Analysis Of Hydrogen Distribution Research Articles

Analysis of Hydrogen Distribution and Diffusion in Pre-Strained SUS316L through Scanning Kelvin Probe Force Microscopy and Thermal Desorption Spectroscopy

Austenitic stainless steels (γ-SS) play an important role in the storage of high-pressure hydrogen. However, hydrogen embrittlement (HE) can significantly degrade the mechanical properties of γ-SS. Measuring the distribution of hydrogen in γ-SS is a vital way to learn about HE. In this paper, scanning Kelvin probe force microscopy (SKPFM) and thermal desorption spectroscopy (TDS) have been utilized to analyze the distribution and diffusion of hydrogen in pre-strained SUS316L. Additionally, the McNabb–Foster model is employed to calculate hydrogen in the lattice and phase boundaries along the sample’s thickness direction. The results demonstrate that the combination of SKPFM and TDS is an effective approach for studying hydrogen distribution and diffusion in metals. It was observed that hydrogen segregation occurs at the boundary between the martensitic (α′) and austenite (γ) phases. The inhibitory effect of the oxide film on hydrogen diffusion is more significant at lower temperatures. However, it should be noted that the McNabb–Foster model exhibits relatively high accuracy in predicting hydrogen desorption at higher temperatures while disregarding the influence of the native oxide film.

3D Analysis of Hydrogen Distribution and Its Mitigation Using Passive Autocatalytic Recombiners (PARs) Inside VVER-1000 Containment

Hydrogen is a flammable gas that can generate thermal and mechanical loads which could jeopardise the containment integrity upon combustion inside nuclear power plants containment. Hydrogen can be generated from various sources and disperses into the containment atmosphere, mixing with steam and air following a loss of coolant accident and its progression. Therefore, the volumetric hydrogen concentration should be examined within the containment to determine whether a flammable mixture is formed or not. Codes with 3D capabilities could serve this examination by providing detailed contours/maps of the hydrogen distribution inside containment in view of the local stratification phenomenon. In this study, a 3D VVER-1000 as-built containment model was sketched in AutoCAD and then processed into GOTHIC nuclear containment analysis code for hydrogen evaluation. The model was modified to a great extent by installing 80 passive autocatalytic recombiners and locating hydrogen sources to evaluate the performance of the hydrogen removal system inside the containment on maintaining the hydrogen concentration below the flammability limit during a large break loss of coolant accident. 2D profiles and 3D contours of volumetric hydrogen concentration with and without PARs are presented as the simulation outcome of this study. The results were validated against the results of the Final Safety Analysis Report, which also demonstrates the effectiveness of the hydrogen removal system as an engineered safety feature to keep the containment within a safe margin. Detailed 3D contours of hydrogen distribution inside containment can be employed to evaluate the local hot spots of hydrogen, rearranging and optimising the number and location of PARs to avoid the hydrogen explosion inside containment.

Atom probe tomography analysis of hydrogen distribution in laser peened Ti6Al4V alloy to control hydrogen embrittlement

Hydrogen embrittlement of Ti6Al4V alloy was investigated under electrochemical cathodic hydrogen charging. Advanced surface treatment and material characterisation, laser shock peening (LSP) or laser peening (LP), atom probe tomography, slow strain rate tensile (SSRT) test, and XRD residual stress are employed for analysis. Results obtained exposed the opportunity to implement surface treatment for controlling hydrogen embrittlement. Induced grain refinement and compressive residual stress restrict the hydrogen uptake in Ti6Al4Valloy. Furthermore, APT results gave wt. % of TiH (titanium hydride) in laser peened hydrogen charged and untreated hydrogen-charged specimens. Thus, it is concluded that compressive stress induced by laser peening process controlled uptake of hydrogen by Ti6Al4V alloy.

Three-dimensional hydrogen distribution and quantitative determination of titanium alloys via neutron tomography.

