Helium Storage Research Articles

Natural reservoir as a geological body for storing helium reserves

In connection with the start of field operation of large oil-and-gas bearing deposits of helium in the south of the Siberian platform (SP) the problem of long-term helium storage arises. Some researchers propose to use reliable underground storages for this purpose. Natural reservoirs, geological bodies representing an association of rocks in which fluids can be contained and circulated, can serve as such a natural depository for the injection and preservation of helium reserves. Therefore, the permeability of caprocks in natural reservoir that can hold helium for a long time is of particular importance. The paper presents the results of lithologic composition, thickness and condition of the caprock formation as the regional impervious fluids in natural reservoir of the SP south. The Lower Cambrian deposits of the Usolie formation being a part of the Vendian-Cambrian oil and gas complex can serve as such a regional impervious fluid.

Природный резервуар как геологическое тело для хранения запасов гелия

With the start of the large helium-rich petroleum deposits exploitation in the Siberian platform south, a problem of long-term helium storage arises. Some researchers propose to use reliable underground storage facilities for this purpose. Geological bodies such as rock associations can be used as natural reservoirs for injecting and storing the helium reserves. The saliferous sediments within the natural reservoirs are of particular importance due to their capacity to keep helium for a long time. To determine the paleofacial conditions for the accumulation of the saliferous impermeable layers, the archive and published data on drilling and geophysical studies of the Eastern Siberia fields have been used. The article presents the research results on the cap rocks’ lithological composition and thickness, as well as on the conditions of their formation as areal impermeable beds within the natural reservoirs of the Siberian platform south. The Lower Cambrian deposits of the Usolie suite, a part of the Vendian-Cambrian oil-and-gas complex, can be considered as an areal impermeable bed of this kind.

Study on collapse controlling of single-wall carbon nanotubes by helium storage

In this paper, we propose a method to control the collapsed nanostructurings of single-walled carbon nanotubes (SWCNTs) by helium storage and the key mechanism is elaborated from the potential energy aspect. The molecular dynamics simulation shows that enough helium atoms could restore the collapsing configuration of (40, 40) carbon nanotubes back to the circular cross section. The length of the flat double carbon atoms layer in the dumbbell type structure and the diameter of nearly circular edges can be precisely altered by adjusting the helium atom numbers. Two key storage rates are introduced to classify the final nanostructures of (5n, 5n) SWCNTs. The relationship between helium numbers and the final configuration is investigated; the analysis method that introduces helium atoms into the cavity of SWCNTs can also be extended to other kinds of molecules.

A liquid helium temperature target with two-stage internally finned cold shield heat exchanger for cylinder compression experiment

The shock compression experiment of specimen at high-energy density state is an important way to get the state equation. The cryogenic technology is commonly used to get the high-energy density state which known as cryogenic target. This paper introduces a new kind of liquid helium cryogenic target for cylinder compression experiment. With two-stage internally finned heat exchanger cold shield and fold cold shield insulation structure, this target realizes the efficient storage of liquid helium and successfully developed the first domestic application in the liquid helium cryogenic target of cylinder compression experiment. The cavity can maintain the minimum temperature 4.77 K and keep stability for 32 min after move away the pump and helium Dewar which meet the requirement of cylinder loading experiment. This paper introduces the structure design of cryogenic target, thermal analysis with ANSYS Steady-Static Thermal module and experimental results of the target. The simulation results agree well with the experimental results.

