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Palladium nanoparticles (PdNp) were revealed as an efficient hydrogen isotope exchange catalyst for the deuterium and tritium labeling of benzylic positions of complex molecules. A practical way to obtain small palladium nanoparticles and to apply them as a catalyst for hydrogen isotope exchange (HIE) is presented. Several model compounds and popular bioactive molecules were submitted to HIE reactions catalyzed by the PdNp. Benzylic positions situated far away from heteroatoms were labeled with high isotopic enrichments. The observed non-directed HIE gave rise to regioselectivities complementary to those obtained with other methods, which typically require specific directing groups. For this reason, the successful deuteration of a broad variety of benzylic positions created a helpful tool to produce internal LC-MS standards of complex drugs. Furthermore, this nanocatalyst paved the way for the radiolabeling of drug molecules with high specific activities by using low pressures of tritium gas.

Getters are among the key functional components in the tritium-producing burnable absorber rods (TPBARs) of light water reactors (LWRs) and are used to capture the released tritium gas. They are nickel-plated zircaloy-4 tubes that, upon exposure to irradiation or tritium in the light water reactors, undergo alteration in structure, chemical composition, and chemistry. Understanding the radial tritium distribution is key to gaining insight into the evolution of new chemistry upon irradiation to predict getter performance. The holy grail is to develop a method akin to selectively peeling off the layers of an onion in an effort to get a radial map of elements and particularly tritium across the getter. Toward this goal, the overall aim of this work is to establish a correlative technique that can be used to determine radial tritium distribution across getters. To this end, this work specifically focuses on the validation of a correlative method for controlled radial dissolution of nickel-plated getters. Here, pristine getters as well as getters loaded with different mass ratios of hydrogen and deuterium are used as the nonradioactive surrogates of tritium, the idea being that the methodology can be readily extended to tritiated getter components. Here, the surface nickel layers as well as the bulk zirconium layers are sequentially dissolved in a controlled, uniform way using voltage-assisted electrochemical dissolution techniques. The dissolution is complemented by periodic elemental analysis of the electrolyte solution during and post dissolution. This is complemented by microscopic analyses on the exposed surfaces to provide a correlative technique for a complete picture of the radial distribution of various elements across the getter.

[3 H]Genipin was synthesized in a single step by Ir(I) catalyzed hydrogen isotope exchange. Conditions for selective exchange of the sp2 CH bond ortho to the methyl ester functionality were developed through deuterium modeling studies through a catalyst screen. Optimized conditions so obtained were then utilized with tritium gas to generate [3 H]genipin at a specific activity of 18.5 Ci/mmol. Racemic [14 C]genipin was prepared in eight steps in overall 5.4% radiochemical yield from potassium [14 C]cyanide.

The results of the development of a radioisotope power supply source based on a semiconductor (AlxGa1 –xAs/GaAs) β-radiation energy converter and tritium as a radiation source are presented. The efficiency of this converter with a tritium saturated titanium disk, a green luminescent tritium lamp, or tritium gas as a radioisotope radiation source is compared. For a converter based on the Al0.35Ga0.65As/GaAs heterostructure in a capsule with tritium, efficiency η = 5.9% at a maximum specific output electrical power of 0.56 μW/cm2. Due to their long service life, such stand-alone and compact power supply sources can be used in space and subsea technologies, implantable cardiac pacemakers, biosensors, and portable equipment of high reliability.

Tritiated wate`r production is ubiquitous in facilities that handle tritium gas. Sources range from decontamination efforts, to the deliberate conversion of elemental tritium to tritiated w...

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the effective electron anti-neutrino mass with an unprecedented sensitivity of 0.2 eV/c2, using β -electrons from tritium decay. Superconducting magnets will guide the electrons through a vacuum beamline from the windowless gaseous tritium source through differential and cryogenic pumping sections to a high resolution spectrometer. At the same time tritium gas has to be prevented from entering the spectrometer. Therefore, the pumping sections have to reduce the tritium flow by at least 14 orders of magnitude. This paper describes various simulation methods in the molecular flow regime used to determine the expected gas flow reduction in the pumping sections for deuterium (commissioning runs) and for radioactive tritium. Simulations with MolFlow+ and with an analytical model are compared with each other, and with the stringent requirements of the KATRIN experiment.

