates of tritium migration through porous concrete

    SciTech Connect

    Fukada, S.; Katayama, K.; Takeishi, T.; Edao, Y.; Kawamura, Y.; Hayashi, T.; Yamanishi, T.

    2015-03-15

    In a nuclear facility when tritium leaks from a glovebox to room accidentally, an atmosphere detritiation system (ADS) starts operating, and HTO released is recovered by ADS. ADS starts when tritium activity in air becomes higher than its controlled level. Before ADS operates, the laboratory walls are the final enclosure facing tritium and are usually made of porous concrete coated with a hydrophobic paint. In the present study, previous data on the diffusivity and adsorption coefficient of concrete and paints are reviewed. Tritium penetrates and migrates into concrete by following 3 ways. First, gaseous HT or T{sub 2} easily penetrates into porous concrete. Its diffusivity is almost equal to that of H{sub 2}. When a gaseous molecule diffuses through pores with a smaller diameter than a mean free path, its migration rate is described by the Knudsen diffusion formula. The second mechanism is H{sub 2}O vapor diffusion in pores. Concrete holds a lot of structural water. Therefore, H{sub 2}O or HTO vapor can diffuse inside concrete pores along with adsorption-desorption and isotopic exchange with structural water, which is the third mechanism. Literature shows that the diffusivity of HTO through the epoxy-resin paint is determined as D(HTO)=1.0*10{sup -16} m{sup 2}/s. We have used this data to set a model and we have applied it to estimate residual tritium in laboratory walls. We have considered 2 accidental cases and a normal case: first, ADS starts operating 1 hour after 100 Ci HTO is released in the room, secondly, ADS starts 24 hours after 100 Ci HTO release and thirdly, when the walls are exposed to HTO for 10 years of normal operation. It appears that the immediate start up of ADS is indispensable for safety.

  11. Development of a tritium recovery system from CANDU tritium removal facility

    SciTech Connect

    Draghia, M.; Pasca, G.; Porcariu, F.

    2015-03-15

    The main purpose of the Tritium Recovery System (TRS) is to reduce to a maximum possible extent the release of tritium from the facility following a tritium release in confinement boundaries and also to have provisions to recover both elemental and vapors tritium from the purging gases during maintenance and components replacement from various systems processing tritium. This work/paper proposes a configuration of Tritium Recovery System wherein elemental tritium and water vapors are recovered in a separated, parallel manner. The proposed TRS configuration is a combination of permeators, a platinum microreactor (MR) and a trickle bed reactor (TBR) and consists of two branches: one branch for elemental tritium recovery from tritiated deuterium gas and the second one for tritium recovery from streams containing a significant amount of water vapours but a low amount, below 5%, of tritiated gas. The two branches shall work in a complementary manner in such a way that the bleed stream from the permeators shall be further processed in the MR and TBR in view of achieving the required decontamination level. A preliminary evaluation of the proposed TRS in comparison with state of the art tritium recovery system from tritium processing facilities is also discussed. (authors)

  12. IN-LINE CHEMICAL SENSOR DEPLOYMENT IN A TRITIUM PLANT

    SciTech Connect

    Tovo, L.; Wright, J.; Torres, R.; Peters, B.

    2013-10-02

    The Savannah River Tritium Plant (TP) relies on well understood but aging sensor technology for process gas analysis. Though new sensor technologies have been brought to various readiness levels, the TP has been reluctant to install technologies that have not been tested in tritium service. This gap between sensor technology development and incorporating new technologies into practical applications demonstrates fundamental challenges that exist when transitioning from status quo to state-of-the-art in an extreme environment such as a tritium plant. These challenges stem from three root obstacles: 1) The need for a comprehensive assessment of process sensing needs and requirements; 2) The lack of a pick-list of process-compatible sensor technologies; and 3) The need to test technologies in a tritium-contaminated process environment without risking production. At Savannah River, these issues are being addressed in a two phase project. In the first phase, TP sensing requirements were determined by a team of process experts. Meanwhile, Savannah River National Laboratory sensor experts identified candidate technologies and related them to the TP processing requirements. The resulting roadmap links the candidate technologies to actual plant needs. To provide accurate assessments of how a candidate sensor technology would perform in a contaminated process environment, an instrument demonstration station was established within a TP glove box. This station was fabricated to TP process requirements and designed to handle high activity samples. The combination of roadmap and demonstration station provides the following assets: Creates a partnership between the process engineers and researchers for sensor selection, maturation, and insertion, Selects the right sensors for process conditions Provides a means for safely inserting new sensor technology into the process without risking production, and Provides a means to evaluate off normal occurrences where and when they occur

  13. Mercury and tritium removal from DOE waste oils

    SciTech Connect

    Klasson, E.T.

    1997-10-01

    This work covers the investigation of vacuum extraction as a means to remove tritiated contamination as well as the removal via sorption of dissolved mercury from contaminated oils. The radiation damage in oils from tritium causes production of hydrogen, methane, and low-molecular-weight hydrocarbons. When tritium gas is present in the oil, the tritium atom is incorporated into the formed hydrocarbons. The transformer industry measures gas content/composition of transformer oils as a diagnostic tool for the transformers` condition. The analytical approach (ASTM D3612-90) used for these measurements is vacuum extraction of all gases (H{sub 2}, N{sub 2}, O{sub 2}, CO, CO{sub 2}, etc.) followed by analysis of the evolved gas mixture. This extraction method will be adapted to remove dissolved gases (including tritium) from the SRS vacuum pump oil. It may be necessary to heat (60{degrees}C to 70{degrees}C) the oil during vacuum extraction to remove tritiated water. A method described in the procedures is a stripper column extraction, in which a carrier gas (argon) is used to remove dissolved gases from oil that is dispersed on high surface area beads. This method appears promising for scale-up as a treatment process, and a modified process is also being used as a dewatering technique by SD Myers, Inc. (a transformer consulting company) for transformers in the field by a mobile unit. Although some mercury may be removed during the vacuum extraction, the most common technique for removing mercury from oil is by using sulfur-impregnated activated carbon (SIAC). SIAC is currently being used by the petroleum industry to remove mercury from hydrocarbon mixtures, but the sorbent has not been previously tested on DOE vacuum oil waste. It is anticipated that a final process will be similar to technologies used by the petroleum industry and is comparable to ion exchange operations in large column-type reactors.

  14. 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.

  15. Imaging of tritium implanted into graphite

    SciTech Connect

    Malinowski, M.E.; Causey, R.A.

    1988-05-01

    The extensive use of graphite in plasma-facing surfaces of tokamaks such as the Tokamak Fusion Test Reactor, which has planned tritium discharges, makes two-dimensional tritium detection techniques important in helping to determine torus tritium inventories. We have performed experiments in which highly oriented pyrolytic graphite (HOPG) samples were first tritium implanted with fluences of approx.10/sup 16/ T/cm/sup 2/ at energies approx. <25 eV and then the near-surface implant distributions were detected in two dimensions using tritium imaging. A portion of the sample was masked off during the implant in order to produce a well-defined implant boundary. Heating of the HOPG samples to temperatures as high as 500 /sup 0/C resulted in no discernible motion of tritium along the basal plane, but did show that significant desorption of the implanted tritium occurred. The current results indicate that tritium in quantities of 10/sup 12/ T/cm/sup 2/ in tritiated components could be readily detected by imaging at lower magnifications.

  16. HYLIFE-II tritium management system

    SciTech Connect

    Longhurst, G.R.; Dolan, T.J.

    1993-06-01

    The tritium management system performs seven functions: (1) tritium gas removal from the blast chamber, (2) tritium removal from the Flibe, (3) tritium removal from helium sweep gas, (4) tritium removal from room air, (5) hydrogen isotope separation, (6) release of non-hazardous gases through the stack, (7) fixation and disposal of hazardous effluents. About 2 TBq/s (5 MCi/day) of tritium is bred in the Flibe (Li{sub 2}BeF{sub 4}) molten salt coolant by neutron absorption. Tritium removal is accomplished by a two-stage vacuum disengager in each of three steam generator loops. Each stage consists of a spray of 0.4 mm diameter, hot Flibe droplets into a vacuum chamber 4 m in diameter and 7 m tall. As droplets fall downward into the vacuum, most of the tritium diffuses out and is pumped away. A fraction {Phi}{approx}10{sup {minus}5} of the tritium remains in the Flibe as it leaves the second stage of the vacuum disengager, and about 24% of the remaining tritium penetrates through the steam generator tubes, per pass, so the net leakage into the steam system is about 4.7 MBq/s (11 Ci/day). The required Flibe pumping power for the vacuum disengager system is 6.6 MW. With Flibe primary coolant and a vacuum disengager, an intermediate coolant loop is not needed to prevent tritium from leaking into the steam system. An experiment is needed to demonstrate vacuum disengager operation with Flibe. A secondary containment shell with helium sweep gas captures the tritium permeating out of the Flibe ducts, limiting leaks there to about 1 Ci/day. The tritium inventory in the reactor is about 190 g, residing mostly in the large Flibe recirculation duct walls. The total cost of the tritium management system is 92 M$, of which the vacuum disengagers cost = 56%, the blast chamber vacuum system = 15%, the cryogenic plant = 9%, the emergency air cleanup and waste treatment systems each = 6%, the protium removal system = 3%, and the fuel storage system and inert gas system each = 2%.

  17. DOE handbook: Tritium handling and safe storage

    SciTech Connect

    1999-03-01

    The DOE Handbook was developed as an educational supplement and reference for operations and maintenance personnel. Most of the tritium publications are written from a radiological protection perspective. This handbook provides more extensive guidance and advice on the null range of tritium operations. This handbook can be used by personnel involved in the full range of tritium handling from receipt to ultimate disposal. Compliance issues are addressed at each stage of handling. This handbook can also be used as a reference for those individuals involved in real time determination of bounding doses resulting from inadvertent tritium releases. This handbook provides useful information for establishing processes and procedures for the receipt, storage, assay, handling, packaging, and shipping of tritium and tritiated wastes. It includes discussions and advice on compliance-based issues and adds insight to those areas that currently possess unclear DOE guidance.

  18. Tritium/ 3He dating of shallow groundwater

    NASA Astrophysics Data System (ADS)

    Schlosser, Peter; Stute, Martin; Dörr, Helmut; Sonntag, Christian; Münnich, Karl Otto

    1988-08-01

    Combined tritium/ 3He data from three multi-level sampling wells (DFG 1, DFG 4, DFG 7) located at Liedern/ Bocholt, West Germany, are presented and principles of the tritium/ 3He method in shallow groundwater studies are discussed. The 3He excess produced by radioactive decay of bomb tritium (released mainly between 1952 and 1963) is clearly reflected in the data. The tritiogenic 3He signal can be detected with a good resolution (signal/1σ error: ≈ 350). The confinement of the tritiogenic 3He is estimated to approximately 77-85% at site DFG 4. For the bomb tritium peak the deviation of the tritium/ 3He age from the age determined by identifying the groundwater layer recharged between 1962 and 1965 is about 3 years (15%). The deviation can be explained by diffusive 3He loss across the groundwater table and by flow dispersion.

  19. Pf/Zeolite Catalyst for Tritium Stripping

    SciTech Connect

    Hsu, R.H.

    2001-03-26

    This report described promising hydrogen (protium and tritium) stripping results obtained with a Pd/zeolite catalyst at ambient temperature. Preliminary results show 90-99+ percent tritium stripping efficiency may be obtained, with even better performance expected as bed configuration and operating conditions are optimized. These results suggest that portable units with single beds of the Pd/zeolite catalyst may be utilized as ''catalytic absorbers'' to clean up both tritium gas and tritiated water. A cart-mounted prototype stripper utilizing this catalyst has been constructed for testing. This portable stripper has potential applications in maintenance-type jobs such as tritium line breaks. This catalyst can also potentially be utilized in an emergency stripper for the Replacement Tritium Facility.

  20. Tritium issues in commercial pressurized water reactors

    SciTech Connect

    Jones, G.

    2008-07-15

    Tritium has become an important radionuclide in commercial Pressurized Water Reactors because of its mobility and tendency to concentrate in plant systems as tritiated water during the recycling of reactor coolant. Small quantities of tritium are released in routine regulated effluents as liquid water and as water vapor. Tritium has become a focus of attention at commercial nuclear power plants in recent years due to inadvertent, low-level, chronic releases arising from routine maintenance operations and from component failures. Tritium has been observed in groundwater in the vicinity of stations. The nuclear industry has undertaken strong proactive corrective measures to prevent recurrence, and continues to eliminate emission sources through its singular focus on public safety and environmental stewardship. This paper will discuss: production mechanisms for tritium, transport mechanisms from the reactor through plant, systems to the environment, examples of routine effluent releases, offsite doses, basic groundwater transport and geological issues, and recent nuclear industry environmental and legal ramifications. (authors)

  1. Uptake of atmospheric tritium by market foods

    SciTech Connect

    Inoue, Y.; Tanaka-Miyamoto, K.; Iwakura, T. )

    1992-03-01

    In this paper uptake of tritium by market foods from tritiated water vapor in the air is investigated using cereals and beans purchased in Deep River, Canada. The concentrations of tissue free water tritium (TFWT) and organically bound tritium (OBT) range from 12 to 79% and from 10 to 38% respectively, of that estimated for atmospheric water vapor of the sampling month. The specific activity ratios of OBT to TFWT were constant for cereals, but variable for beans. The elevated OBT was shown to be the result of isotopic exchange of labile hydrogen by the fact that washing the foods with tritium free-water reduced their tritium contents to levels characteristic of their production sites.

  2. Monolayer-level controlled incorporation of nitrogen in ultra-thin gate dielectrics using remote plasma processing

    NASA Astrophysics Data System (ADS)

    Niimi, Hiroaki

    A low thermal budget approach to monolayer-level controlled incorporation of nitrogen in ultra-thin gate dielectrics using remote plasma processing is discussed. Incorporation of nitrogen at the Si-SiO2 interface, 'N-O' structure, is achieved by 300°C O2/He remote plasma assisted oxidation of the Si surface followed by N2/He remote plasma nitridation at 0.3 Torr. Secondary ion mass spectroscopy (SIMS) showed that the interfacial nitrogen concentration was linearly proportional to the N2/He plasma exposure time. One monolayer of nitrogen, ˜ 7 x 1014 cm-2, at the Si-SiO 2 interface was achieved by the 90-second N2/He plasma nitridation. This monolayer of nitrogen at the interface reduced leakage currents in Fowler-Nordheim (F-N) and direct tunneling regimes. Core-level photoemission spectroscopy (PES) revealed that the post-oxidation nitridation reduced sub-oxide densities at the interface. This interfacial 'modification' contributed to the reduction of tunneling currents. Incorporation of nitrogen on the top surface of oxide, 'O-N' structure, is achieved by 300°C N2/He remote plasma nitridation of the bulk oxide at 0.1 Torr. SIMS data showed the nitrogen was confined only at the top surface of oxide. This top surface 'nitrided' layer suppressed boron diffusion from boron doped p+ poly-Si gate-electrodes. Thus, combining interfacial and top surface nitridation processes, ' N-O-N' structure, reduced leakage currents and prevented boron diffusion, so that this combination is applicable for advanced symmetric complementary metal-oxide-semiconductor (CMOS) technology.

  3. Biological half-life and oxidative stress effects in mice with low-level, oral exposure to tritium.

    PubMed

    Kelsey-Wall, Angel; Seaman, John C; Jagoe, Charles H; Dallas, Cham E

    2006-02-01

    Tritium ((3)H) may enter the environment from human activities, particularly at production, processing, or waste storage sites such as the Department of Energy's Savannah River Site, a former nuclear production facility in South Carolina. Understanding the dynamics and potential adverse effects of tritium in exposed organisms is critical to evaluating risks of tritium releases at such sites. Previous studies estimated the biological half-life of tritium in mice to be approximately 1.13 d; however, these laboratory studies were not conducted under environmentally realistic conditions. In this study, designed to be more representative of environmental exposure, mice were allowed to drink water containing tritium (activity about 300 Bq/ml) for a period of 2 wk. The induction of oxidative stress from tritium exposure was evaluated by comparing the activities of antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase) in exposed and control mice. From this experiment, the biological half-life of tritium was determined to be 2.26 +/- 0.04 d, almost double previous estimates. While positive controls (x-ray irradiated mice) showed responses in antioxidant enzyme activity, there was no indication of oxidative stress induction in mice exposed to tritium at this concentration. PMID:16263691

  4. 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

  5. Out-of-pile tritium extraction from lithium orthosilicate-based ceramics

    NASA Astrophysics Data System (ADS)

    Smaihi, M.; Boilot, J. P.; Botter, F.; Mougin, J.; Boncoeur, M. J.

    1991-11-01

    Ceramics based on the lithium orthosilicate (Li 4SiO 4) are candidates as blanket materials for forthcoming fusion reactors. Lithium ceramics, with controlled stoichiometry and microstructure, have been prepared by sol-gel route and sintering at 650-800 ° C. The enhancement of the lithium conductivity is realized either by introducing mobile ion vacancies in the lithium sites of the orthosilicate type structure, or by formation of a composite material containing a few wt% of LiOH. Tritium extraction experiments, from out-of-pile, show no relation between the tritium release and the lithium bulk-diffusion within the grains. At low temperature, the tritium release is governed by water chemistry and can be described by OH -/OT -recombination and desorption. At high temperature, the tritium release is probably governed by surface reaction between adsorbed H 2 and surface OT -.

  6. PDRD (SR13046) TRITIUM PRODUCTION FINAL REPORT

    SciTech Connect

    Smith, P.; Sheetz, S.

    2013-09-30

    Utilizing the results of Texas A&M University (TAMU) senior design projects on tritium production in four different small modular reactors (SMR), the Savannah River National Laboratory’s (SRNL) developed an optimization model evaluating tritium production versus uranium utilization under a FY2013 plant directed research development (PDRD) project. The model is a tool that can evaluate varying scenarios and various reactor designs to maximize the production of tritium per unit of unobligated United States (US) origin uranium that is in limited supply. The primary module in the model compares the consumption of uranium for various production reactors against the base case of Watts Bar I running a nominal load of 1,696 tritium producing burnable absorber rods (TPBARs) with an average refueling of 41,000 kg low enriched uranium (LEU) on an 18 month cycle. After inputting an initial year, starting inventory of unobligated uranium and tritium production forecast, the model will compare and contrast the depletion rate of the LEU between the entered alternatives. This is an annual tritium production rate of approximately 0.059 grams of tritium per kilogram of LEU (g-T/kg-LEU). To date, the Nuclear Regulatory Commission (NRC) license has not been amended to accept a full load of TPBARs so the nominal tritium production has not yet been achieved. The alternatives currently loaded into the model include the three light water SMRs evaluated in TAMU senior projects including, mPower, Holtec and NuScale designs. Initial evaluations of tritium production in light water reactor (LWR) based SMRs using optimized loads TPBARs is on the order 0.02-0.06 grams of tritium per kilogram of LEU used. The TAMU students also chose to model tritium production in the GE-Hitachi SPRISM, a pooltype sodium fast reactor (SFR) utilizing a modified TPBAR type target. The team was unable to complete their project so no data is available. In order to include results from a fast reactor, the SRNL

  7. Tritium emission reduction at Darlington tritium removal facility using a Bubbler System

    SciTech Connect

    Kalyanam, K.; Leilabadi, A.; El-Behairy, O.; Williams, G. I. D.; Vogt, H. K.

    2008-07-15

    Ontario Power Generation Nuclear (OPGN) has a 4 x 880 MWe CANDU nuclear station at its Darlington Nuclear Div. located in Bowmanville. The station operates a Tritium Removal Facility (TRF) to reduce and maintain low tritium levels in the Moderator and Heat Transport heavy water systems of Ontario's CANDU fleet by extracting, concentrating, immobilizing and storing as a metal tritide. Minimizing tritium releases to the environment is of paramount importance to ensure that dose to the public is as low as reasonably achievable (ALARA) and to maintain credibility with the Public. Tritium is removed from the Cryogenic Distillation System to the Tritium Immobilization System (TIS) glove box via a transfer line that is protected by a rupture disc and relief valve. An overpressure event in 2003 had caused the rupture disc to blow, resulting in the release of a significant quantity of elemental tritium into the relief valve discharge line, which ties into the contaminated exhaust system. As a result of a few similar events occurring over a number of years of TRF operation, the released elemental tritium would have been converted to tritium oxide in the presence of a stagnant moist air environment in the stainless steel discharge line. A significant amount of tritium oxide hold-up in the discharge line was anticipated. To minimize any further releases to the environment, a Bubbler System was designed to remove and recover the tritium from the discharge line. This paper summarizes the results of several Bubbler recovery runs that were made over a period of a month. Approximately 3500 Ci of tritium oxide and 230 Ci of elemental tritium were removed and collected. The tritium contained in the water produced from the Bubbler system was later safely recovered in the station's downgraded D{sub 2}O clean-up and recovery system. (authors)

  8. A Bayesian semiparametric approach for incorporating longitudinal information on exposure history for inference in case-control studies.

    PubMed

    Bhadra, Dhiman; Daniels, Michael J; Kim, Sungduk; Ghosh, Malay; Mukherjee, Bhramar

    2012-06-01

    In a typical case-control study, exposure information is collected at a single time point for the cases and controls. However, case-control studies are often embedded in existing cohort studies containing a wealth of longitudinal exposure history about the participants. Recent medical studies have indicated that incorporating past exposure history, or a constructed summary measure of cumulative exposure derived from the past exposure history, when available, may lead to more precise and clinically meaningful estimates of the disease risk. In this article, we propose a flexible Bayesian semiparametric approach to model the longitudinal exposure profiles of the cases and controls and then use measures of cumulative exposure based on a weighted integral of this trajectory in the final disease risk model. The estimation is done via a joint likelihood. In the construction of the cumulative exposure summary, we introduce an influence function, a smooth function of time to characterize the association pattern of the exposure profile on the disease status with different time windows potentially having differential influence/weights. This enables us to analyze how the present disease status of a subject is influenced by his/her past exposure history conditional on the current ones. The joint likelihood formulation allows us to properly account for uncertainties associated with both stages of the estimation process in an integrated manner. Analysis is carried out in a hierarchical Bayesian framework using reversible jump Markov chain Monte Carlo algorithms. The proposed methodology is motivated by, and applied to a case-control study of prostate cancer where longitudinal biomarker information is available for the cases and controls. PMID:22313248

  9. 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

  10. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  11. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  12. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  13. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  14. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  15. 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.

  16. Tritium related safety considerations for mirror upgrades

    SciTech Connect

    Ghose, S.K.

    1983-11-30

    One of the primary objectives of the MFTF-B upgrades is to demonstrate the technology of tritium breeding in a reactor-like configuration. This requires use and processing of tritium, involving an inventory of several hundred grams at the plant. This paper reviews the results of a preliminary assessment of the radiation hazard associated with the handling of tritium. The radiation dose consequences due to tritium release from normal operation and due to postulated accidents on plant personnel and the public were assessed. Maximum credible (probability < 10/sup -3/, but > 10/sup -7//yr) accidental releases were estimated to be 10 gm in the reactor building and 100 gm in the tritium-processing building. Higher probability (> 10/sup -3//yr) accidents or component failures would result in much smaller releases. In the reactor building, the most severe accident would result from the rupture of a plasma exhaust duct from the end cell or the tritium feed pipe to the neutral beam injector, accompanied by a fire. In the tritium processing building, the most severe accident would be the rupture of the Isotope Separation System (ISS) distillation columns and vacuum jackets accompanied by a fire.

  17. Development of tritium technologies at KAERI

    SciTech Connect

    Chung, H.; Koo, D.; Lee, J.; Park, J.; Yim, S.P.; Yoon, C.; Lim, J.; Choi, W.; Ahn, H.; Kang, H.; Kim, I.; Paek, S.; Yunn, S.H.; Jung, K.J.

    2015-03-15

    Korea has been operating a CANDU nuclear power plant since 1983. Tritium generated in the heavy water of the plant is removed by the Wolsong TRF (Tritium Removal Facility) and measurement campaigns of tritium near the power plant have shown the efficiency of the TRF system. The HANARO reactor uses heavy water as both reflector and moderator. In HANARO the tritiated water removal system consists of compressors, condensers, and adsorption beds. A tritium behavior analysis code (TRIBAC) for a Very High Temperature Gas-Cooled Reactor (VHTR) is under development at KAERI. The TRIBAC computer software has been equipped with models for tritium production, purification, and leakage, as well as chemisorption and tritium behavior, in the hydrogen production system. Korea takes part into the ITER program and is responsible for the supply of an SDS (Tritium Storage and Delivery System). Within this program Korea has launched an experimental program to study the physico-chemical properties of metal and their hydrides in which hydrogen isotope gases can be stored and removed safely.

  18. Tritium Room Air Monitor Operating Experience Review

    SciTech Connect

    L. C. Cadwallader; B. J. Denny

    2008-09-01

    Monitoring the breathing air in tritium facility rooms for airborne tritium is a radiological safety requirement and a best practice for personnel safety. Besides audible alarms for room evacuation, these monitors often send signals for process shutdown, ventilation isolation, and cleanup system actuation to mitigate releases and prevent tritium spread to the environment. Therefore, these monitors are important not only to personnel safety but also to public safety and environmental protection. This paper presents an operating experience review of tritium monitor performance on demand during small (1 mCi to 1 Ci) operational releases, and intentional airborne inroom tritium release tests. The tritium tests provide monitor operation data to allow calculation of a statistical estimate for the reliability of monitors annunciating in actual tritium gas airborne release situations. The data show a failure to operate rate of 3.5E-06/monitor-hr with an upper bound of 4.7E-06, a failure to alarm on demand rate of 1.4E-02/demand with an upper bound of 4.4E-02, and a spurious alarm rate of 0.1 to 0.2/monitor-yr.

  19. Quick management of accidental tritium exposure cases.

    PubMed

    Singh, Vishwanath P; Badiger, N M; Managanvi, S S; Bhat, H R

    2012-07-01

    Removal half-life (RHL) of tritium is one of the best means for optimising medical treatment, reduction of committed effective dose (CED) and quick/easy handling of a large group of workers for medical treatment reference. The removal of tritium from the body depends on age, temperature, relative humidity and daily rainfall; so tritium removal rate, its follow-up and proper data analysis and recording are the best techniques for management of accidental acute tritium exposed cases. The decision of referring for medical treatment or medical intervention (MI) would be based on workers' tritium RHL history taken from their bodies at the facilities. The workers with tritium intake up to 1 ALI shall not be considered for medical treatment as it is a derived limit of annual total effective dose. The short-term MI may be considered for tritium intake of 1-10 ALI; however, if the results show intake ≥100 ALI, extended strong medical/therapeutic intervention may be recommended based on the severity of exposure for maximum CED reduction requirements and annual total effective dose limit. The methodology is very useful for pressurized heavy water reactors (PHWRs) which are mainly operated by Canada and India and future fusion reactor technologies. Proper management will optimise the cases for medical treatment and enhance public acceptance of nuclear fission and fusion reactor technologies.

  20. Lithium Ceramic Blankets for Russian Fusion Reactors and Influence of Breeding Operation Mode on Parameters of Reactor Tritium Systems

    SciTech Connect

    Kapyshev, Victor K.; Chernetsov, Mikhail Yu.; Zhevotov, Sergej I.; Kersnovskij, Alexandr Yu.; Kolbasov, Boris N.; Kovalenko, Victor G.; Paltusov, Nikolaj P.; Sernyaev, Georgeij A.; Sterebkov, Juri S.; Zyryanov, Alexej P.

    2005-07-15

    Russian controlled fusion program supposes development of a DEMO reactor design and participation in ITER Project. A solid breeder blanket of DEMO contains a ceramic lithium orthosilicate breeder and a beryllium multiplier. Test modules of the blanket are developed within the scope of ITER activities. Experimental models of module tritium breeding zones (TBZ), materials and fabrication technology of the TBZ, tritium reactor systems to analyse and process gas released from lithium ceramics are being developed. Two models of tritium breeding and neutron multiplying elements of the TBZ have been designed, manufactured and tested in IVV-2M nuclear reactor. Initial results of the in-pile experiments and outcome of lithium ceramics irradiation in a water-graphite nuclear reactor are considered to be a data base for development of the test modules and initial requirements for DEMO tritium system design. Influence of the tritium release parameters and hydrogen concentration in a purge gas on parameters of reactor system are discussed.

  1. Effects of non-equilibrium particle distributions in deuterium-tritium burning

    SciTech Connect

    Michta, D; Graziani, F; Pruet, J; Luu, T

    2009-08-18

    We investigate the effects of non-equilibrium particle distributions resulting from rapid deuterium-tritium burning in plasmas using a Fokker-Planck code that incorporates small-angle Coulomb scattering, Brehmsstrahlung, Compton scattering, and thermal-nuclear burning. We find that in inertial confinement fusion environments, deviations away from Maxwellian distributions for either deuterium or tritium ions are small and result in 1% changes in the energy production rates. The deuterium and tritium effective temperatures are not equal, but differ by only about 2.5% near the time of peak burn rate. Simulations with high Z (Xe) dopants show that the dopant temperature closely tracks that of the fuel. On the other hand, fusion product ion distributions are highly non-Maxwellian, and careful treatments of energy-exchange between these ions and other particles is important for determining burn rates.

  2. Tritium monitor with improved gamma-ray discrimination

    DOEpatents

    Cox, Samson A.; Bennett, Edgar F.; Yule, Thomas J.

    1985-01-01

    Apparatus and method for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.

  3. Tritium monitor with improved gamma-ray discrimination

    DOEpatents

    Cox, S.A.; Bennett, E.F.; Yule, T.J.

    1982-10-21

    Apparatus and method are presented for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.

  4. Tritium migration to the surfaces of Type 316 stainless steel; aluminum 6061; and oxygen-free, high-conductivity copper

    DOE PAGESBeta

    Sharpe, M.; Shmayda, W. T.; Schroder, W. U.

    2016-05-25

    The migration of tritium to the surfaces of aluminum 6061, oxygen-free, high-conductivity copper (OFHC), and stainless-steel 316 from the bulk metal was studied using low-pressure Tonks–Langmuir argon plasma. The plasma is shown to be effective at removing tritium from metal surfaces in a controlled manner. Tritium is removed in decreasing quantities with successive plasma exposures, which suggests a depletion of the surface and near-surface tritium inventories. A diffusion model was developed to predict tritium migration from the bulk and its accumulation in the water layers present on the metal surface. The model reproduces the rate of tritium re-growth on themore » surface for all three metals and can be used to calculate the triton solubility in the water layers present on metal surfaces. The ratio of surface-to-bulk solubilities at the water-layer/bulk-metal interface uniquely determines the concentration ratio between these two media. Removing the tritium-rich water layers induces tritium to migrate from the bulk to the surface. Furthermore, this process is driven by a concentration gradient that develops in the bulk because of the perturbation on the surface.« less

  5. SHINE Tritium Nozzle Design: Activity 6, Task 1 Report

    SciTech Connect

    Okhuysen, Brett S.; Pulliam, Elias Noel

    2015-11-05

    In FY14, we studied the qualitative and quantitative behavior of a SHINE/PNL tritium nozzle under varying operating conditions. The result is an understanding of the nozzle’s performance in terms of important flow features that manifest themselves under different parametric profiles. In FY15, we will consider nozzle design with a focus on nozzle geometry and integration. From FY14 work, we will understand how the SHINE/PNL nozzle behaves under different operating scenarios. The first task for FY15 is to evaluate the FY14 model as a predictor of the actual flow. Considering different geometries is more time-intensive than parameter studies, therefore we recommend considering any relevant flow features that were not included in the FY14 model. In the absence of experimental data, it is particularly important to consider any sources of heat in the domain or boundary conditions that may affect the flow and incorporate these into the simulation if they are significant. Additionally, any geometric features of the beamline segment should be added to the model such as the orifice plate. The FY14 model works with hydrogen. An improvement that can be made for FY15 is to develop CFD properties for tritium and incorporate those properties into the new models.

  6. Tritium Pumps for ITER Roughing System

    SciTech Connect

    Antipenkov, Alexander; Day, Christian; Mack, August; Wagner, Robert; Laesser, Rainer

    2005-07-15

    The ITER roughing system provides for both the initial pump-down of the vessel itself and the regular pump-out of the batch-regenerating cryopumps. This system must have a large pumping speed and cope with the radioactive gas tritium at the same time. The present paper shall highlight the results of the ITER roughing train optimization, discuss the modification of a Roots pump for tritium, and present the results of a ferrofluidic seal test and the first tests of a tailor-made tritium-proof Roots pump with inactive gases.

  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.

  8. 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.

  9. Predicted fate of tritium residuum from groundwater tracer experiments in the Amargosa Desert, southern Nevada

    SciTech Connect

    Brikowski, T.

    1993-07-01

    Analytic solutions are used in this study to evaluate potential groundwater transport of tritium used in goundwater tracer tests southwest of the Nevada Test Site. Possible transport from this site is of interest because initial radionuclide concentrations were high and the site is close to goundwater discharge points (12 km). Anecdotal evidence indicates that 90 percent of these tracers were removed by pumping at the completion of the tests; this study examines the probable transport of the tracers with and without the removal. Classical dispersive transport analytic solutions are used, treating the tracer test as a point slug injection. Input parameters for the solutions were measured at the site, and consideration of parameter uncertainty is incorporated in the results. With removal of the tracer, the maximum expected region with above-Safe Drinking Water Act (40 CFR 121) concentrations of tritium extends 5 km from the injection point, and does not reach any sites of public access. Detectable tritium from the tests is likely to have reached the Ash Meadows fault zone, but flow along the fault probably diluted the tracer to below detection limits before arrival at springs along the fault. Arrival at the springs would have occurred 20 to 25 years after the tests. Without removal of the tracer, the solutions indicate that tritium concentrations just above Safe Drinking Water Act standards would have reached the Ash Meadows fault zone. In this case, detectable tritium might have been found in Devil`s Hole or Longstreet Spring, the nearest points of possible public exposure.