Thermohydrogen processing (THP) is an attractive technique that uses hydrogen as a temporary alloying element to modify the microstructure and properties of titanium alloys. However, the hydrogen diffusion behavior during THP is not fully understood owing to limited scope of methods to detect hydrogen distributions. Herein, we introduce neutron tomography as an efficient tool for three-dimensional (3D) hydrogen distribution analysis and quantitative determination in hydrogenated titanium alloys after THP. Thus motivated, a series of calibration samples of Ti-6Al-4V alloys with varying hydrogen contents were prepared and elaborated neutron tomography experiments and image data processing were performed. In this way, the 3D hydrogen distribution of the hydrogenated samples was obtained and the quantitative relationship between the hydrogen contents and the tomographic images was determined. To the best of our knowledge, this enabled for the first time the direct 3D visualization and characterization of the hydrogen distribution and concentration in titanium alloys after THP. It was deduced that hydrogen diffused from the surface to the interior of the hydrogenated sample in all directions during THP. In addition, the feasibility of neutron tomography for 3D quantitative hydrogen distribution was validated using continuous sample segmentation and the traditional heat conductivity method. Consequently, neutron tomography can be efficient for determining the hydrogen distribution and concentration in bulk metals and shed light on the hydrogen diffusion behavior and the mechanism of hydrogen-related materials and processing.

Analysis of hydrogen distribution and migration in fired passivating contacts (FPC)

High temperature passivating contacts for c-Si based solar cells are intensively studied because of their potential in boosting solar cell efficiency while being compatible with industrial processes at high temperatures. In this work, the hydrogenation mechanism of fired passivating contacts (FPC) based on c-Si/SiOx/nc-SiCx(p) stacks was investigated. More specifically, the correlation between passivation and local re-distribution of hydrogen resulting from the application of different types of interfacial oxides (SiOx) and post-hydrogenation processes was analyzed. To do so, the applied processing sequence was interrupted at different stages in order to characterize the samples. To assess the hydrogen content, deuterium was introduced (alongside/instead of hydrogen) and secondary ion mass spectroscopy (SIMS) was used for depth profiling. Combining these results with lifetime measurements, the key role played by hydrogen in the passivation of defects at the c-Si/SiOx interface is discussed. The SIMS profiles show that hydrogen almost completely effuses out of the SiCx(p) during firing, but can be re-introduced by hydrogenation via forming gas anneal (FGA) or by release from a hydrogen containing layer such as SiNx:H. A pile-up of H at the c-Si/SiOx interface was observed and identified as a key element in the FPC's passivation mechanism. Moreover, the samples hydrogenated with SiNx:H exhibited higher H content compared to those treated by FGA, resulting in higher iVOC values. Further investigations revealed that the doping of the SiCx layer does not affect the amount of interfacial defects passivated by the hydrogenation process presented in this work. Eventually, an effect of the oxide's nature on passivation quality is evidenced. iVOC values of up to 706 mV and 720 mV were reached with FPC test structures using chemical and UV-O3 tunneling oxides, respectively, and up to 739 mV using a reference passivation sample featuring a ~25 nm thick thermal oxide.

Measurement and Analysis of Hydrogen Distribution in Stress Environment Using Vickers Microhardness Technique

In this paper, the stress distribution field in front of the crack tip was obtained by loading a modified WOL specimen using a bolt. Considering the relationship between microhardness and hydrogen content or internal stress in the metal, a model based on the change of microhardness increment is proposed to describe the trend of hydrogen concentration distribution in the stress environment. The agreement between theoretical model and experimental results is verified by the Vickers microhardness tester. Based on the model, there is a simple additive relationship between the hydrogen‐induced microhardness increment and the stress‐induced microhardness increment. Therefore, the microhardness tester can be employed to evaluate the hydrogen distribution in metals quantitatively. The experimental results demonstrated that the Vickers microhardness method has accurately revealed the hydrogen concentration behavior accurately in a known equibiaxial stress environment. The hydrogen distribution of specimens in the stress environment was analyzed by taking the change of the microhardness increment along the crack propagation direction of specimens as the indicator.

GASFLOW-MPI: A new 3-D parallel all-speed CFD code for turbulent dispersion and combustion simulations: Part I: Models, verification and validation