W samples, previously irradiated with 20 MeV W ions at room temperature to a displacement-damage level of 0.23 displacements per atom (dpa) at the peak of displacements, were exposed to a deuterium-tritium (D2 ― DT ― T2) gas mixture with a tritium content of 6% at a total pressure of 1.2 kPa and temperatures of 773 K and 973 K for 3 h. The concentration of tritium retained in the displacement-damage zone of these W samples was determined by a method combining chemical etching and subsequent analysis of tritium in the etching solution using liquid scintillation counting (CE-LSC). (Some figures may appear in colour only in the online journal)

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the effective electron anti-neutrino mass with an unprecedented sensitivity of $0.2\,\mathrm{eV}/\mathrm{c}^2$, using $\beta$-electrons from tritium decay. The electrons are guided magnetically by a system of superconducting magnets through a vacuum beamline from the windowless gaseous tritium source through differential and cryogenic pumping sections to a high resolution spectrometer and a segmented silicon pin detector. At the same time tritium gas has to be prevented from entering the spectrometer. Therefore, the pumping sections have to reduce the tritium flow by more than 14 orders of magnitude. This paper describes the measurement of the reduction factor of the differential pumping section performed with high purity tritium gas during the first measurement campaigns of the KATRIN experiment. The reduction factor results are compared with previously performed simulations, as well as the stringent requirements of the KATRIN experiment., Comment: 19 pages, 4 figures, submitted to Vacuum

The Pacific Northwest National Laboratory operates the Radiochemical Processing Laboratory, which is a multi-purpose, non-reactor nuclear research facility. Regulations require both continuous sampling and monitoring of radioactive particulates and tritium gas in the exhaust from the main stack. Releases of other radioactive gases, including planned releases of radon, are tracked separately in a database and reported. During the 2015 calibration of the Radiochemical Processing Laboratory stack continuous air monitor, measured alpha and beta background count rates were much higher than expected, especially when compared to count rates from previous calibrations. The source of the higher background count rates was examined by trending of historical continuous air monitor measurements and a comparison to the sampler data. The analysis revealed that the sample results showed no increase in emissions, whereas the continuous air monitor showed a steady increase in count rates. Ultimately, the continuous air monitor filter was analyzed and found to contain higher-than-normal background levels of Rn progeny. Assessments were performed to determine the cause of the increased background values, including reviews of building research activities, radioactive material usage and storage, adequacy of procedures, and the potential for internal continuous air monitor contamination. Project reviews determined that a research activity involving Th was left in an unsealed state, resulting in Rn being released from a hot cell into the exhaust system. The Th source material was subsequently repackaged and contained, resulting in a decrease of continuous air monitor background count rates. An estimate of the Rn release was made and the contribution to the annual offsite dose from the facility was calculated. The released activity and reported dose results were well below the permit limits for the facility.

Li2TiO3-Li4SiO4 biphasic ceramic pebbles have been developed as an advanced tritium breeder due to the potential to combine the advantages of both Li2TiO3 and Li4SiO4. Wet method was developed for the pebble fabrication and Li2TiO3-Li4SiO4 biphasic ceramic pebbles were successfully prepared by wet method using the powders synthesized by hydrothermal method. The tritium release properties of the Li2TiO3-Li4SiO4 biphasic ceramic pebbles were evaluated. The biphasic pebbles exhibited good tritium release property at low temperatures and the tritium release temperature was around 470 °C. Because of the isotope exchange reaction between H2 and tritium, the addition of 0.1%H2 to purge gas He could significantly enhance the tritium gas release and the fraction of molecular form of tritium increased from 28% to 55%. The results indicate that the Li2TiO3-Li4SiO4 biphasic ceramic pebbles fabricated by wet method exhibit good tritium release property and hold promising potential as advanced breeder pebbles.

The evolution of He from Zr-tritides was investigated for aging times up to about 6.5 years using analytical thermal helium desorption spectrometry (THDS). Zr films were deposited onto Mo substrates and then converted into Zr-tritides (ZrT 1.70∼1.95 ) inside a tritiding apparatus loaded with pure tritium gas. During aging, there are at least five forms of He in Zr-tritides, and more than 99% of He atoms are in the form of He bubbles. The isolated He bubbles in lattices begin to link with each other when the He/Zr atom ratio reaches about 0.21, and are connected to grain boundaries or dislocation networks at He concentration of He/Zr ≈ 0.26. An interconnected system of channels decorated by bubbles evolves from the network dislocations, dislocation loops and internal boundaries. These He filled networks are formed completely when the He/Zr atom ratio is about 0.38. Once the He/Zr reached about 0.45, the networks of He bubble penetrate to the film surface and He begins an “accelerated release”. This critical ratio of He to Zr for He accelerated release is much greater than that found previously for Ti-tritides (0.23–0.30). The difference of He retention in Zr-tritides and Ti-tritides was also discussed in this paper.

Summary The gas-liquid separator is a critical component for the online tritium gas removal system in thorium molten salt reactor. In this paper, an isolated bubble trajectory in a single-phase swirling flow field of the separator is investigated theoretically. The mathematical modeling of the forces acting on the bubble is established, and the motion equations of bubble are solved numerically. The axial and circumferential velocities of the swirling flow are approximated by the combination of 2 co-flow Batchelor vortices. Notably, it is a promising way to obtain the analytical expression of velocity field in this gas-liquid separator. The results indicate that the separation length will increase as decreasing diameter of bubble and swirl number. Hence, the numerical simulation provides an effective tool to predict bubble trajectory and optimize the design of the gas-liquid separator.