  10. Tritium containing polymers having a polymer backbone substantially void of tritium

    DOEpatents

    Jensen, George A.; Nelson, David A.; Molton, Peter M.

    1992-01-01

    A radioluminescent light source comprises a solid mixture of a phosphorescent substance and a tritiated polymer. The solid mixture forms a solid mass having length, width, and thickness dimensions, and is capable of self-support. In one aspect of the invention, the phosphorescent substance comprises solid phosphor particles supported or surrounded within a solid matrix by a tritium containing polymer. The tritium containing polymer comprises a polymer backbone which is essentially void of tritium.

  11. Tritium containing polymers having a polymer backbone substantially void of tritium

    DOEpatents

    Jensen, G.A.; Nelson, D.A.; Molton, P.M.

    1992-03-31

    A radioluminescent light source comprises a solid mixture of a phosphorescent substance and a tritiated polymer. The solid mixture forms a solid mass having length, width, and thickness dimensions, and is capable of self-support. In one aspect of the invention, the phosphorescent substance comprises solid phosphor particles supported or surrounded within a solid matrix by a tritium containing polymer. The tritium containing polymer comprises a polymer backbone which is essentially void of tritium. 2 figs.

  12. Tritium laboratory with multiple purposes at NIPNE Magurele Romania

    SciTech Connect

    Matei, L.; Postolache, C.

    2008-07-15

    The Tritium Laboratory from NIPNE (Romania)) is part of Radioisotope Research and Production Center. The Tritium Laboratory has been in operation since 1960, and carries out R and D activities involving tritium sources in gaseous, liquids and solid state, provides specialized service to CANDU NPP Cernavoda (Romania)), and provides tritium assay services to internal and external customers. The paper presents the activities and perspectives of Tritium Laboratory and its performances in accordance with Quality System Management. (authors)

  13. 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

  14. Effectiveness of phototherapy incorporated into an exercise program for osteoarthritis of the knee: study protocol for a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Osteoarthritis is a chronic disease with a multifactor etiology involving changes in bone alignment, cartilage, and other structures necessary to joint stability. There is a need to investigate therapeutic resources that combine different wavelengths as well as different light sources (low-level laser therapy and light-emitting diode therapy) in the same apparatus for the treatment of osteoarthritis. The aim of the proposed study is to analyze the effect of the incorporation of phototherapy into a therapeutic exercise program for individuals with osteoarthritis of the knee. Methods/Design A double-blind, controlled, randomized clinical trial will be conducted involving patients with osteoarthritis of the knee. Evaluations will be performed using functional questionnaires before and after the treatment protocols, in a reserved room with only the evaluator and participant present, and no time constraints placed on the answers or evaluations. The following functional tests will also be performed: stabilometry (balance assessment), dynamometry (muscle strength of gluteus medius and quadriceps), algometry (pain threshold), fleximeter (range of motion), timed up-and-go test (functional mobility), and the functional reach test. The participants will then be allocated to three groups through a randomization process using opaque envelopes: exercise program, exercise program + phototherapy, or exercise program + placebo phototherapy, all of which will last for eight weeks. Discussion The purpose of this randomized clinical trial is to analyze the effect of the incorporation of phototherapy into a therapeutic exercise program for osteoarthritis of the knee. The study will support the practice based on evidence to the use of phototherapy in individuals with a diagnosis of osteoarthritis of the knee. Data will be published after the study is completed. Trial registration The protocol for this study has been submitted to Clinical Trials, registration number

  15. 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.

  16. The Concentration Of Tritium In Urine And Internal Radiation Dose Estimation Of PTNBR Radiation Workers

    NASA Astrophysics Data System (ADS)

    Tjahaja, Poppy Intan; Sukmabuana, Putu; Aisyah, Neneng Nur

    2010-12-01

    The operation of Triga 2000 reactor in Nuclear Technology Center for Materials and Radiometry (PTNBR BATAN) normally produce tritium radionuclide which is the activation product of deuterium atom in reactor primary cooling water. According to previous monitoring, tritium was detected with the concentration of 8.236±0.677 kBq/L and 1.704±0.046 Bq/L in the primary cooling water and in reactor hall air, respectively. The tritium in reactor hall air chronically can be inhaled by the workers. In this research, tritium content in radiation workers' urine was determined to estimate the internal radiation doses received by the workers. About 50-100 mL of urine samples were collected from 48 PTNBR workers that is classified as 24 radiation workers and 24 administration staffs as a control. Urine samples of 25 mL were then prepared by active charcoal and KMnO4 addition and followed with complete distillation. The 2 mL of distillate was added with 13 mL scintillator, shaked vigorously and remained in cool and dark condition for about 24 hours. The tritium in the samples was then measured using liquid scintillation counter (LSC) for 1 hour. From the measurement results it was obtained that the tritium concentration in the urine of radiation workers were in the range of not detected and 5.191 Bq/mL, whereas in the administration staffs the concentration were between not detected and 4.607 Bq/mL. Internally radiation doses were calculated using the tritium concentration data, and it was found the averages about 0.602 μSv/year and 0.532 μSv/year for radiation workers and administration staffs, respectively. The doses received by the workers were lower than that of the permissible doses from tritium, i.e. 40 μSv/year.

  17. The Concentration Of Tritium In Urine And Internal Radiation Dose Estimation Of PTNBR Radiation Workers

    SciTech Connect

    Tjahaja, Poppy Intan; Sukmabuana, Putu; Aisyah, Neneng Nur

    2010-12-23

    The operation of Triga 2000 reactor in Nuclear Technology Center for Materials and Radiometry (PTNBR BATAN) normally produce tritium radionuclide which is the activation product of deuterium atom in reactor primary cooling water. According to previous monitoring, tritium was detected with the concentration of 8.236{+-}0.677 kBq/L and 1.704{+-}0.046 Bq/L in the primary cooling water and in reactor hall air, respectively. The tritium in reactor hall air chronically can be inhaled by the workers. In this research, tritium content in radiation workers' urine was determined to estimate the internal radiation doses received by the workers. About 50-100 mL of urine samples were collected from 48 PTNBR workers that is classified as 24 radiation workers and 24 administration staffs as a control. Urine samples of 25 mL were then prepared by active charcoal and KMnO{sub 4} addition and followed with complete distillation. The 2 mL of distillate was added with 13 mL scintillator, shaked vigorously and remained in cool and dark condition for about 24 hours. The tritium in the samples was then measured using liquid scintillation counter (LSC) for 1 hour. From the measurement results it was obtained that the tritium concentration in the urine of radiation workers were in the range of not detected and 5.191 Bq/mL, whereas in the administration staffs the concentration were between not detected and 4.607 Bq/mL. Internally radiation doses were calculated using the tritium concentration data, and it was found the averages about 0.602 {mu}Sv/year and 0.532 {mu}Sv/year for radiation workers and administration staffs, respectively. The doses received by the workers were lower than that of the permissible doses from tritium, i.e. 40 {mu}Sv/year.

  18. An analysis of the tritium content in fish from Upper Three Runs Creek

    SciTech Connect

    Murphy, C.E. Jr.

    1991-05-02

    In November of 1988 the F/H-area effluent treatment facility (ETF) began releasing treated waste water to Upper Three Runs Creek. Previous to that time, there has been minimal discharge of plant waste water to this tributary of the Savannah River. The ETF is designed to remove the toxic and radioactive waste materials from the effluent stream and to meet the discharge limits of the South Carolina Department of Health and Environmental Control (SCDHEC). The only radioactive nuclide not removed by the process is tritium. Tritium, an isotope of hydrogen, is chemically associated with the water molecules in the waste stream and can not be economically removed at this time. The objective of this study was to determine the relationship between the concentration of tritium in the stream water and the concentration of tritium in the fish. Fish collections were made at two locations. The most upstream location was 50 meters downstream from the SRS Road C bridge. This is immediately downstream of the effluent discharge pipe from the ETF. The other location was at the bridge of SRS Road A (SC Highway 125). The water is removed from the fish by freeze drying under vacuum. This study suggests that, on the average, the tritium concentration of fish in Upper Three Runs Creek will be in equilibrium with the tritium in the water of the creek. The water in the fish comes into equilibrium with the water in the stream quite rapidly and it is quite likely that any single fish sampled will be higher or lower in tritium content of an integrated water sample, such as those collected by the Environmental Monitoring samplers. Both the time of sampling and the sampling of a sufficient number of fish is important in obtaining an accurate estimate of the average tritium concentration in the tissue water of the fish.

  19. Tritium Release Estimate from CLWR-Tritium Extraction Facility Waste Overpack

    SciTech Connect

    Clark, E.A.

    2001-05-23

    Spent targets (Tritium Producing Burnable Absorber Rods, TPBARs) from the Commercial Light Water Reactor-Tritium Extraction Facility (CLWR-TEF) at the Savannah River Site will be sent to waste disposal contained in a so-called ''overpack''. The tritium permeation rate through a welded stainless steel overpack was estimated using a finite difference computer program in a previous report. This report is an evaluation of tritium permeation through three additional overpack designs: (1) a stainless steel overpack sealed using a mechanical closure with a metal gasket, (2) a mild steel overpack with the same mechanical closure, and (3) an aluminum overpack sealed by welding.

  20. Procedures for a modified tritium trick-helium doping and residual tritium analysis of vanadium alloys

    NASA Astrophysics Data System (ADS)

    Ramey, D. W.; Braski, D. N.

    1985-05-01

    A modified tritium trick technique was used to implant three levels of 3He in V-15% Cr-5% Ti and Vanstar-7 specimens. The modifications include: (1) wrapping of the specimens with tantalum foil to minimize oxygen contamination and (2) tritiation treatment at 400°C to prevent vanadium tritide formation and to produce a 3He bubble distribution similar to that produced during elevated temperature irradiation. Preliminary results show that both modifications were successful. An electrochemical dissolution technique was developed to determine residual tritium levels in the vanadium alloys. Measured residual tritium levels after tritium removal were in the range of 500 to 1400 μCi/g (0.88 to 2.99 appm tritium in the alloy). Tritium solubilities in the alloys were calculated from the tritium decay time and the measured 3He content. Vanstar-7 specimens consistently absorbed about half as much tritium, and subsequently contained half as much 3He as V-15% Cr-5% Ti. Implanting 3He in vanadium alloys via the tritium trick offers a convenient technique to study the mechanism of helium embrittlement without irradiation and should provide a rapid screening method to help develop embrittlement-resistant vanadium alloys.

  1. Tritium permeation and recovery for the helium-cooled molten salt fusion breeder

    SciTech Connect

    Sherwood, A.E.

    1984-09-01

    Design concepts are presented to control tritium permeation from a molten salt/helium fusion breeder reactor. This study assumes tritium to be a gas dissolved in molten salt, with TF formation suppressed. Tritium permeates readily through the hot steel tubes of the reactor and steam generator and will leak into the steam system at the rate of about one gram per day in the absence of special permeation barriers, assuming that 1% of the helium coolant flow rate is processed for tritium recovery at 90% efficiency per pass. The proposed permeation barrier for the reactor tubes is a 10 ..mu..m layer of tungsten which, in principle, will reduce tritium blanket permeation by a factor of about 300 below the bare-steel rate. A research and development effort is needed to prove feasibility or to develop alternative barriers. A 1 mm aluminum sleeve is proposed to suppress permeation through the steam generator tubes. This gives a calculated reduction factor of more than 500 relative to bare steel, including a factor of 30 due to an assumed oxide layer. The permeation equations are developed in detail for a multi-layer tube wall including a frozen salt layer and with two fluid boundary-layer resistances. Conditions are discussed for which Sievert's or Henry's Law materials become flux limiters. An analytical model is developed to establish the tritium split between wall permeation and reactor-tube flow.

  2. Evolution of tritium from deuterided palladium subject to high electrical currents

    SciTech Connect

    Claytor, T.N.; Tuggle, D.G.; Taylor, S.F.

    1992-12-31

    An increase in the tritium level was detected in deuterium when various configurations of palladium foil or powder and silicon wafers or powder were subject to a high pulsed current. The deuterium, at one atmosphere pressure, and was circulated in a sealed loop containing the cell and an ionization chamber to measure the tritium increase as a function of time. Over 4800 hours of data, spanning 10 cells (including deuterium and hydrogen controls), were collected with this system. Average tritium production has varied from 0.02 to 0.2 nCi/h. Due to experimental constraints we have not been able to measure neutron output with these cells while simultaneously measuring the tritium increase. The question of tritium contamination in the palladium has been primarily resolved by the development of techniques that allow the palladium powder or foil to be reused. Various methods for increasing the tritium production, such as, increased current density, surface modifiers, and higher deuterium loading, will be discussed. 8 refs, 5 figs.

  3. Evolution of tritium from deuterided palladium subject to high electrical currents

    SciTech Connect

    Claytor, T.N.; Tuggle, D.G.; Taylor, S.F.

    1992-01-01

    An increase in the tritium level was detected in deuterium when various configurations of palladium foil or powder and silicon wafers or powder were subject to a high pulsed current. The deuterium, at one atmosphere pressure, and was circulated in a sealed loop containing the cell and an ionization chamber to measure the tritium increase as a function of time. Over 4800 hours of data, spanning 10 cells (including deuterium and hydrogen controls), were collected with this system. Average tritium production has varied from 0.02 to 0.2 nCi/h. Due to experimental constraints we have not been able to measure neutron output with these cells while simultaneously measuring the tritium increase. The question of tritium contamination in the palladium has been primarily resolved by the development of techniques that allow the palladium powder or foil to be reused. Various methods for increasing the tritium production, such as, increased current density, surface modifiers, and higher deuterium loading, will be discussed. 8 refs, 5 figs.

  4. A 1600 Liter Tritium Hydride Storage Vessel

    SciTech Connect

    Klein, J.E.

    2001-07-26

    Titanium was selected for evaluation as a tritium storage material. Titanium-deuterium desorption isotherm data at 550, 600, 649, 700, ad 760 degrees C are presented and were used to evaluate storage vessel design loading limits.

  5. Tritium glovebox stripper system seismic design evaluation

    SciTech Connect

    Grinnell, J. J.; Klein, J. E.

    2015-09-01

    The use of glovebox confinement at US Department of Energy (DOE) tritium facilities has been discussed in numerous publications. Glovebox confinement protects the workers from radioactive material (especially tritium oxide), provides an inert atmosphere for prevention of flammable gas mixtures and deflagrations, and allows recovery of tritium released from the process into the glovebox when a glovebox stripper system (GBSS) is part of the design. Tritium recovery from the glovebox atmosphere reduces emissions from the facility and the radiological dose to the public. Location of US DOE defense programs facilities away from public boundaries also aids in reducing radiological doses to the public. This is a study based upon design concepts to identify issues and considerations for design of a Seismic GBSS. Safety requirements and analysis should be considered preliminary. Safety requirements for design of GBSS should be developed and finalized as a part of the final design process.

  6. Tritium Depth Profiles in 316 Stainless Steel

    NASA Astrophysics Data System (ADS)

    Torikai, Yuji; Murata, Daiju; Penzhorn, Ralf-Dieter; Akaishi, Kenya; Watanabe, Kuniaki; Matsuyama, Masao

    To investigate the behavior of hydrogen uptake and release by 316 stainless steel (SS316), as-received and finely polished stainless steel specimens were exposed at 573 K to tritium gas diluted with hydrogen. Then tritium concentration in the exposed specimens was measured as a function of depth using a chemical etching method. All the tritium concentration profiles showed a sharp drop in the range of 10 μm from the top surface up to the bulk. The amount of tritium absorbed into the polished specimens was three times larger than that into the as-received specimen. However, the polishing effects disappeared by exposing to the air for a long time.

  7. Tritium Measurements in Slovenia - Chronology Till 2004

    SciTech Connect

    Logar, Jasmina Kozar; Vaupotic, Janja; Kobal, Ivan

    2005-07-15

    Almost all the analyses of tritium in Slovenia have been performed by the tritium laboratory at the Jozef Stefan Institute. Nearly 90 % of its measurements have been covered by two national programs, both approved by the Slovenian Nuclear Safety Administration: the radioactive monitoring program in the environs of Krsko Nuclear Power Plant (KNPP) and the program of global radioactive contamination monitoring in the environment. These programs include samples of groundwaters, surface waters, precipitation and drinking waters, as well as liquid and gaseous effluents from KNPP. Tritium was determined in some research projects and in hydrological studies of thermal waters, groundwater and coalmine waters. Tritium in the Karst region was mapped as well as the springs of entire territory of Slovenia. Around 5500 samples have been analyzed up to 2004.

  8. Tritium measurements with a tandem accelerator

    NASA Astrophysics Data System (ADS)

    Middleton, R.; Klein, J.; Fink, D.

    1990-06-01

    Tritium concentrations ( 3H: 2H) of less than 10 -15 are readily measurable with almost any tandem accelerator and with an overall detection efficiency as high as 4.5%. The isobar, 3He, and other potential sources of interference (mainly 6Li, 2H and 1H) can all be removed by an absorber in front of the triton detector, so there is little need for analyzing elements other than the negative-and positive-ion magnets found on most tandems. The technique is particularly well suited for detecting tritium in deuterium absorbed in a metal and testing for cold fusion. We caution that tritium can occur in commercial deuterium and heavy water from sources other than cold fusion; one sample was observed to have a tritium-to-deuterium ratio of 10 -10.

  9. Functionalized, biodegradable hydrogels for control over sustained and localized siRNA delivery to incorporated and surrounding cells.

    PubMed

    Nguyen, Khanh; Dang, Phuong Ngoc; Alsberg, Eben

    2013-01-01

    Currently, the most severe limitation to applying RNA interference technology is delivery, including localizing the molecules to a specific site of interest to target a specific cell population and sustaining the presentation of these molecules for a controlled period of time. In this study, we engineered a functionalized, biodegradable system created by covalent incorporation of cationic linear polyethyleneimine (LPEI) into photocrosslinked dextran (DEX) hydrogels through a biodegradable ester linkage. The key innovation of this system is that control over the sustained release of short interference RNA (siRNA) was achieved, as LPEI could electrostatically interact with siRNA to maintain siRNA within the hydrogels and degradation of the covalent ester linkages between the LPEI and the hydrogels led to tunable release of LPEI/siRNA complexes over time. The covalent conjugation of LPEI did not affect the swelling or degradation properties of the hydrogels, and the addition of siRNA and LPEI had minimal effect on their mechanical properties. These hydrogels exhibited low cytotoxicity against human embryonic kidney 293 cells (HEK293). The release profiles could be tailored by varying DEX (8 and 12% w/w) and LPEI (0, 5, 10 μg/100 μl gel) concentrations with nearly 100% cumulative release achieved at day 9 (8% w/w gel) and day 17 (12% w/w gel). The released siRNA exhibited high bioactivity with cells surrounding and inside the hydrogels over an extended time period. This controllable and sustained siRNA delivery hydrogel system that permits tailored siRNA release profiles may be valuable to guide cell fate for regenerative medicine and other therapeutic applications such as cancer treatment.

  10. Tritium level along Romanian Black Sea Coast

    SciTech Connect

    Varlam, C.; Stefanescu, I.; Popescu, I.; Faurescu, I.

    2008-07-15

    Establishing the tritium level along the Romanian Black Sea Coast, after 10 years of exploitation of the nuclear power plant from Cernavoda, is a first step in evaluating its impact on the Black Sea ecosystem. The monitoring program consists of tritium activity concentration measurement in sea water and precipitation from Black Sea Coast between April 2005 and April 2006. The sampling points were spread over the Danube-Black Sea Canal - before the locks Agigea and Navodari, and Black Sea along the coast to the Bulgarian border. The average tritium concentration in sea water collected from the sampling locations had the value of 11.1 {+-} 2.1 TU, close to tritium concentration in precipitation. Although an operating nuclear power plant exists in the monitored area, the values of tritium concentration in two locations are slightly higher than those recorded elsewhere. To conclude, it could be emphasized that until now, Cernavoda NPP did not had any influence on the tritium concentration of the Black Sea Shore. (authors)

  11. Tritium evolution from various morphologies of palladium

    SciTech Connect

    Tuggle, D.G.; Claytor, T.N.; Taylor, S.F. |

    1994-04-01

    The authors have been able to extend the tritium production techniques to various novel morphologies of palladium. These include small solid wires of various diameters and a type of pressed powder wire and a plasma cell. In most successful experiments, the amount of palladium required, for an equivalent tritium output, has been reduced by a factor of 100 over the older powder methods. In addition, they have observed rates of tritium production (>5 nCi/h) that far exceed most of the previous results. Unfortunately, the methods that they currently use to obtain the tritium are poorly understood and consequently there are numerous variables that need to be investigated before the new methods are as reliable and repeatable as the previous techniques. For instance, it seems that surface and/or bulk impurities play a major role in the successful generation of any tritium. In those samples with total impurity concentrations of >400 ppM essentially no tritium has been generated by the gas loading and electrical simulation methods.

  12. Management of tritium European Spallation Source

    SciTech Connect

    Ene, D.; Andersson, K.; Jensen, M.; Nielsen, S.; Severin, G.

    2015-03-15

    The European Spallation Source (ESS) will produce tritium via spallation and activation processes during operational activities. Within the location of ESS facility in Lund, Sweden site it is mandatory to demonstrate that the management strategy of the produced tritium ensures the compliance with the country regulation criteria. The aim of this paper is to give an overview of the different aspects of the tritium management in ESS facility. Besides the design parameter study of the helium coolant purification system of the target the consequences of the tritium releasing into the environment were also analyzed. Calculations show that the annual release of tritium during the normal operations represents a small fraction from the estimated total dose. However, more refined calculations of migration of activated-groundwater should be performed for higher hydraulic conductivities, with the availability of the results on soil examinations. With the assumption of 100% release of tritium to the atmosphere during the occurring of the extreme accidents, it was found as well that the total dose complies with the constraint. (authors)

  13. Circulation of tritium in the Pacific Ocean

    SciTech Connect

    Fine, R.A.; Reid, J.L.; Goete Ostlund, H.

    1981-01-01

    The input of bomb tritium into the high-latitude Northern Hemisphere waters has demonstrated the spread of a tracer in three dimensions in the North Pacific Ocean. Subsurface tritium maxima in middle and low latitudes clearly show the importance of lateral mixing (along isopycnals) in the upper waters. The tritium pattern as mapped on isopycnal surfaces puts definite time bounds on the exchange between the subtropical anticyclonic gyre of the North Pacific and both the subarctic cyclonic gyre and the system of zonal flows in the equatorial region. The penetration of bomb tritium to depths below 1000 m in the western North Pacific Ocean shows that these waters have been ventilated at least partially in the past 17 years of the post-bomb era. From the tritium pattern the upper waters of the North Pacific can be divided into three regions: a mixed layer that exchanges rapidly with the atmosphere, a laterally ventilated intermediate region (between the mixed layer and at most the winter-outcrop isopycnal) that exchanges on decadal time scales with the atmosphere, and a deeper layer penetrated by vertical diffusion alone, with a longer atmospheric exchange time scale. The greatest percentage of the tritium inventory of the North Pacific is in the intermediate region. This indicates that such lateral ventilations, which take place from all high-latitude regions, are a major source of penetration for atmospheric constituents into the oceans on decadal time scales.

  14. Recommended tritium surface contamination release guides

    SciTech Connect

    Johnson, J.R.; Draper, D.G.; Foulke, J.D.; Hafner, R.S.; Jalbert, R.A.; Kennedy, W.E.; Myers, D.S.; Strain, C.D. )

    1991-03-01

    This document was prepared to provide scientific basis for recommended changes in specific limits for tritium surface contamination in DOE Order 5480.11. A summary of the physical and biological characteristics of tritium has been provided that illustrate the unique nature of this radionuclide when compared to other pure beta emitters or to beta-gamma emitting radionuclides. This document is divided into nine sections. The introduction and the purpose and scope are addressed in Section 1.0 and Section 2.0, respectively. Section 3.0 contains recommended interpretation of terms used in this document. Section 4.0 addresses recommended methods for evaluating surface contamination. Biological and physical characteristics of tritium compounds are discussed in Section 5.0, as they relate to tritium radiotoxicity. Scenarios and dose calculations for selected, conservatively limiting cases of tritium intake are given and discussed in Section 6.0 and Section 7.0. Section 8.0 provides conclusions on the information given and recommendations for changes in the surface contamination limits for total tritium to 1 {times} 10{sup 6} dpm per 100 cm{sup 2}. 30 refs., 2 tabs.

  15. The design of an automated electrolytic enrichment apparatus for tritium

    SciTech Connect

    Myers, J.L.

    1994-12-01

    The Radiation Analytical Sciences Section at Laboratory at Lawrence Livermore National Laboratory performs analysis of low-level tritium concentrations in various natural water samples from the Tri-Valley Area, DOE Nevada Test Site, Site 300 in Tracy, CA, and other various places around the world. Low levels of tritium, a radioactive isotope of hydrogen, which is pre-concentrated in the RAS laboratory using an electrolytic enrichment apparatus. Later these enriched waters are analyzed by liquid scintillation counting to determine the activity of tritium. The enrichment procedure and the subsequent purification process by vacuum distillation are currently undertaken manually, hence being highly labor-intensive. The whole process typically takes about 2 to 3 weeks to complete a batch of 30 samples, with a dedicated personnel operating the process. The goal is to automate the entire process, specifically having the operation PC-LabVIEW{trademark} controlled with real-time monitoring capability. My involvement was in the design and fabrication of a prototypical automated electrolytic enrichment cell. Work will be done on optimizing the electrolytic process by assessing the different parameters of the enrichment procedure. Hardware and software development have also been an integral component of this project.

  16. Minor elements incorporation control by ionic radius and growth rate on a stalagmite from the Chauvet Cave (SE-France)

    NASA Astrophysics Data System (ADS)

    Bourdin, C.; Douville, E.; Genty, D.

    2009-12-01

    A multi-elemental study focusing on earth-alkalis (Mg, Ca, Sr and Ba), uranium and rare-earth elements (REE) in the calcite of a stalagmite from the Chauvet Cave (SE of France) has been achieved by ICP-MS. The Chau-stm6 stalagmite which grew from 33 to 11.5 ky had already been dated and the published d13C and d18O profile is used as a paleoclimatic benchmark. Ba and Sr profiles show an abrupt concentration increase at the beginning of the last deglaciation whereas U and Mg feature a decreasing trend. REY (REE+yttrium) concentrations decrease markedly during early deglaciation (between 15 and 14.5 ky). The transition corresponds to a change from a slow to a fast growth rate. These variations can be explained by the crystallographic control of ionic radii of the minor elements: incorporation of small ions compared to Ca such as U, Mg, heavy REE are favoured during slow growth period (i.e. glacial) whereas large ions such as Ba, Sr and light REE are preferentially precipitated during fast growth period (i.e. Bolling-Allerod). This crystallographic effect seems to be dominant here because the soil above the cave is sparse. And may not have played a major role on the opposite to the water-limestone interaction.

  17. Calibration of a transient transport model to tritium measurements in rivers and streams in the Western Lake Taupo catchment, New Zealand

    NASA Astrophysics Data System (ADS)

    Gusyev, M. A.; Toews, M.; Morgenstern, U.; Stewart, M.; Daughney, C.; Hadfield, J.

    2012-08-01

    Here we present a general approach of calibrating transient transport models to tritium concentrations in river waters developed for the MT3DMS/MODFLOW model of the Western Lake Taupo catchment, New Zealand. Tritium is a time-dependent tracer with radioactive half-life of 12.32 yr. In the transport model, the tritium input (measured in rain) passes through the groundwater system, and the modelled tritium concentrations are compared to the measured tritium concentrations in the river outlets for the Waihaha, Whanganui, Whareroa, Kuratau and Omori river catchments from 2000-2007. For the Kuratau River, tritium was also measured between 1960 and 1970, which allowed us to fine-tune the transport model. In order to incorporate all surface flows from rivers to small streams, an 80 m uniform grid cell size was selected in the steady-state MODFLOW model for the model area of 1072 km2. The groundwater flow model was first calibrated to groundwater levels and stream flow observations. Then, the transport model was calibrated to the measured tritium concentrations in the river waters. The MT3DMS model results show good agreement with the measured tritium values in all five river catchments. Finally, the calibrated MT3DMS model is applied to simulate groundwater ages that are used to construct groundwater age distributions for the river catchments.

  18. Enhanced Control of In Vivo Bone Formation with Surface Functionalized Alginate Microbeads Incorporating Heparin and Human Bone Morphogenetic Protein-2

    PubMed Central

    Abbah, Sunny Akogwu; Liu, Jing; Goh, James Cho Hong

    2013-01-01

    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 C2C12 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

  19. 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

  20. Tritium hydrology of the Mississippi River basin

    USGS Publications Warehouse

    Michel, R.L.

    2004-01-01

    In the early 1960s, the US Geological Survey began routinely analysing river water samples for tritium concentrations at locations within the Mississippi River basin. The sites included the main stem of the Mississippi River (at Luling Ferry, Louisiana), and three of its major tributaries, the Ohio River (at Markland Dam, Kentucky), the upper Missouri River (at Nebraska City, Nebraska) and the Arkansas River (near Van Buren, Arkansas). The measurements cover the period during the peak of the bomb-produced tritium transient when tritium concentrations in precipitation rose above natural levels by two to three orders of magnitude. Using measurements of tritium concentrations in precipitation, a tritium input function was established for the river basins above the Ohio River, Missouri River and Arkansas River sampling locations. Owing to the extent of the basin above the Luling Ferry site, no input function was developed for that location. The input functions for the Ohio and Missouri Rivers were then used in a two-component mixing model to estimate residence times of water within these two basins. (The Arkansas River was not modelled because of extremely large yearly variations in flow during the peak of the tritium transient.) The two components used were: (i) recent precipitation (prompt outflow) and (ii) waters derived from the long-term groundwater reservoir of the basin. The tritium concentration of the second component is a function of the atmospheric input and the residence times of the groundwaters within the basin. Using yearly time periods, the parameters of the model were varied until a best fit was obtained between modelled and measured tritium data. The results from the model indicate that about 40% of the flow in the Ohio River was from prompt outflow, as compared with 10% for the Missouri River. Mean residence times of 10 years were calculated for the groundwater component of the Ohio River versus 4 years for the Missouri River. The mass flux of

  1. The Accelerator Production of Tritium (APT) Project*

    NASA Astrophysics Data System (ADS)

    Lisowski, Paul W.

    1997-05-01

    A reliable supply of tritium is necessary to maintain the United States' nuclear defense capability. Because tritium decays to ^3He at the rate of 5.5 percent per year, it must be replenished continously. To make the required amount of tritium using an accelerator, neutrons will be generated by high-energy proton reactions with tungsten and lead, moderated in light water, and captured in ^3He. The plant will be operational in 2007 at the Department of Energy's Savannah River Site in South Carolina. It will consist of a proton linear accelerator, tritium-production target/blankets, tritium-extraction, and conventional balance-of-plant systems. The accelerator will be a radio-frequency linac operating at 100 percent duty factor. It will have a combination of normal-conducting copper structures to accelerate a 100-mA beam to 217 MeV followed by superconducting niobium cavities to boost the beam energy to 1700 MeV. After acceleration, a high-energy transport system will expand the beam to a rectangular, 16-cm wide by 160-cm high distribution and deliver it to one of two identical target/blanket assemblies where tritium production and extraction will take place. Inside a target/blanket the proton beam will strike heavy-water cooled tungsten rods to produce neutrons. The tungsten will be surrounded by a decoupler consisting of aluminum tubes containing ^3He to reduce parasitic capture. Additional lead modules with aluminum tubes containing ^3He will lie outside the central region. The lead will produce additional neutrons from spallation and (n,xn) reactions. Light water coolant continuously circulated through the lead will moderate the neutrons to low energy, where they will be efficiently captured by ^3He gas to produce tritium. Tritium will be removed by continuous separation using permeation through a heated palladium-silver alloy membrane. Once separated, standard cryogenic distillation techniques will be used to isotopically purify the tritium. This presentation

  2. Tritium levels in milk in the vicinity of chronic tritium releases.

    PubMed

    Le Goff, P; Guétat, Ph; Vichot, L; Leconte, N; Badot, P M; Gaucheron, F; Fromm, M

    2016-01-01

    Tritium is the radioactive isotope of hydrogen. It can be integrated into most biological molecules. Even though its radiotoxicity is weak, the effects of tritium can be increased following concentration in critical compartments of living organisms. For a better understanding of tritium circulation in the environment and to highlight transfer constants between compartments, we studied the tritiation of different agricultural matrices chronically exposed to tritium. Milk is one of the most frequently monitored foodstuffs in the vicinity of points known for chronic release of radionuclides firstly because dairy products find their way into most homes but also because it integrates deposition over large areas at a local scale. It is a food which contains all the main nutrients, especially proteins, carbohydrates and lipids. We thus studied the tritium levels of milk in chronic exposure conditions by comparing the tritiation of the main hydrogenated components of milk, first, component by component, then, sample by sample. Significant correlations were found between the specific activities of drinking water and free water of milk as well as between the tritium levels of cattle feed dry matter and of the main organic components of milk. Our findings stress the importance of the metabolism on the distribution of tritium in the different compartments. Overall, dilution of hydrogen in the environmental compartments was found to play an important role dimming possible isotopic effects even in a food chain chronically exposed to tritium. PMID:26551587

  3. Tritium levels in milk in the vicinity of chronic tritium releases.

    PubMed

    Le Goff, P; Guétat, Ph; Vichot, L; Leconte, N; Badot, P M; Gaucheron, F; Fromm, M

    2016-01-01

    Tritium is the radioactive isotope of hydrogen. It can be integrated into most biological molecules. Even though its radiotoxicity is weak, the effects of tritium can be increased following concentration in critical compartments of living organisms. For a better understanding of tritium circulation in the environment and to highlight transfer constants between compartments, we studied the tritiation of different agricultural matrices chronically exposed to tritium. Milk is one of the most frequently monitored foodstuffs in the vicinity of points known for chronic release of radionuclides firstly because dairy products find their way into most homes but also because it integrates deposition over large areas at a local scale. It is a food which contains all the main nutrients, especially proteins, carbohydrates and lipids. We thus studied the tritium levels of milk in chronic exposure conditions by comparing the tritiation of the main hydrogenated components of milk, first, component by component, then, sample by sample. Significant correlations were found between the specific activities of drinking water and free water of milk as well as between the tritium levels of cattle feed dry matter and of the main organic components of milk. Our findings stress the importance of the metabolism on the distribution of tritium in the different compartments. Overall, dilution of hydrogen in the environmental compartments was found to play an important role dimming possible isotopic effects even in a food chain chronically exposed to tritium.