The objective of the presented work is to develop an efficient and validated approach based on a multi-dimensional computational fluid dynamics (CFD) code for predicting turbulent gaseous dispersion, conjugated heat and mass transfer, multi-phase flow, and combustion of hydrogen mixtures. Applications of interest are accident scenarios relevant to nuclear power plant safety, renewable energy systems involved in hydrogen transport, hydrogen storage, facilities operating with hydrogen, as well as conventional large scale energy systems involving combustible gases. All model development is conducted within the framework of the high-performance scientific computing software GASFLOW-Multi-Physics-Integration (MPI). GASFLOW-MPI is the advanced parallel version of the GASFLOW sequential code with many newly developed and validated models and features. The code provides reliability, robustness and excellent parallel scalability in predicting all-speed flow-fields associated with hydrogen safety, including distribution, turbulent combustion and detonation. In the meanwhile, it has been well verified and validated by many international blind and open benchmarks.The recently developed combustion models in GASFLOW-MPI code are based on the transport equation of a reaction progress variable. The sources consist of turbulence dominated and chemistry kinetics dominated terms. Models have been implemented to compute the turbulent burning velocity for the turbulence controlled combustion rate. One-step and two-step models are included to obtain the chemical kinetics controlled reaction rate. These models, combined with the efficient and verified all-speed solver of the GASFLOW-MPI code, can be used for simulations of deflagration, detonation and the important transition processes like flame acceleration (FA) and deflagration-to-detonation-transition (DDT), without additional need for expert judgment and intervention. It should be noted that the major goal is to develop a reliable and efficient numerical tool for large-scale engineering analysis, instead of resolving the extremely complex physical phenomena and detailed chemistry kinetics on microscopic scales. During the course of this development, new verification and validation studies were completed for phenomena relevant to hydrogen-fueled combustion, such as shock wave capturing, premixed and non-premixed turbulent combustion with convective, conductive and radiation heat losses, detonation of unconfined hydrogen–air mixtures, and confined detonation waves in tubes. Excellent agreements between test data and model predictions support the predictive capabilities of the combustion models in GASFLOW-MPI code. In Part II of the paper, the newly developed CFD methodology has been successfully applied to a first analysis of hydrogen distribution and explosion in the Fukushi Daicchi Unit 1 accident.The major advantage of GASFLOW-MPI code is the all-speed capability of simulating laminar and turbulent distribution processes, slow deflagration, transition to fast hydrogen combustion modes including detonation, within a single scientific software framework without the need of transforming data between different solvers or codes. Since the code can model the detailed heat transfer mechanisms, including convective heat transfer, thermal radiation, steam condensation and heat conduction, the effects of heat losses on hydrogen deflagrations or detonations can also be taken into account. Consequently, the code provides more accurate and reliable mechanical and thermal loads to the confining structures, compared to the overly conservative results from numerical simulations with the adiabatic assumptions.Predictions of flame acceleration mechanisms associated with turbulent flames and flow obstacles, as well as DDT modeling and their comparisons to available data will be presented in future papers. A structural analysis module will be further developed. The ultimate goal is to expand the GASFLOW-MPI code into an integral high-performance multi-physics simulation tool to cover the entire spectrum of phenomena involved in the mechanistic hydrogen safety analysis of large scale industrial facilities.

Proposed methodology for Passive Autocatalytic Recombiner sizing and location for a BWR Mark-III reactor containment building

The Stress Tests accomplished by the European nuclear plants assume to be a complementary and comprehensive review of the safety of nuclear facilities, taking into account the events occurred in Fukushima Daiichi. The analysis of Passive Autocatalytic Recombiners (PARs) installation in Cofrentes NPP (BWR Mark III, 1092 MWe) was a requirement emerged from those tests and developed by Iberdrola Engineering and Construction jointly with Universidad Politécnica de Madrid (UPM). The study established a methodology for location and number of PARs for being installed to minimize the risk arising from an hydrogen release and its distribution in containment building during a severe accident (SA). In this paper, the implementation of this methodology was deeply analyzed for Cofrentes NPP.The proposed methodology presented herein for PARs installation analysis is divided in four steps: identification of the most limiting scenarios to be simulated with a severe accident code (MAAP4) in order to obtain mass and energy sources (step 1); hydrogen distribution analysis in containment with a 3D containment code (GOTHIC 8.0) (step 2 and 3); and PAR sizing and location analysis (step 4). The most limiting scenarios chosen for a BWR were: Station Blackout (SBO); Total Loss of Feed Water (TLOFW); and Loss of Coolant Accident (LOCA). Several sensitivity analyzes of different PAR sizes and configurations were accomplished, and the most suitable PARs configuration was determined. This optimal configuration consisted in a total of 53 PARs: 47 units placed inside the containment and 6 units in the drywell. For data analysis, an in-house code was developed, providing combustion and deflagration data in a clear and accurate way, showing the combustion windows and their span.The proposed methodology was established as accurate enough for analysing PARs installation within containment applied to a BWR Mark III. The fact of having a very detailed 3D GOTHIC model allowed creating a strategy of implementation based on the preferred hydrogen pathways and areas of accumulation.