Tritium release behavior from the Li 4 SiO 4 pebbles with high densities (∼96%TD) and large grain sizes (100–300 μm) fabricated by a melt-based method (the M-OSi sample) was investigated through out-of-pile experiments. Another batch of Li 4 SiO 4 pebbles with relatively low densities (∼86%TD) and small grain sizes (10–50 μm) fabricated by a wet method (the W-OSi sample) was used for comparative study. Comparing with the W-OSi sample, the temperature of tritium release from the M-OSi sample was found much higher. Moreover, the fraction of tritium gas released from the M-OSi sample was much larger, especially under helium purge gas. The big differences between the characteristics of tritium release from the two batches of samples can be explained reasonably by the effect of grain size, implying that the grain size played an important role in the tritium release behavior. This study can provide a guideline for optimizing the fabrication process of Li 4 SiO 4 pebbles.

One of the methods used for tritium gas analysis is beta-ray induced X-ray spectrometry (BIXS). Gas cell design is important in this method. The structure of the gas cell for BIXS was optimized by Monte Carlo simulation of beta-ray induced X-ray spectra in various window geometries using the Geant4 tool kit (version 10.01.p02). The simulated spectrum from tritium decay fitted the observed one, and the simulation model was used to obtain the cell parameters for BIXS. The optimum thickness of the gold layer on a beryllium window was around 150 nm. This simulation model also considered the relationship between self-absorption by hydrogen gas and the cell length. Self-absorption increased with increasing cell length and the relationship between the sample pressure and cell length was formulated.

Luminescence of various inorganic compounds of rare earth elements as radioluminophores was studied with the aim of fabricating weak permanent light sources. Under the action of UV and tritium radiation, all the luminophores tested emit light of different colors. In the tritium gas medium, six luminophores showed emission, and for three of them (Y2O3:Eu, Y2O3:Eu, Bi, Gd2O3:Eu) the emission brightness was acceptable for practical use. Attempt to prepare permanent light sources with new types of luminophores using a phosphoric acid solution as a binder demonstrated the need for searching for a new binder firmly fixing the luminophore on the glass surface.

Korea is operating 24 nuclear power plants and a highly advanced neutron application reactor HANARO (High-flux Advanced Neutron Application Reactor). In addition, Korea is designing a tritium storage and delivery system (SDS) for ITER. We have been developing detritiation and tritium storage technologies since the operation of Wolsong CANDU (Canada Deuterium-Uranium) station in 1983. The Wolsong Tritium Removal System (TRF) was designed to remove tritium generated in heavy water of the moderator and heat transport. Catalysts transfer tritium from the tritiated heavy water to gaseous tritiated deuterium. The hydrogen isotopes, including tritium, are transported to a cryogenic distillation system where the tritium is removed for safe storage. Conventional high-pressure storage tanks can be dangerous for the storage of radioactive tritium gas. We have been studying various kinds of metal hydride, such as titanium, zirconium cobalt, and depleted uranium. Titanium was proven to store tritium safely and...

Normetex® Model 15 scroll pump backed by metal bellows (MB) pump made by Senior Aerospace Inc. has been the preferred technology for use in tritium facilities world-wide. Normetex pumps are no longer available and identification of alternate pumps is required for performance and compatibility with tritium gas. Many of the pumps that could be used to meet the functional performance requirements (e.g. pressure and flow conditions) of the Normetex pump have features that include the use of polymers or oils and greases that are not directly compatible with tritium service. Though they are less desirable, alternative pumps may be used in tritium service with appropriate engineered controls to mitigate the impact of degraded organic compounds. These alternative pumps require characterization for potential application in tritium service.One pump that has been identified as a potential replacement for the Normetex pump in some tritium service applications is the Edwards nXDS15iC. A series of pump tests we...

Tritium is highly reactive with many materials. It is adsorbed onto and absorbed through the surface of containment vessels subsequently modifying the contained gas composition by isotopic exchange and catalytic reactions with surface elements and adsorbed gas species. Savannah River Tritium Enterprise (SRTE) uses a proprietary surface treatment that is intended to render the surface inert. Unfortunately, this process has not proven to be sufficiently robust for containing tritium gas standards. SRTE has funded a project that will explore the effects of electropolishing and vacuum and oxidizing thermal treatments on surface passivation of stainless steel (SS). Herein, a statistically designed series of experiments will be discussed that will inform optimized parameters for acid composition, current density, and other electrochemical process variables for the passivation of SS. The surfaces were analyzed using Laser Induced Breakdown Spectroscopy (LIBS), Auger Electron Spectroscopy (AES), Atomic Fo...