  4. Metal getters for tritium storage

    SciTech Connect

    Willin, E.; Sirch, M.; Penzhorn, R.D.; Devillers, M.

    1988-09-01

    Whereas titanium is a getter material mainly suitable for the long-term storage of tritium, zirconium cobalt alloy can also be employed for the interim storage and transport of this gas. Activated zirconium cobalt alloy reacts within minutes with hydrogen at room temperature. At the composition of /ZrCoH/sub 0.8/ the dissociation pressure at room temperature is estimated to be 10/sup -3/ Pa. The zirconium cobalt/H/sub 2/ system is not pyrophoric at room temperature. Methane is partially cracked on Ti and on ZrCo at temperatures above 600 and 300/sup 0/C respectively. With titanium the corresponding carbide is formed without affecting the storage properties of the getter. After reaction of ZrCo with CH/sub 4/ or N/sub 2/ the hydrogen adsorption capacity is reduced. Titanium powder, sponge or sheet react with nitrogen at temperatures above 750/sup 0/C with a parabolic rate law. In the overlayer of the metal substrate the phases N dissolved in /alpha/-Ti, Ti/sub 2/N and TiN were identified. The same phases were observed when NH/sub 3/ reacts with this metal.

  5. Information for establishing bioassay measurements and evaluations of tritium exposure

    SciTech Connect

    Brodsky, A.

    1983-06-01

    This report summarizes information and references used in developing regulatory guidance on programs for the bioassay of tritium as well as information useful in planning and conducting tritium bioassay programs and evaluating bioassay data. A review of literature on tritium radiobiology is included to provide a ready source of information useful for estimating internal doses of tritium and risks for the various tritium compounds and forms, including elemental (gaseous) tritium. Simplified and conservative dose conversion factors are derived and tabulated for easy reference in program planning, safety evaluations, and compliance determinations.

  6. 2001 Evaluation of Tritium Removal & Mitigation Technologies for Waste Water Treatment

    SciTech Connect

    PENWELL, D.L.

    2001-06-01

    This report contains the 2001 biennial update evaluation of separation technologies and other mitigation techniques to control tritium in liquid effluents and groundwater at the Hanford site. A thorough literature review was completed, and national and international experts in the field of tritium separation and mitigation techniques were consulted. Current state-of-the-art technologies to address the control of tritium in wastewaters were identified and are described. This report was prepared to satisfy the Hanford Federal Facility Agreement and Consent Order Tri-Party Agreement, Milestone M-29-O5H (Ecology, EPA, and DOE 1996). Tritium separation and isolation technologies are evaluated on a biennial basis to determine their feasibility for implementation for the control of Hanford site liquid effluents and groundwater to meet the US. Code of Federal Regulations (CFR), Title 40 CFR 141.16, drinking water maximum contaminant level (MCL) for tritium of 0.02 {mu} Ci/l ({approx}2 parts per quadrillion [10{sup -15}]) and/or DOE Order 5400.5 as low as reasonably achievable (ALARA) policy The objectives of this evaluation were to (1) status the development of potentially viable tritium separations technologies with regard to reducing tritium concentrations in current Hanford site process waters and existing groundwater to MCL levels and (2) status control methods to prevent the flow of tritiated water at concentrations greater than the MCL to the environment. Current tritium releases are in compliance with applicable US Environmental Protection Agency, Washington State Department of Ecology, and U.S. Department of Energy requirements under the Tri-Party Agreement. Advances in technologies for the separation of tritium from wastewater since the 1999 Hanford Site evaluation report include: (1) construction and testing of the Combined Industrial Reforming and Catalytic Exchange (CIRCE) Prototype Plant by Atomic Energy Canada Limited (AECL). The plant has a stage that uses

  7. The Safety and Tritium Applied Research (STAR) Facility: Status-2004*

    SciTech Connect

    R. A. Anderl; G. R. Longhurst; R. J. Pawelko; J. P. Sharpe; S. T. Schuetz; D. A. Petti

    2004-09-01

    The purpose of this paper is to present the current status of the development of the Safety and Tritium Applied Research (STAR) Facility at the Idaho National Engineering and Environmental Laboratory (INEEL). Designated a National User Facility by the US DOE, the primary mission of STAR is to provide laboratory infrastructure to study tritium science and technology issues associated with the development of safe and environmentally friendly fusion energy. Both tritium and non-tritium fusion safety research is pursued along three key thrust areas: (1) plasma-material interactions of plasma-facing component (PFC) materials exposed to energetic tritium and deuterium ions, (2) fusion safety concerns related to PFC material chemical reactivity and dust/debris generation, activation product mobilization, and tritium behavior in fusion systems, and (3) molten salts and fusion liquids for tritium breeder and coolant applications. STAR comprises a multi-room complex with operations segregated to permit both tritium and non-tritium activities in separately ventilated rooms. Tritium inventory in STAR is limited to 15,000 Ci to maintain its classification as a Radiological Facility. Experiments with tritium are typically conducted in glovebox environments. Key components of the tritium infrastructure have been installed and tested. This includes the following subsystems: (1) a tritium Storage and Assay System (SAS) that uses two 50-g depleted uranium beds for tritium storage and PVT/beta-scintillation analyses for tritium accountability measurements, (2) a Tritium Cleanup System (TCS) that uses catalytic oxidation and molecular sieve water absorption to remove tritiated species from glovebox atmosphere gases and gaseous effluents from experiment and process systems, and (3) tritium monitoring instrumentation for room air, glovebox atmosphere and stack effluent tritium concentration measurements. Integration of the tritium infrastructure subsystems with the experimental and

  8. Tritium production from a low voltage deuterium discharge on palladium and other metals

    SciTech Connect

    Claytor, T.N.; Jackson, D.D.; Tuggle, D.G.

    1995-09-01

    Over the past year the authors have been able to demonstrate that a plasma loading method produces an exciting and unexpected amount of tritium from small palladium wires. In contrast to electrochemical hydrogen or deuterium loading of palladium, this method yields a reproducible tritium generation rate when various electrical and physical conditions are met. Small diameter wires (100--250 microns) have been used with gas pressures above 200 torr at voltages and currents of about 2,000 V at 3--5 A. By carefully controlling the sputtering rate of the wire, runs have been extended to hundreds of hours allowing a significant amount (> 10`s nCi) of tritium to accumulate. they show tritium generation rates for deuterium-palladium foreground runs that are up to 25 times larger than hydrogen-palladium control experiments using materials from the same batch. They illustrate the difference between batches of annealed palladium and as received palladium from several batches as well as the effect of other metals (Pt, Ni, Nb, Zr, V, W, Hf) to demonstrate that the tritium generation rate can vary greatly from batch to batch.

  9. FINAL REPORT FOR TRITIUM WATER MONITOR

    SciTech Connect

    Sigg, R.; Ferguson, B.; DiPrete, D.

    2011-04-25

    The objective of this Plant Directed Research and Demonstration (PDRD) task was to develop a system to safetly analyze tritium in moisture collected from glovebox atmospheres in the Savannah River Site (SRS) Tritium Facility. In order to minimize potential radiation exposures that could occur in handling and diluting high-tritium-content water, SRS sought alternatives to liquid-scintillation counting. The proposed system determines tritium concentrations by measuring Bremsstrahlung radiation induced by low-energy beta interactions in liquid samples. Results show that, after a short counting period (30 seconds), detection limits are three orders of magnitude below the described concentration of tritiated water in the zeolite beds. Additionally, this report covers the analysis of process samples and the investigation of several cell window materials including beryllium, aluminum, and copper. Final tests reveal that alternate window materials and thicknesses can be used to obtain useful results. In particular, a window of stainless steel of moderate thickness (0.3 cm) can be used for counting relatively high levels of tritium.

  10. Experiences with decontaminating tritium-handling apparatus

    SciTech Connect

    Maienschein, J.L.; Garcia, F.; Garza, R.G.; Kanna, R.L.; Mayhugh, S.R.; Taylor, D.T.

    1991-07-01

    Tritium-handling apparatus has been decontaminated as part of the shutdown of the LLNL Tritium Facility. Two stainless-steel gloveboxes that had been used to process lithium deuteride-tritide (LiDT) salt were decontaminated using the Portable Cleanup System so that they could be flushed with room air through the facility ventilation system. Further surface decontamination was performed by scrubbing the interior with paper towels and ethyl alcohol or Swish{trademark}. The surface contamination, as shown by swipe surveys, was reduced from 4{times}10{sup 4}--10{sup 6} disintegrations per minute (dpm)/cm{sup 2} to 2{times}10{sup 2}--4{times}10{sup 4} dpm/cm{sup 2}. Details on the decontamination operation are provided. A series of metal (palladium and vanadium) hydride storage beds have been drained of tritium and flushed with deuterium in order to remove as much tritium as possible. The bed draining and flushing procedure is described, and a calculational method is presented which allows estimation of the tritium remaining in a bed after it has been drained and flushed. Data on specific bed draining and flushing are given.

  11. Tritium in the Savannah River Site environment

    SciTech Connect

    Murphy, C.E. Jr.; Bauer, L.R.; Hayes, D.W.; Marter, W.L.; Zeigler, C.C.; Stephenson, D.E.; Hoel, D.D.; Hamby, D.M.

    1991-05-01

    Tritium is released to the environment from many of the operations at the Savannah River Site. The releases from each facility to the atmosphere and to the soil and streams, both from normal operations and inadvertent releases, over the period of operation from the early 1950s through 1988 are presented. The fate of the tritium released is evaluated through environmental monitoring, special studies, and modeling. It is concluded that approximately 91% of the tritium remaining after decay is now in the oceans. A dose and risk assessment to the population around the site is presented. It is concluded that about 0.6 fatal cancers may be associated with the tritium released during all the years of operation to the population of about 625,000. This same population (based on the overall US cancer statistics) is expected to experience about 105,000 cancer fatalities from all types of cancer. Therefore, it is considered unlikely that a relationship between any of the cancer deaths occurring in this population and releases of tritium from the SRS will be found.

  12. Controlled-release of tea polyphenol from gelatin films incorporated with different ratios of free/nanoencapsulated tea polyphenols into fatty food simulants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gelatin films having controlled-release properties were developed by incorporation of different free/encapsulated tea polyphenol (TP) ratios through modifying the encapsulation efficiency (EE) of TP-loaded chitosan nanoparticles. Different EEs were obtained by adjusting the chitosan hydrochloride (C...

  13. A low tritium hydride bed inventory estimation technique

    SciTech Connect

    Klein, J.E.; Shanahan, K.L.; Baker, R.A.; Foster, P.J.

    2015-03-15

    Low tritium hydride beds were developed and deployed into tritium service in Savannah River Site. Process beds to be used for low concentration tritium gas were not fitted with instrumentation to perform the steady-state, flowing gas calorimetric inventory measurement method. Low tritium beds contain less than the detection limit of the IBA (In-Bed Accountability) technique used for tritium inventory. This paper describes two techniques for estimating tritium content and uncertainty for low tritium content beds to be used in the facility's physical inventory (PI). PI are performed periodically to assess the quantity of nuclear material used in a facility. The first approach (Mid-point approximation method - MPA) assumes the bed is half-full and uses a gas composition measurement to estimate the tritium inventory and uncertainty. The second approach utilizes the bed's hydride material pressure-composition-temperature (PCT) properties and a gas composition measurement to reduce the uncertainty in the calculated bed inventory.

  14. SUMMARY REPORT FOR ZINC 65 CONTAMINATION CONTROL

    SciTech Connect

    Korinko, P.

    2011-07-14

    Radioactive zinc, {sup 65}Zn, was detected after extraction of 215 TPBARs in from TVA reactor fuel cycle 6. A team consisting of Tritium Engineering, Tritium Operations, Tritium Radiation Control, and Savannah River National Laboratory personnel evaluated the risk and response and developed short, medium and long term goals for contamination control. One of the goals was incorporated into site Performance Based Incentive CO 3.4, to optimize the filter geometry and operating conditions for the Tritium Extraction Facility. This goal included a scoping study to determine if the contamination could be contained within the high radiation environment of the furnace module as well. In order to optimize the filters studies were conducted to independently evaluate the effect of pore size on pumping efficiency and zinc trapping efficiency (1). A study was also conducted to evaluate the effect of temperature on the trapping efficiency and adhesion (2). In addition, the potential for chemically trapping zinc in the lithium trap was evaluated using a thermodynamic study (3) followed by preliminary experimental testing (4). Based on the work that was completed it is determined that a 20 {mu}m filter heated to between 120 and 200 C will act as an effective physical trap for zinc vapors. It may be possible to chemically react zinc with copper or cobalt to form zinc intermetallic compounds or alloys but additional work under more prototypic conditions are required.

  15. Calibration of a transient transport model to tritium data in streams and simulation of groundwater ages in the western Lake Taupo catchment, New Zealand

    NASA Astrophysics Data System (ADS)

    Gusyev, M. A.; Toews, M.; Morgenstern, U.; Stewart, M.; White, P.; Daughney, C.; Hadfield, J.

    2013-03-01

    Here we present a general approach of calibrating transient transport models to tritium concentrations in river waters developed for the MT3DMS/MODFLOW model of the western Lake Taupo catchment, New Zealand. Tritium has a known pulse-shaped input to groundwater systems due to the bomb tritium in the early 1960s and, with its radioactive half-life of 12.32 yr, allows for the determination of the groundwater age. In the transport model, the tritium input (measured in rainfall) passes through the groundwater system, and the simulated tritium concentrations are matched to the measured tritium concentrations in the river and stream outlets for the Waihaha, Whanganui, Whareroa, Kuratau and Omori catchments from 2000-2007. For the Kuratau River, tritium was also measured between 1960 and 1970, which allowed us to fine-tune the transport model for the simulated bomb-peak tritium concentrations. In order to incorporate small surface water features in detail, an 80 m uniform grid cell size was selected in the steady-state MODFLOW model for the model area of 1072 km2. The groundwater flow model was first calibrated to groundwater levels and stream baseflow observations. Then, the transient tritium transport MT3DMS model was matched to the measured tritium concentrations in streams and rivers, which are the natural discharge of the groundwater system. The tritium concentrations in the rivers and streams correspond to the residence time of the water in the groundwater system (groundwater age) and mixing of water with different age. The transport model output showed a good agreement with the measured tritium values. Finally, the tritium-calibrated MT3DMS model is applied to simulate groundwater ages, which are used to obtain groundwater age distributions with mean residence times (MRTs) in streams and rivers for the five catchments. The effect of regional and local hydrogeology on the simulated groundwater ages is investigated by demonstrating groundwater ages at five model

  16. Hydrogen isotope separation installation for tritium facility

    SciTech Connect

    Andreev, B.M.; Perevezentsev, A.N.; Selivanenko, I.L.; Tenyaev, B.N.; Vedeneev, A.I.; Golubkov, A.N.

    1995-10-01

    The separation of hydrogen isotopes in the hydrogen-palladium system in sectioned separation columns with the simulation of counter-current isotopic exchange is described. The separation efficiency of sectioned columns is investigated with the experimental installation as a function of various parameters. The separation of deuterium-tritium mixtures with high tritium concentrations is tested with the pilot installation operating at room temperature and atmospheric hydrogen pressure. Due to very high separation efficiency, flexibility and simplicity of operation separation installations with sectioned columns are ideally suitable for tritium laboratories and facilities dealing with separation of hydrogen isotopes. Estimation of applicability of sectioned columns for regeneration of exhaust gas in a fuel cycle of thermonuclear reactors, such as JET and ITER, shows the number of advantages of separation installations with sectioned columns. 12 refs., 3 figs., 2 tabs.

  17. Low-exposure tritium radiotoxicity in mammals

    SciTech Connect

    Dobson, R.L.

    1982-02-11

    Studies of tritium radiotoxicity involving chronic /sup 3/H0H exposures in mammals demonstrate in both mice and monkeys that biological effects can be measured following remarkably low levels of exposure - levels in the range of serious practical interest to radiation protection. These studies demonstrate also that deleterious effects of /sup 3/H beta radiation do not differ significantly from those of gamma radiation at high exposures. In contrast, however, at low exposures tritium is significantly more effective than gamma rays, rad for rad, by a factor approaching 3. This is important for hazard evaluation and radiation protection because knowledge concerning biological effects of chronic low-level radiation exposure has come mainly from gamma-ray data; and predictions based on gamma-ray data will underestimate tritium effects - especially at low exposures - unless the RBE is fully taken into account.

  18. Advancement Of Tritium Powered Betavoltaic Battery Systems

    SciTech Connect

    Staack, G.; Gaillard, J.; Hitchcock, D.; Peters, B.; Colon-Mercado, H.; Teprovich, J.; Coughlin, J.; Neikirk, K.; Fisher, C.

    2015-10-14

    Due to their decades-long service life and reliable power output under extreme conditions, betavoltaic batteries offer distinct advantages over traditional chemical batteries, especially in applications where frequent battery replacement is hazardous, or cost prohibitive. Although many beta emitting isotopes exist, tritium is considered ideal in betavoltaic applications for several reasons: 1) it is a “pure” beta emitter, 2) the beta is not energetic enough to damage the semiconductor, 3) it has a moderately long half-life, and 4) it is readily available. Unfortunately, the widespread application of tritium powered betavoltaics is limited, in part, by their low power output. This research targets improving the power output of betavoltaics by increasing the flux of beta particles to the energy conversion device (the p-n junction) through the use of low Z nanostructured tritium trapping materials.

  19. First tritium results of the KATRIN test experiment TRAP

    SciTech Connect

    Eichelhardt, F.; Bornschein, B.; Bornschein, L.; Kazachenko, O.; Kernert, N.; Sturm, M.

    2008-07-15

    The TRAP experiment (Tritium Argon frost Pump) has been built at the Tritium Laboratory Karlsruhe (TLK) as a test rig for the Cryogenic Pumping Section (CPS) of the Karlsruhe Tritium Neutrino Experiment (KATRIN). TRAP employs a heterogeneous layer of pre-condensed argon to adsorb hydrogen isotopes at {approx} 4.2 K This paper presents results obtained in the first three tritium experiments with TRAP. (authors)

  20. DESIGN OF A CONTAINMENT VESSEL CLOSURE FOR SHIPMENT OF TRITIUM GAS

    SciTech Connect

    Eberl, K; Paul Blanton, P

    2007-07-03

    This paper presents a design summary of the containment vessel closure for the Bulk Tritium Shipping Package (BTSP). This new package is a replacement for a package that has been used to ship tritium in a variety of content configurations and forms since the early 1970s. The new design is based on changes in the regulatory requirements. 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 that enhance the package's ability to withstand dynamic loading and thermal effects. This paper will specifically summarize the design philosophy and engineered features of the BTSP containment vessel closure. The closure design incorporates a concave closure lid, metallic C-Ring seals for containing tritium gas, a metal bellows valve and an elastomer O-Ring for leak testing. The efficient design minimizes the overall vessel height and protects the valve housing from damage during postulated drop and crush scenarios. Design features will be discussed.

  1. Control of carbonate alkalinity on Mg incorporation in calcite: Insights on the occurrence of high Mg calcites in diagenetic environments

    NASA Astrophysics Data System (ADS)

    Purgstaller, Bettina; Mavromatis, Vasileios; Dietzel, Martin

    2015-04-01

    High Mg calcites (HMC), with up to 25 mol % of Mg, are common features in early diagenetic environments and are frequently associated with bio-induced anaerobic oxidation of methane (AOM). Such archives hold valuable information about the biogeochemical processes occurring in sedimentary environments in the geological past. Despite the frequency AOM-induced HMC observed in marine diagenetic settings and their potential role in dolomitization, only a minor number of experimental studies has been devoted on deciphering their formation conditions. Thus, in order to improve our understanding on the formation mechanism of HMC induced by elevated carbonate ion concentrations, we precipitated HMC by computer controlled titration of a (Mg,Ca)Cl2 solution at different Mg/Ca ratios into a NaHCO3 solution under precisely defined physicochemical conditions (T = 25.00 ±0.03°C; pH = 8.3 ±0.1). The formation of carbonates was monitored at a high temporal resolution using in situ Raman spectroscopy as well as by continuous sampling and analyzing of precipitates and reactive solutions. We identified two distinct mechanisms of HMC formation. In solutions with molar Mg/Ca ratios ≤ 1/8 calcium carbonate was precipitated as crystalline phases directly from homogeneous solution. In contrast, higher Mg/Ca ratios induced the formation of Mg-rich ACC (up to 10 mol % of Mg), which was subsequently transformed to HMC with up 20 mol % of Mg. Our experimental results highlight that the finally formed HMC has a higher Mg content than the ACC precursor phase. Considering experimental data for Mg containing ACC transformation to crystalline calcium carbonate from literature, the continuous enrichment of Mg in the precipitate throughout transformation of amorphous to crystalline CaCO3 most likely occurs due to the high carbonate alkalinity (DIC about 0.1 M) of our reactive solutions. The Mg incorporation into calcite lattice seems to be favored by intensive supply of carbonate ions as

  2. Tritium Aging Effects in Palladium on Kieselguhr

    SciTech Connect

    Shanahan, K.L.; Holder, J.S.; Wermer, J.R.

    1998-10-01

    50 weight % Pd on kieselguhr (Pd/k) is used in hydrogen isotope separation processes at the Savannah River Site. Long term aging studies on this material were undertaken in June, 1992. P-c-T data showing the aging effect of tritium loading for long periods will be presented and discussed covering from June, 1992 to March, 1997. Lowering of plateau pressures and increasing indications of in homogeneities have been observed in both tritium and deuterium absorption isotherms at 0 C, and desorption isotherms at 80 and 120 C.

  3. Decommissioning of a tritium-contaminated laboratory

    SciTech Connect

    Harper, J.R.; Garde, R.

    1981-11-01

    A tritium laboratory facility at the Los Alamos National Laboratory, Los Alamos, New Mexico, was decommissioned in 1979. The project involved dismantling the laboratory equipment and disposing of the equipment and debris at an on-site waste disposal/storage area. The laboratory was constructed in 1953 and was in service for tritium research and fabrication of lithium tritide components until 1974. The major features of the laboratory included some 25 meters of gloveboxes and hoods, associated vacuum lines, utility lines, exhaust ducts, electrodryers, blowers, and laboratory benches. This report presents details on the decommissioning, health physics, waste management, environmental surveillance, and costs for the operation.

  4. A tritium target system for. mu. CF

    SciTech Connect

    Zmeskal, J.; Ackerbauer, P. . Inst. fuer Mittelenergiephysik); Sherman, R.H. ); Durham, W.B.; Heard, H.C. ); Neumann, W. ); Bossy, H. Lawrence Berkeley Lab., CA (

    1990-12-01

    An apparatus has been constructed for the safe handling of tritium as part of a series of muon-catalyzed fusion experiments. The equipment was designed to handle 100 kCi of tritium. The main parts of this system are the oil-free high vacuum and transfer system, and the quadrupole mass analyzer for a direct determination of the target content. The system was used successfully for five continuous periods of operation of over one month each. A new target system was constructed at Lawrence Livermore National Laboratory (LLNL) for ultimate use at Paul Scherrer Institute (PSI) to investigate the high temperature and high pressure region. 9 refs., 4 figs.

  5. Tritium handling experience at Atomic Energy of Canada Limited

    SciTech Connect

    Suppiah, S.; McCrimmon, K.; Lalonde, S.; Ryland, D.; Boniface, H.; Muirhead, C.; Castillo, I.

    2015-03-15

    Canada has been a leader in tritium handling technologies as a result of the successful CANDU reactor technology used for power production. Over the last 50 to 60 years, capabilities have been established in tritium handling and tritium management in CANDU stations, tritium removal processes for heavy and light water, tritium measurement and monitoring, and understanding the effects of tritium on the environment. This paper outlines details of tritium-related work currently being carried out at Atomic Energy of Canada Limited (AECL). It concerns the CECE (Combined Electrolysis and Catalytic Exchange) process for detritiation, tritium-compatible electrolysers, tritium permeation studies, and tritium powered batteries. It is worth noting that AECL offers a Tritium Safe-Handling Course to national and international participants, the course is a mixture of classroom sessions and hands-on practical exercises. The expertise and facilities available at AECL is ready to address technological needs of nuclear fusion and next-generation nuclear fission reactors related to tritium handling and related issues.

  6. Electrical Discharge Machining Techniques for Evaluating the Effects of Tritium on Materials

    SciTech Connect

    IMRICH, KENNETH

    2004-03-24

    In this investigation, new ways to evaluate the long-term effects of tritium on the structural properties of components were developed. Electric discharge machining (EDM) techniques for cutting tensile and fracture toughness samples from the tritium-exposed regions of returned reservoirs were demonstrated. An existing electric discharge machine was used to cut sub-size tensile and fracture toughness samples from the inside walls of reservoir mock-ups. Tensile properties from the EDM tensile samples were similar to those measured using full-size samples cut from similar stock. Although the existing equipment could not be used for machining tritium-exposed hardware, off-the-shelf EDM units are available that could. With the right equipment and the required radiological controls in place, similar machining and testing techniques could be used to directly measure the effects of tritium on the properties of material cut from reservoir returns. Stress-strain property data from tritium-exposed reservoirs would improve finite-element modeling of reservoir performance because the data are representative of the true state of the reservoir material in the field. Tensile data from samples cut directly from reservoirs complement existing shelf storage and burst test data of the Life Storage Program and help answer questions about a specific reservoir's processing history and properties.

  7. Electric-Discharge Machining Techniques for Evaluating Tritium Effects on Materials

    SciTech Connect

    Morgan, M.J.

    2003-11-07

    In this investigation, new ways to evaluate the long-term effects of tritium on the structural properties of components were developed. Electric-discharge machining (EDM) techniques for cutting tensile and fracture toughness samples from tritium exposed regions of returned reservoirs were demonstrated. An existing electric discharge machine was used to cut sub-size tensile and fracture toughness samples from the inside surfaces of reservoir mockups. Tensile properties from the EDM tensile samples were similar to those measured using full-size samples cut from similar stock. Although the existing equipment could not be used for machining tritium-exposed hardware, off-the shelf EDM units are available that could. With the right equipment and the required radiological controls in place, similar machining and testing techniques could be used to directly measure the effects of tritium on the properties of material cut from reservoir returns. Stress-strain properties from tritium-exposed reservoirs would improve finite element modeling of reservoir performance because the data would be representative of the true state of the reservoir material in the field. Tensile data from samples cut directly from reservoirs would also complement existing shelf storage and burst test data of the Life Storage Program and help answer questions about a specific reservoir's processing history and properties.

  8. Tritium removal from various lithium aluminates irradiated by fast and thermal neutrons (COMPLIMENT experiment)

    NASA Astrophysics Data System (ADS)

    Alvani, C.; Carconi, P. L.; Casadio, S.; Moauro, A.

    1994-02-01

    Within the frame of the COMPLIMENT experiment, γ-LiAlO 2 specimens with different microstructures (grain size distributions) were tested in the same environmental conditions to compare the effects caused by 6Li(n, α)T reaction and by fast neutron scattering, the damaging dose being held at about the same level (1.6-1.8 dpa). The tritium retention times were obtained by the tritium removal of isothermal annealing under He + 0.1% H 2 sweeping gas. In spite of the different Li burnups (2.5% and 0.25%) and the residual tritium concentrations which were found in the irradiated specimens (4.3 Ci/g and 0.09 Ci/g, respectively, for specimens held at 450°C during the irradiations), the kinetics of tritium removal was not found to be discriminated by the two different irradiations. Moreover, the results were found to agree with those previously obtained by the "in-situ" TEQUILA experiment, performed on the same type of Li ceramics. Hence, the apparent first order desorption mechanism has been confirmed to control the kinetics of tritium removal from the porous fine grain γ-LiAlO 2 ceramics.

  9. Measurement of tritium permeation in flibe (2LiF•BeF2)

    SciTech Connect

    P. Calderoni; P. Sharpe; M. Hara; Y. Oya

    2007-10-01

    This paper reports on the experimental investigation of tritium permeation in flibe (2LiF-BeF2) at the Safety and Tritium Applied Research facility of the Idaho National Laboratory. A stainless steel cell formed by two independent volumes separated by a 2mm thick nickel membrane is maintained at temperatures between 500 and 700 degrees Celsius. A controlled amount of T2 gas is flown in excess of argon in the source volume in contact with the bottom side of the nickel membrane, while a layer of molten salt is in contact with the top side. The tritium permeating above the liquid surface is carried by an argon flow to a diagnostic system comprised of a quadrupole mass spectrometer, a gas chromatographer and a proportional counter. Tritium permeability in flibe as a function of temperature is determined by the measured permeation flow rates reached in steady-state conditions, while the diffusivity is determined by fitting the transient process with the analytical solution for the diffusion process. As a result, the solubility of tritium in flibe as a function of temperature is also determined.

  10. Validation test for CAP88 predictions of tritium dispersion at Los Alamos National Laboratory.

    PubMed

    Michelotti, Erika; Green, Andrew; Whicker, Jeffrey; Eisele, William; Fuehne, David; McNaughton, Michael

    2013-08-01

    Gaussian plume models, such as CAP88, are used regularly for estimating downwind concentrations from stack emissions. At many facilities, the U.S. Environmental Protection Agency (U.S. EPA) requires that CAP88 be used to demonstrate compliance with air quality regulations for public protection from emissions of radionuclides. Gaussian plume models have the advantage of being relatively simple and their use pragmatic; however, these models are based on simplifying assumptions and generally they are not capable of incorporating dynamic meteorological conditions or complex topography. These limitations encourage validation tests to understand the capabilities and limitations of the model for the specific application. Los Alamos National Laboratory (LANL) has complex topography but is required to use CAP88 for compliance with the Clean Air Act Subpart H. The purpose of this study was to test the accuracy of the CAP88 predictions against ambient air measurements using released tritium as a tracer. Stack emissions of tritium from two LANL stacks were measured and the dispersion modeled with CAP88 using local meteorology. Ambient air measurements of tritium were made at various distances and directions from the stacks. Model predictions and ambient air measurements were compared over the course of a full year's data. Comparative results were consistent with other studies and showed the CAP88 predictions of downwind tritium concentrations were on average about three times higher than those measured, and the accuracy of the model predictions were generally more consistent for annual averages than for bi-weekly data.

  11. Membrane Protein Incorporation into Nano-Bioelectronics: An insight into Rhodopsin Controlled SiNW-FET Devices

    NASA Astrophysics Data System (ADS)

    Tunuguntla, Ramya

    that the manipulation of lipid composition can indeed control orientation of an asymmetrically charged membrane protein, proteorhodopsin, in liposomes. One-dimensional inorganic nanostructures, which have critical dimensions comparable to the sizes of biological molecules, form an excellent materials platform for building such integrated structures. Researchers already use silicon nanowire-based field effect transistors functionalized with molecular recognition sites in a diverse array of biosensors. In our group, we have been developing a platform for integration of membrane protein functionality and electronic devices using a 1-D phospholipid bilayer device architecture. In these devices, the membrane proteins reside within the lipid bilayer that covers a nanowire channel of a field-effect transistor. This lipid bilayer performs several functions: it shields the nanowire from the solution species; it serves as a native-like environment for membrane proteins and preserves their functionality, integrity, and even vectorality. In this work, we show that a 1-D bilayer device incorporating a rhodopsin proton pump allows us to couple light-driven proton transport to a bioelectronic circuit. We also report that we were able to adapt another distinctive feature of biological signal processing---their widespread use of modifiers, co-factors, and mediator molecules---to regulate and fine-tune the operational characteristics of the bioelectronic device. In our example, we use co-assembly of protein channels and ionophores in the 1-D bilayer to modify the device output levels and response time.

  12. Incorporation of Photosynthetic Reaction Centers in the Membrane of Human Cells: Toward a New Tool for Optical Control of Cell Activity

    SciTech Connect

    Pennisi, Cristian P.; Jensen, Poul Erik; Zachar, Vladimir; Greenbaum, Elias; Yoshida, Ken

    2009-01-01

    The Photosystem I (PSI) reaction center is a photosynthetic membrane complex in which light-induced charge separation is accompanied by the generation of an electric potential. It has been recently proposed as a means to confer light sensitivity to cells possessing voltage-activated ion channels, but the feasibility of heterologous incorporation has not been demonstrated. In this work, methods of delivery and detection of PSI in the membrane of human cells are presented. Purified fractions of PSI were reconstituted in proteoliposomes that were used as vehicles for the membrane incorporation. A fluorescent impermeable dye was entrapped in the vesicles to qualitatively analyze the nature of the vesicle cell interaction. After incorporation, the localization and orientation of the complexes in the membrane was studied using immuno-fluorescence microscopy. The results showed complexes oriented as in native membranes, which were randomly distributed in clusters over the entire surface of the cell. Additionally, analysis of cell viability showed that the incorporation process does not damage the cell membrane. Taken together, the results of this work suggest that the mammalian cellular membrane is a reasonable environment for the incorporation of PSI complexes, which opens the possibility of using these molecular photovoltaic structures for optical control of cell activity.

  13. [Mechanism of tritium persistence in porous media like clay minerals].