Development of sump model for containment hydrogen distribution calculations using CFD code

Computational Fluid Dynamics (CFD) simulations are necessary for obtaining accurate predictions and local behaviour for carrying out containment hydrogen distribution studies. However, commercially available CFD codes do not have all necessary models for carrying out hydrogen distribution analysis. One such model is sump or suppression pool evaporation model. The water in the sump may evaporate during the accident progression and affect the mixture concentrations in the containment. Hence, it is imperative to study the sump evaporation and its effect. Sump evaporation is modelled using three different approaches in the present work. The first approach deals with the calculation of evaporation flow rate and sump liquid temperature and supplying these quantities through user defined functions as boundary conditions. In this approach, the mean values of the domain are used. In the second approach, the mass, momentum, energy and species sources arise due to the sump evaporation are added to the domain through user defined functions. Cell values adjacent to the sump interface are used in this. Heat transfer between gas and liquid is calculated automatically by the code itself. However, in these two approaches, the evaporation rate was computed using an experimental correlation. In the third approach, the evaporation rate is directly estimated using diffusion approximation. The performance of these three models is compared with the sump behaviour experiment conducted in TOSQAN facility.Classification: K. Thermal hydraulics

Scattering influences in quantitative fission neutron radiography for the in situ analysis of hydrogen distribution in metal hydrides

In situ neutron radiography allows for the time-resolved study of hydrogen distribution in metal hydrides. However, for a precise quantitative investigation of a time-dependent hydrogen content within a host material, an exact knowledge of the corresponding attenuation coefficient is necessary. Additionally, the effect of scattering has to be considered as it is known to violate Beer׳s law, which is used to determine the amount of hydrogen from a measured intensity distribution. Within this study, we used a metal hydride inside two different hydrogen storage tanks as host systems, consisting of steel and aluminum. The neutron beam attenuation by hydrogen was investigated in these two different setups during the hydrogen absorption process. A linear correlation to the amount of absorbed hydrogen was found, allowing for a readily quantitative investigation. Further, an analysis of scattering contributions on the measured intensity distributions was performed and is described in detail.

Research efforts for the resolution of hydrogen risk

During the past 10 years, the Korea Atomic Energy Research Institute (KAERI) has performed a study to control hydrogen gas in the containment of the nuclear power plants. Before the Fukushima accident, analytical activities for gas distribution analysis in experiments and plants were primarily conducted using a multidimensional code: the GASFLOW. After the Fukushima accident, the COM3D code, which can simulate a multidimensional hydrogen explosion, was introduced in 2013 to complete the multidimensional hydrogen analysis system. The code validation efforts of the multidimensional codes of the GASFLOW and the COM3D have continued to increase confidence in the use of codes using several international experimental data. The OpenFOAM has been preliminarily evaluated for APR1400 containment, based on experience from coded validation and the analysis of hydrogen distribution and explosion using the multidimensional codes, the GASFLOW and the COM3D. Hydrogen safety in nuclear power has become a much more important issue after the Fukushima event in which hydrogen explosions occurred. The KAERI is preparing a large-scale test that can be used to validate the performance of domestic passive autocatalytic recombiners (PARs) and can provide data for the validation of the severe accident code being developed in Korea.

Study on Hydrogen Risk Induced by Dust for Fusion Device

Dust could be generated due to the interaction between hot plasma and wall materials in the ITER vacuum vessel, in which hydrogen could be generated when induced by water or steam reacting with dust in some hypothesis accident scenarios, such as loss of coolant accident, wet bypass and loss of vacuum accident. Under such conditions air ingress may led to hydrogen explosion which could damage the integrity of ITER device and would cause the radioactivity releasing to the environment. Computational fluid dynamics method is proposed to study the distributions of the hydrogen, steam and air in the ITER devices and evaluate hydrogen risk control with inert gas injection and hydrogen removal with passive autocatalytic recombination. To verify the computational models to study hydrogen risk induced by wet bypass accident, STARDUST experiment is modeled and simulated, in which the calculated results compared with the experimental results show that RNG k-e turbulence model can be used in the hydrogen distribution analysis. The calculated results of the hydrogen distribution show that there is hydrogen combustion or explosion risk under the accident conditions. Then the hydrogen mitigation measures is applied to the system, and the analytical result shows that inert gas injection at the early stage of the accident with a large rate could mitigate the hydrogen risk effectively, and that hydrogen recombiners play an important role to mitigate the hydrogen risk in suppression tank, which is helpful for the safety design.