Retention and release behavior of tritium charged into stainless steel type 316 by two different methods were tracked by β-ray-induced X-ray spectrometry (BIXS). Exposure to tritium gas and irradiation of tritium ions were employed. Effects of pre-irradiation of helium ions on tritium retention were also investigated. After charging tritium by these methods and tracking by BIXS, thermal release behavior of tritium was examined by BIXS. The observed X-ray spectrum showed clearly that thermally charged tritium at a high temperature diffused into the bulk of SS316, but tritium ions irradiated at room temperature were trapped in surface layers of the sample irrespective of tritium ion energy. Thermally charged tritium was not able to remove completely even heating at high temperature of 973 K. On the contrary, it was seen that the ion-irradiated tritium decreased almost linearly with temperature irrespective of ion energy. Furthermore, rapid decrease of tritium appeared in the helium pre-irradiated samples.

The initial discovery and establishment of a family of novel iridium catalysts possessing N-heterocyclic carbene units alongside bulky phosphine ligands allowed selected substrates to be labelled using deuterium or tritium gas at desirably low catalyst loadings via an ortho-directed C-H insertion process. Such a method has broad applicability and offers distinct advantages within the pharmaceutical industry, directly facilitating the ability to carefully monitor a potential drug molecule’s biological fate. Over the past decade since these initial protocols were divulged, many additional advances have been made in terms of catalyst design and substrate scope. This review describes the broadened array of new iridium catalysts and associated protocols for direct and selective C-H activation and hydrogen isotope insertion within a number of new chemical entities of direct relevance to the pharmaceutical industry.

A general-purpose manifold is described, which is useful for numerous procedures involving tritium gas and tritium-labeled materials. Methods are given in detail for (a) converting tritium gas to tritium oxide, (b) preparing tritium-labeled lithium borohydride, and (c) conducting a variety of reactions in a closed system. Auxiliary equipment is shown, including water traps, reaction flasks, and apparatus for preparing solutions and making filtrations in closed systems. Methods are presented for assaying tritium-labeled water by (a) dissolving it in a phosphoric anhydride-sulfuric acid solution and counting in a windowless, gas-flow, proportional counter, or (b) converting it to hydrogen-t and assaying it in an ionization chamber. The use of tritium-labeled lithium borohydride is illustrated by the preparation of d-galactitol-1-t from d-galactose. Subsequent papers will describe the use of this apparatus in the synthesis of tritium-labeled carbohydrates. The detailed description of techniques and apparatus should be helpful to others who are interested in using tritium.

The Marble campaign on the National Ignition Facility investigates the effect of heterogeneous mix on thermonuclear burn for comparison to a probability distribution function (PDF) burn model. Marble utilizes plastic capsules filled with deuterated plastic foam and a fill gas containing tritium. As the capsules implode, the deuterium in the foam mixes with the tritium gas, and DT neutrons are produced as the shocks compress and heat the mixture. The yield of DT neutrons is dependent on the uniformity of the mix, with more heterogeneous mix producing fewer neutrons. In Marble, the heterogeneity of the mix is controlled by varying the diameter of voids introduced into the foam. The first NIF Marble campaign has been executed in which the Marble capsules were indirectly driven with a single strong shock using NIF hohlraums. The experiments produce a low-convergence, high-ion-temperature implosion. The ratio of DT to DD neutron yield is largely consistent with uniform atomic mix for fine-pore foam, and increases slightly with void diameter, contrary to 1D simulations using the PDF burn model. Recent 3D high-resolution simulations of similar experiments performed on the Omega Laser Facility suggest an explanation.

Metal hydride bed will be one of the key components for safe handling of tritium in fusion fuel cycle. In case of normal or emergency shutdown of fuel cycle, metal hydride bed installed in storage and delivery system (SDS) of tritium plant will absorb tritium gas in the system as soon as possible. Supply of hydrogen isotope gas to fueling system of fusion reactor will start from the metal hydride beds. Rapid delivery, rapid recovery including rapid heating and cooling are key issues. For better performance of metal hydride bed, various forms of heat transfer enhancing component or design can be applied. This study aims to help the selection of heat transfer enhancing component. Two small ZrCo beds with copper foam and copper fin were developed and experimented with hydrogen gas. Recovery and delivery performance, heating and cooling performance are compared. Experimental results show metal hydride bed with copper foam has improved performance. Uniform heating of metal hydride during desorption and removal of reaction heat during absorption are more efficient with copper foam bed than copper fin bed.