Helium incorporation and diffusion in polycrystalline olivine

Helium is a key tracer of mantle geochemical and isotopic heterogeneities and can constrain our understanding of mantle geodynamics. Nevertheless, the mechanisms of helium storage and transport in mantle minerals remain poorly understood. Polycrystalline olivine was doped with helium at high temperature (1050 ± 25 °C) and high pressure (0.30 ± 0.01 GPa), followed by step heating extraction experiments to investigate helium storage and diffusion in Earth's upper mantle. We also tested the effect of heterogeneous initial concentrations on the extracted diffusivities, and demonstrate the robustness of diffusion parameters obtained in this study. Our results show that two diffusion processes are acting in polycrystalline olivine: (i) a high temperature process with high activation energy (Ea) where diffusion is only controlled by lattice diffusion, and (ii) a lower temperature process with lower Ea where diffusion is controlled by both grain boundary and lattice diffusion. These two diffusion processes are separated by a transition temperature that depends on the depletion of helium hosted in grain boundaries, i.e., the amount of helium stored at grain boundaries and the temperature and duration of the step heating sequence. Our results confirm that grain boundaries can represent a significant storage site for He. Moreover, we report two different populations of diffusion parameters in the lattice diffusion field, which are interpreted as diffusion in interstitials (Ea = 95 ± 15 kJ·mol−1 and log(D0) = −8.26 ± 2.13) and Mg vacancies (Ea = 168 ± 19 kJ·mol−1 and log(D0) = −3.59 ± 2.12). Similar diffusion parameters populations are observed in literature data after reprocessing the diffusivities. Furthermore, we determine grain boundary diffusion parameters: Ea = 57 ± 14 kJ·mol−1 and log(D0) = −9.20 ± 0.99. Applying these results to the upper mantle reveals that an important amount of He can be stored at grain boundaries for typical mantle grain size (22% for a grain size of 1 mm) and that most helium can be stored at grain boundaries for relatively small grain sizes (≤290 μm and ≤10 μm for segregation factors of 1/10−5 and 1/0.0025, respectively). As a consequence, bulk diffusivities can be significantly higher than lattice diffusivities. Although our study cannot be applied directly to the lower mantle, the similar storage sites and diffusion mechanisms are expected in lower mantle silicates if high pressure does not inhibit diffusion.

Design, Fabrication, Installation and Commissioning of the Helium Refrigeration system Supporting Superconducting Radio Frequency Testing at Facility for Rare Isotope Beams at Michigan State University

The Facility for Rare Isotope Beams (FRIB) will be a scientific user facility for the Office of Nuclear Physics in the U.S. Department of Energy Office of Science (DOE-SC). The FRIB linear accelerator (LINAC) will be comprised of cryomodules each with multiple Superconducting Radio Frequency (SRF) cavities operating at 2 K. A helium refrigeration system was designed, fabricated, installed and commissioned in the SRF high bay building to test and certify these cavities and cryomodules before installation in the FRIB LINAC tunnel. The helium refrigeration system includes a helium refrigerator which has nominal capacity of 900 W at 4 K, 5000 L liquid helium storage Dewar, helium gas storage, two room temperature vacuum pumps capable of 2.5 g/s each for 2 K testing, purifier, purifier recovery compressor, and the distribution system for liquid nitrogen and helium. The helium refrigeration system is now operational supporting three below grade cavity testing Dewars and one cryomodule testing bunker meeting the required throughput of 1 cavity per day.

Manufacturing and installation of the JT-60SA helium storage vessels for the cryogenic plant

The JT-60SA Tokamak is provided with a cryogenic system with a refrigeration capacity of 9kW (eqv.) at 4.5K. Before commissioning and during occasional warm-up periods the total 3.6t helium inventory (at ∼1.5Mpa(g)) is stored in six pressure vessels. Each vessel is 22m long, has a diameter of 4m, 250m3 volume, and weighs about 73t. As the vessels will store pure helium, the tightness and cleanliness requirements were quite demanding. One of the vessels is also used to receive the cold helium (20K) from the cryogenic system quench line, following a fast discharge of the superconducting coils. A special 18m long helium diffuser system and a thermal barrier connector at the quench line flange have been designed and manufactured to avoid local chilling of the vessel wall below the minimum allowed temperature of the material.

XFEL AMTF operation completed: results and lessons learned

In order to produce short pulsed electron beam of 17.5 GeV energy, the XFEL linear accelerator is being built at DESY in Hamburg. Before being installed in the accelerator tunnel, 103 accelerator modules have to be tested in Accelerator Module Test Facility (AMTF). Cavities and cryomodules are tested at two vertical cryostats and three horizontal test benches. Two valve boxes and a liquid helium (LHe) storage tank are installed to enable cryogenic operation of AMTF. This paper describes our experience of three years cryogenic operation of AMTF. All 800 cavities and almost all cryomodules have been tested. The test results and lessons learned are also summarized