CFD code benchmark against the air/helium tests performed in the MISTRA facility

The behaviour of hydrogen mixing and distribution has always been an important safety issue and the hydrogen distribution studies gained importance especially after Fukushima accident. The hydrogen generated due to metal water reaction releases into the containment and may get stratified locally under accident conditions. The stratification of hydrogen may be eroded by diffusion or by other means. CFD codes are increasingly being used for hydrogen distribution analysis and need to be validated before applying it to full scale containment simulations. In this context, the CFD code FLUENT is validated against the experiment conducted in the MISTRA facility on stratification and erosion behaviour. This paper deals with the validation of the CFD code FLUENT against the experiment conducted in MISTRA facility to study the stratification behaviour. Turbulence model sensitivity was carried out to identify the best suited turbulence model.

Analysis of hydrogen distribution in simulated welds of 14Cr-(4-9)Ni steel welding wires

Analysis of hydrogen distribution in simulated welds of 14Cr-(4-9)Ni steel welding wires

Analysis of hydrogen distribution on Mg–Ni alloy surface by scanning electron-stimulated desorption ion microscope (SESDIM)

Hydrogen distribution and behavior on a Mg–Ni alloy surface are studied by using a time-of-flight electron-stimulated desorption (TOF-ESD) microscopy and a scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDX). The desorbed hydrogen ions are energy-discriminated and distinguished into two characters in the adsorbed states, which belong to Mg 2Ni grains and the other to oxygen-contaminated Mg phase at the grain boundaries. Adsorbed hydrogen is found to be stable up to 150 °C, but becomes thermally unstable around at 200 °C.

Plasma hydrogenation of MgAl thin films and H 2 effusion

The accommodation of hydrogen in 4–5 μm thick MgAl films deposited by dc magnetron sputtering on (1 1 1) oriented Si substrate and submitted to hydrogenation using 2 keV H 2 + plasma immersion ion implantation technique at 473 K and 10 Pa pressure in 90% H 2+10% Ar and 90% H 2+10% O 2 working gas plasmas was investigated. Morphological and structural properties were studied by scanning electron microscopy and X-ray diffraction. Glow discharge optical emission spectroscopy was used for the analysis of hydrogen distribution in hydrogenated films. Thermal desorption spectroscopy analysis revealed the hydrogen effusion kinetics. It was shown that the surface oxide barrier layer plays an important role on the hydrogenation efficiency and controls the H 2 thermal effusion. The maximum efficiency of hydrogenation was obtained in H 2+O 2 plasma when incident hydrogen ions pass the surface oxide barrier layer without destroying it. The Ar sputtering during hydrogenation in H 2+Ar plasma erodes the surface barrier layer and decreases the retention probability of the implanted hydrogen atoms.

Analysis of hydrogen distribution in hydrogen storage alloy using neutron radiography

The initial stage of hydrogen absorption was investigated on Mg–Ni based alloys, such as Mg 2Ni and Mg 3Ni (the eutectic mixture of Mg 2Ni and Mg), using neutron radiography (NRG). The NRG images were obtained by not only a simple transmission method but also a tomographic one, which could clearly visualize hydrogen distribution in the alloys. The hydrogen diffusion coefficient in these alloys was estimated to be ≈2×10 −7 cm 2 s −1 from the change in hydrogen absorption depth with hydrogenation time. The comparison of the volume expansion rate due to hydrogen absorption for the alloys showed that Mg 3Ni has better toughness than Mg 2Ni until Mg 3Ni was partly degraded to form magnesium hydride. Thus, NRG was found to be a powerful tool to clarify the behavior of hydrogen in hydrogen storage alloys.