    PubMed

    Wu, Dong-Jie; Wang, Jin-Sheng; Teng, Yan-Guo; Zhang, Ke-Ni

    2011-03-01

    To investigate the mechanisms of tritium persistence in clay minerals, three types of clay soils (montmorillonite, kaolinite and illite) and tritiated water were used in this study to conduct the tritium sorption tests and the other related tests. Firstly, the ingredients, metal elements and heat properties of clay minerals were studied with some instrumental analysis methods, such as ICP and TG. Secondly, with a specially designed fractionation and condensation experiment, the adsorbed water, the interlayer water and the structural water in the clay minerals separated from the tritium sorption tests were fractionated for investigating the tritium distributions in the different types of adsorptive waters. Thirdly, the location and configuration of tritium adsorbed into the structure of clay minerals were studied with infrared spectrometry (IR) tests. And finally, the forces and mechanisms for driving tritium into the clay minerals were analyzed on the basis of the isotope effect of tritium and the above tests. Following conclusions have been reached: (1) The main reason for tritium persistence in clay minerals is the entrance of tritium into the adsorbed water, the interlayer water and the structural water in clay minerals. The percentage of tritium distributed in these three types of adsorptive water are in the range of 13.65% - 38.71%, 0.32% - 5.96%, 1.28% - 4.37% of the total tritium used in the corresponding test, respectively. The percentages are different for different types of clay minerals. (2) Tritium adsorbed onto clay minerals are existed in the forms of the tritiated hydroxyl radical (OT) and the tritiated water molecule (HTO). Tritium mainly exists in tritiated water molecule for adsorbed water and interlayer water, and in tritiated hydroxyl radical for structural water. (3) The forces and effects driving tritium into the clay minerals may include molecular dispersion, electric charge sorption, isotope exchange and tritium isotope effect.

  14. Tritium storage effects on La-Ni-Al alloys: helium, and tritium trapping

    SciTech Connect

    Walters, R.T.; Mosley, W.C.

    1988-01-01

    The use of La-Ni-Al metal hydrides to process and store tritium presents unique problems to the handling of tritium. All hydrogen isotopes are ''trapped'' in La-Ni-Al alloys as a function of homogeneity and the degree of activation, or number of full cycles the material experiences before being exposed to tritium. To a lesser extent, the mole fraction of aluminum has an effect on the number of cycles needed for full activation. Data is presented which shows the effect of La-rich second phases on the retentium of protium, the x-ray diffraction line broadening as a function of number of cycles, and the observed ''heel'' in the alpha region of the isotherm due to Ni-Al second phases. There also appears to be an increase in solubility of tritium due to the lattice expansion on the metal.

  15. Development of nuclear micro-battery with solid tritium source.

    PubMed

    Lee, Sook-Kyung; Son, Soon-Hwan; Kim, KwangSin; Park, Jong-Wan; Lim, Hun; Lee, Jae-Min; Chung, Eun-Su

    2009-01-01

    A micro-battery powered by tritium is being developed to utilize tritium produced from the Wolsong Tritium Removal Facility. The 3D p-n junction device has been designed and fabricated for energy conversion. Titanium tritide is adopted to increase tritium density and safety. Sub micron films or nano-powders of titanium tritide is applied on silicon semiconductor device to reduce the self absorption of beta rays. Until now protium has been used instead of tritium for safety. Hydrogen was absorbed up to atomic ratio of approximately 1.3 and approximately 1.7 in titanium powders and films, respectively. PMID:19328704

  16. Operating and maintenance experience in tritium environments

    SciTech Connect

    Tuer, G.L.

    1987-01-01

    This presentation is a summary of practical experience gained over more than twenty years from analyzing failures of process equipment operated in tritium and deuterium environments. Significant improvements have been achieved in design and procurement of new equipment, testing and selection of materials, and gradually more favorable maintenance experience. Preferred materials and inspection methods are described. 6 tabs.

  17. Stereo and regioselectivity in ''Activated'' tritium reactions

    SciTech Connect

    Ehrenkaufer, R.L.E.; Hembree, W.C.; Wolf, A.P.

    1988-01-01

    To investigate the stereo and positional selectivity of the microwave discharge activation (MDA) method, the tritium labeling of several amino acids was undertaken. The labeling of L-valine and the diastereomeric pair L-isoleucine and L-alloisoleucine showed less than statistical labeling at the ..cap alpha..-amino C-H position mostly with retention of configuration. Labeling predominated at the single ..beta.. C-H tertiary (methyne) position. The labeling of L-valine and L-proline with and without positive charge on the ..cap alpha..-amino group resulted in large increases in specific activity (greater than 10-fold) when positive charge was removed by labeling them as their sodium carboxylate salts. Tritium NMR of L-proline labeled both as its zwitterion and sodium salt showed also large differences in the tritium distribution within the molecule. The distribution preferences in each of the charge states are suggestive of labeling by an electrophilic like tritium species(s). 16 refs., 5 tabs.

  18. Small system for tritium accelerator mass spectrometry

    DOEpatents

    Roberts, M.L.; Davis, J.C.

    1993-02-23

    Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and [sup 3]He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

  19. Small system for tritium accelerator mass spectrometry

    DOEpatents

    Roberts, Mark L.; Davis, Jay C.

    1993-01-01

    Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

  20. Tritium management in fusion synfuel designs

    SciTech Connect

    Galloway, T.R.

    1980-04-25

    Two blanket types are being studied: a lithium-sodium pool boiler and a lithium-oxide- or lithium-sodium pool boiler and a lithium-oxide- or aluminate-microsphere moving bed. For each, a wide variety of current technology was considered in handling the tritium. Here, we show the pool boiler with the sulfur-iodine thermochemical cycle first developed and now being piloted by the General Atomic Company. The tritium (T/sub 2/) will be generated in the lithium-sodium mixture where the concentration is approx. 10 ppM and held constant by a scavenging system consisting mainly of permeators. An intermediate sodium loop carries the blanket heat to the thermochemical cycle, and the T/sub 2/ in this loop is held to 1 ppM by a similar scavenging system. With this design, we have maintained blanket inventory at 1 kg of tritium, kept thermochemical cycle losses to 5 Ci/d and environmental loss to 10 Ci/d, and held total plant risk inventory at 7 kg tritium.

  1. Improving tritium exposure reconstructions using accelerator mass spectrometry

    PubMed Central

    Hunt, J. R.; Vogel, J. S.; Knezovich, J. P.

    2010-01-01

    Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were previously demonstrated for a tree growing on known levels of tritiated water and for trees exposed to atmospheric releases of tritiated water vapor. In these analyses, tritium levels were measured from milligram-sized samples with sample preparation times of a few days. Hundreds of samples were analyzed within a few months of sample collection and resulted in the reconstruction of spatial and temporal exposure from tritium releases. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. PMID:14735274

  2. Technology benefits associated with accelerator production of tritium

    SciTech Connect

    Tuyle, G.J. van

    1998-12-31

    The Accelerator Production of Tritium (APT) offers a clean, safe, and reliable means of producing the tritium needed to maintain the nuclear deterrent. Tritium decays away naturally at a rate of about 5.5% per year; therefore, the tritium reservoirs in nuclear weapons must be periodically replenished. In recent years this has been accomplished by recycling tritium from weapons being retired from the stockpile. Although this strategy has served well since the last US tritium production reactor was shut down in 1988, a new tritium production capability will be required within ten years. Important technology benefits will result from direct utilization of some of the APT proton beam; others could result from advances in the technologies of particle accelerators and high power spallation targets. This report addresses those technology benefits.

  3. Investigation of tritium in groundwater at Site 300

    SciTech Connect

    Buddemeier, R.W.

    1985-12-30

    In 1984, landfill monitoring wells at Site 300, a Lawrence Livermore National Laboratory (LLNL) explosive test site, revealed the presence of groundwater contaminated with tritium. These tritium levels were in excess of the State of California drinking water standard. A major investigation was initiated that included a search of records concerning tritium use, disposal, and previous analyses, and a survey of tritium levels in soil, vegetation, and water in contaminated and potentially contaminated areas. Over 50 boreholes were drilled for this investigation to characterize the local hydrogeology and tritium distributions, and a network of soil moisture and groundwater monitoring points was installed. This report presents the work completed through the end of September 1985: the records search; records for drilling completed as part of this study; characterization of the geology, hydrology, and tritium distributions in the contaminated area; and an initial assessment of the probable tritium sources, pathways, and migration rates. 19 refs.

  4. Plasma wall interaction and tritium retention in TFTR

    SciTech Connect

    Skinner, C. H.; Amarescu, E.; Ascione, G.; Synakowski, E.

    1996-05-01

    The Tokamak Fusion Test Reactor (TFTR) has been operating safely and routinely with deuterium-tritium fuel for more than two years. In this time, TFTR has produced an impressive number of record breaking results including core fusion power, ~ 2 MW/m³, comparable to that expected for ITER. Advances in wall conditioning via lithium pellet injection have played an essential role in achieving these results. Deuterium-tritium operation has also provided a special opportunity to address the issues of tritium recycling and retention. Tritium retention over two years of operation was approximately 40%. Recently, the in-torus tritium inventory was reduced by half through a combination of glow discharge cleaning, moist-air soaks, and plasma discharge cleaning. The tritium inventory is not a constraint in continued operations. The authors present recent results from TFTR in the context of plasma wall interactions and deuterium-tritium issues.

  5. Studying of tritium content in snowpack of Degelen mountain range.

    PubMed

    Turchenko, D V; Lukashenko, S N; Aidarkhanov, A O; Lyakhova, O N

    2014-06-01

    The paper presents the results of investigation of tritium content in the layers of snow located in the streambeds of the "Degelen" massif contaminated with tritium. The objects of investigation were selected watercourses Karabulak, Uzynbulak, Aktybai located beyond the "Degelen" site. We studied the spatial distribution of tritium relative to the streambed of watercourses and defined the borders of the snow cover contamination. In the centre of the creek watercourses the snow contamination in the surface layer is as high as 40 000 Bq/L. The values of the background levels of tritium in areas not related to the streambed, which range from 40 to 50 Bq/L. The results of snow cover measurements in different seasonal periods were compared. The main mechanisms causing tritium transfer in snow were examined and identified. The most important mechanism of tritium transfer in the streams is tritium emanation from ice or soil surface.

  6. REMOTE ANALYSIS OF HIGH-TRITIUM-CONTENT WATER

    SciTech Connect

    Diprete, D; Raymond Sigg, R; Leah Arrigo, L; Donald Pak, D

    2007-08-07

    Systems to safely analyze for tritium in moisture collected from glovebox atmospheres are being developed for use at Savannah River Site (SRS) tritium facilities. Analysis results will guide whether the material contains sufficient tritium for economical recovery, or whether it should be stabilized for disposal as waste. In order to minimize potential radiation exposures that could occur in handling and diluting high-tritium-content water, SRS sought alternatives to the process laboratory's routine analysis by liquid-scintillation counting. The newer systems determine tritium concentrations by measuring bremsstrahlung radiation induced by low-energy beta interactions. One of the systems determines tritium activity in liquid streams, the other determines tritium activity in water vapor. Topics discussed include counting results obtained by modeling and laboratory testing and corrections that are made for low-energy photon attenuation.

  7. Measurement of Tritium Surface Distribution on TFTR Bumper Limiter Tiles

    SciTech Connect

    K. Sugiyama; T. Tanabe; C.H. Skinner; C.A. Gentile

    2004-06-28

    The tritium surface distribution on graphite tiles used in the Tokamak Fusion Test Reactor (TFTR) bumper limiter and exposed to TFTR deuterium-tritium (D-T) discharges from 1993 to 1997 was measured by the Tritium Imaging Plate Technique (TIPT). The TFTR bumper limiter shows both re-/co-deposition and erosion. The tritium images for all tiles measured are strongly correlated with erosion and deposition patterns, and long-term tritium retention was found in the re-/co-depositions and flakes. The CFC tiles located at erosion dominated areas clearly showed their woven structure in their tritium images owing to different erosion yields between fibers and matrix. Significantly high tritium retention was observed on all sides of the erosion tiles, indicating carbon transport via repetition of local erosion/deposition cycles.

  8. Use of antimicrobial films and edible coatings incorporating chemical and biological preservatives to control growth of Listeria monocytogenes on cold smoked salmon.

    PubMed

    Neetoo, Hudaa; Mahomoodally, Fawzi

    2014-01-01

    The relatively high incidence of Listeria monocytogenes in cold smoked salmon (CSS) is of concern as it is a refrigerated processed food of extended durability (REPFED). The objectives of this study were to compare and optimize the antimicrobial effectiveness of films and coatings incorporating nisin (Nis) and sodium lactate (SL), sodium diacetate (SD), potassium sorbate (PS), and/or sodium benzoate (SB) in binary or ternary combinations on CSS. Surface treatments incorporating Nis (25000 IU/mL) in combination with PS (0.3%) and SB (0.1%) had the highest inhibitory activity, reducing the population of L. monocytogenes by a maximum of 3.3 log CFU/cm(2) (films) and 2.9 log CFU/cm(2) (coatings) relative to control samples after 10 days of storage at 21°C. During refrigerated storage, coatings were more effective in inhibiting growth of L. monocytogenes than their film counterparts. Cellulose-based coatings incorporating Nis, PS, and SB reduced the population of L. monocytogenes, and anaerobic and aerobic spoilage flora by a maximum of 4.2, 4.8, and 4.9 log CFU/cm(2), respectively, after 4 weeks of refrigerated storage. This study highlights the effectiveness of cellulose-based edible coatings incorporating generally regarded as safe (GRAS) natural and chemical antimicrobials to inhibit the development of L. monocytogenes and spoilage microflora thus enhancing the safety and quality of CSS. PMID:25089272

  9. Use of Antimicrobial Films and Edible Coatings Incorporating Chemical and Biological Preservatives to Control Growth of Listeria monocytogenes on Cold Smoked Salmon

    PubMed Central

    Mahomoodally, Fawzi

    2014-01-01

    The relatively high incidence of Listeria monocytogenes in cold smoked salmon (CSS) is of concern as it is a refrigerated processed food of extended durability (REPFED). The objectives of this study were to compare and optimize the antimicrobial effectiveness of films and coatings incorporating nisin (Nis) and sodium lactate (SL), sodium diacetate (SD), potassium sorbate (PS), and/or sodium benzoate (SB) in binary or ternary combinations on CSS. Surface treatments incorporating Nis (25000 IU/mL) in combination with PS (0.3%) and SB (0.1%) had the highest inhibitory activity, reducing the population of L. monocytogenes by a maximum of 3.3 log CFU/cm2 (films) and 2.9 log CFU/cm2 (coatings) relative to control samples after 10 days of storage at 21°C. During refrigerated storage, coatings were more effective in inhibiting growth of L. monocytogenes than their film counterparts. Cellulose-based coatings incorporating Nis, PS, and SB reduced the population of L. monocytogenes, and anaerobic and aerobic spoilage flora by a maximum of 4.2, 4.8, and 4.9 log CFU/cm2, respectively, after 4 weeks of refrigerated storage. This study highlights the effectiveness of cellulose-based edible coatings incorporating generally regarded as safe (GRAS) natural and chemical antimicrobials to inhibit the development of L. monocytogenes and spoilage microflora thus enhancing the safety and quality of CSS. PMID:25089272

  10. Use of antimicrobial films and edible coatings incorporating chemical and biological preservatives to control growth of Listeria monocytogenes on cold smoked salmon.

    PubMed

    Neetoo, Hudaa; Mahomoodally, Fawzi

    2014-01-01

    The relatively high incidence of Listeria monocytogenes in cold smoked salmon (CSS) is of concern as it is a refrigerated processed food of extended durability (REPFED). The objectives of this study were to compare and optimize the antimicrobial effectiveness of films and coatings incorporating nisin (Nis) and sodium lactate (SL), sodium diacetate (SD), potassium sorbate (PS), and/or sodium benzoate (SB) in binary or ternary combinations on CSS. Surface treatments incorporating Nis (25000 IU/mL) in combination with PS (0.3%) and SB (0.1%) had the highest inhibitory activity, reducing the population of L. monocytogenes by a maximum of 3.3 log CFU/cm(2) (films) and 2.9 log CFU/cm(2) (coatings) relative to control samples after 10 days of storage at 21°C. During refrigerated storage, coatings were more effective in inhibiting growth of L. monocytogenes than their film counterparts. Cellulose-based coatings incorporating Nis, PS, and SB reduced the population of L. monocytogenes, and anaerobic and aerobic spoilage flora by a maximum of 4.2, 4.8, and 4.9 log CFU/cm(2), respectively, after 4 weeks of refrigerated storage. This study highlights the effectiveness of cellulose-based edible coatings incorporating generally regarded as safe (GRAS) natural and chemical antimicrobials to inhibit the development of L. monocytogenes and spoilage microflora thus enhancing the safety and quality of CSS.

  11. Tritium effects on germ cells and fertility

    SciTech Connect

    Dobson, R.L.; Kwan, T.C.; Straume, T.

    1982-11-19

    Primordial oocytes in juvenile mice show acute gamma-ray LD/sub 50/ as low as 6 rad. This provides opportunities for determining dose-response relations at low doses and chronic exposure in the intact animal - conditions of particular interest for hazard evaluation. Examined in this way, /sup 3/HOH in body water is found to kill murine oocytes exponentially with dose, the LD/sub 50/ level for chronic exposure being only 2..mu..Ci/ml (delivering 0.4 rad/day). At very low doses and dose rates, where comparisons between tritium and other radiations are of special significance for radiological protection, the RBE of tritium compared with /sup 60/Co gamma radiation reaches approximately 3. Effects on murine fertility from tritium-induced oocyte loss have been quantified by reproductive capacity measurements. Chronic low-level exposure has been examined also in three primate species - squirrel, rhesus, and bonnet monkeys. In squirrel monkeys the ovarian germ-cell supply is 99% destroyed by the time of birth from prenatal exposure to body-water levels of /sup 3/HOH (administered in maternal drinking water) of only 3 ..mu..Ci/ml, the LD/sub 50/ level being 0.5 ..mu..Ci/ml (giving 0.1 rad/day), one fourth that in mice. Though not completely ruled out, similar high sensitivity of female germ cells has not been found in macaques; and it probably does not occur in man. The exquisite radiosensitivity of primordial oocytes in mice is apparently due to vulnerability of the plasma membrane (or something of similar geometry and location), not DNA. Evidence for this comes from tritium data as well as neutron studies. Tritium administered as /sup 3/HOH, and therefore generally distributed, is much more effective in killing murine oocytes than is tritium administered as /sup 3/H-TdR, localized in the nucleus. This situation in the mouse may have implications for estimating radiation genetic risk in the human female.

  12. Use of Tritium Accelerator Mass Spectrometry for Tree Ring Analysis

    PubMed Central

    LOVE, ADAM H.; HUNT, JAMES R.; ROBERTS, MARK L.; SOUTHON, JOHN R.; CHIARAPPA - ZUCCA, MARINA L.; DINGLEY, KAREN H.

    2010-01-01

    Public concerns over the health effects associated with low-level and long-term exposure to tritium released from industrial point sources have generated the demand for better methods to evaluate historical tritium exposure levels for these communities. The cellulose of trees accurately reflects the tritium concentration in the source water and may contain the only historical record of tritium exposure. The tritium activity in the annual rings of a tree was measured using accelerator mass spectrometry to reconstruct historical annual averages of tritium exposure. Milligram-sized samples of the annual tree rings from a Tamarix located at the Nevada Test Site are used for validation of this methodology. The salt cedar was chosen since it had a single source of tritiated water that was well-characterized as it varied over time. The decay-corrected tritium activity of the water in which the salt cedar grew closely agrees with the organically bound tritium activity in its annual rings. This demonstrates that the milligram-sized samples used in tritium accelerator mass spectrometry are suited for reconstructing anthropogenic tritium levels in the environment. PMID:12144257

  13. Tritium in Australian precipitation: A 50 year record

    NASA Astrophysics Data System (ADS)

    Tadros, Carol V.; Hughes, Catherine E.; Crawford, Jagoda; Hollins, Suzanne E.; Chisari, Robert

    2014-05-01

    Tritium in precipitation has been measured in Australia over the past 50 years, as an essential research tool in hydro-climate studies, and to contribute to the Global Network for Isotopes in Precipitation (GNIP). Tritium, a component of the water molecule (HTO), is the only true age tracer for waters. The elevated level of tritium in the environment as a result of last century’s atmospheric thermonuclear testing delivers the benefit of tracing groundwater systems over a 100 year timeframe. The concentration of tritium in Australian precipitation reached a maximum of 160 Tritium Units (TU) in 1963, during one of the most intense periods of nuclear weapons testing. From 1963 to present we observe a rapid drop in the concentration of tritium, more than expected from natural decay, and this can be attributed to the wash out of tritium into the oceans and groundwater. Spikes in the tritium level are superimposed over this general trend; the first around 1969, with levels ranging from 39.4 to 84.4 TU was due to French atmospheric weapon testing, and again in 1990, levels peaked between 6.6 and 12.9 TU, which is attributed to tritium leaking from underground tests in the French Pacific. Since 1990 the levels of tritium have declined globally and regionally. Currently the levels of tritium in Australia are stabilising to around 2-3 TU increasing with latitude across the continent, suggesting that today the tritium in precipitation is predominantly natural. The spatial distribution of tritium is presented and found to be dominated by the annual stratosphere-troposphere exchange in combination with latitude and continental effects. A precipitation amount effect is also observed for inland sites.

  14. Modification of a method-of-characteristics solute-transport model to incorporate decay and equilibrium-controlled sorption or ion exchange

    USGS Publications Warehouse

    Goode, D.J.; Konikow, L.F.

    1989-01-01

    The U.S. Geological Survey computer model of two-dimensional solute transport and dispersion in ground water (Konikow and Bredehoeft, 1978) has been modified to incorporate the following types of chemical reactions: (1) first-order irreversible rate-reaction, such as radioactive decay; (2) reversible equilibrium-controlled sorption with linear, Freundlich, or Langmuir isotherms; and (3) reversible equilibrium-controlled ion exchange for monovalent or divalent ions. Numerical procedures are developed to incorporate these processes in the general solution scheme that uses method-of- characteristics with particle tracking for advection and finite-difference methods for dispersion. The first type of reaction is accounted for by an exponential decay term applied directly to the particle concentration. The second and third types of reactions are incorporated through a retardation factor, which is a function of concentration for nonlinear cases. The model is evaluated and verified by comparison with analytical solutions for linear sorption and decay, and by comparison with other numerical solutions for nonlinear sorption and ion exchange.

  15. TOPICAL REVIEW: Tritium inventory in ITER plasma-facing materials and tritium removal procedures

    NASA Astrophysics Data System (ADS)

    Roth, Joachim; Tsitrone, Emmanuelle; Loarer, Thierry; Philipps, Volker; Brezinsek, Sebastijan; Loarte, Alberto; Counsell, Glenn F.; Doerner, Russell P.; Schmid, Klaus; Ogorodnikova, Olga V.; Causey, Rion A.

    2008-10-01

    Interactions between the plasma and the vessel walls constitute a major engineering problem for next step fusion devices, such as ITER, determining the choice of the plasma-facing materials. A prominent issue in this choice is the tritium inventory build-up in the vessel, which must be limited for safety reasons. The initial material selection, i.e. beryllium (Be) on the main vessel walls, tungsten (W) on the divertor upper baffle and dome, and carbon fibre composite around the strike points on the divertor plates, results both from the attempt to reduce the tritium inventory and to optimize the lifetime of the plasma-facing components. In the framework of the EU Task Force on Plasma-Wall Interaction (PWI TF), the many physics aspects governing the tritium inventory are brought together. Together with supporting information from international experts represented by the ITPA SOL/DIV section, this paper describes the present status of knowledge of the in-vessel tritium inventory build-up. Firstly, the main results from present fusion devices in this field are briefly reviewed. Then, the processes involved are discussed: implantation, trapping and diffusion in plasma-facing materials are considered as well as surface erosion and co-deposition of tritium with eroded material. The intermixing of the different materials and its influence on hydrogen retention and co-deposition is a major source of uncertainty on present estimates and is also addressed. Based on the previous considerations, estimates for the tritium inventory build-up are given for the initial choice of ITER materials, as well as for alternative options. Present estimates indicate a build-up of the tritium inventory to the administrative limit within a few hundred nominal full power D : T discharges, co-deposition with carbon being the dominant process. Therefore, tritium removal methods are also an active area of research within the EU PWI TF, and are discussed. An integrated operational scheme to slow

  16. Measurement of tritium in natural water

    NASA Astrophysics Data System (ADS)

    Li, Meifen

    1985-06-01

    A detergent-scintillation liquid mixture applied to measure low specific activity of tritium in natural water was studied. The DYS-1 low level liquid scintillation counter designed and manufactured by our institute was employed. In comparing the Triton X-100 scintillation liquid mixture with the dioxane-based-scintillation liquid, a better formula for Triton X-100 scintillation liquid mixture was determined, the mixture possesses the quality of high water content; high efficiency and low back-ground in measuring tritium in water. Chemiluminescence of the Triton X-100 scintillation liquid mixture can be totally de-excited in short time. It can be employed at ambient temperature 11 28°C. For 20ml sample in quartz vials, counting efficiency is 15% with a background 2.17 cpm, Y=31 TU (t=30 min).

  17. Apparatus to recover tritium from tritiated molecules

    DOEpatents

    Swansiger, William A.

    1988-01-01

    An apparatus for recovering tritium from tritiated compounds is provided, including a preheater for heating tritiated water and other co-injected tritiated compounds to temperatures of about 600.degree. C. and a reactor charged with a mixture of uranium and uranium dioxide for receiving the preheated mixture. The reactor vessel is preferably stainless steel of sufficient mass so as to function as a heat sink preventing the reactor side walls from approaching high temperatures. A disposable copper liner extends between the reaction chamber and stainless steel outer vessel to prevent alloying of the uranium with the outer vessel. The uranium dioxide functions as an insulating material and heat sink preventing the reactor side walls from attaining reaction temperatures to thereby minimize tritium permeation rates. The uranium dioxide also functions as a diluent to allow for volumetric expansion of the uranium as it is converted to uranium dioxide.

  18. Study of Tritium Behavior in Cement Paste

    SciTech Connect

    Takata, H.; Motoshima, T.; Satake, S.; Nishikawa, M.

    2005-07-15

    The concrete materials are used as the partition wall of the tritium handling facilities. It is important to grasp the tritium behavior in the concrete wall for radiation safety. It is considered in this study that the surface water on the concrete materials consists of physically adsorbed water, chemically adsorbed water and structural water as in the case of porous adsorption materials. The adsorption capacity due to physically and chemically adsorption isotherms observed in this study shows that the amount of water adsorption on the cement paste is a quarter of the amount adsorbed onto the surface of activated alumina or molecular sieves 5A (MS-5A). It shows that concrete is easily contaminated with tritiated water.

  19. IN-SITU TRITIUM BETA DETECTOR

    SciTech Connect

    J.W. Berthold; L.A. Jeffers

    1998-04-15

    The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype

  20. Evaluation of Unfixed Tritium Surface Contamination

    SciTech Connect

    Postolache, C.; Matei, Lidia

    2005-07-15

    Surface unfixed radioactive contamination represents the amount of surface total radioactive contamination which can be eliminated by pure mechanical processes. This unfixed contamination represents the main risk factor for contamination of the personnel which operates in tritium laboratories. Unfixed contamination was determined using sampling smears type FPCSN-PSE-AA. Those FPCSN-PSE-AA smears are disks of expanded polystyrene which contain acrylic acid fragments superficially grafted. Sampling factor was determinated by contaminated surface wiping with moisten smears in 50 {mu}L butylic alcohol and activity measuring at liquid scintillation measuring device. Sampling factor was determined by the ratio between measured activity and initially real conventional activity. The sampling factor was determined for Tritium Laboratory existent surfaces: stainless steel, aluminum, glass, ceramics, linoleum, washable coats, epoxy resins type ALOREX LP-52.The sampling factors and the reproducibility were determined in function of surface nature.

  1. Tritium handling and processing experience at TSTA

    SciTech Connect

    Anderson, J.L.; Okuno, K.

    1994-06-01

    In 1987, the Japan Atomic Energy Research Institute (JAERI) and the US Department of Energy (DOE) signed a collaborative agreement (Annex IV) for the joint funding and operation of the Tritium Systems Test Assembly (TSTA) at the Los Alamos National Laboratory (LANL) for a five year period ending June, 1992. After this initial five year collaboration, the Annex IV agreement was extended for another two year period ending June, 1994. During the first five years, a number of the integrated process loop tests of TSTA were conducted, as well as off-line testing of TSTA subsystems. During integrated loop testing the vacuum system, fuel cleanup systems, isotope separation system, transfer pumping system and gas analysis system, are interconnected and tested using 100 g-inventories of tritium to demonstrate steady-state operation of a tritium fuel processing cycle for a fusion reactor. These tests have resulted in a number of significant accomplishments and an experience data base on research, development and operation of the fuel processing system. One of the most significant accomplishments during the initial five year period was the continuous operation of the fuel processing loop for 25 days. During this 25-day extended operation, both the JAERI fuel cleanup system (J-FCU) and the original TSTA fuel cleanup system (FCU) were operated under similar conditions of flow, pressure, and impurity content of the DT gas. Both fuel cleanup systems were demonstrated to provide adequate impurity removal for plasma exhaust gas processing. The isotope separation system was operated continuously, producing pure tritium while rejecting protium as an impurity.

  2. Progress report on the tritium remission simulation

    SciTech Connect

    Barbieri, J. F.

    1997-05-01

    A mathematical model has been developed which computes the concentration of tritiated water reemitted into the atmosphere by surface evaporation and plant transpiration using the Penman-Monteith equation. Using these rates, and assuming a deposition velocity for tritium, a coupled set of diffusion equations are then solved which yield the concentration of tritiated water as a function of time. The model is driven by a number of environmental parameters.

  3. Tritium monitoring of groundwater and surfaces

    SciTech Connect

    MacArthur, D.; Aamodt, P.; Bounds, J.; Koster, J.

    1999-03-01

    There are numerous facilities, both within the US and in the rest of the world, within the complex of radiation laboratories and production plants where tritium has been released into the environment because of historic or ongoing mission-related operations. Many of environmental restoration projects have detected low levels of tritium contamination in local streams, ponds, and/or ground water. Typically these waters are moving or have the potential to move offsite and are viewed as a potential risk to the public and environment. Los Alamos National Laboratory will modify the well-proven long-range alpha detection (LRAD) technique for detection of ionizing radiation to optimize a system for detecting tritium in groundwater and other surfaces. The LRAD technique relies on detection of ionized air molecules rather than direct detection of ionizing radiation. The detected electrical current is proportional to the number of ionized air molecules present, which is in turn a measure of the amount of contamination present. Although this technique has been used commercially to measure alpha contamination on objects and surfaces, the technique is also ideal for monitoring low-energy beta particles. The authors have demonstrated beta detection using {sup 54}Mn, {sup 14}C, {sup 147}Pm, {sup 99}Tc, {sup 90}Sr, and {sup 36}Cl sources. Thus, the detector technology and detection of beta particles using this technology have both been demonstrated. The extreme short range of tritium beta particles necessitates an optimization of the detector system. In this paper, the authors will discuss these new designs.

  4. Recovery of tritium from tritiated molecules

    DOEpatents

    Swansiger, William A.

    1987-01-01

    A method of recovering tritium from tritiated compounds comprises the steps of heating tritiated water and other co-injected tritiated compounds in a preheater to temperatures of about 600.degree. C. The mixture is injected into a reactor charged with a mixture of uranium and uranium dioxide. The injected mixture undergoes highly exothermic reactions with the uranium causing reaction temperatures to occur in excess of the melting point of uranium, and complete decomposition of the tritiated compounds to remove tritium therefrom. The uranium dioxide functions as an insulating material and heat sink preventing the reactor side walls from attaining reaction temperatures to thereby minimize tritium permeation rates. The uranium dioxide also functions as a diluent to allow for volumetric expansion of the uranium as it is converted to uranium dioxide. The reactor vessel is preferably stainless steel of sufficient mass so as to function as a heat sink preventing the reactor side walls from approaching high temperatures. A disposable copper liner extends between the reaction chamber and stainless steel outer vessel to prevent alloying of the uranium with the outer vessel. Apparatus used to carry out the method of the invention is also disclosed.

  5. Tritium and tritons in cold fusion

    SciTech Connect

    Wolf, K.L.; Whitesell, L.; Jabs, H.; Shoemaker, J. )

    1991-05-10

    An analysis is conducted on reports of tritium production and of charged-particle emission from deuterated palladium and titanium. Possible sources of error are outline and the lack of definitive experiments is discussed. Extensive sets of experiments are reported in which two previously reported results are checked in detail. A search for charged-particle emission was conducted on deuterated titanium and 6{minus}6{minus}2 titanium alloy that was subjected to cryogenic cycling. Two delta E-E silicon telescopes were used to count 42 samples for 3--4 cycles each from 84K to room temperature. No charge-one particles were detected and alpha particle yields of a few counters per day corresponded to background levels. A search for tritium production from 1 mm diameter palladium wire was conducted on 130 electrolytic cells in D{sub 2}O and H{sub 2}O, and in 250 metal samples. Several samples associated with one lot of palladium stock showed latent tritium levels well above background. No evidence was obtained for the occurrence of nuclear reactions in the electrolytic cells.

  6. Tritium labelled alkenes via the Shapiro reaction

    SciTech Connect

    Saljoughian, Manouchehr; Morimoto, Hiromi; Than, Chit; Williams, P.G.

    1995-12-31

    The authors report a simple synthesis of a variety of tritiated alkenes with high specific activity. The labelling steps involved in situ generation of the vinyllithium derivatives of the intermediate trisylhydrazone at low temperature, followed by quenching with high specific activity Tritiated water as an electrophile to generate the final tritiated alkenes. Several ketonic precursors with cyclopentanone and cyclohexanone rings, {alpha},{beta}-unsaturated and large ring cyclic ketones were selected and the corresponding trisylhydrazone derivatives were prepared. The Shapiro reaction conditions were optimized to work at a millimolar scale using deuteriated water as the electrophile. The successful reaction conditions were finally applied to the tritiation reactions. The chemical and radiochemical purity, and the specific radioactivity of the reaction products were determined by radio-hplc, gas chromatography and liquid scintillation counting as well as tritium NMR spectroscopy. The stereochemistry and specificity of tritium labelling was also established with tritium NMR spectroscopy. Application of different organolithium bases and the reaction mechanisms will be discussed.