To address the transport and trapping of hydrogen isotopes, several permeation experiments are being pursued at both Sandia National Laboratories (deuterium gas-driven permeation) and Idaho National Laboratories (tritium gas- and plasma-driven tritium permeation). These experiments are in part a collaboration between the US and Japan to study the performance of tungsten at divertor relevant temperatures (PHENIX). Here we report on the development of a high temperature (≤1150 °C) gas-driven permeation cell and initial measurements of deuterium permeation in several types of tungsten: high purity tungsten foil, ITER-grade tungsten (grains oriented through the membrane), and dispersoid-strengthened ultra-fine grain (UFG) tungsten being developed in the US. Experiments were performed at 500–1000 °C and 0.1–1.0 atm D2 pressure. Permeation through ITER-grade tungsten was similar to earlier W experiments by Frauenfelder (1968–69) and Zaharakov (1973). Data from the UFG alloy indicates marginally higher permeability (

A solid phase extraction method for removing polar tritiated contaminants from tritium-containing waste oils has been developed. The composition of the degradation products present in the waste oil was determined. The results indicated that upon exposure to tritium gas, fragment methyl ketones, carboxylic acids, and lactones were the main polar products of the mineral-based oil oxidation. The nonpolar fragmentation products included n-alkanes, monomethylalkanes, and acyclic isoprenoids and were analogous to those formed during \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\gamma$$\end{document}γ-irradiation of the oil. Various polar and nonpolar fragmentation products containing an isoprenoid skeleton were found to be formed via an oxidative/radiation scission of long-chain acyclic isoprenoids. Electronic supplementary material The online version of this article (doi:10.1007/s10967-016-4953-8) contains supplementary material, which is available to authorized users.

The CXCR2 antagonist AZD5069 has been synthesized in tritium and carbon-14-labelled forms. [(3) H]AZD5069 was prepared via reductive dehalogenation of an iodinated precursor with tritium gas to provide material with a specific activity of 25.1 Ci/mmol. [(14) C]AZD5069 was labelled in the pyrimidine ring from [(14) C]thiourea in an overall radiochemical yield of 18%. In addition, a synthetic route to the major metabolite of AZD5069 was developed. The synthesis of this metabolite was achieved from AZD5069 using a chemoselective Lindgren-Pinnick reaction in order to minimize oxidation of the sulphide group.

The tritium storage bed receives and supplies tritium gas for fusion facilities. Inert gases, such as helium-3, which is produced by tritium beta decay, disturb the absorption behavior of tritium in the bed and this is called the Helium Blanketing Effect (HBE). This study focused on the HBE and gas circulation as a way of breaking the HBE for the hydriding reaction with ZrCo. The hydriding reaction with the application of 100 % hydrogen without helium-4 was completed within five minutes under 120 kPa initial hydrogen partial pressure and 20 °C reactor temperature. With 5% helium-4 in the hydrogen, it took more than 1000 min for the hydriding reaction to be completed under the same conditions. The HBE was broken with the application of a gas-circulation process. Even with 50 % helium-4 in the hydrogen, the hydriding reaction was completed in five minutes under the same conditions. In an experiment conducted at various flow rates of gas circulation, breaking the HBE was observed even at a small flow rate. The gas circulation process can efficiently break the HBE and separate the helium-3 produced in the tritium storage bed.

In the present study, successive exposure to tritium gas and deuterium gas was performed at elevated temperatures for tungsten samples with irradiation defects created by helium ion irradiation to investigate the effects of hydrogen isotope exchange on tritium removal. It was found that, under the present heating conditions, heating treatment in deuterium gas was more effective for tritium removal than heating in a vacuum. In addition, heating in deuterium gas was effective to remove tritium retained in a deep region of sample comparing to the case of heating in a vacuum. The enhanced tritium release was explained by enhanced tritium detrapping due to trap occupation by deuterium and/or the increase in probability of surface recombination under deuterium gas exposure.

Zircaloy-4 (Zr-4) based liners and getters are the principle functional components of Tritium-Producing Burnable Absorber Rods (TPBARs) in light water nuclear reactors where they reduce tritiated water into tritium gas. Upon tritium exposure, zirconium tritide is formed, which changes the chemical composition, structure and morphology of these materials. Their thermodynamic properties are affected by (i) the hydride phase identity, (ii) radial and spatial tritide/hydride (T/H) distribution, and (iii) the changes in structure and morphology of the material upon T/H-migration, and their comprehensive knowledge is needed to predict performance of these materials. This work demonstrates that controlled potential electrochemistry techniques to be highly efficient for controlled oxidative radial dissolution of Zr-4 based liners (both unloaded and loaded with hydride/deuteride as chemical surrogates for tritium). The electrodissolution is further combined with microscopic techniques to accurately determine the distribution of hydride phases. This work demonstrates a reliable technique for radially etching the liners after irradiation to provide insight into the radial and spatial distribution of tritium within the TPBAR, improving the fundamental understanding of tritium transport and providing a basis for validating predictive models.

Heating glycine (Gly) and methyl glycinate (GlyOCH3) supported on 5% Pd/C or 5% Pt/C in a deuterium or tritium gas atmosphere gave the isotope-labeled products. The experiments were carried out at 180°C for 10 min. The deuterium atom inclusion under these conditions averaged up to 1.8 atoms per molecule for Gly and up to 1.0 atom per molecule for GlyOCH3. The reaction with tritium gas gave labeled products with a specific radioactivity of 27–31 Ci/mmol for Gly and 18 Ci/mmol for GlyOCH3.