Technology demonstration for reusable launchers

Reusable launchers have been studied under CNES contracts for more than 30 years, with early concepts such as STS-2000 or Oriflamme, more recently with very significant efforts devoted to Liquid Fly Back Boosters as with the Bargouzin project led with Tsniimash, TSTO with the Everest concept studied by Airbus-DS as prime contractor or the RFS Reusable First Stage concept of a large first stage associated to a cryotechnic second stage. These investigations, summarized in the first part of the paper, enabled CNES to identify clearly the technology requirements associated to reusability, as well as cost efficiency through detailed non-recurring costs and mission costs analysis. In parallel, CNES set in place development logic for sub-systems and equipment based on demonstrators, hardware test benches enabling maturation of technologies up to a TRL such that an actual development can be decided with limited risk. This philosophy has been applied so far to a large number of cases, such as TPTech and TPX for Hydrogen turbo pump, GGPX as demonstrator of innovative gas generator, HX demonstrator of modern cryotechnic upper stage with a dozen of different objectives (Thermal Protection, 20K Helium storage, measurements …). This virtuous approach, “learn as you test”, is currently applied in the phased approach towards scaled down reusable booster stage, whose possibility to be used as first stage of a microlaunch vehicle is under investigation. The selected technologies allow paving the way towards reusable booster stages for Ariane 6 evolutions or main reusable stage for a further generation of heavy launchers. The paper describes the logic behind this project, together with the demonstration objectives set for the various sub-systems as well as operations.

ESS Cryogenic System Process Design

The European Spallation Source (ESS) is a neutron-scattering facility funded and supported in collaboration with 17 European countries in Lund, Sweden. Cryogenic cooling at ESS is vital particularly for the linear accelerator, the hydrogen target moderators, a test stand for cryomodules, the neutron instruments and their sample environments. The paper will focus on specific process design criteria, design decisions and their motivations for the helium cryoplants and auxiliary equipment. Key issues for all plants and their process concepts are energy efficiency, reliability, smooth turn-down behaviour and flexibility. The accelerator cryoplant (ACCP) and the target moderator cryoplant (TMCP) in particular need to be prepared for a range of refrigeration capacities due to the intrinsic uncertainties regarding heat load definitions. Furthermore the paper addresses questions regarding process arrangement, 2 K cooling methodology, LN2 precooling, helium storage, helium purification and heat recovery.

Experience with cryogenic operation of Accelerator Module Test Facility during testing of one third of XFEL cryomodules

In order to produce pulsed electron beam with the energy of 17.5 GeV, the XFEL linear accelerator is under construction. After the assembly but before being installed in the accelerator tunnel, 100 accelerator modules have to be tested in Accelerator Module Test Facility (AMTF). Two vertical cryostats and three horizontal test benches are devoted to the testing of cavities and cryomodules as well as two other cold boxes and liquid helium (LHe) storage tank are installed to enable their operation. This paper describes our experience with cryogenic operation of AMTF after two years of operation.

PERFORMANCE ANALYSIS OF HELIUM INVENTORY CONTROL OF RGTT200K COOLING SYSTEM

RGTT200K is a power reactor, designed based on HTGR tech-nology having capability to operate at high temperatures. RGTT200K features are 200 MWth power, helium-cooled, graphite moderator and reflector, pebble fuel type, and uses the Brayton direct cycle. Helium Inventory Control System (HICS) is one of its safety system which maintains the pressure, the helium coolant quality and quantity to meet safety requirements. The HICS consists of 3 subsys-tems, namely: Inventory Control System (ICS), Helium Purification System (HPS), and Helium Make-Up System (HMS). All of the systems have the function to maintain pressure, helium quality and quantity so that the reactor can operate reliable and safely. This paper discusses the performance of the ICS, which is integrated to the reactor coolant. The research objective was to determine the helium storage tank response rate, when primary coolant is overpressured and depressurized. The methodology used in this research is modeling and simulation by using ChemCAD. In previous re-search, the HPS, ICS and HMS have been modeled but have not been integrated yet in to the primary coolant. The simulation results showed that the time required for the injection tank back to the cool-ant normal pressure of 52 bars, due to depressurization up to 5 % was 160 seconds. While the time required for bleeding / blowdown to the storage tanks due to overpressurization up to 5 % was 186 seconds.