  7. Optimization of simultaneous tritium-radiocarbon internal gas proportional counting

    NASA Astrophysics Data System (ADS)

    Bonicalzi, R. M.; Aalseth, C. E.; Day, A. R.; Hoppe, E. W.; Mace, E. K.; Moran, J. J.; Overman, C. T.; Panisko, M. E.; Seifert, A.

    2016-03-01

    Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a natural methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill of P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium-counting efficiency while minimizing radiocarbon beta-decay interference.

  8. Tritium test of a ferro-fluidic rotary seal

    SciTech Connect

    Antipenkov, A.; Day, C.; Adami, H. D.

    2008-07-15

    The ferro-fluidic seal is being investigated as an internal rotary seal for tritium compatible mechanical roots type vacuum pumps. After its successful testing with helium and integration into a small (250 m{sup 3}/h) test roots pump, the seal, made as a cartridge, has been integrated into a special test unit and is currently being tested with tritium in order to define the leak rates and the possible degradation of the ferro-fluid under long term exposure to tritium radiation. The tritium pressure from one side of the seal is 0.125 MPa, the nitrogen pressure from the other side is 0.075 MPa, the rotation speed is maintained at 1500 rpm. The tritium leak through the cartridge contributes to the tritium concentration in the nitrogen, which is continuously measured by an ionisation chamber; the pressure in both chambers is continuously registered by precise pressure gauges. The experimental program is discussed. (authors)

  9. Measurements of tritium retention and removal on TFTR

    SciTech Connect

    Skinner, C.H.; Blanchard, W.; Kamperschroer, J.

    1996-05-01

    Recent experiments on the Tokamak Fusion Test Reactor (TFTR) have afforded an opportunity to measure the retention of tritium in a graphite limiter that is subject to erosion, codeposition and high neutron flux. The tritium was injected by both gas puff and neutral beams. The isotopic mix of hydrogenic recycling was measured spectroscopically and the tritium fraction T/(H+D+T) increased to as high as 75%. Some tritium was pumped out during the experimental run and some removed in a subsequent campaign using various clean-up techniques. While the short term retention of tritium was high, various conditioning techniques were successful in removing {approx} 8,000 Ci and restoring the tritium inventory to a level well below the administrative limit.

  10. Aedes aegypti Control Strategies in Brazil: Incorporation of New Technologies to Overcome the Persistence of Dengue Epidemics

    PubMed Central

    Araújo, Helena R. C.; Carvalho, Danilo O.; Ioshino, Rafaella S.; Costa-da-Silva, André L.; Capurro, Margareth L.

    2015-01-01

    Dengue is considered to be the most important mosquito-borne viral disease in the world. The Aedes aegypti mosquito, its vector, is highly anthropophilic and is very well adapted to urban environments. Although several vaccine candidates are in advanced stages of development no licensed dengue vaccine is yet available. As a result, controlling the spread of dengue still requires that mosquitoes be targeted directly. We review the current methods of dengue vector control focusing on recent technical advances. We first examine the history of Brazil’s National Dengue Control Plan in effect since 2002, and we describe its establishment and operation. With the persistent recurrence of dengue epidemics, current strategies should be reassessed to bring to the forefront a discussion of the possible implementation of new technologies in Brazil’s mosquito control program. PMID:26463204

  11. Aedes aegypti Control Strategies in Brazil: Incorporation of New Technologies to Overcome the Persistence of Dengue Epidemics.

    PubMed

    Araújo, Helena R C; Carvalho, Danilo O; Ioshino, Rafaella S; Costa-da-Silva, André L; Capurro, Margareth L

    2015-01-01

    Dengue is considered to be the most important mosquito-borne viral disease in the world. The Aedes aegypti mosquito, its vector, is highly anthropophilic and is very well adapted to urban environments. Although several vaccine candidates are in advanced stages of development no licensed dengue vaccine is yet available. As a result, controlling the spread of dengue still requires that mosquitoes be targeted directly. We review the current methods of dengue vector control focusing on recent technical advances. We first examine the history of Brazil's National Dengue Control Plan in effect since 2002, and we describe its establishment and operation. With the persistent recurrence of dengue epidemics, current strategies should be reassessed to bring to the forefront a discussion of the possible implementation of new technologies in Brazil's mosquito control program. PMID:26463204

  12. Tritium Loading of Pinellas U-Bed No. 874

    SciTech Connect

    Shanahan, K.L.

    1999-09-15

    The DOE-Richland Office has requested WSRC to supply PNNL with a Pinellas U-bed loaded with tritium for permeation experiments. It is desired to have less than 1000 Ci tritium in the bed to allow shipping without excessive packaging requirements. Pinellas U-Bed No. 874 was loaded with approximately 955 Ci of 98 percent purity tritium on the ETM manifold in the Materials Test Facility in Building 232-H.

  13. EFFECTS OF TRITIUM GAS EXPOSURE ON EPDM ELASTOMER

    SciTech Connect

    Clark, E.

    2009-12-11

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

  14. Tritium release during nuclear power operation in China.

    PubMed

    Yang, D J; Chen, X Q; Li, B

    2012-06-01

    Overviews were evaluated of tritium releases and related doses to the public from airborne and liquid effluents from nuclear power plants on the mainland of China before 2009. The differences between tritium releases from various nuclear power plants were also evaluated. The tritium releases are mainly from liquid pathways for pressurised water reactors, but tritium releases between airborne and liquid effluents are comparable for heavy water reactors. The airborne release from a heavy water reactor is obviously higher than that from a pressurised water reactor.

  15. Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

    SciTech Connect

    C.A. Gentile; S.W. Langish; C.H. Skinner; L.P. Ciebiera

    2004-09-10

    In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. Tritium decontamination, by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying motivational forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination.

  16. Oxidation of tritium atoms at a stainless steel surface

    SciTech Connect

    Finn, P.A.; VanDeventer, E.H.

    1986-10-01

    The dynamic reaction of oxygen and tritium on a stainless steel surface was studied for low oxygen concentrations (less than 1 ppM oxygen in helium). The oxygen was swept over a stainless surface through which 20 to 90 ..mu..Ci/d of tritium permeated. Dynamic conditions were maintained for three to five days with gas flow rates maintained at 40 to 100 mL/min. The ratio between the tritiated water collected and the tritium gas collected was less than one. At oxygen levels greater than 50 ppM, the ratio of tritiated water to tritium gas appears to be greater than 10.

  17. 2012 ACCOMPLISHMENTS - TRITIUM AGING STUDIES ON STAINLESS STEELS

    SciTech Connect

    Morgan, M.

    2013-01-31

    This report summarizes the research and development accomplishments during FY12 for the tritium effects on materials program. The tritium effects on materials program is designed to measure the long-term effects of tritium and its radioactive decay product, helium-3, on the structural properties of forged stainless steels which are used as the materials of construction for tritium reservoirs. The FY12 R&D accomplishments include: (1) Fabricated and Thermally-Charged 150 Forged Stainless Steel Samples with Tritium for Future Aging Studies; (2) Developed an Experimental Plan for Measuring Cracking Thresholds of Tritium-Charged-and-Aged Steels in High Pressure Hydrogen Gas; (3) Calculated Sample Tritium Contents For Laboratory Inventory Requirements and Environmental Release Estimates; (4) Published report on “Cracking Thresholds and Fracture Toughness Properties of Tritium-Charged-and-Aged Stainless Steels”; and, (5) Published report on “The Effects of Hydrogen, Tritium, and Heat Treatment on the Deformation and Fracture Toughness Properties of Stainless Steels”. These accomplishments are highlighted here and references given to additional reports for more detailed information.

  18. Tritium Formation and Mitigation in High-Temperature Reactor Systems

    SciTech Connect

    Piyush Sabharwall; Carl Stoots; Hans A. Schmutz

    2013-03-01

    Tritium is a radiologically active isotope of hydrogen. It is formed in nuclear reactors by neutron absorption and ternary fission events and can subsequently escape into the environment. To prevent the tritium contamination of proposed reactor buildings and surrounding sites, this study examines the root causes and potential mitigation strategies for permeation of tritium (such as: materials selection, inert gas sparging, etc...). A model is presented that can be used to predict permeation rates of hydrogen through metallic alloys at temperatures from 450–750 degrees C. Results of the diffusion model are presented for a steady production of tritium

  19. Tritium Formation and Mitigation in High-Temperature Reactors

    SciTech Connect

    Piyush Sabharwall; Carl Stoots

    2012-10-01

    Tritium is a radiologically active isotope of hydrogen. It is formed in nuclear reactors by neutron absorption and ternary fission events and can subsequently escape into the environment. To prevent the tritium contamination of proposed reactor buildings and surrounding sites, this study examines the root causes and potential mitigation strategies for permeation of tritium (such as: materials selection, inert gas sparging, etc...). A model is presented that can be used to predict permeation rates of hydrogen through metallic alloys at temperatures from 450–750 degrees C. Results of the diffusion model are presented for a steady production of tritium

  20. Influence of the tritium beta(-) decay on low-temperature thermonuclear burn-up in deuterium-tritium mixtures

    PubMed

    Frolov

    2000-09-01

    Low-temperature (Ttritium mixtures with various deuterium-tritium-helium-3 ratios is considered. The general dependence is studied for the critical burn-up parameter x(c)=rhor(c) upon the initial temperature T, density rho(0), and tritium molar concentration y for the [D]:y[T]:(1-y)[3He] mixture. In particular, it is shown that, if the tritium concentration y decreases, then the critical burn-up parameter x(c)(T,rho(0),y) grows very quickly (at fixed T and rho(0)). This means that tritium beta(-) decay significantly complicates thermonuclear burn-up in deuterium-tritium mixtures.

  1. Benefit-cost analysis of spruce budworm (Choristoneura fumiferana Clem.) control: incorporating market and non-market values.

    PubMed

    Chang, Wei-Yew; Lantz, Van A; Hennigar, Chris R; MacLean, David A

    2012-01-01

    This study employs a benefit-cost analysis framework to estimate market and non-market benefits and costs of controlling future spruce budworm (Choristoneura fumiferana) outbreaks on Crown forest lands in New Brunswick, Canada. We used: (i) an advanced timber supply model to project potential timber volume saved, timber value benefits, and costs of pest control efforts; and (ii) a recent contingent valuation method analysis that evaluated non-market benefits (i.e., changes in recreation opportunities and existence values) of controlling future spruce budworm outbreaks in the Province. A total of six alternative scenarios were evaluated, including two uncontrolled future budworm outbreak severities (moderate vs. severe) and, for each severity, three control program levels (protecting 10%, 20%, or 40% of the susceptible Crown land forest area). The economic criteria used to evaluate each scenario included benefit-cost ratios and net present values. Under severe outbreak conditions, results indicated that the highest benefit-cost ratio (4.04) occurred when protecting 10% (284,000 ha) of the susceptible area, and the highest net present value ($111 M) occurred when protecting 20% (568,000 ha) of the susceptible area. Under moderate outbreak conditions, the highest benefit-cost ratio (3.24) and net present value ($58.7 M) occurred when protecting 10% (284,000 ha) of the susceptible area. Inclusion of non-market values generally increased the benefit-cost ratios and net present values of the control programs, and in some cases, led to higher levels of control being supported. Results of this study highlight the importance of including non-market values into the decision making process of forest pest management. PMID:22054576

  2. Regional and sectoral marginal abatement cost curves 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...

  3. Comparison between different sets of suspension parameters and introduction of new modified skyhook control strategy incorporating varying road condition

    NASA Astrophysics Data System (ADS)

    Abul Kashem, Saad Bin; Ektesabi, Mehran; Nagarajah, Romesh

    2012-07-01

    This study examines the uncertainties in modelling a quarter car suspension system caused by the effect of different sets of suspension parameters of a corresponding mathematical model. To overcome this problem, 11 sets of identified parameters of a suspension system have been compared, taken from the most recent published work. From this investigation, a set of parameters were chosen which showed a better performance than others in respect of peak amplitude and settling time. These chosen parameters were then used to investigate the performance of a new modified continuous skyhook control strategy with adaptive gain that dictates the vehicle's semi-active suspension system. The proposed system first captures the road profile input over a certain period. Then it calculates the best possible value of the skyhook gain (SG) for the subsequent process. Meanwhile the system is controlled according to the new modified skyhook control law using an initial or previous value of the SG. In this study, the proposed suspension system is compared with passive and other recently reported skyhook controlled semi-active suspension systems. Its performances have been evaluated in terms of ride comfort and road handling performance. The model has been validated in accordance with the international standards of admissible acceleration levels ISO2631 and human vibration perception.

  4. In-line chemical sensor deployment in a tritium plant

    SciTech Connect

    Wright, J.S.; Hope, D.T.; Torres, R.D.; Peters, B.; Tovo, L.L.

    2015-03-15

    The Savannah River Tritium Plant (TP) relies on well understood but aging sensor technology for process gas analysis. The use of alternative sensing and detection technologies for in-line and real-time analysis would aid process control and optimization. The TP upgrading follows a 2-phase projects. In the first phase, TP sensing requirements were determined by a team of process experts. Meanwhile, Savannah River National Laboratory sensor experts identified candidate technologies and related them to the TP processing requirements. The resulting road-map links the candidate technologies to actual plant needs. In the second phase an instrument demonstration station was established within a TP glove box in order to provide accurate assessments of how a candidate sensor technology would perform in a contaminated process environment.

  5. Impact evaluation of a refrigeration control system installed at Vitamilk Dairy, Incorporated under the Energy $avings Plan

    SciTech Connect

    Brown, D.R.; Dixon, D.R.; Spanner, G.E.

    1995-01-01

    This impact evaluation of a refrigeration control system (RCS) recently installed at Vitamilk Dairy, Inc. (Vitamilk) was conducted for the Bonneville Power Administration (Bonneville) as part of an evaluation of its Energy $avings Plan (E$P) Program. The RCS installation at Vitamilk uses microcomputer- based controls to automate refrigeration equipment previously controlled manually. This impact evaluation assessed how much electricity is being saved at Vitamilk as a result of the E$P and to determine how much the savings cost Bonneville and the region. On a unit savings basis, this project will save 9.7 kWh/tonne (8-8 kWh/ton) of milk and ice cream produced, based on the product mix for June 1992 through May 1993, representing a 28% reduction in energy consumption. The project was installed in 1992 for a total cost of $129,330, and Vitamilk received payment of $62,974 from Bonneville in 1993 for the acquisition of energy savings. The real levelized cost of these energy savings to Bonneville is 8.5 mills/kWh (in 1993 dollars) over the project`s assumed 15-year life, and the real levelized cost to the region is 17.9 mills/kWh (in 1993 dollars), not including transmission and distribution effects. Based on the expected project installation costs and energy savings benefits, the RCS would not have been implemented by Vitamilk without the E$P acquisition payment. The expected acquisition payment reduced the estimated payback period from 7.0 to 2.8 years. Although Vitamilk would generally require an energy conservation project to have a payback period of two years or less, the slightly longer payback period was accepted in this case.

  6. INCORPORATION OF HUMAN FACTORS ENGINEERING ANALYSES AND TOOLS INTO THE DESIGN PROCESS FOR DIGITAL CONTROL ROOM UPGRADES.

    SciTech Connect

    O'HARA,J.M.; BROWN,W.

    2004-09-19

    Many nuclear power plants are modernizing with digital instrumentation and control systems and computer-based human-system interfaces (HSIs). The purpose of this paper is to summarize the human factors engineering (HFE) activities that can help to ensure that the design meets personnel needs. HFE activities should be integrated into the design process as a regular part of the engineering effort of a plant modification. The HFE activities will help ensure that human performance issues are addressed, that new technology supports task performance, and that the HSIs are designed in a manner that is compatible with human physiological, cognitive and social characteristics.

  7. Sustained attention in mice: expanding the translational utility of the SAT by incorporating the Michigan Controlled Access Response Port (MICARP).

    PubMed

    St Peters, Megan; Cherian, Ajeesh Koshy; Bradshaw, Marc; Sarter, Martin

    2011-12-01

    Advances in mouse genetic technology have spurred increasing interest in the development of cognitive tasks for mice. Here, we describe and discuss the modifications necessary to adapt a task for the assessment of sustained attention performance for use in mice, including for taxing the top-down control of such performance. The validity of the Sustained Attention Task (SAT), including the distractor version (dSAT), has previously been demonstrated in rats and humans. This task requires moveable or retractable operanda; insertion of operanda into the operant chambers cues animals to respond to a prior signal or non-signal event, reporting either a hit or a miss, or a correct rejection or false alarm, respectively. Retractable levers did not support sufficiently high and stable levels of performance in mice. Given the widespread use of static nose-poke devices for testing operant performance in mice, we therefore designed and fabricated a retractable nose-poke device. As this device extends into chambers, a hole for nose-poking is slowly opened and closed again as the device retracts (termed the "Michigan Controlled Access Response Port", MICARP). Results describe the effects of variation of signal duration and event rate, trial outcome and trial type probability, effects of mice deprivation levels, and the reliability of SAT and dSAT performance. Mice perform the SAT and dSAT at levels comparable to those observed in rats. This task will be of assistance in expanding the translational usefulness of the SAT and dSAT. PMID:21888929

  8. Emergence of Virtual Reality as a Tool for Upper Limb Rehabilitation: Incorporation of Motor Control and Motor Learning Principles

    PubMed Central

    Weiss, Patrice L.; Keshner, Emily A.

    2015-01-01

    The primary focus of rehabilitation for individuals with loss of upper limb movement as a result of acquired brain injury is the relearning of specific motor skills and daily tasks. This relearning is essential because the loss of upper limb movement often results in a reduced quality of life. Although rehabilitation strives to take advantage of neuroplastic processes during recovery, results of traditional approaches to upper limb rehabilitation have not entirely met this goal. In contrast, enriched training tasks, simulated with a wide range of low- to high-end virtual reality–based simulations, can be used to provide meaningful, repetitive practice together with salient feedback, thereby maximizing neuroplastic processes via motor learning and motor recovery. Such enriched virtual environments have the potential to optimize motor learning by manipulating practice conditions that explicitly engage motivational, cognitive, motor control, and sensory feedback–based learning mechanisms. The objectives of this article are to review motor control and motor learning principles, to discuss how they can be exploited by virtual reality training environments, and to provide evidence concerning current applications for upper limb motor recovery. The limitations of the current technologies with respect to their effectiveness and transfer of learning to daily life tasks also are discussed. PMID:25212522

  9. Code development incorporating environmental, safety, and economic aspects of fusion reactors (FY 89--91)

    SciTech Connect

    Ho, S.K.; Fowler, T.K.; Holdren, J.P.

    1991-11-01

    This report discusses the following aspects of Fusion reactors.: Activation Analysis; Tritium Inventory; Environmental and Safety Indices and Their Graphical Representation; Probabilistic Risk Assessment (PRA) and Decision Analysis; Plasma Burn Control -- Application to ITER; and Other Applications.

  10. Tritium and stable isotopes of magmatic waters

    NASA Astrophysics Data System (ADS)

    Goff, F.; McMurtry, G. M.

    2000-04-01

    To investigate the isotopic composition and age of water in volcanic gases and magmas, we analyzed samples from 11 active volcanoes ranging in composition from tholeiitic basalt to rhyolite: Mount St. Helens (USA), Kilauea (USA), Pacaya (Guatemala), Galeras (Colombia), Satsuma Iwo-Jima (Japan), Sierra Negra and Alcedo (Ecuador), Vulcano (Italy), Parı´cutin (Mexico), Kudryavy (Russia), and White Island (New Zealand). Tritium at relatively low levels (0.1-5 T.U.) is found in most emissions from high-temperature volcanic fumaroles sampled, even at discharge temperatures >700°C. Although magmatic fluids sampled from these emissions usually contain high CO 2, S total, HCl, HF, B, Br, 3He R/ RA, and low contents of air components, stable isotope and tritium relations of nearly all such fluids show mixing of magmatic volatiles with relatively young meteoric water (model ages≤75 y). Linear δD/ δ18O and 3H/ δ18O mixing trends of these two end-members are invariably detected at arc volcanoes. Tritium is also detected in fumarole condensates at hot spot basalt volcanoes, but collecting samples approaching the composition of end-member magmatic fluid is exceedingly difficult. In situ production of 3H, mostly from spontaneous fission of 238U in magmas is calculated to be <0.001 T.U., except for the most evolved compositions (high U, Th, and Li and low H 2O contents). These values are below the detection limit of 3H by conventional analytical techniques (about 0.01 T.U. at best). We found no conclusive evidence that natural fusion in the Earth produces anomalous amounts of detectable 3H (>0.05 T.U.).

  11. Tritium concentration measurements in the JET divertor by optical spectroscopy of a Penning discharge

    SciTech Connect

    Hillis, D.L.; Morgan, P.D.; Ehrenberg, J.K.; Groth, M.; Stamp, M.F.; Hellermann, M. von; Kumar, V.

    1998-06-01

    Obtaining precision measurements of the relative concentrations of hydrogen, deuterium, tritium, and helium in the divertor of a tokamak are an important task for nuclear fusion research. Control of the deuterium-tritium isotopic ratio while limiting the helium ash content in a fusion plasma are key factors for optimizing the fuel burn in a fusion reactor, like the International Tokamak Experimental Reactor (ITER). A diagnostic technique has been developed to measure the deuterium-tritium isotopic ratio in the divertor of the Joint European Torus (JET) with a species-selective Penning vacuum gauge. The Penning discharge provides a source of electrons to excite the neutral hydrogen isotopes in the pumping duct. Subsequently, the visible light from the hydrogen isotopes is collected in an optical fiber bundle, transferred away from the tokamak into a low radiation background area, and analyzed in a high resolution Czerny-Turner spectrometer, which is equipped with a fast charge coupled device (CCD) camera for optical detection. The intensity of the observed line emission (D{sub {alpha}} -- 6561.03 {angstrom}; and T{sub {alpha}} -- 6560.44 {angstrom}) is directly proportional to the partial pressure of each gas found in the divertor. The line intensity of each isotope is calibrated as a function of pressure. The ratio of the line intensities thus provides a direct measurement of the deuterium-tritium isotopic ratio. The lower limit for the determination of the deuterium-tritium isotopic ratio is about 0.5%. The applicable pressure range for this system is from 10{sup {minus}5} mbar to a few times 10{sup {minus}3} mbar.

  12. Tritiation methods and tritium NMR spectroscopy

    SciTech Connect

    Jaiswal, D.K.; Morimoto, H.; Salijoughian, M.; Williams, P.G.

    1991-09-01

    We have used a simple process for the production of highly tritiated water and characterized the product species by {sup 1}H and {sup 3}H NMR spectroscopy. The water is readily manipulated and used in subsequent reactions either as T{sub 2}O, CH{sub 3}COOT or CF{sub 3}COOT. Development of tritiated diimide has progressed to the point where cis-hydrogenated products at 1-20 Ci/mmole S.A. are possible. Tri-n-butyl tin tritide has been produced at >95% tritium content and well characterized by multinuclear NMR techniques. 27 refs., 3 figs.

  13. Case management vocational rehabilitation for women with breast cancer after surgery: a feasibility study incorporating a pilot randomised controlled trial

    PubMed Central

    2013-01-01

    Background There is a paucity of methodologically robust vocational rehabilitation (VR) intervention trials. This study assessed the feasibility and acceptability of a VR trial of women with breast cancer to inform the development of a larger interventional study. Methods Women were recruited in Scotland and randomised to either a case management VR service or to usual care. Data were collected on eligibility, recruitment and attrition rates to assess trial feasibility, and interviews conducted to determine trial acceptability. Sick leave days (primary outcome) were self-reported via postal questionnaire every 4 weeks during the first 6 months post-surgery and at 12 months. Secondary outcome measures were change in employment pattern, quality of life and fatigue. Results Of the 1,114 women assessed for eligibility, 163 (15%) were eligible. The main reason for ineligibility was age (>65 years, n = 637, 67%). Of those eligible, 111 (68%) received study information, of which 23 (21%) consented to participate in the study. Data for 18 (78%) women were analysed (intervention: n = 7; control: n = 11). Participants in the intervention group reported, on average, 53 fewer days of sick leave over the first 6 months post-surgery than those in the control group; however, this difference was not statistically significant (p = 0.122; 95% confidence interval −15.8, 122.0). No statistically significant differences were found for secondary outcomes. Interviews with trial participants indicated that trial procedures, including recruitment, randomisation and research instruments, were acceptable. Conclusions Conducting a pragmatic trial of effectiveness of a VR intervention among cancer survivors is both feasible and acceptable, but more research about the exact components of a VR intervention and choice of outcomes to measure effectiveness is required. VR to assist breast cancer patients in the return to work process is an important component of cancer survivorship plans. Trial

  14. Sustained attention in mice: expanding the translational utility of the SAT by incorporating the Michigan Controlled Access Response Port (MICARP)

    PubMed Central

    St. Peters, Megan; Cherian, Ajeesh Koshy; Bradshaw, Marc; Sarter, Martin

    2011-01-01

    Advances in mouse genetic technology have spurred increasing interest in the development of cognitive tasks for mice. Here, we describe and discuss the modifications necessary to adapt a task for the assessment of sustained attention performance for use in mice, including for taxing the top-down control of such performance. The validity of the Sustained Attention Task (SAT), including the distractor version (dSAT), have previously been demonstrated in rats and humans. This task requires moveable or retractable operanda; insertion of operanda into the operant chambers cues animals to respond to a prior signal or non-signal event, reporting either a hit or a miss, or a correct rejection or false alarm, respectively. Retractable levers did not support sufficiently high and stable levels of performance in mice. Given the widespread use of static nose-poke devices for testing operant performance in mice, we therefore designed and fabricated a retractable nose-poke device. As this device extends into chambers, a hole for nose-poking is slowly opened and closed again as the device retracts (termed the “Michigan Controlled Access Response Port”; MICARP). Results describe the effects of variation of signal duration and event rate, trial outcome and trial type probability, effects of mice deprivation levels, and the reliability of SAT and dSAT performance. Mice perform the SAT and dSAT at levels comparable to those observed in rats. This task will be of assistance in expanding the translational usefulness of the SAT and dSAT. PMID:21888929

  15. Controlled Dual Growth Factor Delivery From Microparticles Incorporated Within Human Bone Marrow-Derived Mesenchymal Stem Cell Aggregates for Enhanced Bone Tissue Engineering via Endochondral Ossification

    PubMed Central

    Dang, Phuong N.; Dwivedi, Neha; Phillips, Lauren M.; Yu, Xiaohua; Herberg, Samuel; Bowerman, Caitlin; Solorio, Loran D.; Murphy, William L.

    2016-01-01

    Bone tissue engineering via endochondral ossification has been explored by chondrogenically priming cells using soluble mediators for at least 3 weeks to produce a hypertrophic cartilage template. Although recapitulation of endochondral ossification has been achieved, long-term in vitro culture is required for priming cells through repeated supplementation of inductive factors in the media. To address this challenge, a microparticle-based growth factor delivery system was engineered to drive endochondral ossification within human bone marrow-derived mesenchymal stem cell (hMSC) aggregates. Sequential exogenous presentation of soluble transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2) at various defined time courses resulted in varying degrees of chondrogenesis and osteogenesis as demonstrated by glycosaminoglycan and calcium content. The time course that best induced endochondral ossification was used to guide the development of the microparticle-based controlled delivery system for TGF-β1 and BMP-2. Gelatin microparticles capable of relatively rapid release of TGF-β1 and mineral-coated hydroxyapatite microparticles permitting more sustained release of BMP-2 were then incorporated within hMSC aggregates and cultured for 5 weeks following the predetermined time course for sequential presentation of bioactive signals. Compared with cell-only aggregates treated with exogenous growth factors, aggregates with incorporated TGF-β1- and BMP-2-loaded microparticles exhibited enhanced chondrogenesis and alkaline phosphatase activity at week 2 and a greater degree of mineralization by week 5. Staining for types I and II collagen, osteopontin, and osteocalcin revealed the presence of cartilage and bone. This microparticle-incorporated system has potential as a readily implantable therapy for healing bone defects without the need for long-term in vitro chondrogenic priming. Significance This study demonstrates the regulation of chondrogenesis

  16. Controlled Dual Growth Factor Delivery From Microparticles Incorporated Within Human Bone Marrow-Derived Mesenchymal Stem Cell Aggregates for Enhanced Bone Tissue Engineering via Endochondral Ossification.

    PubMed

    Dang, Phuong N; Dwivedi, Neha; Phillips, Lauren M; Yu, Xiaohua; Herberg, Samuel; Bowerman, Caitlin; Solorio, Loran D; Murphy, William L; Alsberg, Eben

    2016-02-01

    Bone tissue engineering via endochondral ossification has been explored by chondrogenically priming cells using soluble mediators for at least 3 weeks to produce a hypertrophic cartilage template. Although recapitulation of endochondral ossification has been achieved, long-term in vitro culture is required for priming cells through repeated supplementation of inductive factors in the media. To address this challenge, a microparticle-based growth factor delivery system was engineered to drive endochondral ossification within human bone marrow-derived mesenchymal stem cell (hMSC) aggregates. Sequential exogenous presentation of soluble transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2) at various defined time courses resulted in varying degrees of chondrogenesis and osteogenesis as demonstrated by glycosaminoglycan and calcium content. The time course that best induced endochondral ossification was used to guide the development of the microparticle-based controlled delivery system for TGF-β1 and BMP-2. Gelatin microparticles capable of relatively rapid release of TGF-β1 and mineral-coated hydroxyapatite microparticles permitting more sustained release of BMP-2 were then incorporated within hMSC aggregates and cultured for 5 weeks following the predetermined time course for sequential presentation of bioactive signals. Compared with cell-only aggregates treated with exogenous growth factors, aggregates with incorporated TGF-β1- and BMP-2-loaded microparticles exhibited enhanced chondrogenesis and alkaline phosphatase activity at week 2 and a greater degree of mineralization by week 5. Staining for types I and II collagen, osteopontin, and osteocalcin revealed the presence of cartilage and bone. This microparticle-incorporated system has potential as a readily implantable therapy for healing bone defects without the need for long-term in vitro chondrogenic priming. Significance: This study demonstrates the regulation of chondrogenesis

  17. Target-controlled formation of silver nanoclusters in abasic site-incorporated duplex DNA for label-free fluorescence detection of theophylline

    NASA Astrophysics Data System (ADS)

    Park, Ki Soo; Oh, Seung Soo; Soh, H. Tom; Park, Hyun Gyu

    2014-08-01

    A novel, label-free, fluorescence based sensor for theophylline has been developed. In the new sensor system, an abasic site-incorporated duplex DNA probe serves as both a pocket for recognition of theophylline and a template for the preparation of fluorescent silver nanoclusters. The strategy relies on theophylline-controlled formation of fluorescent silver nanoclusters from abasic site-incorporated duplex DNA. When theophylline is not present, silver ions interact with the cytosine groups opposite to the abasic site in duplex DNA. This interaction leads to efficient formation of intensely red fluorescent silver nanoclusters. In contrast, when theophylline is bound at the abasic site through pseudo base-pairing with appropriately positioned cytosines, silver ion binding to the cytosine nucleobase is prevented. Consequently, fluorescent silver nanoclusters are not formed causing a significant reduction of the fluorescence signal. By employing this new sensor, theophylline can be highly selectively detected at a concentration as low as 1.8 μM. Finally, the diagnostic capability and practical application of this sensor were demonstrated by its use in detecting theophylline in human blood serum.A novel, label-free, fluorescence based sensor for theophylline has been developed. In the new sensor system, an abasic site-incorporated duplex DNA probe serves as both a pocket for recognition of theophylline and a template for the preparation of fluorescent silver nanoclusters. The strategy relies on theophylline-controlled formation of fluorescent silver nanoclusters from abasic site-incorporated duplex DNA. When theophylline is not present, silver ions interact with the cytosine groups opposite to the abasic site in duplex DNA. This interaction leads to efficient formation of intensely red fluorescent silver nanoclusters. In contrast, when theophylline is bound at the abasic site through pseudo base-pairing with appropriately positioned cytosines, silver ion binding to

  18. Polyimide and polyamide-imide in a tritium atmosphere

    SciTech Connect

    Wylie, K.F.; Hockett, J.E.; Buxton, T.L.

    1981-01-01

    Five different commercial polyamide-imide and polyimide specimens were kept in a tritium atmosphere (96.9 mol %, 101 kPa, initial fill conditions) for three months. Selected physical and mechanical properties of the five plastics were examined. Mass spectrometric data showed the growth of protium and HT impurity in the tritium gas.

  19. Tritium labeling of organic compounds deposited on porous structures

    DOEpatents

    Ehrenkaufer, Richard L. E.; Wolf, Alfred P.; Hembree, Wylie C.

    1979-01-01

    An improved process for labeling organic compounds with tritium is carried out by depositing the selected compound on the extensive surface of a porous structure such as a membrane filter and exposing the membrane containing the compound to tritium gas activated by the microwave discharge technique. The labeled compound is then recovered from the porous structure.