To develop a convenient tool for in-line tritium gas monitoring, the TRitium Activity Chamber Experiment (TRACE) was built and commissioned at the Tritium Laboratory Karlsruhe (TLK). The detection system is based on beta-induced X-ray spectrometry (BIXS), which observes the bremsstrahlung X-rays generated by tritium decay electrons in a gold layer. The setup features a measuring chamber with a gold-coated beryllium window and a silicon drift detector. Such a detection system can be used for accountancy and process control in tritium processing facilities like the Karlsruhe Tritium Neutrino Experiment (KATRIN). First characterization measurements with tritium were performed. The system demonstrates a linear response between tritium partial pressure and the integral count rate in a pressure range of 1 Pa up to 60 Pa. Within 100 s measurement time the lower detection limit for tritium is (143.63 ± 5.06) · 104 Bq. The system stability of TRACE is limited by a linear decrease of integral count rate of 0.041 %/h. This decrease is most probably due to exchange interactions between tritium and the stainless steel walls. By reducing the interaction surface with stainless steel, the decrease of the integral count rate was reduced to 0.008 %/h. Based on the first results shown in this paper it can be concluded that TRACE is a promising complement to existing tritium monitoring tools.

The Ka rlsruhe Tri tium N eutrino (KATRIN) experiment will investigate the tritium β-decay close to the energetic endpoint with unprecedented precision, to determine the effective mass of the electron antineutrino. Therefore it has stringent requirements on the stability of the tritium source. The tritium loop system has the task to provide the stabilized flow rate of tritium gas into the KATRIN tritium source with a throughput of 40 g/day and a tritium purity >95%. In this paper the physical setup of the injection system will be described, followed by the description of inactive commissioning measurements. Their analysis shows that the stringent requirements will be perfectly met by the newly designed injection system.

The precise compositional analysis of tritium-containing gases is of high interest for tritium accountancy, e.g. in future fusion power plants. Raman spectroscopy provides a fast and contact-free g...

The Active Gas Handling System (AGHS) at JET is a unique facility enabling JET to perform reactor like, DT operations. As a future DT experimental campaign (DTE2) is scheduled for 2017 this paper provides a brief overview of the AGHS and a summary of ongoing work supporting the currently JET experimental campaign. In order to improve tritium accountancy a solid state based detector for tritium is being developed. Another important upgrade concerns tritium injection, 4 existing GIMs (Tritium Gas Introduction Module) will inject a mix of D and T rather than T{sub 2} in the divertor region rather than in the torus mid plane enabling a far better control and variability of the introduction of tritium into the plasma. An overview of the scale of DTE2 is included as well as an example of some of the upgrades currently being undertaken to fully exploit the learning opportunities for ITER and DEMO DTE2 provides. (authors)

Out-of-pile tritium release experiments were performed on Li4SiO4 pebbles produced from lithium hydroxide under various compositions of sweep gas (He, 1.1% H2/He) and environmental moisture conditions. The experimental results indicate that tritium gas can be released directly from “dry” Li4SiO4 under pure He gas. This phenomenon did not happen on “wet” samples, which means that the chemical form of released tritium is sensitive to moisture. Adding H2 to sweep gas may increase the overall desorption rate of tritium gas through H2 isotope exchange reaction, which occurs at a lower temperature than those of directly released tritium gas. Yet, the threshold of the H2 isotope exchange reaction is higher than the desorption reaction of tritiated water. Consequently, the effect of H2 isotope exchange reaction would reduce significantly on water adsorbed Li4SiO4 samples.

Anti-reflection coated windows are part of Raman spectroscopy systems for tritium analytics in the KATRIN experiment and fusion-related applications. Damages of such windows were observed after thr...

To investigate the behavior of hydrogen on a water–metal boundary, a series of experiments have been performed that studied tritium permeation into a pressurized water jacket through pure iron piping, which contained approximately 1 kPa of pure tritium gas at 423 K, while monitoring the chemical forms of tritium. Additionally, the behavior of deuterium, which was generated on the heavy water–metal boundary and transferred to the metal, was also investigated using a pressure-proof heavy water vessel. Actual deuterium transfer through various metal piping, such as Fe, Ni, SS304, etc., was detected clearly by QMS at 423–573 K. Moreover, using the above heavy water system, we have succeeded in detecting hydrogen isotopes simultaneously transferring from and to the metal surface by introducing hydrogen gas to the Ni piping after deuterium permeation from the heavy water side had stabilized.