Modelling and Experimental Verification of Pressure Wave Following Gaseous Helium Storage Tank Rupture

Helium inventory in high energy accelerators, tokamaks and free electron lasers may exceed tens of tons. The gaseous helium is stored in steel tanks under a pressure of about 20bar and at environment temperature. Accidental rupture of any of the tanks filled with the gaseous helium will create a rapid energy release in form of physical blast. An estimation of pressure wave distribution following the tank rupture and potential consequences to the adjacent research infrastructure and buildings is a very important task, critical in the safety aspect of the whole cryogenic system. According to the present regulations the TNT equivalent approach is to be applied to evaluate the pressure wave following a potential gas storage tank rupture. A special test stand was designed and built in order to verify experimentally the blast effects in controlled conditions. In order to obtain such a shock wave a pressurized plastic tank was used. The tank was ruptured and the resulting pressure wave was recorded using a spatially-distributed array of pressure sensors connected to a high-speed data acquisition device. The results of the experiments and the comparison with theoretical values obtained from thermodynamic model of the blast are presented. A good agreement between the simulated and measured data was obtained. Recommendations regarding the applicability of thermodynamic model of physical blast versus TNT approach, to estimate consequences of gas storage tank rupture are formulated. The laboratory scale experimental results have been scaled to ITER pressurized helium storage tanks.

Design of radiation resistant metallic multilayers for advanced nuclear systems

Helium implantation from transmutation reactions is a major cause of embrittlement and dimensional instability of structural components in nuclear energy systems. Development of novel materials with improved radiation resistance, which is of the utmost importance for progress in nuclear energy, requires guidelines to arrive at favorable parameters more efficiently. Here, we present a methodology that can be used for the design of radiation tolerant materials. We used synchrotron X-ray reflectivity to nondestructively study radiation effects at buried interfaces and measure swelling induced by He implantation in Cu/Nb multilayers. The results, supported by transmission electron microscopy, show a direct correlation between reduced swelling in nanoscale multilayers and increased interface area per unit volume, consistent with helium storage in Cu/Nb interfaces in forms that minimize dimensional changes. In addition, for Cu/Nb layers, a linear relationship is demonstrated between the measured depth-dependent swelling and implanted He density from simulations, making the reflectivity technique a powerful tool for heuristic material design.

Stable Storage of Helium in Nanoscale Platelets at Semicoherent Interfaces

He implanted into metals precipitates into nanoscale bubbles that may later grow into voids, degrading the properties of engineering alloys. Using multiscale modeling, we show that a different class of He precipitates may form at semicoherent interfaces: nanoscale platelets. These platelets grow by wetting high-energy interface regions, remain stable under irradiation, and reduce He-induced swelling. Stable storage of He at interfaces may impart unprecedented He resistance to future structural materials.

Mitigation of Effects of Pulsed Heat Loads in Helium Refrigerators for Fusion Devices Using Supercritical Helium Storage

Supercritical fluid is increasingly getting attention for storing mass and energy in energy systems. In a fusion device such as a tokamak, which is one of the futuristic energy generation systems, the heat loads generated from superconducting magnets and nuclear heating are pulsating in nature. Large-scale helium refrigerators are employed for cooling of these magnets. The immediate effect of pulsed load in such refrigerators is the fluctuation of the return stream mass flow rate, which needs to be mitigated to an acceptable level, to avoid instability in plant operation and to reduce loss of refrigeration. In this paper, a novel technique to mitigate flow fluctuation is suggested, where a part of high-pressure helium at supercritical state from the inlet of a Joule-Thomson valve of a modified Claude-cycle-based refrigerator is stored in a storage vessel during high heat load condition and released during low load condition. Through thermodynamic analysis, the advantages and concept of supercritical storage for mitigation of mass fluctuation have been discussed. Verification of the concept through dynamic simulation in Aspen HYSYS has revealed that mitigations of about 78% and 74% of fluctuations in return stream during high and low heat load conditions, respectively, could be achieved by utilizing the scheme. Advantages and feasibility of this scheme vis-a-vis helium inventory, buffer size, and control for its implementation are discussed.