  20. Locating tritium sources in a research reactor building.

    PubMed

    Fukui, Masami

    2005-10-01

    Despite renovation of the D2O facility, tritium concentrations in the condensates of reactor room air showed tens of Bq mL before venting resumption on July 1997. This suggested the presence of tritium sources in the research reactor-containment building. An investigation was therefore initiated to locate the source and determine the distribution of tritium in the containment building. Air monitoring in the working area using a dish of water placed in the building suggested that the source of tritium was near the reactor core. Monitoring exhaust air from the two facilities (a cold neutron source and a D(2)O tank) showed high specific activity on the order of 10 Bq mL(-1), suggesting the presence of tritium in condensates near the reactor core. The major concern was whether the leakage of liquid deuterium (4 L) and heavy water (2 x 10(3) L) used as a moderator had occurred. The concentration of tritium in condensates has not increased over the past few years in either the exhaust line or working area, and the deuterium itself has not been found in the surrounding environment. The concentration of tritium measured using an ionization chamber after Ar decay was dependent on the thermal output of the research reactor, indicating that the tritium was produced by the irradiation process within shielding/moderator materials or cover gas with neutrons.

  1. Effectiveness Monitoring Report, MWMF Tritium Phytoremediation Interim Measures.

    SciTech Connect

    Hitchcock, Dan; Blake, John, I.

    2003-02-10

    This report describes and presents the results of monitoring activities during irrigation operations for the calendar year 2001 of the MWMF Interim Measures Tritium Phytoremediation Project. The purpose of this effectiveness monitoring report is to provide the information on instrument performance, analysis of CY2001 measurements, and critical relationships needed to manage irrigation operations, estimate efficiency and validate the water and tritium balance model.

  2. Tritium measurement technique using in-bed'' calorimetry

    SciTech Connect

    Klein, J.E.; Mallory, M.K.; Nobile, A. Jr.

    1991-01-01

    One of the new technologies that has been introduced to the Savannah River Site (SRS) is the production scale use of metal hydride technology to store, pump, and compress hydrogen isotopes. For tritium stored in metal hydride storage beds, a unique relationship does not exist between the amount of tritium in the bed and the pressure-volume-temperature properties of the hydride material. Determining the amount of tritium in a hydride bed after desorbing the contents of the bed to a tank and performing pressure, volume, temperature, and composition (PVTC) measurements is not practical due to long desorption/absorption times and the inability to remove tritium heels'' from the metal hydride materials under normal processing conditions. To eliminate the need to remove tritium from hydride storage beds for measurement purposes, and in-bed'' tritium calorimetric measurement technique has been developed. The steady-state temperature rise of a gas stream flowing through a jacketed metal hydride storage bed is measured and correlated with power input to electric heaters used to simulate the radiolytic power generated by the decay of tritium to {sup 3}He. Temperature rise results for prototype metal hydride storage beds and the effects of using different gases in the bed are shown. Linear regression results shows that for 95% confidence intervals, temperature rise measurements can be obtained in 14 hours and have an accuracy of {plus minus}1.6% of a tritium filled hydride storage bed.

  3. Tritium measurement technique using ``in-bed`` calorimetry

    SciTech Connect

    Klein, J.E.; Mallory, M.K.; Nobile, A. Jr.

    1991-12-31

    One of the new technologies that has been introduced to the Savannah River Site (SRS) is the production scale use of metal hydride technology to store, pump, and compress hydrogen isotopes. For tritium stored in metal hydride storage beds, a unique relationship does not exist between the amount of tritium in the bed and the pressure-volume-temperature properties of the hydride material. Determining the amount of tritium in a hydride bed after desorbing the contents of the bed to a tank and performing pressure, volume, temperature, and composition (PVTC) measurements is not practical due to long desorption/absorption times and the inability to remove tritium ``heels`` from the metal hydride materials under normal processing conditions. To eliminate the need to remove tritium from hydride storage beds for measurement purposes, and ``in-bed`` tritium calorimetric measurement technique has been developed. The steady-state temperature rise of a gas stream flowing through a jacketed metal hydride storage bed is measured and correlated with power input to electric heaters used to simulate the radiolytic power generated by the decay of tritium to {sup 3}He. Temperature rise results for prototype metal hydride storage beds and the effects of using different gases in the bed are shown. Linear regression results shows that for 95% confidence intervals, temperature rise measurements can be obtained in 14 hours and have an accuracy of {plus_minus}1.6% of a tritium filled hydride storage bed.

  4. Plant-Based Plume-Scale Monitoring Reveals the Extents and Pathways of Tritium Transport

    NASA Astrophysics Data System (ADS)

    Andraski, B. J.; Michel, R. L.; Halford, K. J.; Stonestrom, D. A.; Abraham, J. D.

    2005-05-01

    Cost-effective methods are needed to detect contamination near radioactive-waste and other contaminated sites. Such methods should be capable of providing an early warning of contaminant releases and be accurate and robust enough for monitoring the long-term performance of waste-isolation facilities and remediation measures. Plant-based methods were developed adjacent to a closed low-level radioactive waste (LLRW) facility in the Amargosa Desert, Nevada. Objectives were to (i) characterize and map the spatial variability of plant-water tritium, (ii) develop empirical relations to predict subsurface tritium contamination from plant-water concentrations, and (iii) gain insight into transport pathways and processes. Tritium was selected because it is a common radionuclide disposed at radioactive waste sites and it is a good tracer of water movement. Solar-distillation and solid-phase-extraction were used to collect and prepare plant (creosote bush, Larrea tridentata) foliage water for direct-scintillation counting. The maximum plant-water tritium concentration was 4,890 Bq/L; background values averaged 2.5 Bq/L. Geostatistical analysis showed that plant concentrations were spatially correlated to a distance of 380 m. Simple-contour and kriged maps of plant concentrations identified "hot spots" that were verified by soil-water-vapor measurements. Empirical linear relations between plant water and soil-water-vapor concentrations measured at the 0.5- and 1.5-m sampling depths were used to map the spatial distributions of root-zone and sub-root-zone tritium, respectively. Results showed that tritium migration away from the waste source primarily occurs in the gas phase with preferential transport through a dry, gravelly layer beneath the root zone, from which it moves upward and is subsequently released to the surface environment. Shallow and deep geologic units controlling preferential transport through the unsaturated zone were mapped by direct-current electrical

  5. SOLERAS - Solar Controlled Environment Agriculture Project. Final report, Volume 9. Science Applications, Incorporated Phase 2 - definition study

    SciTech Connect

    Not Available

    1985-01-01

    This report describes the effort required to implement the design of the Solar Controlled Environment Agriculture Engineering Test Facility, SCEA-ETF. This report is a basic blueprint for the Phase 2 activities which have as a goal the construction of the ETF. These activities have been broken down into five major tasks, namely Project Management; Engineering and Design; Procurement/Fabrication; Construction, Installation and Checkout; and Operation and Maintenance. The type of activities required under each of these tasks are described followed by a detailed work breakdown structure. The Phase 2 project organization is discussed. A 13 month schedule for the total project is also given. Lastly, two appendices discuss cost adjustment factors for an ETF located in the KSA, and an update of the commercial system cost estimate based on preliminary cost quotations for the ETF. The results show a 63% cost increase for the KSA ETF primarily due to higher construction costs and greater well depth. The commercial system cost required an adjustment upwards of 7.7%.

  6. Tritium analysis in titanium films by the BIXS method

    NASA Astrophysics Data System (ADS)

    Zhang, W. G.; Sun, H. W.; Zeng, F. Y.; Mao, L.; Wu, Q. Q.; Zhu, J. J.; An, Z.

    2012-03-01

    In this paper, tritium analyses in titanium films has been carried out by β-decay induced X-ray spectroscopy (BIXS), based on Monte Carlo simulations and the Tikhonov regularization. In our analysis, for the first time the internal bremsstrahlung of tritium β-decay has been taken into account in the BIXS method. Meanwhile, parallel computation using the Monte Carlo code PENELOPE has been realized within the frame of a message passing interface. The tritium depth distributions, surface homogeneity and the total tritium content of the analyzed samples have been obtained. The total tritium contents obtained by the present BIXS method are found to be in good agreement with those obtained by the PVT method.

  7. Tritium target fabrication for the rotating target neutron source

    NASA Astrophysics Data System (ADS)

    Adair, H. L.; Kobisk, E. H.; Byrum, B. L.

    1982-09-01

    The Isotope Research Materials Laboratory (IRML) of the Oak Ridge National Laboratory (ORNL) prepares tritium targets that are used to produce an intense beam of 14.5 MeV neutrons by the 13H( 12H, 01n) 24He reaction. The intense beams of 14.5 MeV neutrons are used in programs involving cancer research, materials evaluation, and materials identification. Many of the tritium targets prepared by IRML for the past four years have been used in support of the Rotating Target Neutron Source (RTNS) programs at the Lawrence Livermore National Laboratory (LLNL). The tritium targets are prepared by the vacuum evaporation of titanium from a rod-fed electron beam gun. The resulting vapor-condensed titanium layers are exposed to a tritium atmosphere to form titanium tritide. A summary of tritium target development at IRML with an emphasis on the RTNS programs is presented.

  8. Neutral Beam Injection in the JET Trace Tritium Experiment

    SciTech Connect

    Surrey, E.; Ciric, D.; Cox, S. J.; Hackett, L.; Homfray, D.; Jenkins, I.; Jones, T.T.C.; Keeling, D.; King, R.; Young, A.; Whitehead, D.

    2005-07-15

    Operation of the JET Neutral Beam Injectors with tritium is described. Supplying the tritium feed via the special electrically grounded gas feed compromised the performance of the up-graded high current triode Positive Ion Neutral Injectors (PINI) due to gas starvation of the source and the methods adopted to ameliorate this effect are described. A total of 362 PINI beam pulses were requested, circulating a total of 4.73g tritium, of which 9.3mg was injected into the torus. Safety considerations required a continuous, cumulative total to be maintained of the mass of tritium adsorbed onto the cryo-pumping panel; a daily limit of 0.5g was adopted for the Trace Tritium Experiment (TTE). A subsequent clean up phase using 115keV deuterium beams completed the isotopic exchange of components in the beamline.

  9. Tritium trapping on the plasma irradiated tungsten surface

    SciTech Connect

    Torikai, Y.; Alimov, V.K.; Penzhorn, R.D.; Isobe, K.; Oyaidzu, M.; Yamanishi, T.; Ueda, Y.; Kurishita, H.; Philipps, V.; Kreter, A.; Zlobinski, M.

    2015-03-15

    Tungsten (W) is a candidate material for plasma-facing high heat-flux structures in future fusion reactors. The aim of this study is to assess how reasonably one can predict the tritium inventory in actual fusion machines using data on the hydrogen isotope inventory obtained in laboratory experiments. W specimens previously exposed to deuterium (D) plasmas both in the TEXTOR tokamak and high flux linear plasma generator (LPG) were subsequently loaded with tritium at 573 K for 3 h. The retention of tritium in the near-surface W layer was examined by imaging plate technique. The study shows that on the TEXTOR-plasma-exposed W surface, tritium was mainly trapped in carbon deposits, and for LPG-plasma-exposed W specimens, tritium was trapped in defects created in the near-surface layer during the course of D plasma exposure.

  10. A field study of tritium migration in groundwater.

    PubMed

    Zhang, L X; Zhang, M S; Tu, G R

    1995-12-01

    A field study of tritium migration from an underground nuclear explosion was carried out for more than 7 years. A series of satellite wells was drilled around the explosion cavity, which is within a nuclear test site water-supply aquifer. Samples from various wells were analysed. In this way, variations in the tritium concentration of water from different wells were determined, and the extent of tritium migration during the 7 years after the detonation was examined. The maximum tritium concentration reached in water from various wells is just 52-times higher than the maximum permissible concentration for drinking water and decreased afterwards. According to the results obtained, the flow rate of groundwater was inferred to be about 91 m per year and the maximum contamination distance of water supplies by the tritium were < or = 2 km from the explosion cavity.

  11. Chemical form of tritium released from solid breeder materials

    NASA Astrophysics Data System (ADS)

    Nishikawa, Masabumi; Kinjyo, Tomohiro; Nishida, Yoshiteru

    2004-02-01

    The fraction of HTO in total tritium was measured at release of the bred tritium to the purge gas with hydrogen using the thermal release after irradiation method, where neutron irradiation was performed at the Japan Research Reactor-3 (JRR-3) in Japan Atomic Energy Research Institute (JAERI) or the Kyoto University Research Reactor (KUR reactor) in Kyoto University. It is experimentally confirmed in this study that not a small portion of bred tritium is released to the blanket purge gas in the form of HTO from ceramic breeder materials even when hydrogen is added to the purge gas. Observation in this study implies that it is necessary to have a bred tritium recovery system useful for both HT and HTO form tritium. The water formation properties from Li 2TiO 3 bed placed in the hydrogen atmosphere were also discussed in this study.

  12. Refurbishment of the tritium laboratories at SCK-CEN

    SciTech Connect

    Braet, J.; Dylst, K.; Vanderbiesen, S.

    2008-07-15

    The SCK-CEN tritium laboratories were commissioned in 1975 for a maximum tritium inventory of 37 TBq. With an aim to improve the infrastructure, the capabilities and safety, SCK-CEN's general management decided to refurbish the laboratories. A new ventilation system, including a stack and gloveboxes equipped with a detritiation installation, will allow a higher tritium inventory limit of 0.37 PBq. This paper discusses the ongoing refurbishment of the two neighboring tritium laboratories. Currently one laboratory has been de-nuclearized whilst the other is still in operation. Nevertheless a number of conclusions can already be drawn. We succeeded in de-nuclearizing most of the equipment and infrastructure without personnel receiving measurable tritium doses. If the free released metals had been disposed off at a nuclear melting facility, 22% of the costs could have been saved, however free release is more socially acceptable. (authors)

  13. Estimation of dose to man from environmental tritium

    SciTech Connect

    Rohwer, P S; Etnier, E L

    1980-01-01

    Factors important for characterization of tritium in environmental pathways leading to exposure of man are reviewed and quantification of those factors is discussed. Parameters characterizing the behavior of tritium in man are also subjected to review. Factors to be discussed include organic binding, bioaccumulation, quality factor and transmutation. A variety of models are presently in use to estimate dose to man from environmental releases of tritium. Results from four representative models are compared and discussed. Site-specific information is always preferable when parameterizing models to estimate dose to man. There may be significant differences in dose potential among geographic regions due to variable factors. An example of one such factor examined is absolute humidity. It is concluded that adequate methodologies exist for estimation of dose to man from environmental tritium although a number of areas are identified where additional tritium research is desirable.

  14. Tritium release from ceramic breeder materials deposited with noble metals

    NASA Astrophysics Data System (ADS)

    Munakata, Kenzo; Mochizuki, Kazuhiro; Wajima, Takaaki; Wada, Kohei; Hara, Keisuke; Shinozaki, Takashi; Takeishi, Toshiharu; Knitter, Regina; Bekris, Nicolas; Fujii, Toshiyuki; Yamana, Hajimu; Okuno, Kenji

    2011-10-01

    Lithium orthosilicate and lithium aluminate are the candidates of the breeder material of the tritium-breeding blanket. To enhance the rate of tritium release from these breeder materials, 0.2 wt.% of palladium was impregnated into the breeder materials by the incipient wet impregnation method. The lithium orthosilicate and the lithium aluminate pebbles with or without Pd were irradiated in the Kyoto university research reactor, and out-of-pile annealing experiments were performed. When the breeder materials were deposited with a catalytic additive, such as Pd the ratio of the tritium discharged in the molecular form of tritium (HT) increased. It was also found that the amount of the tritium discharged from the lithium orthosilicate pebbles with a catalytic additive at the low temperatures is greater compared with lithium aluminate.

  15. Fusion reactor high vacuum pumping: Charcoal cryosorber tritium exposure results

    SciTech Connect

    Sedgley, D.W.; Walthers, C.R.; Jenkins, E.M. )

    1991-01-01

    Recent experiments, have shown the practically of using activated charcoal (coconut charcoal) at 4{degrees}K to pump helium and hydrogen isotopes for a fusion reactor. Both speed and capacity for deuterium/helium and tritium/helium-3 mixtures were shown to be satisfactory. The long term effects of tritium on the charcoal/cement system developed by Grumman and LLNL were not known and a program was undertaken to see what, if any, effect long term tritium exposure has on the cryosorber. Several charcoal on aluminum test samples were subjected to six months exposure of tritium at approximately 77{degrees}K. The tritium was scanned several times with a residual gas analyzer and the speed-capacity performance of the samples was measured before, approximately half way through and after the exposure. Modest effects were noted which would not seriously restrict charcoal's use as a cryosorber for fusion reactor high vacuum pumping applications. 4 refs., 8 figs.

  16. Tritium concentrations in the Columbia River at Richland

    SciTech Connect

    Dirkes, R.L.

    1993-01-01

    The concentrations of tritium in the Columbia River, which are measurable using special analytical techniques, have been decreasing during recent years. Tritium levels are significantly greater at the Richland Pumphouse downstream of the Hanford Site than upstream at Priest Rapids Dam. Tritium is known to enter the river along the Hanford Site as direct effluent discharges, which have been virtually eliminated, and through the seepage of ground water contaminated as a result of past operations. The seepage of contaminated ground water has continued, expanding over time to encompass a larger portion of the Hanford shoreline nearer to the downstream Columbia River monitoring station. Cross-sectional sampling of the river was conducted to determine the distribution of tritium across the river and evaluate the relationship between average tritium concentrations in the river and those measured by the downstream river sampling system.

  17. Modulation of Bone-Specific Tissue Regeneration by Incorporating Bone Morphogenetic Protein and Controlling the Shell Thickness of Silk Fibroin/Chitosan/Nanohydroxyapatite Core-Shell Nanofibrous Membranes.

    PubMed

    Shalumon, K T; Lai, Guo-Jyun; Chen, Chih-Hao; Chen, Jyh-Ping

    2015-09-30

    The presence of both osteoconductive and osteoinductive factors is important in promoting stem cell differentiation toward the osteogenic lineage. In this study, we prepared silk fibroin/chitosan/nanohydroxyapatite/bone morphogenetic protein-2 (SF/CS/nHAP/BMP-2, SCHB2) nanofibrous membranes (NFMs) by incorporating BMP-2 in the core and SF/CS/nHAP as the shell layer of a nanofiber with two different shell thicknesses (SCHB2-thick and SCHB-thin). The physicochemical properties of SCHB2 membranes were characterized and compared with those of SF/CS and SF/CS/nHAP NFMs. When tested in release studies, the release rate of BMP-2 and the concentration of BMP-2 in the release medium were higher for SCHB2-thin NFMs because of reduced shell thickness. The BMP-2 released from the nanofiber retained its osteoinductive activity toward human-bone-marrow-derived mesenchymal stem cells (hMSCs). Compared with SF/CS and SF/CS/nHAP NFMs, the incorporation of BMP-2-promoted osteogenic differentiation of hMSCs and the SCHB-thin NFM is the best scaffold during in vitro cell culture. Gene expression analysis by real-time quantitative polymerase chain reaction detected the evolution of both early and late marker genes of bone formation. The relative mRNA expression is in accordance with the effect of BMP-2 incorporation and shell thickness, while the same was reconfirmed through the quantification of bone marker protein osteocalcin. In vivo experiments were carried out by subcutaneously implanting hMSC-seeded SCHB2-thin NFMs and acellular controls on the back sides of nude mice. Immunohistochemical and histological staining confirmed ectopic bone formation and osteogenesis of hMSCs in SCHB2-thin NFMs. In conclusion, the SCHB2-thin NFM could be suggested as a promising scaffold for bone tissue engineering. PMID:26355766

  18. Five-year Local Control in a Phase II Study of Hypofractionated Intensity Modulated Radiation Therapy With an Incorporated Boost for Early Stage Breast Cancer

    SciTech Connect

    Freedman, Gary M.; Anderson, Penny R.; Bleicher, Richard J.; Litwin, Samuel; Li Tianyu; Swaby, Ramona F.; Ma, Chang-Ming Charlie; Li Jinsheng; Sigurdson, Elin R.; Watkins-Bruner, Deborah; Morrow, Monica; Goldstein, Lori J.

    2012-11-15

    Purpose: Conventional radiation fractionation of 1.8-2 Gy per day for early stage breast cancer requires daily treatment for 6-7 weeks. We report the 5-year results of a phase II study of intensity modulated radiation therapy (IMRT), hypofractionation, and incorporated boost that shortened treatment time to 4 weeks. Methods and Materials: The study design was phase II with a planned accrual of 75 patients. Eligibility included patients aged {>=}18 years, Tis-T2, stage 0-II, and breast conservation. Photon IMRT and an incorporated boost was used, and the whole breast received 2.25 Gy per fraction for a total of 45 Gy, and the tumor bed received 2.8 Gy per fraction for a total of 56 Gy in 20 treatments over 4 weeks. Patients were followed every 6 months for 5 years. Results: Seventy-five patients were treated from December 2003 to November 2005. The median follow-up was 69 months. Median age was 52 years (range, 31-81). Median tumor size was 1.4 cm (range, 0.1-3.5). Eighty percent of tumors were node negative; 93% of patients had negative margins, and 7% of patients had close (>0 and <2 mm) margins; 76% of cancers were invasive ductal type: 15% were ductal carcinoma in situ, 5% were lobular, and 4% were other histology types. Twenty-nine percent of patients 29% had grade 3 carcinoma, and 20% of patients had extensive in situ carcinoma; 11% of patients received chemotherapy, 36% received endocrine therapy, 33% received both, and 20% received neither. There were 3 instances of local recurrence for a 5-year actuarial rate of 2.7%. Conclusions: This 4-week course of hypofractionated radiation with incorporated boost was associated with excellent local control, comparable to historical results of 6-7 weeks of conventional whole-breast fractionation with sequential boost.

  19. Anisohydric but isohydrodynamic: seasonally constant plant water potential gradient explained by a stomatal control mechanism incorporating variable plant hydraulic conductance.

    PubMed

    Franks, Peter J; Drake, Paul L; Froend, Ray H

    2007-01-01

    Isohydric and anisohydric regulations of plant water status have been observed over several decades of field, glasshouse and laboratory studies, yet the functional significance and mechanism of both remain obscure. We studied the seasonal trends in plant water status and hydraulic properties in a natural stand of Eucalyptus gomphocephala through cycles of varying environmental moisture (rainfall, groundwater depth, evaporative demand) in order to test for isohydry and to provide physiological information for the mechanistic interpretation of seasonal trends in plant water status. Over a 16 month period of monitoring, spanning two summers, midday leaf water potential (psi(leaf)) correlated with predawn psi(leaf), which was correlated with water table depth below ground level, which in turn was correlated with total monthly rainfall. Eucalyptus gomphocephala was therefore not seasonally isohydric. Despite strong stomatal down-regulation of transpiration rate in response to increasing evaporative demand, this was insufficient to prevent midday psi(leaf) from falling to levels below -2 MPa in the driest month, well into the region likely to induce xylem air embolisms, based on xylem vulnerability curves obtained in the study. However, even though midday psi(leaf) varied by over 1.2 MPa across seasons, the hydrodynamic (transpiration-induced) water potential gradient from roots to shoots (delta psi(plant)), measured as the difference between predawn and midday psi(leaf), was relatively constant across seasons, averaging 0.67 MPa. This unusual pattern of hydraulic regulation, referred to here as isohydrodynamic, is explained by a hydromechanical stomatal control model where plant hydraulic conductance is dependent on transpiration rate.

  20. Quantification of the activity of tritium produced during the routine synthesis of (18)F fluorodeoxyglucose for positron emission tomography.

    PubMed

    Marshall, C; Talboys, M A; Bukhari, S; Evans, W D

    2014-06-01

    Gamma emitting radioactive by-products generated during the cyclotron irradiation of (18)O labelled water by protons to produce (18)FDG (fluorodeoxyglucose) for positron emission tomography are well characterised. However, the production of tritium ((3)H) through the (18)O(p,t)(16)O nuclear reaction has not been investigated in detail. The aim of this study was to measure tritium activity produced during a large number of (18)FDG production runs in order to obtain a better perspective on its impact on radioactive waste management, particularly as regards storage and disposal. Tritium was assayed by liquid scintillation counting in recovered (18)O water from 24 separate production runs. The mean (SD) values of activity and activity concentration were 170 (20) kBq and 81 (8) kBq ml(-1) respectively. Both quantities were positively correlated with the activity of (18)F. Tritium was detected in much lower concentration in water used to rinse the target vessel. The activity of tritium is such that it is exempt from regulatory control and may be combined with bulk non-active waste for disposal as Very Low Level Waste. However, variations in the irradiation conditions or the procedures for the collection of recovered water might result in its classification as Low Level Waste, necessitating a more complex disposal regime. PMID:24894021

  1. Preheating temperature effect on tritium retention in VPS-W

    SciTech Connect

    Sato, M.; Uchimura, H.; Toda, K.; Oya, Y.; Okuno, K.; Tokunaga, T.; Watanabe, H.; Yoshida, N.; Hatano, Y.; Kasada, R.; Kimura, A.; Nagasaka, T.

    2015-03-15

    The W coating by Vacuum Plasma Spraying (VPS) technology is thought to be reasonable for most plasma facing components in future fusion reactors. In this paper the deuterium retention behavior for the Vacuum Plasma Spraying (VPS) tungsten (W) coating has been studied to demonstrate the tritium retention as a function of heating temperature. It has been found that two major deuterium desorption stages were observed at the temperature regions of 400 - 700 K (Stage 1) and 900 - 1100 K (Stage 2), considering that Stage 1 has been linked to the desorption of deuterium trapped by near surface and intrinsic defects, and Stage 2 has been related to the desorption of deuterium bound to impurities as C-D bonds. By heating the sample above 673 K, the major peak of C-1s shifted from C-O bond to C-C bond, where the retention of deuterium as Stage 2 has increased. Therefore it indicates that the hydrogen isotope retention was controlled by the amount of C-C bond in VPS, most of which was contaminated during the VPS coating process. The comparison of several samples (VPS-W with shading, VPS-W without shading and Polycrystalline W (PCW)) shows that the carbon impurity has a large affinity with deuterium and makes stable trapping states compared to that with intrinsic defects and grain boundaries. However, most of them was reduced by heating at 1173 K. Therefore, heating treatment is quite important to get rid of carbon impurities and refrain higher tritium retention in VPS. (authors)

  2. Derivation of dose conversion factors for tritium

    SciTech Connect

    Killough, G. G.

    1982-03-01

    For a given intake mode (ingestion, inhalation, absorption through the skin), a dose conversion factor (DCF) is the committed dose equivalent to a specified organ of an individual per unit intake of a radionuclide. One also may consider the effective dose commitment per unit intake, which is a weighted average of organ-specific DCFs, with weights proportional to risks associated with stochastic radiation-induced fatal health effects, as defined by Publication 26 of the International Commission on Radiological Protection (ICRP). This report derives and tabulates organ-specific dose conversion factors and the effective dose commitment per unit intake of tritium. These factors are based on a steady-state model of hydrogen in the tissues of ICRP's Reference Man (ICRP Publication 23) and equilibrium of specific activities between body water and other tissues. The results differ by 27 to 33% from the estimate on which ICRP Publication 30 recommendations are based. The report also examines a dynamic model of tritium retention in body water, mineral bone, and two compartments representing organically-bound hydrogen. This model is compared with data from human subjects who were observed for extended periods. The manner of combining the dose conversion factors with measured or model-predicted levels of contamination in man's exposure media (air, drinking water, soil moisture) to estimate dose rate to an individual is briefly discussed.

  3. Organically bound tritium analysis in environmental samples

    SciTech Connect

    Baglan, N.; Cossonnet, C.; Fournier, M.; Momoshima, N.; Ansoborlo, E.

    2015-03-15

    Organically bound tritium (OBT) has become of increased interest within the last decade, with a focus on its behaviour and also its analysis, which are important to assess tritium distribution in the environment. In contrast, there are no certified reference materials and no standard analytical method through the international organization related to OBT. In order to resolve this issue, an OBT international working group was created in May 2012. Over 20 labs from around the world participated and submitted their results for the first intercomparison exercise results on potato (Sep 2013). The samples, specially-prepared potatoes, were provided in March 2013 to each participant. Technical information and results from this first exercise are discussed here for all the labs which have realised the five replicates necessary to allow a reliable statistical treatment. The results are encouraging as the increased number of participating labs did not degrade the observed dispersion of the results for a similar activity level. Therefore, the results do not seem to depend on the analytical procedure used. From this work an optimised procedure can start to be developed to deal with OBT analysis and will guide subsequent planned OBT trials by the international group.

  4. Tau neutrino component to tritium beta decay

    SciTech Connect

    Snyderman, N.J.

    1995-06-01

    A framework is given for explaining anomalous results of neutrino mass experiments that measure the high energy electron spectrum of tritium {beta} decay. The experimental results have been fit to a negative neutrino mass square. We show that there is a consistent phenomenological interpretation due to a positive mass tau neutrino component of the {beta} decay spectrum, with strong near threshold final state interactions with the He nucleus. If this enhancement is due to new interactions between low energy tau neutrinos and nuclei, then the tritium 0 decay experiments could be used as detectors for cosmic background tau neutrinos. The model predicts a distinctive spectrum shape that is consistent with a recent high statistics LLNL experiment. A fit to the experiment gives a tau neutrino mass of 23 eV. Tau neutrinos of this mass would dominate the mass of the universe. Requirements for a theoretical model are given, as well as models that realize different aspects of these requirements. While qualitatively successful, the theoretical models have such severe quantitative difficulties that the accuracy of the molecular physics of the T-{sup 3}He ion, assumed in the analysis of the experimental data, is called into question.

  5. Target-controlled formation of silver nanoclusters in abasic site-incorporated duplex DNA for label-free fluorescence detection of theophylline.

    PubMed

    Park, Ki Soo; Oh, Seung Soo; Soh, H Tom; Park, Hyun Gyu

    2014-09-01

    A novel, label-free, fluorescence based sensor for theophylline has been developed. In the new sensor system, an abasic site-incorporated duplex DNA probe serves as both a pocket for recognition of theophylline and a template for the preparation of fluorescent silver nanoclusters. The strategy relies on theophylline-controlled formation of fluorescent silver nanoclusters from abasic site-incorporated duplex DNA. When theophylline is not present, silver ions interact with the cytosine groups opposite to the abasic site in duplex DNA. This interaction leads to efficient formation of intensely red fluorescent silver nanoclusters. In contrast, when theophylline is bound at the abasic site through pseudo base-pairing with appropriately positioned cytosines, silver ion binding to the cytosine nucleobase is prevented. Consequently, fluorescent silver nanoclusters are not formed causing a significant reduction of the fluorescence signal. By employing this new sensor, theophylline can be highly selectively detected at a concentration as low as 1.8 μM. Finally, the diagnostic capability and practical application of this sensor were demonstrated by its use in detecting theophylline in human blood serum.

  6. Controllable formation of heterotrimetallic coordination compounds: systematically incorporating lanthanide and alkali metal ions into the manganese 12-metallacrown-4 framework.

    PubMed

    Azar, Michael R; Boron, Thaddeus T; Lutter, Jacob C; Daly, Connor I; Zegalia, Kelcie A; Nimthong, Ruthairat; Ferrence, Gregory M; Zeller, Matthias; Kampf, Jeff W; Pecoraro, Vincent L; Zaleski, Curtis M

    2014-02-01

    The inclusion of Ln(III) ions into the 12-MC-4 framework generates the first heterotrimetallic complexes of this molecular class. The controllable and deliberate preparations of these compounds are demonstrated through 12 crystal structures of the Ln(III)M(I)(OAc)4[12-MCMn(III)(N)shi-4](H2O)4·6DMF complex, where OAc(-) is acetate, shi(3-) is salicylhydroximate, and DMF is N,N-dimethylformamide. Compounds 1-12 have M(I) as Na(I), and Ln(III) can be Pr(III) (1), Nd(III) (2), Sm(III) (3), Eu(III) (4), Gd(III) (5), Tb(III) (6), Dy(III) (7), Ho(III) (8), Er(III) (9), Tm(III) (10), Yb(III) (11), and Y(III) (12). An example with M(I) = K(I) and Ln(III) = Dy(III) is also reported (Dy(III)K(OAc)4[12-MCMn(III)(N)shi-4](DMF)4·DMF (14)). When La(III), Ce(III), or Lu(III) is used as the Ln(III) ions to prepare the Ln(III)Na(I)(OAc)4[12-MCMn(III)(N)shi-4] complex, the compound Na2(OAc)2[12-MCMn(III)(N)shi-4](DMF)6·2DMF·1.60H2O (13) results. For compounds 1-12, the identity of the Ln(III) ion affects the 12-MCMn(III)(N)shi-4 framework as the largest Ln(III), Pr(III), causes an expansion of the 12-MCMn(III)(N)shi-4 framework as demonstrated by the largest metallacrown cavity radius (0.58 Å for 1 to 0.54 Å for 11), and the Pr(III) causes the 12-MCMn(III)(N)shi-4 framework to be the most domed structure as evident in the largest average angle about the axial coordination of the ring Mn(III) ions (103.95° for 1 to 101.69° for 11). For 14, the substitution of K(I) for Na(I) does not significantly affect the 12-MCMn(III)(N)shi-4 framework as many of the structural parameters such as the metallacrown cavity radius (0.56 Å) fall within the range of compounds 1-12. However, the use of the larger K(I) ion does cause the 12-MCMn(III)(N)shi-4 framework to become more planar as evident in a smaller average angle about the axial coordination of the ring Mn(III) ions (101.35°) compared to the analogous Dy(III)/Na(I) (7) complex (102.40°). In addition to broadening the range of

  7. Environmental health-risk assessment for tritium releases from the National Tritium Labeling Facility (NTLF) at Lawrence Berkeley Laboratory

    SciTech Connect

    McKone, T.E.; Brand, K.P.

    1994-12-01

    This report is a health risk assessment that addresses continuous releases of tritium to the environment from the National Tritium Labeling Facility (NTLF) at the Lawrence Berkeley Laboratory (LBL). The NTLF contributes approximately 95% of all tritium releases from LBL. Transport and transformation models were used to determine the movement of tritium releases from the NRLF to the air, surface water, soils, and plants and to determine the subsequent doses to humans. These models were calibrated against environmental measurements of tritium levels in the vicinity of the NTLF and in the surrounding community. Risk levels were determined for human populations in each of these zones. Risk levels to both individuals and populations were calculated. In this report population risks and individual risks were calculated for three types of diseases--cancer, heritable genetic effects, and developmental and reproductive effects.