The Li2TiO3 is one of candidate breeding materials of a water cooled ceramic breeding (WCCB) blanket. In order to clarify the tritium recovery property of the WCCB blanket with the Li2TiO3 breeding material, we have performed the tritium recovery online experiment with the DT neutron source at the Fusion Neutronics Source facility in Japan Atomic Energy Agency (JAEA-FNS). We irradiated an experimental assembly simulating the WCCB blanket and recovered the tritium recovered from the Li2TiO3 pebbles put into the assembly with a heater system, sweep gases and bubblers. The activity of the recovered tritium was measured with a liquid scintillation counter. From our tritium recovery online experiment and calculation, the followings were found out: (1) the recovered tritium corresponded to the calculated tritium production within the experimental error in the range of 573–1073 K and (2) the recovered HTO tended to be easily recovered at lower temperature and high water moisture. The recovered HT increases at higher temperature and dry hydrogen circumstance. However, the maximum level of the tritium gas recovery is around 90% even at higher temperature and 1% H2 circumstance.

The storage and delivery system bed provides rapid and safe functions for storage and delivery of tritium gas in a fusion power plant. In order to investigate the hydrogen isotope effect, we prepared a small-sized (1/10) ZrCo bed. Based on hydrogen-deuterium gas mixtures with various composition 0, 25, 50, 75 and 100 volume %, we observed the hydriding and dehydriding dynamic behaviors. In the case of hydriding performances at room temperature, 100% hydrogen gas provided the fastest delivery rate among the mixtures. In the case of the dehydriding performance at temperatures below 350 °C, however, there was no significant difference among the mixtures. Vacuum driving can provide a stronger effect for this apparatus than various hydrogen compositions.

Titanium films were deposited onto molybdenum substrates and then converted into titanium tritides (TiT1.5–1.8) films inside a tritiding apparatus loaded with pure tritium gas. Evolution of tritium and helium in the titanium tritide films over a period of four years was investigated using a thermal desorption technique, together with X-ray diffraction analysis. Results showed that desorption profiles of the tritium varied significantly with the evolution of He contents. Apart from the primary peak from tritium desorption located at a temperature between 610 and 840 K, another higher temperature tritium desorption peak (at ∼950 K) was observed, attributed to damages in the lattice structures induced by generation of 3He bubbles. Release of helium in the tritide film became significant after a long term aging process (i.e., after a few years). Depending on the amount of the 3He bubbles generated due to the decay of tritium, spectra of the thermal helium desorption showed five peaks in the range from room temperature to ∼1750 K, corresponding to different states of helium evolution during aging of the titanium tritide films. The amounts of helium desorption in different stages were estimated, and the dissociation energy of helium from different trap states as a function of the aging duration was obtained.

Tritiated compounds are invaluable tools for in vitro and in vivo studies on bioactive molecules. Here we describe a ‘click-chemistry’-based strategy for deuteration and tritiation of multifunctional compounds and multimodal molecular imaging probes. The method relies on a palladium-mediated reductive deiodination of 5-iodo-1,2,3-triazoles in the presence of NaBD4, deuterium or tritium gas.

Handling of radioisotopes often accompanies their transfer to handling equipment/tools and its environment, referred as contamination . If the transferred radioactivity is higher than regulation level, its removal or decontamination is required. Except very high energy radiation and neutron from radioisotopes, exposure to the radiation generally does not transfer the radioactivity , in other words, no activation of the handling tools and the environments occurs. Since tritium (T), a radioisotope of hydrogen, is chemically active, T handling always resulting in T contamination of handling tools and environments. Hence, direct T handling of workers is prohibited and handling tools are always required. This chapter focuses to contamination and decontamination of T for solid materials. T contamination of workers which is mostly caused by internal exposure through inhalation and/or skin absorption of tritiated water or vapor is described in Chap. 15 based on the details of safety regulation of T given in Chap. 14.

N-Acyl-L-homoserine lactones (AHLs) are signalling molecules found in Gram-negative bacteria that enable bacteria to communicate with each other through quorum sensing and with their eukaryotic host cells through inter-kingdom signalling. Very little is known about inter-kingdom signalling mechanisms. Deuterium- and tritium-labelled AHLs were synthesized in an effort to detect the cellular distribution and monitor the membrane transport of AHLs. Most tritium labelling methods use tritium gas, which is difficult to handle, however, here we present a novel, gas-free method with which to obtain deuterium- and tritium-label terminally unsaturated AHLs through catalytic reduction of the double bond. This uncommon double bond reduction employs either sodium borohydride-[2H] or sodium borohydride-[3H] and is performed in the presence of palladium(II) acetate, which acts as a catalyst in the unique layer-by-layer system. Moreover, detailed NMR analysis of the resulting isotopologues is presented.