Helium distribution in a mantle shear zone from the Josephine Peridotite

A previous study of oceanic mylonites suggested that peridotite helium concentrations are correlated with the degree of high-temperature ductile deformation in the mantle. In order to test this result, this study combines helium measurements with characterization of the deformation state of harzburgite samples in a small (6m width) ductile mantle shear zone from the Josephine Peridotite, Oregon, USA. All measurements were made by coupled in vacuo crushing and melting, demonstrating that most of the helium (>80%) resides within the solid phases rather than fluid or melt inclusions. The present study confirms the influence of deformation on helium contents, but only at the highest shear strain (γ>20) are helium contents significantly higher. The highest helium concentration, by roughly a factor of two, is found in the center-most sample, which also has grain size reduction by a factor of ∼4. Dislocations and sub-grain boundaries are present in all samples and do not correlate with helium concentrations. Mineralogy also appears to have a negligible influence in this shear zone, as modal mineralogy is relatively homogeneous, with all samples being harzburgites. These observations suggest that the increase in helium concentration is related to grain size reduction, with grain boundaries proposed as an additional storage site for helium in the mantle.The present data also characterize the isotopic composition of the Josephine Peridotite: 3He/4He=6.7±0.2Ra (n=33, between 6.3 and 7.1Ra). The presence of cosmogenic 3He in the matrix is indicated by the helium isotopic composition released by melting: 3He/4He=8.5±0.3Ra (n=10; from 7.9 to 10.9). This corresponds to an exposure age of 10Kyr, which is approximately concordant with the end of the last glacial maximum. Very little radiogenic helium is present in the samples, suggesting extremely low uranium and thorium contents ([U]<0.3ppb). Helium isotope measurements in four samples outside the shear zone suggest that mineralogy and melt infiltration are also important factors for understanding helium storage in the mantle.

A first-principles study of helium storage in oxides and at oxide–iron interfaces

Density-functional theory calculations based on conventional as well as hybrid exchange-correlation functionals have been carried out to study the properties of helium in various oxides (Al2O3, TiO2, Y2O3, YAP, YAG, YAM, MgO, CaO, BaO, SrO) as well as at oxide-iron interfaces. Helium interstitials in bulk oxides are shown to be energetically more favorable than substitutional helium, yet helium binds to existing vacancies. The solubility of He in oxides is systematically higher than in iron and scales with the free volume at the interstitial site nearly independently of the chemical composition of the oxide. In most oxides, He migration is significantly slower and He–He binding is much weaker than in iron. To quantify the solubility of helium at oxide-iron interfaces two prototypical systems are considered (Fe—MgO, Fe—FeO—MgO). In both cases, the He solubility is markedly enhanced in the interface compared to either of the bulk phases. The results of the calculations allow to construct a schematic energy landscape for He interstitials in iron. The implications of these results are discussed in the context of helium sequestration in oxide dispersion strengthened steels, including the effects of interfaces and lattice strain.

Development of Superconducting Level Sensor for Liquid Helium Level Measurements

Liquid helium storage and transport Dewars of different types and different storage capacities are used in laboratories for experimental measurements at low temperatures. Liquid helium is used as a cryogen for cooling the sample to a temperature of 4.2 Kelvin. To measure the level of the liquid helium in the experimental cryostat or Dewar, imported superconducting level sensors are presently being used but are relatively expensive. In view of this, experimental work related to design and development of the superconducting level sensor based on NbTi superconducting wire was undertaken. This work includes the fabrication, characterization and calibration of the superconducting level sensor. The characterization work involves the measurement of the resistance of the level sensor at different levels of liquid helium in the Dewar for different values of excitation current to determine the optimum excitation current with a view to establish a single valued relationship between the measured resistance and the liquid helium level. A program has been written by using LABVIEW software to automate the characterization process. Based on the measurements, display system is being developed to display the level of liquid helium in the Dewar.

An automated cryogenic current comparator resistance ratio bridge for routine resistance measurements

A design of an automated cryogenic current comparator (CCC) resistance ratio bridge for routine measurements in a national metrology institute or standards laboratory is described. It employs a type II CCC for use in a low loss liquid helium storage vessel and can be continuously operated from the mains power via specialized isolated supplies. All parameters including the servo control loops are digitally controlled. Noise sources in the system are analysed using the Allan deviation and it is demonstrated that non-white noise sources can be eliminated by choosing an appropriate current reversal rate.