  8. Investigation of the tritium content in surface water, bottom sediments (zoobenthos), macrophytes, and fish in the mid-stream region of the Yenisei River (Siberia, Russia).

    PubMed

    Bondareva, Lydia; Schultz, Michael K

    2015-11-01

    The potential sources of tritium input to the Yenisei River ecosystem are derived from local operations of nuclear facilities of the Mining and Chemical Combine operated by the state-owned Rosatom corporation and from sources derived from global weapons testing fallout and nuclear power. The background tritium concentrations in zoobenthos, bottom sediments, relevant commercial fish species, and widespread endogenous aquatic plants have been obtained for the first time in this region. Our results demonstrate that the major input term of tritium to this region of the Yenisei is derived from nearby mining operations of Rosatom, with tritium concentrations in aquatic plants marginally exceeding the observed background values obtained from upstream control sample collection sites. PMID:26178837

  9. Control of the Helicity Content of a Gun-Generated Spheromak by Incorporating a Conducting Shell into a Magnetized Coaxial Plasma Gun

    NASA Astrophysics Data System (ADS)

    Matsumoto, Tadafumi; Sekiguchi, Jun'ichi; Asai, Tomohiko

    In the formation of magnetized plasmoid by a magnetized coaxial plasma gun (MCPG), the magnetic helicity content of the generated plasmoid is one of the critical parameters. Typically, the bias coil to generate a poloidal flux is mounted either on the outer electrode or inside the inner electrode. However, most of the flux generated in the conventional method spreads even radially outside of the formation region. Thus, only a fraction of the total magnetic flux is actually exploited for helicity generation in the plasmoid. In the proposed system, the plasma gun incorporates a copper shell mounted on the outer electrode. By changing the rise time of the discharge bias coil current and the geometrical structure of the shell, the magnetic field structure and its time evolution can be controlled. The effect of the copper shell has been numerically simulated for the actual gun structure, and experimentally confirmed. This may increase the magnetic helicity content results, through increased poloidal magnetic field.

  10. Polarization properties and disorder effects in H{sub 3} photonic crystal cavities incorporating site-controlled, high-symmetry quantum dot arrays

    SciTech Connect

    Surrente, Alessandro; Felici, Marco; Gallo, Pascal; Dwir, Benjamin; Rudra, Alok; Kapon, Eli; Biasiol, Giorgio

    2015-07-20

    We report on the effects of optical disorder on breaking the symmetry of the cavity modes of H{sub 3} photonic crystal cavities incorporating site-controlled pyramidal quantum dots (QDs) as the internal light source. The high in-plane symmetry of the polarization states of the pyramidal QDs simplifies the analysis of the polarization states of the H{sub 3} cavities. It is shown that the optical disorder induced by fabrication imperfections lifts the degeneracy of the two quadrupole cavity modes and tilts the elongation axes of the cavity mode patterns with respect to the ideal, hexagonal symmetry case. These results are useful for designing QD-cavity structures for polarization-entangled photon sources and few-QD lasers.

  11. Tritium retention in individual metallic dust particles examined by a tritium imaging plate technique

    NASA Astrophysics Data System (ADS)

    Otsuka, T.; Hatano, Y.

    2016-02-01

    Tritium imaging plate technique (TIPT) has been applied to examine tritium (T) retention in individual particles made of titanium (Ti) with 30 and 100 μm in diameter and tungsten (W) with 50 μm in diameter. Distribution of T radioactivity observed by TIPT corresponded well to spatial distribution of the particles. In a limited case of uniform and high T concentration in the bulk of the individual particle, the amount of T is directly quantified from T radioactivity by a master curve method. Density and size of the particle and T concentration profiles in the bulk of the particle are important factors to change emission behavior of T β-ray and thus accurate quantification of the amount of T in the individual particle.

  12. Accelerator Production of Tritium Programmatic Environmental Impact Statement Input Submittal

    SciTech Connect

    Miller, L.A.; Greene, G.A.; Boyack, B.E.

    1996-02-01

    The Programmatic Environmental Impact Statement for Tritium Supply and Recycling considers several methods for the production of tritium. One of these methods is the Accelerator Production of Tritium. This report summarizes the design characteristics of APT including the accelerator, target/blanket, tritium extraction facility, and the balance of plant. Two spallation targets are considered: (1) a tungsten neutron-source target and (2) a lead neutron-source target. In the tungsten target concept, the neutrons are captured by the circulating He-3, thus producing tritium; in the lead target concept, the tritium is produced by neutron capture by Li-6 in a surrounding lithium-aluminum blanket. This report also provides information to support the PEIS including construction and operational resource needs, waste generation, and potential routine and accidental releases of radioactive material. The focus of the report is on the impacts of a facility that will produce 3/8th of the baseline goal of tritium. However, some information is provided on the impacts of APT facilities that would produce smaller quantities.

  13. In situ measurement of tritium permeation through stainless steel

    SciTech Connect

    Walter G. Luscher; David J. Senor; Kevin K. Clayton; Glen R. Longhurst

    2013-06-01

    The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292 degrees C and 330 degrees C. In situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. Results from in situ permeation measurements were compared with predictions based on an ex-reactor permeation correlation in the literature. In situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure over the ranges considered in this study. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330 degrees C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

  14. IN-SITU MEASUREMENT OF TRITIUM PERMEATION THROUGH STAINLESS STEEL

    SciTech Connect

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin; Longhurst, Glen R.

    2013-06-01

    The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292° and 330°C. In-situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. An irradiation enhancement factor (IEF) was determined by comparing in-situ permeation data with a correlation for ex-reactor hydrogen permeation through austenitic stainless steel developed from literature data and reported by Le Claire. Nominal values for the IEF ranged between 3 and 5 for 316 SS. In-situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330°C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

  15. In Situ Measurement of Tritium Permeation Through Stainless Steel

    SciTech Connect

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin; Longhurst, Glen

    2013-06-01

    The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292° and 330°C. In-situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. An irradiation enhancement factor (IEF) was determined by comparing in-situ permeation data with a correlation for ex-reactor hydrogen permeation through austenitic stainless steel developed from literature data and reported by Le Claire. Nominal values for the IEF ranged between 3 and 5 for 316 SS. In-situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330°C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

  16. MEASUREMENT OF TRITIUM DURING VOLOXIDATION OF ZIRCALOY-2 FUEL HULLS

    SciTech Connect

    Crowder, M.; Laurinat, J.; Stillman, J.

    2010-10-14

    A straightforward method to evaluate the tritium content of Zircaloy-2 cladding hulls via oxidation of the hull and capture of the volatilized tritium in liquids has been demonstrated. Hull samples were heated in air inside a thermogravimetric analyzer (TGA). The TGA was rapidly heated to 1000 C to oxidize the hulls and release absorbed tritium. To capture tritium, the TGA off-gas was bubbled through a series of liquid traps. The concentrations of tritium in bubbler solutions indicated that tritiated water vapor was captured nearly quantitatively. The average tritium content measured in the hulls was 19% of the amount of tritium produced by the fuel, according to ORIGEN2 isotope generation and depletion calculations. Published experimental data show that Zircaloy-2 oxidation follows an Arrhenius model, and that an initial, nonlinear oxidation rate is followed by a faster, linear rate after 'breakaway' of the oxide film. This study demonstrates that the linear oxidation rate of Zircaloy samples at 974 C is faster than predicted by the extrapolation of data from lower temperatures.

  17. Tritium stripping in a nitrogen glovebox using SAES St 198

    SciTech Connect

    Klein, J.E.; Wermer, J.R.

    1994-08-31

    SAES metal getter material St 198 was chosen for glovebox stripper tests to evaluate its effectiveness of removing tritium from a nitrogen atmosphere. The St 198 material is unique from a number of other metal hydride-based getter materials in that it is relatively inert to nitrogen and can thus be used in nitrogen glovebox atmospheres. Six tritium stripper experiments which mock-up the use of a SAES St 198 stripper bed for a full-scale (10,500 liter) nitrogen glovebox have been completed. Experiments consisted of a release of small quantity of protium/deuterium spiked with tritium which were scaled to simulate tritium releases of 0.1 g., 1.0 g., and 10 g. into the glovebox. The tritium spike allows detection using tritium ion chambers. The St 198 stripper system produced a reduction in tritium activity of approximately two orders of magnitude in 24 hours (6--8 atmosphere turn-overs) of stripper operation.

  18. MODELING ATMOSPHERIC RELEASES OF TRITIUM FROM NUCLEAR INSTALLATIONS

    SciTech Connect

    Okula, K

    2007-01-17

    Tritium source term analysis and the subsequent dispersion and consequence analyses supporting the safety documentation of Department of Energy nuclear facilities are especially sensitive to the applied software analysis methodology, input data and user assumptions. Three sequential areas in tritium accident analysis are examined in this study to illustrate where the analyst should exercise caution. Included are: (1) the development of a tritium oxide source term; (2) use of a full tritium dispersion model based on site-specific information to determine an appropriate deposition scaling factor for use in more simplified, broader modeling, and (3) derivation of a special tritium compound (STC) dose conversion factor for consequence analysis, consistent with the nature of the originating source material. It is recommended that unless supporting, defensible evidence is available to the contrary, the tritium release analyses should assume tritium oxide as the species released (or chemically transformed under accident's environment). Important exceptions include STC situations and laboratory-scale releases of hydrogen gas. In the modeling of the environmental transport, a full phenomenology model suggests that a deposition velocity of 0.5 cm/s is an appropriate value for environmental features of the Savannah River Site. This value is bounding for certain situations but non-conservative compared to the full model in others. Care should be exercised in choosing other factors such as the exposure time and the resuspension factor.

  19. Technology benefits resulting from accelerator production of tritium

    SciTech Connect

    1998-12-31

    One of the early and most dramatic uses of nuclear transformations was in development of the nuclear weapons that brought World War II to an end. Despite that difficult introduction, nuclear weapons technology has been used largely as a deterrent to war throughout the latter half of the twentieth century. The Accelerator Production of Tritium (APT) offers a clean, safe, and reliable means of producing the tritium (a heavy form of hydrogen) needed to maintain the nuclear deterrent. Tritium decays away naturally at a rate of about 5.5% per year; therefore, the tritium reservoirs in nuclear weapons must be periodically replenished. In recent years this has been accomplished by recycling tritium from weapons being retired from the stockpile. Although this strategy has served well since the last US tritium production reactor was shut down in 1988, a new tritium production capability will be required within ten years. Some benefits will result from direct utilization of some of the APT proton beam; others could result from advances in the technologies of particle accelerators and high power spallation targets. The APT may save thousands of lives through the production of medical isotopes, and it may contribute to solving the nation`s problem in disposing of long-lived nuclear wastes. But the most significant benefit may come from advancing the technology, so that the great potential of accelerator applications can be realized during our lifetimes.

  20. Tritium Removal by Laser Heating and Its Application to Tokamaks

    SciTech Connect

    C.H. Skinner; C.A. Gentile; G. Guttadora; A. Carpe; S. Langish; K.M. Young; M. Nishi; W. Shu

    2001-11-16

    A novel laser heating technique has recently been applied to removing tritium from carbon tiles that had been exposed to deuterium-tritium (DT) plasmas in the Tokamak Test Fusion Reactor (TFTR). A continuous wave neodymium laser, of power up to 300 watts, was used to heat the surface of the tiles. The beam was focused to an intensity, typically 8 kW/cm{sup 2}, and rapidly scanned over the tile surface by galvanometer-driven scanning mirrors. Under the laser irradiation, the surface temperature increased dramatically, and temperatures up to 2,300 degrees C were recorded by an optical pyrometer. Tritium was released and circulated in a closed-loop system to an ionization chamber that measured the tritium concentration. Most of the tritium (up to 84%) could be released by the laser scan. This technique appears promising for tritium removal in a next-step DT device as it avoids oxidation, the associated deconditioning of the plasma facing surfaces, and the expense of processing large quantities of tritium oxide. Some engineering aspects of the implementation of this method in a next-step fusion device will be discussed.

  1. In situ measurement of tritium permeation through stainless steel

    NASA Astrophysics Data System (ADS)

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin K.; Longhurst, Glen R.

    2013-06-01

    The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292 °C and 330 °C. In situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. Results from in situ permeation measurements were compared with predictions based on an ex-reactor permeation correlation in the literature. In situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure over the ranges considered in this study. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330 °C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

  2. Tritium: An analysis of key environmental and dosimetric questions

    SciTech Connect

    Till, J E; Meyer, H R; Etnier, E L; Bomar, E S; Gentry, R D; Killough, G G; Rohwer, P S; Tennery, V J; Travis, C C

    1980-05-01

    This document summarizes new theoretical and experimental data that may affect the assessment of environmental releases of tritium and analyzes the significance of this information in terms of the dose to man. Calculated doses resulting from tritium releases to the environment are linearly dependent upon the quality factor chosen for tritium beta radiation. A reevaluation of the tritium quality factor by the ICRP is needed; a value of 1.7 would seem to be more justifiable than the old 1.0 value. A new exposure model is proposed, based primarily upon the approach recommended by the National Council on Radiation Protection and Measurements. Employing a /open quotes/typical/close quotes/ LMFBR reprocessing facility source term, a /open quotes/base case/close quotes/ dose commitment to total body (for a maximally exposed individual) was calculated to be 4.0 /times/ 10/sup /minus/2/ mSv, with 3.2 /times/ 10/sup /minus// mSv of the dose due to intake of tritium. The study analyzes models which exist for evaluating the buildup of global releases of tritium from man-made sources. Scenarios for the release of man-made tritium to the environment and prediction of collective dose commitment to future generations suggest that the dose from nuclear weapons testing will be less than that from nuclear energy even though the weapons source term is greater than that for any of our energy scenarios.

  3. Current understanding of organically bound tritium (OBT) in the environment.

    PubMed

    Kim, S B; Baglan, N; Davis, P A

    2013-12-01

    It has become increasingly recognized that organically bound tritium (OBT) is the more significant tritium fraction with respect to understanding tritium behaviour in the environment. There are many different terms associated with OBT; such as total OBT, exchangeable OBT, non-exchangeable OBT, soluble OBT, insoluble OBT, tritiated organics, and buried tritium, etc. A simple classification is required to clarify understanding within the tritium research community. Unlike for tritiated water (HTO), the environmental quantification and behaviour of OBT are not well known. Tritiated water cannot bio-accumulate in the environment. However, it is not clear whether or not this is the case for OBT. Even though OBT can be detected in terrestrial biological materials, aquatic biological materials and soil samples, its behaviour is still in question. In order to evaluate the radiation dose from OBT accurately, further study will be required to understand OBT measurements and determine OBT fate in the environment. The relationship between OBT speciation and the OBT/HTO ratio in environmental samples will be useful in this regard, providing information on the previous tritium exposure conditions in the environment and the current tritium dynamics. PMID:23962797

  4. Uptake of tritium by plants from atmosphere and soil

    SciTech Connect

    Amano, H; Garten Jr, Charles T

    1991-01-01

    Uptake of tritiated water (HTO) by plants was examined under field conditions when tritium was available to leaves from only the atmosphere and when tritium was available from both the soil (root uptake) and the atmosphere. Maple, oak, and elm trees, planted in clean soil, were transported to a tritium-contaminated forest, where the atmospheric tritium concentration was elevated, to examine HTO uptake by tree leaves when the source was only in the atmosphere. The results partially agreed with a diffusion model of tritium uptake by plants. Discrepancies found between predicted and measured leaf HTO/air HTO ratios should be attributed to the existence of some isolated water, which is isolated from the transpiration stream in the leaves, that was not available for rapid turnover. The uptake of tritium by trees, when the source was both in the soil and atmosphere, was also examined using deciduous trees (maple and elm) resident to the tritium-contaminated forest. The results were in agreement with a prediction model.

  5. Tritium uptake by fish in a small stream. [Largemouth Bass

    SciTech Connect

    Eaton, D.; Murphy, C.E. Jr.

    1992-09-17

    The tritium concentration in the water from freeze drying and the water from combustion of the dry tissue was measured in fish (largemouth bass), stream macrophytes, and streamside vegetation at five sampling locations in Four Mile Branch on the Savannah River Site (SRS). Four Mile Branch has elevated tritium concentration, largely from migration of water through the soil from adjacent seepage basins that received industrial wastewater containing tritium. The stream water and the vegetation, through the food chain, are thought to be the two sources of tritium reaching the fish. Comparision of the tritium activity of the freeze-dried water from fish flesh and of the sources of tritium, indicates that the fish flesh approaches a steady-state concentration with the stream water. The freeze-dry water from the vegetation is also at a lower specific activity than the stream water. The water of combustion from the vegetation is also at a lower specific activity than stream water. The water of combustion from the fish flesh is somewhat higher in specific activity than the stream water or the water in the fish. The distribution of tritium among the components of this system can be explain in terms of the turnover of water and organic hydrogen in the components.

  6. Tritium uptake by fish in a small stream. Revision 1

    SciTech Connect

    Eaton, D.; Murphy, C.E. Jr.

    1992-09-17

    The tritium concentration in the water from freeze drying and the water from combustion of the dry tissue was measured in fish (largemouth bass), stream macrophytes, and streamside vegetation at five sampling locations in Four Mile Branch on the Savannah River Site (SRS). Four Mile Branch has elevated tritium concentration, largely from migration of water through the soil from adjacent seepage basins that received industrial wastewater containing tritium. The stream water and the vegetation, through the food chain, are thought to be the two sources of tritium reaching the fish. Comparision of the tritium activity of the freeze-dried water from fish flesh and of the sources of tritium, indicates that the fish flesh approaches a steady-state concentration with the stream water. The freeze-dry water from the vegetation is also at a lower specific activity than the stream water. The water of combustion from the vegetation is also at a lower specific activity than stream water. The water of combustion from the fish flesh is somewhat higher in specific activity than the stream water or the water in the fish. The distribution of tritium among the components of this system can be explain in terms of the turnover of water and organic hydrogen in the components.

  7. Apparatus for monitoring tritium in tritium-contaminating environments using a modified Kanne chamber

    DOEpatents

    Anderson, D.F.

    1981-01-27

    A conventional Kanne tritium monitor has been redesigned to reduce its sensitivity to such contaminants as tritiated water vapor and tritiated oil. The high voltage electrode has been replaced by a wire cylinder and the collector electrode has been reduced in diameter. The area sensitive to contamination has thereby been reduced by about a factor of forty while the overall apparatus sensitivity and operation has not been affected. The design allows for in situ decontamination of the chambers, if necessary.

  8. Apparatus for monitoring tritium in tritium contaminating environments using a modified Kanne chamber

    DOEpatents

    Anderson, David F.

    1984-01-01

    A conventional Kanne tritium monitor has been redesigned to reduce its sensitivity to such contaminants as tritiated water vapor and tritiated oil. The high voltage electrode has been replaced by a wire cylinder and the collector electrode has been reduced in diameter. The area sensitive to contamination has thereby been reduced by about a factor of forty while the overall apparatus sensitivity and operation has not been affected. The design allows for in situ decontamination of the chambers, if necessary.

  9. Wear, bone density, functional outcome and survival in vitamin E-incorporated polyethylene cups in reversed hybrid total hip arthroplasty: design of a randomized controlled trial

    PubMed Central

    2012-01-01

    Background Aseptic loosening of total hip arthroplasties is generally caused by periprosthetic bone resorption due to tissue reactions on polyethylene wear particles. In vitro testing of polyethylene cups incorporated with vitamin E shows increased wear resistance. The objective of this study is to compare vitamin E-stabilized highly cross-linked polyethylene with conventional cross-linked polyethylene in “reversed hybrid” total hip arthroplasties (cemented all-polyethylene cups combined with uncemented femoral stems). We hypothesize that the adjunction of vitamin E leads to a decrease in polyethylene wear in the long-term. We also expect changes in bone mineral density, less osteolysis, equal functional scores and increased implant survival in polyethylene cemented cups incorporated with vitamin E in the long-term. Design A double-blinded randomized controlled trial will be conducted. Patients to be included are aged under 70, suffer from non-inflammatory degenerative joint disease of the hip and are scheduled for a primary total hip arthroplasty. The study group will receive a reversed hybrid total hip arthroplasty with a vitamin E-stabilized highly cross-linked polyethylene cemented cup. The control group will receive a reversed hybrid total hip arthroplasty with a conventional cross-linked polyethylene cemented cup. Radiological follow-up will be assessed at 6 weeks and at 1, 3, 5, 7 and 10 years postoperatively, to determine polyethylene wear and osteolysis. Patient-reported functional status (HOOS), physician-reported functional status (Harris Hip Score) and patients’ physical activity behavior (SQUASH) will also be assessed at these intervals. Acetabular bone mineral density will be assessed by dual energy X-ray absorptiometry (DEXA) at 6 weeks and at 1 year and 2 years postoperatively. Implant survival will be determined at 10 years postoperatively. Discussion In vitro results of vitamin E-stabilized polyethylene are promising, showing increased wear

  10. Tritium monitor calibration at Los Alamos National Laboratory

    SciTech Connect

    Bjork, C.J.; Aikin, D.J.; Houlton, T.W.

    1997-08-01

    Tritium in air is monitored at Los Alamos National Laboratory (LANL) with air breathing instruments based on ionization chambers. Stack emissions are continuously monitored from sample tubes which each connect to a Tritium bubble which differentially collects HTO and HT. A set of glass vials of glycol capture the HTO. The HT is oxidized with a palladium catalyst and the resultant HTO is captured in a second set of vials of glycol. The glycol is counted with a liquid scintillation counter. All calibrations are performed with tritium containing gas. The Radiation Instrumentation and Calibration (RIC) Team has constructed and maintains two closed loop gas handling systems based on femto TECH model U24 tritium ion chamber monitors: a fixed system housed in a fume hood and a portable system mounted on two two wheeled hand trucks. The U24 monitors are calibrated against tritium in nitrogen gas standards. They are used as standard transfer instruments to calibrate other ion chamber monitors with tritium in nitrogen, diluted with air. The gas handling systems include a circulation pump which permits a closed circulation loop to be established among the U24 monitor and typically two to four other monitors of a given model during calibration. Fixed and portable monitors can be calibrated. The stack bubblers are calibrated in the field by: blending a known concentration of tritium in air within the known volume of the two portable carts, coupled into a common loop; releasing that gas mixture into a ventilation intake to the stack; collecting oxidized tritium in the bubbler; counting the glycol; and using the stack and bubbler flow rates, computing the bubbler`s efficiency. Gas calibration has become a convenient and quality tool in maintaining the tritium monitors at LANL.

  11. Hydrogen isotope separation installation for the regeneration of tritium from gas mixtures in tritium facilities

    SciTech Connect

    Andrew, B.M.; Perevezentsev, A.N.; Selivanenko, I.L.

    1994-12-31

    The advantages and disadvantages of different methods for hydrogen isotope separation are considered in terms of their applicability for tritium regeneration in a tritium facility. Due to low inventory, simplicity of operation, flexibility, and safety the methods of separation using solid phases are preferable for tritium facility. The detail consideration of the separation processes with a solid phase reveals that highest efficiency of separation should be achieved in a counter-current separation column, which allow multiplying the thermodynamic isotopic effect. Because of difficulties of the organization of a solid phase motion in a separation column this method did not found practical application for separation of hydrogen isotopic mixtures. The main efforts of a few researches groups were devoted to improve the chromatographic separation process and equipment. The detail comparison of the separation in sectioned column with that in chromatographic as well as in cryodistillation columns show that counter-current separation in a sectioned column is more effective and has other advantages when middle throughput is required. Complete regeneration of an isotopic mixture with separation into three practically pure isotopes independently from isotopic composition of feed can be provided using two sectioned separation columns. Separation installation can operate continuously as well as periodically.

  12. Tritium Superpermeability: Experimental Investigation and Simulation of Tritium Recirculation in 'Prometheus' Setup

    SciTech Connect

    Musyaev, R.K.; Lebedev, B.S.; Grishechkin, S.K.; Yukhimchuk, A.A.; Busnyuk, A.A; Notkin, M.E.; Samartsev, A.A.; Livshits, A.I.

    2005-07-15

    The superpermeability phenomenon was suggested to use in fusion machines to separate the fuel mixture from helium ashes, to arrange in-vessel fuel recirculation contours and effective evacuation of fuel mixture out of machine exhaust. To develop this technology and to simulate tritium recirculation in RFNC-VNIIEF at the 'Prometheus' setup the experiments on superpermeation of hydrogen isotopes through metal membrane were realized.The results of experiments on superpermeation of hydrogen isotopes through cylindrical niobium membrane are presented. As the experiment has shown, membrane pumping rate is inversely proportional to square root of isotope mass and amount to 2.5 l/cm{sup 2}s for protium, 1.8 l/cm{sup 2}s for deuterium and 1.5 l/cm{sup 2}s for tritium. The possibility of effective pumping, separation of hydrogen isotopes from helium and residual gas, compression and recuperation of hydrogen isotopes by means of superpermeable membrane was demonstrated. It follows from results that the separation of D/T from He with employment of the techniques of superpermeable membranes might reduce the total amount of tritium in fuel cycle and substantially enhance the resource of cryogenic pumps evacuating helium.

  13. Second national topical meeting on tritium technology in fission, fusion and isotopic applications

    SciTech Connect

    Anderson, J.L.; Barlit, J.R.

    1985-09-01

    This conference presented information on the following topics: the development of a tritium dispersion code; global environmental transport models for tritium; HT/HTO conversion in mammals; tritium production, releases and population doses at nuclear power reactors; design of tritium processing facilities and equipment for aqueous and gaseous streams; tritium removal from circulating helium by hydriding of rare earth metals; the determination of deuterium and tritium in effluent wastewater by pulsed nuclear magnetic resonance spectroscopy; tritium surface contamination: process calculations for a moderator detritiation plant; recent developments in magnetically coupled vane pumps for tritium service; recovery and storage of tritium by Zr-V-Fe getter; gas handling systems using titanium-sponge and uranium bulk getters; isotope effects and helium retention behavior in vanadium tritide; interaction of hydrogen isotopes with stainless steel 316 L; and the interaction of polyethylene and tritium gas as monitored by Raman spectroscopy.

  14. Titanium tritide radioisotope heat source development : palladium-coated titanium hydriding kinetics and tritium loading tests.

    SciTech Connect

    Van Blarigan, Peter; Shugard, Andrew D.; Walters, R. Tom

    2012-01-01

    We have found that a 180 nm palladium coating enables titanium to be loaded with hydrogen isotopes without the typical 400-500 C vacuum activation step. The hydriding kinetics of Pd coated Ti can be described by the Mintz-Bloch adherent film model, where the rate of hydrogen absorption is controlled by diffusion through an adherent metal-hydride layer. Hydriding rate constants of Pd coated and vacuum activated Ti were found to be very similar. In addition, deuterium/tritium loading experiments were done on stacks of Pd coated Ti foil in a representative-size radioisotope heat source vessel. The experiments demonstrated that such a vessel could be loaded completely, at temperatures below 300 C, in less than 10 hours, using existing department-of-energy tritium handling infrastructure.

  15. Suppression of tritium retention in remote areas of ITER by nonperturbative reactive gas injection.

    PubMed

    Tabarés, F L; Ferreira, J A; Ramos, A; van Rooij, G; Westerhout, J; Al, R; Rapp, J; Drenik, A; Mozetic, M

    2010-10-22

    A technique based on reactive gas injection in the afterglow region of the divertor plasma is proposed for the suppression of tritium-carbon codeposits in remote areas of ITER when operated with carbon-based divertor targets. Experiments in a divertor simulator plasma device indicate that a 4  nm/min deposition can be suppressed by addition of 1  Pa·m³ s⁻¹ ammonia flow at 10 cm from the plasma. These results bolster the concept of nonperturbative scavenger injection for tritium inventory control in carbon-based fusion plasma devices, thus paving the way for ITER operation in the active phase under a carbon-dominated, plasma facing component background.

  16. Depth profiling of tritium in materials for fusion technology

    SciTech Connect

    Sawicki, J.A.

    1988-09-01

    The paper outlines recent progress in depth profiling of tritium distribution near the surface of materials by two ion beam techniques; elastic recoil detection (ERD) and T(d,/alpha/)n nuclear reaction analysis (NRA). The sensitivity and depth-resolution of both methods are examined for a series of tritiated titanium films. Calculated depth profiles and ranges of implanted tritium ions in selected candidate materials for thermonuclear fusion devices are also given. Depth profiles of tritium implanted into specimens of graphite and lithium oxides as a function of temperature are discussed as the examples of applications.

  17. AL-SX permeation studies and evaluation using tritium gas

    SciTech Connect

    Roth, R.W. )

    1992-04-01

    The AL-SX/2 and AL-SX/3 are recently certified Type B shipping containers for tritium reservoirs. Both AL-SX models are sealed with elastomeric O-rings. O-rings of this type allow gases to permeate through the elastomeric material. This report summarizes experiments conducted on a full-size mock-up of the AL-SX sealing geometry that quantify permeation rates through the O-rings. Also, a six month experiment was conducted with tritium and showed that a tritium getter could be used in combination with elastomeric O-rings to meet normal condition leak rate requirements of 10 CFR 71.

  18. Mathematical comparison of three tritium system effluent HTO cleanup systems

    SciTech Connect

    Willms, R.Scott; Gentile, Charles; Rule, Keith; Than, Chit; Williams, Philip

    2002-03-22

    It is important that air emissions from tritium systems be kept as low as reasonably achievable. Thus, over the years a number of gas detritiation systems have been developed. Recently there has been interest in lower-cost, simpler systems which do not convert HT to the much more hazardous HTO form. Examples of such systems are (1) a bubbler/dehumidifier, (2) a bubbler/collector, and (3) an adsorber/collector. A computer model of each configuration was written and run. Each system's performance, including tritium buildup in liquid water, and tritium exhausted to the environment, are presented and compared.

  19. Tritium analyses of COBRA-1A2 beryllium pebbles

    SciTech Connect

    Baldwin, D.L.

    1998-03-01

    Selected tritium measurements have been completed for the COBRA-1A2 experiment C03 and D03 beryllium pebbles. The completed results, shown in Tables 1, 2, and 3, include the tritium assay results for the 1-mm and 3-mm C03 pebbles, and the 1-mm D03 pebbles, stepped anneal test results for both types of 1-mm pebbles, and the residual analyses for the stepped-anneal specimens. All results have been reported with date-of-count and are not corrected for decay. Stepped-anneal tritium release response is provided in addenda.

  20. Visual tritium imaging of in-vessel surfaces

    SciTech Connect

    Gentile, C.A.; Zweben, S.J.; Skinner, C.H.; Young, K.M.; Langish, S.W.; Nishi, M.F.; Shu, W.M.; Parker, J.; Isobe, K.

    2000-05-22

    An imaging detector has been developed for the purpose of providing a non-destructive, real time method of determining tritium concentrations on the surface of internal TFTR vacuum vessel components. The detector employs a green phosphor screen (P31, zinc sulfide: copper) with a wave length peak of 530 nm, a charge-coupled device (CCD) camera linked to a computer, and a detection chamber for inserting components recovered from the vacuum vessel. This detector is capable of determining tritium concentrations on the surfaces. The detector provides a method of imaging tritium deposition on the surfaces in a fairly rapid fashion.

  1. Tritium as an indicator of venues for nuclear tests.

    PubMed

    Lyakhova, O N; Lukashenko, S N; Mulgin, S I; Zhdanov, S V

    2013-10-01

    Currently, due to the Treaty on the Non-proliferation of Nuclear Weapons there is a highly topical issue of an accurate verification of nuclear explosion venues. This paper proposes to consider new method for verification by using tritium as an indicator. Detailed studies of the tritium content in the air were carried in the locations of underground nuclear tests - "Balapan" and "Degelen" testing sites located in Semipalatinsk Test Site. The paper presents data on the levels and distribution of tritium in the air where tunnels and boreholes are located - explosion epicentres, wellheads and tunnel portals, as well as in estuarine areas of the venues for the underground nuclear explosions (UNE). PMID:23639690

  2. Glovebox stripper system tritium capture efficiency-literature review

    SciTech Connect

    James, D. W.; Poore, A. S.

    2015-09-28

    Glovebox Stripper Systems (GBSS) are intended to minimize tritium emissions from glovebox confinement systems in Tritium facilities. A question was raised to determine if an assumed 99% stripping (decontamination) efficiency in the design of a GBBS was appropriate. A literature review showed the stated 99% tritium capture efficiency used for design of the GBSS is reasonable. Four scenarios were indicated for GBSSs. These include release with a single or dual stage setup which utilizes either single-pass or recirculation for stripping purposes. Examples of single-pass as well as recirculation stripper systems are presented and reviewed in this document.

  3. Proportional counting techniques for routine tritium analyses at environmental levels

    SciTech Connect

    Bowman, W W; Hughes, M B

    1981-01-01

    Techniques and procedures were developed to routinely analyze samples for tritium as part of research and monitoring programs on the transport of radionuclides released from the Savannah River Plant site. Because tritium concentrations in the environment are low, trace analysis methods were developed. The primary analysis technique involves converting aqueous samples to hydrogen gas which is mixed with propane and assayed in proportional counters. Counter background is reduced by massive shielding, anticoincidence gating with plastic scintillators, and pulse shape discrimination. The overall sensitivity for tritium is 0.02 pCi/g of water with a demonstrated precision of 6.3% at 1 pCi/g of water.

  4. Tritium distribution in ground water around large underground fusion explosions

    USGS Publications Warehouse

    Stead, F.W.

    1963-01-01

    Tritium will be released in significant amounts from large underground nuclear fusion explosions in the Plowshare Program. The tritium could become highly concentrated in nearby ground waters, and could be of equal or more importance as a possible contaminant than other long-lived fission-product and induced radionuclides. Behavior of tritiated water in particular hydrologic and geologic environments, as illustrated by hypothetical explosions in dolomite and tuff, must be carefully evaluated to predict under what conditions high groundwater concentrations of tritium might occur.