The syntheses of [(3) H]SCH 444877, [(2) H4 ]SCH 444877, and [(14) C]SCH 444877 are described. [(3) H]SCH 444877 was prepared in three steps from tritium gas. [(2) H4 ]SCH 444877 was synthesized from [(2) H4 ]ethanolamine in four steps with an overall yield of 40%. [(14) C]SCH 444877 was prepared from barium [(14) C]cyanamide in 10 steps with an overall yield of 8.1%.

The Karlsruhe Tritium Neutrino (KATRIN) experiment aims to measure the neutrino mass via high-precision electron spectroscopy of the tritium β -decay with a sensitivity of m ν = 200 meV/c 2 (90% C.L.). This can only be achieved if systematic uncertainties are minimized. An important parameter is the isotopic composition of the tritium gas used as the gaseous β -electron source, which is measured inline by Raman spectroscopy. The KATRIN experiment requires a measurement trueness of better than 10% of said composition; to achieve this, accurate calibration of the Raman system for all hydrogen isotopologues (H 2 , HD, D 2 , HT, DT, T 2 ) is required. Here we present two independent calibration methods, namely (i) a gas sampling technique, which promises high accuracy, but which is difficult to apply to tritiated species; and (ii) an approach via theoretical Raman signals (theoretical intensities plus spectral sensitivity), which in principle includes all six isotopologues. For the latter method we incorporated ab initio off-diagonal matrix elements of the polarizability from the literature; these have been verified by depolarization measurements. The system’s spectral sensitivity was determined by a NIST-traceable SRM2242 luminescence standard. Both methods exhibited their individual merits and difficulties, but in cross calibration proved to be successful: a comparison for the non-radioactive isotopologues (H 2 , HD, D 2 ) yielded agreement to better than 2% for the relative Raman response function. This is within the estimated (dominant) uncertainty of the theoretical Raman signal approach of about 3%. Therefore, one can be confident that, when using this approach, the trueness requirement of 10% for the KATRIN-relevant species (T 2 , DT, D 2 and HT) will in all likelihood be exceeded.

Knowledge brought by survey data review from CEA Valduc about transfers in the different environmental compartments. The objective of this document is to describe the behavior of tritium in the environmentfromthesitesurvey dataofaFrench researchcenter.Sincethelate60s, the nuclear site of Valduc has discharged tritium gas and tritiated water into the atmosphere. Those discharges have led to a transfer to the nearby groundwater and rivers. An assessment of the tritium migrating through the hydrogeological system during the 1969-2009 period is presented. Surface survey data also provide a lot of information about transfers by the air pathway to the different compartments: air, rain, soil, plants and animals. The ratios between the different compartment concentrations show that air-leaf transfer is significant, that rain and air deposition are of the same order of magnitude, and that a relatively good equilibrium exists between the free and organic material water of plants. Some outdoor experiments confirm, in agreement with the literature, the level of incorporation in organic materials. Outside the center, water always remained below the present WHO limit

The observed phenomena of changes of chemical compositions in previous reports [1, 2] allowed us to develop a phenomenological nuclear fusion-fission model with taking into consideration the elastic and inelastic scattering of photoprotons and photoneutrons, heating of surrounding deuterium nuclei, following d-d fusion reactions and fission of middle-mass nuclei by “hot” protons, deuterons and various-energy neutrons. Such chain processes could produce the necessary number of neutrons, “hot” deuterons for explanation of observed experimental results [1, 2]. The developed approach can be a basis for creation of deuterated nuclear fission reactors (DNFR) with high-density deuterium gas and the so-called deuterated metals. Also, this approach can be used for the study of nuclear reactions in high-density deuterium or tritium gas and deuterated metals.

Tritium exposure experiments were carried out for three kinds of EAST SiC coated doped-graphite (SiC/C) samples, one from the original graphite tiles without being irradiated, and the other two from erosion and deposition areas of first wall after the 2009 campaign in EAST. β-ray-induced X-ray spectrometry (BIXS) was used to characterize the exposed samples. It is showed that the significant amount of tritium was absorbed in the surface of deposition sample in comparison with that of original sample, which was also supported by the results of imaging plate (IP) measurements. In addition, it was found that drastic decrease in tritium retention appeared by lowering exposure temperature, and the trapped tritium was maintained stably with time. Computer simulation is used to analyze the details of depth profile of tritium in different kinds of samples.

Co-deposited carbon film with different deuterium concentration, D/C, were exposed to tritium gas at the temperature of 423 K, and then the atomic ratio of absorbed tritium to carbon, T/C, was evaluated. The obtained data were discussed with crystal structure of the carbon film. The T/C increased with decreasing D/C of carbon film. The carbon film with low D/C had more defective structure. The reduction of D/C by the heating before tritium exposure led to the increase of absorption amount. These results suggest that carbon film with more defective structure and low D/C film could absorb large amount of tritium. The hydrogen isotope concentration in the present experiment was saturated below the orders of 10 −4 , which was 3–4 orders of magnitude smaller than that of co-deposited carbon film with hydrogen isotope.