  5. Tritium Experience in Large Tokamaks: Application to ITER

    SciTech Connect

    Skinner, C.H.; Gentile, C.; Hosea, J.; Mueller, D; Gentile, C.; Federici, G.; Haanges, R.

    1998-05-01

    Recent experience with the use of tritium fuel in the Tokamak Fusion Test Reactor and the Joint European Torus, together with progress in developing the technical design of the International Thermonuclear Experimental Reactor has expanded the technical knowledge base for tritium issues in fusion. This paper reports on an IEA workshop that brought together scientists and engineers to share experience and expertise on all fusion-related tritium issues. Extensive discussion periods were devoted to exploring outstanding issues and identifying potential R{ampersand}D avenues to address them. This paper summarizes the presentations, discussions, and recommendations.

  6. Tritium as an indicator of venues for nuclear tests.

    PubMed

    Lyakhova, O N; Lukashenko, S N; Mulgin, S I; Zhdanov, S V

    2013-10-01

    Currently, due to the Treaty on the Non-proliferation of Nuclear Weapons there is a highly topical issue of an accurate verification of nuclear explosion venues. This paper proposes to consider new method for verification by using tritium as an indicator. Detailed studies of the tritium content in the air were carried in the locations of underground nuclear tests - "Balapan" and "Degelen" testing sites located in Semipalatinsk Test Site. The paper presents data on the levels and distribution of tritium in the air where tunnels and boreholes are located - explosion epicentres, wellheads and tunnel portals, as well as in estuarine areas of the venues for the underground nuclear explosions (UNE).

  7. Tritium Formation and Mitigation in High Temperature Reactors

    SciTech Connect

    Piyush Sabharwall; Carl Stoots

    2012-08-01

    Tritium is a radiologically active isotope of hydrogen. It is formed in nuclear reactors by neutron absorption and ternary fission events and can subsequently escape into the environment. In order to prevent the tritium contamination of proposed reactor buildings and surrounding sites, this paper examines the root causes and potential solutions for the production of this radionuclide, including materials selection and inert gas sparging. A model is presented that can be used to predict permeation rates of hydrogen through metallic alloys at temperatures from 450–750°C. Results of the diffusion model are presented for one steadystate value of tritium production in the reactor.

  8. On-line tritium production monitor

    DOEpatents

    Mihalczo, J.T.

    1993-11-23

    A scintillation optical fiber system for the on-line monitoring of nuclear reactions in an event-by-event manner is described. In the measurement of tritium production one or more optical fibers are coated with enriched {sup 6}Li and connected to standard scintillation counter circuitry. A neutron generated {sup 6}Li(n)T reaction occurs in the coated surface of {sup 6}Li-coated fiber to produce energetic alpha and triton particles one of which enters the optical fiber and scintillates light through the fiber to the counting circuit. The coated optical fibers can be provided with position sensitivity by placing a mirror at the free end of the fibers or by using pulse counting circuits at both ends of the fibers. 5 figures.

  9. On-line tritium production monitor

    DOEpatents

    Mihalczo, John T.

    1993-01-01

    A scintillation optical fiber system for the on-line monitoring of nuclear reactions in an event-by-event manner is described. In the measurement of tritium production one or more optical fibers are coated with enriched .sup.6 Li and connected to standard scintillation counter circuitry. A neutron generated .sup.6 Li(n )T reaction occurs in the coated surface of .sup.6 Li-coated fiber to produce energetic alpha and triton particles one of which enters the optical fiber and scintillates light through the fiber to the counting circuit. The coated optical fibers can be provided with position sensitivity by placing a mirror at the free end of the fibers or by using pulse counting circuits at both ends of the fibers.

  10. Ignition of deuterium-tritium fuel targets

    DOEpatents

    Musinski, D.L.; Mruzek, M.T.

    1991-08-27

    Disclosed is a method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom. 5 figures.

  11. Pyrophoricity of tritium-storage bed materials

    SciTech Connect

    Longhurst, G. R.

    1988-03-01

    Experiments were conducted on samples of depleted uranium and on intermetallic compounds of zirconium--cobalt and lanthanum--nickel--aluminide to evaluate the pyrophoricity of the activated materials and their hydrides and deuterides on exposure to air. It was found that none of the materials spontaneously ignited when exposed to room temperature air, but the uranium and the zirconium--cobalt both ignited in air at moderately elevated temperatures. Activated (dehydrided) materials showed stronger reactions than did the hydrides, but they ignited at essentially the same temperatures. Deuterides showed effectively the same characteristics as the hydrides except the ignition temperature of zirconium--cobalt deuteride was reduced by 20--50 K from that of the hydride. The possibility of a fire in tritium storage beds is real, especially if uranium or zirconium--cobalt are used as storage materials, but fires may not occur until the bed is heated. 9 refs., 12 figs., 1 tab.

  12. Pyrophoricity of tritium-storage bed materials

    SciTech Connect

    Longhurst, G.R.

    1988-09-01

    Experiments were conducted on samples of depleted uranium and on intermetallic compounds of zirconium-cobalt and lanthanum-nickel-aluminide to evaluate the pyrophoricity of the activated materials and their hydrides and deuterides on exposure to air. None of the materials spontaneously ignited when exposed to room temperature air, but the uranium and the zirconium-cobalt both ignited in air at moderately elevated temperatures. Activated dehyrdided materials ignited at essentially the same temperatures. Deuterides showed effectively the same characteristics as the hydrides except the ignition temperature of zirconium-cobalt deuteride was reduced by 20 - 50 K from that of the hydride. The pyrophoricity of these materials raises concern about the possibility of fires in tritium-storage beds with attendant damage to the bed and dispersal of tritiated debris, but fires may not occur until the bed is heated.

  13. Commercial Light Water Reactor Tritium Extraction Facility

    SciTech Connect

    McHood, M D

    2000-10-12

    A geotechnical investigation program has been completed for the Commercial Light Water Reactor - Tritium Extraction Facility (CLWR-TEF) at the Savannah River Site (SRS). The program consisted of reviewing previous geotechnical and geologic data and reports, performing subsurface field exploration, field and laboratory testing, and geologic and engineering analyses. The purpose of this investigation was to characterize the subsurface conditions for the CLWR-TEF in terms of subsurface stratigraphy and engineering properties for design and to perform selected engineering analyses. The objectives of the evaluation were to establish site-specific geologic conditions, obtain representative engineering properties of the subsurface and potential fill materials, evaluate the lateral and vertical extent of any soft zones encountered, and perform engineering analyses for slope stability, bearing capacity and settlement, and liquefaction potential. In addition, provide general recommendations for construction and earthwork.

  14. Model of tritium dispersion by ground water

    NASA Astrophysics Data System (ADS)

    Golubev, A. V.; Mavrin, S. V.; Sten'gach, A. V.

    2000-07-01

    A three-dimensional model of ground-water contamination in the zone of a steady source of tritium is presented. The model is oriented toward long-term modeling of contamination (for up to several decades) on a large area (of up to several hundred square kilometers) where the contaminant arrives through the roof of the aquiferous stratum by infiltration. The three-dimensional equation of convective diffusion is solved numerically by the method of splitting. The convective component is calculated by the method of particles. The dispersion component of the transfer is calculated using the finite-difference method. A transformation of the vertical coordinate is introduced. A solution of the model problem is presented and an interpretation of the results is given.

  15. HEAT TRANSFER AND TRITIUM PRODUCING SYSTEM

    DOEpatents

    Johnson, E.F.

    1962-06-01

    This invention related to a circulating lithium-containing blanket system in a neution source hav'ing a magnetic field associated therewith. The blanket serves simultaneously and efficiently as a heat transfer mediunm and as a source of tritium. The blanket is composed of a lithium-6-enriched fused salt selected from the group consisting of lithium nitrite, lithium nitrate, a mixture of said salts, a mixture of each of said salts with lithium oxide, and a mixture of said salts with each other and with lithium oxide. The moderator, which is contained within the blanket in a separate conduit, can be water. A stellarator is one of the neutron sources which can be used in this invention. (AEC)

  16. Raman spectroscopy at the tritium laboratory Karlsruhe

    SciTech Connect

    Schloesser, M.; Bornschein, B.; Fischer, S.; Kassel, F.; Rupp, S.; Sturm, M.; James, T.M.; Telle, H.H.

    2015-03-15

    Raman spectroscopy is employed successfully for analysis of hydrogen isotopologues at the Tritium Laboratory Karlsruhe (TLK). Raman spectroscopy is based on the inelastic scattering of photons off molecules. Energy is transferred to the molecules as rotational/vibrational excitation being characteristic for each type of molecule. Thus, qualitative analysis is possible from the Raman shifted light, while quantitative information can be obtained from the signal intensities. After years of research and development, the technique is now well-advanced providing fast (< 10 s), precise (< 0.1%) and true (< 3%) compositional analysis of gas mixtures of hydrogen isotopologues. In this paper, we summarize the recent achievements in the further development on this technique, and the various applications for which it is used at TLK. Raman spectroscopy has evolved as a versatile, highly accurate key method for quantitative analysis complementing the port-folio of analytic techniques at the TLK.

  17. Tritium transfer in pigs - A model test

    SciTech Connect

    Melintescu, A.; Galeriu, D.

    2008-07-15

    In the frame of IAEA EMRAS (Environmental Modelling for Radiation Safety) programme, there was developed a scenario for models ' testing starting with unpublished data for a sow fed with OBT for 84 days. The scenario includes model predictions for the dynamics of tritium in urine and faeces and HTO and OBT in organs at sacrifice. There have been done two inter-comparison exercises and most of the models succeeded to give predictions better than a factor 3 to 5, excepting faeces. There has been done an analysis of models' structure, performance and limits in order to be able to build a model of moderate complexity with a reliable predictive power, able to be applied for human dosimetry, also, when OBT data are missing. (authors)

  18. Tritium permeation model for plasma facing components

    SciTech Connect

    Longhurst, G.R.

    1992-12-01

    This report documents the development of a simplified one-dimensional tritium permeation and retention model. The model makes use of the same physical mechanisms as more sophisticated, time-transient codes such as implantation, recombination, diffusion, trapping and thermal gradient effects. It takes advantage of a number of simplifications and approximations to solve the steady-state problem and then provides interpolating functions to make estimates of intermediate states based on the steady-state solution. The model is developed for solution using commercial spread-sheet software such as Lotus 123. Comparison calculations are provided with the verified and validated TMAP4 transient code with good agreement. Results of calculations for the ITER CDA diverter are also included.

  19. Testing the integrity of stable isotope records of two Spitsbergen ice cores by using high-resolution tritium data.

    NASA Astrophysics Data System (ADS)

    van der Wel, L. G.; Meijer, H. A. J.; Isaksson, E.; Helsen, M. M.; van de Wal, R. S. W.; Martma, T.; Pohjola, V. A.; Moore, J. C.

    2009-04-01

    The ratios of 1H16O2H and 1H18O1H in precipitation water vary with temperature and can therefore be used as a proxy for past climate. Ever since the 1960-s, retrieving these isotope signals has been the main motivation for the drilling of deep ice cores. Most of the ice core records originate from selected sites in Greenland and Antarctica. Other Arctic locations are much less used. However, since the late 1990-s ice cores have been drilled on the Lomonosovfonna and Holtedahlfonna ice caps in Spitsbergen. The advantages of drilling at these sites lies in the high accumulation rate present in Spitsbergen, as well as the very location of the Spitsbergen archipelago. However, due to relatively high temperatures in this region, the isotope record is affected by melt and subsequent percolation, thereby potentially losing its value for climatic studies. In an attempt to test the integrity of the Spitsbergen cores, we measured the concentration of the radioactive isotope of hydrogen (tritium) at high spatial (and thus temporal) resolution. Due to above-ground nuclear bomb tests in the 1950-s and 1960-s, the tritium signal in the atmosphere has been highly variable in that period, with distinct peaks. Moreover, due to the high load of tritium in the stratosphere at that time, spring and early summer mixing between stratosphere and troposphere induced a clear seasonal pattern in precipitation records for two decades. The tritium concentration in precipitation has been measured (monthly average) since the 1950-s. After precipitation the tritium record is altered due to decay, diffusion and melt. Incorporating information of these three processes into a numerical model, we produce a quantitative estimate how much the isotope record is influenced by melt and percolation. This gives us a tool to determine whether the stable isotope record is a valid proxy for past temperatures.

  20. JUPITER-II Molten Salt Flibe Research: An Update On Tritium, Mobilization and Redox Chemistry Experiments

    SciTech Connect

    D.A. Petti; D. A. Petti; G. R. Smolik; Michael F. Simpson; John P. Sharpe; R. A. Anderl; S. Fukada; Y. Hatano; Masanori Hara; Y. Oya; T. Terai; D.-K. Sze; S. Tanaka

    2005-05-01

    The second Japan/US Program on Irradiation Tests for Fusion Research (JUPITER-II) began on April 1, 2001. Part of the collaborative research centers on studies of the molten salt 2LiF2–BeF2 (also known as Flibe) for fusion applications. Flibe has been proposed as a self-cooled breeder in both magnetic and inertial fusion power plant designs over the last 25 years. The key feasibility issues associated with the use of Flibe are the corrosion of structural material by the molten salt, tritium behavior and control in the molten salt blanket system, and safe handling practices and releases from Flibe during an accidental spill. These issues are all being addressed under the JUPITER-II program at the Idaho National Laboratory in the Safety and Tritium Applied Research (STAR) facility. In this paper, we review the program to date in the area of tritium/deuterium behavior, Flibe mobilization under accident conditions and testing of Be as a redox agent to control corrosion. Future activities planned through the end of the collaboration are also presented.

  1. Study on the Tritium Behaviors in the VHTR System. Part 1: Development of Tritium Analysis Code for VHTR and Verification

    SciTech Connect

    Eung Soo Kim; Chang Ho Oh; Mike Patterson

    2010-07-01

    A tritium permeation analyses code (TPAC) has been developed in Idaho National Laboratory (INL) by using MATLAB SIMULINK package for analysis of tritium behaviors in the VHTRs integrated with hydrogen production and process heat application systems. The modeling is based on the mass balance of tritium containing species and hydrogen (i.e., HT, H2, HTO, HTSO4, and TI) coupled with a variety of tritium source, sink, and permeation models. The code includes (1) tritium sources from ternary fission and neutron reactions with 6Li, 7Li 10B, 3He, (2) tritium purification system, (3) leakage of tritium with coolant, (4) permeation through pipes, vessels, and heat exchangers, (4) electrolyzer for high temperature steam electrolysis (HTSE), and (5) isotope exchange for SI process. Verification of the code has been performed by comparisons with the analytical solutions, the experimental data, and the benchmark code results based on the Peach Bottom reactor design. The results showed that all the governing equations are well implemented into the code and correctly solved. This paper summarizes all the background, the theory, the code structures, and some verification results related to the TPAC code development in Idaho National Laboratory (INL).

  2. Effects of glacial meltwater inflows and moat freezing on mixing in an ice-covered antarctic lake as interpreted from stable isotope and tritium distributions

    USGS Publications Warehouse

    Miller, L.G.; Aiken, G.R.

    1996-01-01

    Perennially ice-covered lakes in the McMurdo Dry Valleys have risen several meters over the past two decades due to climatic warming and increased glacial meltwater inflow. To elucidate the hydrologic responses to changing climate and the effects on lake mixing processes we measured the stable isotope (??18O and ??D) and tritium concentrations of water and ice samples collected in the Lake Fryxell watershed from 1987 through 1990. Stable isotope enrichment resulted from evaporation in stream and moat samples and from sublimation in surface lake-ice samples. Tritium enrichment resulted from exchange with the postnuclear atmosphere in stream and moat samples. Rapid injection of tritiated water into the upper water column of the make and incorporation of this water into the ice cover resulted in uniformly elevated tritium contents (> 3.0 TU) in these reservoirs. Tritium was also present in deep water, suggesting that a component of bottom water was recently at the surface. During summer, melted lake ice and stream water forms the moat. Water excluded from ice formation during fall moat freezing (enriched in solutes and tritium, and depleted in 18O and 2H relative to water below 15-m depth) may sink as density currents to the bottom of the lake. Seasonal lake circulation, in response to climate-driven surface inflow, is therefore responsible for the distribution of both water isotopes and dissolved solutes in Lake Fryxell.

  3. Diffusion and solubility of tritium in Path A Prime Candidate Alloy

    SciTech Connect

    Causey, R.A.; Steck, L.M.; Van Namen, R.

    1985-09-01

    The tritium recoil injection technique was used to determine the tritium diffusion coefficient for Path A Prime Candidate Alloy (PCA) over the temperature range 323K to 523K. Dissolution tritium counting of samples saturated in a tritium-hydrogen mixture was used to determine the tritium solubility for PCA over the temperature range 673K to 973K. No evidence of high energy trapping due to the titanium carbide precipitates in PCA was seen.

  4. Tritium activities in Canada supporting CANDU{sup R} nuclear power reactors

    SciTech Connect

    Miller, J. M.

    2008-07-15

    An overview of the various Canadian tritium research and operational activities supporting the development, refurbishment and operation of CANDU{sup R} nuclear power reactors is presented. These activities encompass tritium health and safety, tritium in the environment, tritium interaction with materials, and tritium processing, and relate to both supporting R and D advances as well as operational best practices. The collective results of these activities contribute to our goals of improving worker and public safety, and operational efficiency. (authors)

  5. Measured and modelled tritium concentrations in freshwater Barnes mussels (Elliptio complanata) exposed to an abrupt increase in ambient tritium levels.

    PubMed

    Yankovich, T L; Kim, S B; Baumgärtner, F; Galeriu, D; Melintescu, A; Miyamoto, K; Saito, M; Siclet, F; Davis, P

    2011-01-01

    To improve understanding of environmental tritium behaviour, the International Atomic Energy Agency (IAEA) included a Tritium and C-14 Working Group (WG) in its EMRAS (Environmental Modelling for Radiation Safety) program. One scenario considered by the WG involved the prediction of time-dependent tritium concentrations in freshwater mussels that were subjected to an abrupt increase in ambient tritium levels. The experimental data used in the scenario were obtained from a study in which freshwater Barnes mussels (Elliptio complanata) were transplanted from an area with background tritium concentrations to a small Canadian Shield lake that contains elevated tritium. The mussels were then sampled over 88 days, and concentrations of free-water tritium (HTO) and organically-bound tritium (OBT) were measured in the soft tissues to follow the build-up of tritium in the mussels over time. The HTO concentration in the mussels reached steady state with the concentration in lake water within one or two hours. Most models predicted a longer time (up to a few days) to equilibrium. All models under-predicted the OBT concentration in the mussels one hour after transplantation, but over-predicted the rate of OBT formation over the next 24h. Subsequent dynamics were not well modelled, although all participants predicted OBT concentrations that were within a factor of three of the observation at the end of the study period. The concentration at the final time point was over-predicted by all but one of the models. The relatively low observed concentration at this time was likely due to the loss of OBT by mussels during reproduction. PMID:20943295

  6. Measured and modelled tritium concentrations in freshwater Barnes mussels (Elliptio complanata) exposed to an abrupt increase in ambient tritium levels.

    PubMed

    Yankovich, T L; Kim, S B; Baumgärtner, F; Galeriu, D; Melintescu, A; Miyamoto, K; Saito, M; Siclet, F; Davis, P

    2011-01-01

    To improve understanding of environmental tritium behaviour, the International Atomic Energy Agency (IAEA) included a Tritium and C-14 Working Group (WG) in its EMRAS (Environmental Modelling for Radiation Safety) program. One scenario considered by the WG involved the prediction of time-dependent tritium concentrations in freshwater mussels that were subjected to an abrupt increase in ambient tritium levels. The experimental data used in the scenario were obtained from a study in which freshwater Barnes mussels (Elliptio complanata) were transplanted from an area with background tritium concentrations to a small Canadian Shield lake that contains elevated tritium. The mussels were then sampled over 88 days, and concentrations of free-water tritium (HTO) and organically-bound tritium (OBT) were measured in the soft tissues to follow the build-up of tritium in the mussels over time. The HTO concentration in the mussels reached steady state with the concentration in lake water within one or two hours. Most models predicted a longer time (up to a few days) to equilibrium. All models under-predicted the OBT concentration in the mussels one hour after transplantation, but over-predicted the rate of OBT formation over the next 24h. Subsequent dynamics were not well modelled, although all participants predicted OBT concentrations that were within a factor of three of the observation at the end of the study period. The concentration at the final time point was over-predicted by all but one of the models. The relatively low observed concentration at this time was likely due to the loss of OBT by mussels during reproduction.

  7. Tritium in unsaturated zone gases and air at the Amargosa Desert Research Site, and in spring and river water, near Beatty, Nevada, May 1997

    USGS Publications Warehouse

    Striegl, R.G.; Healy, R.W.; Michel, R.L.; Prudic, D.E.

    1998-01-01

    Elevated tritium concentrations in the unsaturated zone at the Amargosa Desert Research Site (ADRS), immediately south and west of the low-level radioactive-waste burial site south of Beatty, Nevada, have stimulated research of processes that control the transport of tritium in arid unsaturated zones. In May 1997, 58 samples were collected from 1.5 m (meters) depth within a 250 m by 250 m grid at the ADRS. Measured concentrations ranged from 16 ? 9 to 36,900 ? 300 tritium units (TU), decreasing from northeast to southwest, possibly along an ancestral Amargosa River channel. The 10 air ports at test hole UZB-2 also were sampled, including ports at 57.6, 106.4, and 108.8 m depths that had not been sampled since 1994. Of the remaining seven ports, five were sampled in 1994, 1995, and 1996, and two were sampled in 1994 and 1996. Tritium concentrations at the four ports deeper than 50 m ranged from 791 ? 15 to 1765 ? 29 TU, having increased since they were last sampled. Tritium concentrations at the six ports shallower than 50 m ranged from 367 ? 11 to 1283 ? 20 TU, and appear to have stabilized since 1996. Tritium concentration in water vapor collected from air within the creosote bush canopy was 75 ? 9 TU near test hole UZB-2 and 9 ? 6 TU near the uncontaminated Fischer test hole, 3.2 km to the south. Elevated tritium concentration in air near test hole UZB-2 was attributed to plant transpiration removing water from the unsaturated zone. Nearby surface water tritium concentrations were 6.3 ? 0.4 TU at Specie Spring, 0.0 ? 0.3 TU at Lower Indian Springs and at Upper Indian Springs, and 0.8 ? 0.6 TU in Amargosa River water.

  8. Integration of Nevada Test Site (NTS) Work Control Programs and Incorporating Integrated Safety Management (ISM) into Activity Level Work Planning and Control

    SciTech Connect

    Mike Kinney and Kevin Breen

    2008-08-30

    This session will examine a method developed by Federal and Contractor personnel at the Nevada Site Office (NSO) to improve the planning and execution of work activities utilizing an Activity Level Work Control process in response to Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 2004-1, Oversight of Complex, High-Hazard Nuclear Operations. The process was initially developed during Fiscal Year (FY) 2007, and implementation is commencing during the fourth quarter of FY 2008. This process will significantly enhance the flexibility and the appropriate rigor in the performance of work activities.

  9. Development of Tritium Permeation Analysis Code and Tritium Transport in a High Temperature Gas-Cooled Reactor Coupled with Hydrogen Production System

    SciTech Connect

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

    2010-06-01

    Abstract – A tritium permeation analyses code (TPAC) was developed by Idaho National Laboratory for the purpose of analyzing tritium distributions in very high temperature reactor (VHTR) systems, including integrated hydrogen production systems. A MATLAB SIMULINK software package was used in developing the code. The TPAC is based on the mass balance equations of tritium-containing species and various forms of hydrogen coupled with a variety of tritium sources, sinks, and permeation models. In the TPAC, ternary fission and neutron reactions with 6Li, 7Li 10B, and 3He were taken into considerations as tritium sources. Purification and leakage models were implemented as main tritium sinks. Permeation of tritium and H2 through pipes, vessels, and heat exchangers were considered as main tritium transport paths. In addition, electroyzer and isotope exchange models were developed for analyzing hydrogen production systems, including high temperature electrolysis and sulfur-iodine processes.

  10. Application of tritium in precipitation and baseflow in Japan: a case study of groundwater transit times and storage in Hokkaido watersheds

    NASA Astrophysics Data System (ADS)

    Gusyev, Maksym A.; Morgenstern, Uwe; Stewart, Michael K.; Yamazaki, Yusuke; Kashiwaya, Kazuhisa; Nishihara, Terumasa; Kuribayashi, Daisuke; Sawano, Hisaya; Iwami, Yoichi

    2016-07-01

    Japanese groundwater will reach natural levels in a decade, when one tritium measurement will be sufficient to estimate a unique MTT. Using a series of tritium measurements over the next few years with 3-year intervals will enable us to estimate the correct MTT without ambiguity in this period. These unique MTTs will allow estimation of groundwater storage volumes for water resources management during droughts and improvement of numerical model simulations. For example, the groundwater storage ranges between 0.013 and 5.07 km3 with saturated water thickness from 0.2 and 24 m. In summary, we emphasise three important points from our findings: (1) one tritium measurement is already sufficient to estimate MTTs for some Japanese catchments, (2) the hydrogeological settings control the tritium transit times of subsurface groundwater storage during baseflow, and (3) in the future, one tritium measurement will be sufficient to estimate MTTs in most Japanese watersheds.

  11. Tritium in waters of international importance in 1981-1984

    SciTech Connect

    Anisimov, V.V.; Blinov, V.A.; Gedeonov, L.I.; Il'in, L.I.; Tishkov, V.P.

    1988-03-01

    A study has been carried out on the radiation situation with respect to tritium in the drainage basin of the Baltic Sea and in the Soviet section of the Danube in the period of 1981-1984. Pollution of the Baltic during this period turned out to be quite constant and coincident with the tritium level of the preceding five years. Concentrations increased slightly in the Gulf of Riga and in a number of rivers flowing into the Baltic (Daugava, Pirita, etc.). In the same period the tritium contamination of Danube water was 2-3 times greater that of the Baltic. The tritium content of the Baltic was calculated: its average value in the period 1981-1984 was 1.56 x 10/sup 17/ Bq.

  12. Tritium release properties of neutron-irradiated Be 12Ti

    NASA Astrophysics Data System (ADS)

    Uchida, M.; Ishitsuka, E.; Kawamura, H.

    2002-12-01

    Be 12Ti has a high melting point and good chemical stability and is a promising advanced material for the neutron multiplier of the DEMO reactor that requires temperatures higher than 600 °C in a blanket. To evaluate the tritium inventory in the breeding blanket, a tritium release experiment of neutron-irradiated Be 12Ti with a total fast fluence of about 4×10 20 n/cm 2 ( E>1 MeV) was carried out at 330, 400 and 500 °C. It was clear that tritium could be released easier than from beryllium, and the apparent diffusion coefficient in Be 12Ti was about two orders larger than that in beryllium at 600-100 °C. In addition to the good tritium release property, the swelling calculated from the density change of the specimens up to 1100 °C in this test was smaller than that of beryllium.

  13. Tritium permeation losses in HYLIFE-II heat exchanger tubes

    SciTech Connect

    Longhurst, G.R.; Dolan, T.J.

    1990-01-01

    Tritium permeation through the intermediate heat exchanger of the HYLIFE-II inertial fusion design concept is evaluated for routine operating conditions. The permeation process is modelled using the Lewis analogy combined with surface recombination. It is demonstrated that at very low driving potentials, permeation becomes proportional to the first power of the driving potential. The model predicts that under anticipated conditions the primary cooling loop will pass about 6% of the tritium entering it to the intermediate coolant. Possible approached to reducing tritium permeation are explored. Permeation is limited by turbulent diffusion transport through the molten salt. Hence, surface barriers with impendance factors typical of present technology can do very little to reduce permeation. Low Flibe viscosity is desirable. An efficient tritium removal system operating on the Flibe before it gets to the intermediate heat exchanger is required. Needs for further research are highlighted. 9 refs., 2 figs., 1 tab.

  14. Rapid assessment of soil and groundwater tritium by vegetation sampling

    SciTech Connect

    Murphy, C.E. Jr.

    1995-09-01

    A rapid and relatively inexpensive technique for defining the extent of groundwater contamination by tritium has been investigated. The technique uses existing vegetation to sample the groundwater. Water taken up by deep rooted trees is collected by enclosing tree branches in clear plastic bags. Water evaporated from the leaves condenses on the inner surface of the bag. The water is removed from the bag with a syringe. The bags can be sampled many times. Tritium in the water is detected by liquid scintillation counting. The water collected in the bags has no color and counts as well as distilled water reference samples. The technique was used in an area of known tritium contamination and proved to be useful in defining the extent of tritium contamination.

  15. [Internal contamination by tritium caused by radioluminescent paints].

    PubMed

    Adamiak-Ziemba, J; Doniec, J

    1985-01-01

    The internal contamination investigations covered 23 persons using radioluminescence paints containing tritium, assembling devices painted with those paints, and those having no contact with active paints but working next to the painting room. Determined were concentrations of tritium excreted with urine, air contamination at workplaces, contamination of workplace areas and hand skin. At the time covered by the investigations, the mean annual equivalent doses for those using tritium paints were reduced from 14-20 mSv to about 5 mSv. In those working next to the painting room they were reduced from 5.8-15 to 0.23 mSv. The exposure of those assembling the devices does not exceed 1 mSv. It was demonstrated that the main cause of the tritium exposure level was air contamination in working rooms.

  16. Assessment of tritium in the Savannah River Site environment

    SciTech Connect

    Carlton, W.H.; Murphy, C.E. Jr.; Bauer, L.R.

    1993-10-01

    This report is the first revision to a series of reports on radionuclides inn the SRS environment. Tritium was chosen as the first radionuclide in the series because the calculations used to assess the dose to the offsite population from SRS releases indicate that the dose due to tritium, through of small consequence, is one of the most important the radionuclides. This was recognized early in the site operation, and extensive measurements of tritium in the atmosphere, surface water, and ground water exist due to the effort of the Environmental Monitoring Section. In addition, research into the transport and fate of tritium in the environment has been supported at the SRS by both the local Department of Energy (DOE) Office and DOE`s Office of Health and Environmental Research.

  17. Increasing the performance of tritium analysis by electrolytic enrichment.

    PubMed

    Groning, M; Auer, R; Brummer, D; Jaklitsch, M; Sambandam, C; Tanweer, A; Tatzber, H

    2009-06-01

    Several improvements are described for the existing tritium enrichment system at the Isotope Hydrology Laboratory of the International Atomic Energy Agency for processing natural water samples. The improvements include a simple method for pretreatment of electrolytic cells to ensure a high tritium separation factor, an improved design of the exhaust system for explosive gases, and a vacuum distillation line for faster initial preparation of water samples for electrolytic enrichment and for tritium analysis. Achievements included the reduction of variation of individual enrichment parameters of all cells to less than 1% and an improvement of 50% of the stability of the background mean. It resulted in an improved detection limit of less than 0.4 TU (at 2s), important for application of tritium measurements in the future at low concentration levels, and resulted in measurement precisions of+/-0.2 TU and+/-0.15 TU for liquid scintillation counting and for gas proportional counting, respectively. PMID:20183225

  18. Evaluation of a tritium runway-lighting system. Technical note

    SciTech Connect

    Katz, E.S.

    1992-04-01

    A tritium powered runway lighting system was installed and evaluated at the Federal Aviation Administration (FAA) Technical Center. The purpose of this evaluation was to determine if the tritium runway lighting system would safely support Federal Aviation Regulations (FAR) Part 135 commercial operations, during nighttime visual flight rules (VFR) conditions at remote airports. Subject pilots having flight experience levels appropriate for pilots conducting FAR Part 135 air taxi operations were afforded the opportunity of flight testing the system. Results of the evaluation indicate that the tritium runway lighting system does not meet all of the minimum criteria necessary for FAA approval and, therefore, would not guarantee an acceptable level of safety. Tritium Runway Lighting System, Remote Airports.

  19. Zeolite membrane cascade for tritium extraction and recovery systems

    SciTech Connect

    Borisevich, O.; Demange, D.; Lefebvre, X.; Kind, M.

    2015-03-15

    Membrane separation by zeolite membranes has been proposed as a pre-concentration stage for the tritium extraction from the purge helium of the breeding blanket combined with a final recovery by the catalytic membrane reactor PERMCAT. This fully continuous operation improves the tritium management in fusion machines, minimizing the tritium inventory. For the first time, the permeation measurements for H{sub 2} - He mixtures through a MFI-alumina hollow fibre membrane has been measured for different compositions (0.1 - 20% H{sub 2}) and temperatures. Such a highly permeable membrane, although it shows a limited selectivity, appears attractive for tritium recovery in the blanket. This will imply its operation in a membrane cascade, for which simulation work is ongoing. Mathematically the process is modeled using mass balance equations that can be transformed into the matrix form and solved iteratively assuming a permeate concentration on the first step of iteration, until the separation requirements are fulfilled.

  20. Development of a wide-range tritium-concentration detector

    SciTech Connect

    Jun, F.; Zhe, L.; Shicheng, L.; Jiangfeng, S.; Deli, L.

    2015-03-15

    According to the requirements of the tritium related systems of the TBM (Test Blanket Module) for monitoring the on-line tritium concentration, a wide-range tritium-concentration detector has been developed to measure the tritium concentration in the range of 10{sup 4} Bq/ml - 5*10{sup 8} Bq/ml. This detector is combined with a low-memory helium ionization chamber. The weak current signal collected in the ionization chamber is converted to the voltage signal by an I-V converter. The minimum weak current which the detector could be measured is 10{sup -14} A. The performance of the background current and the current response linearity of the prototype have been tested. The test result indicates that the linear response of the current signal of the prototype without connecting the ionization chamber is good. The linear correlation coefficient is R{sup 2} = 0.998.