Multi-dimensional simulation of hydrogen distribution and turbulent combustion in severe accidents

A joint research project was carried out in the EU Fourth Framework Programme with the goal to develop verified and commonly agreed physical and numerical models for the analysis of hydrogen distribution, turbulent combustion and mitigation, which are suited for the multi-dimensional CFD codes that exist at the institutions of the participating partners. The work programme and the activities of the partners are described. Significant progress has been made in the areas of experiments, model development, model verification and model application to nuclear power plants. Joint benchmark tests were defined and analysed. In addition to the regular partners meetings, topical workshops were conducted to harmonize the experimental and theoretical work. The paper presents major experimental results, gives examples for the achieved multi-dimensional modelling capabilities, describes implementation into and validation of codes, and presents results of plant analysis activities.

Hydrogen 3D distribution in solids by ERDA imaging

A method for quantitative analysis of hydrogen distribution in 3D has been developed using the elastic recoil detection analysis (ERDA) technique in conjunction with a nuclear microprobe. 2–3 MeV alpha particles, focused down to 2–5 μm, were applied at incident angles of 10–15° to the sample surface. Using an absorber placed in front of surface barrier (SB) detector in order to stop forward-scattered alpha particles, we have achieved a hydrogen detection limit of about 0.1 at.% and a depth resolution of about 80–100 nm. The technique was applied simultaneously with Rutherford backscattering spectrometry (RBS) to measure and image the hydrogen distribution in thin films and solid state bulk materials.

97/01463 Inspection of the operation of cooling towers for final cooling of coke-oven gas

The objective of the presented work is to develop an efficient and validated approach based on a multi-dimensional computational fluid dynamics (CFD) code for predicting turbulent gaseous dispersion, conjugated heat and mass transfer, multi-phase flow, and combustion of hydrogen mixtures. Applications of interest are accident scenarios relevant to nuclear power plant safety, renewable energy systems involved in hydrogen transport, hydrogen storage, facilities operating with hydrogen, as well as conventional large scale energy systems involving combustible gases. All model development is conducted within the framework of the high-performance scientific computing software GASFLOW-Multi-Physics-Integration (MPI). GASFLOW-MPI is the advanced parallel version of the GASFLOW sequential code with many newly developed and validated models and features. The code provides reliability, robustness and excellent parallel scalability in predicting all-speed flow-fields associated with hydrogen safety, including distribution, turbulent combustion and detonation. In the meanwhile, it has been well verified and validated by many international blind and open benchmarks.The recently developed combustion models in GASFLOW-MPI code are based on the transport equation of a reaction progress variable. The sources consist of turbulence dominated and chemistry kinetics dominated terms. Models have been implemented to compute the turbulent burning velocity for the turbulence controlled combustion rate. One-step and two-step models are included to obtain the chemical kinetics controlled reaction rate. These models, combined with the efficient and verified all-speed solver of the GASFLOW-MPI code, can be used for simulations of deflagration, detonation and the important transition processes like flame acceleration (FA) and deflagration-to-detonation-transition (DDT), without additional need for expert judgment and intervention. It should be noted that the major goal is to develop a reliable and efficient numerical tool for large-scale engineering analysis, instead of resolving the extremely complex physical phenomena and detailed chemistry kinetics on microscopic scales. During the course of this development, new verification and validation studies were completed for phenomena relevant to hydrogen-fueled combustion, such as shock wave capturing, premixed and non-premixed turbulent combustion with convective, conductive and radiation heat losses, detonation of unconfined hydrogen–air mixtures, and confined detonation waves in tubes. Excellent agreements between test data and model predictions support the predictive capabilities of the combustion models in GASFLOW-MPI code. In Part II of the paper, the newly developed CFD methodology has been successfully applied to a first analysis of hydrogen distribution and explosion in the Fukushi Daicchi Unit 1 accident.The major advantage of GASFLOW-MPI code is the all-speed capability of simulating laminar and turbulent distribution processes, slow deflagration, transition to fast hydrogen combustion modes including detonation, within a single scientific software framework without the need of transforming data between different solvers or codes. Since the code can model the detailed heat transfer mechanisms, including convective heat transfer, thermal radiation, steam condensation and heat conduction, the effects of heat losses on hydrogen deflagrations or detonations can also be taken into account. Consequently, the code provides more accurate and reliable mechanical and thermal loads to the confining structures, compared to the overly conservative results from numerical simulations with the adiabatic assumptions.Predictions of flame acceleration mechanisms associated with turbulent flames and flow obstacles, as well as DDT modeling and their comparisons to available data will be presented in future papers. A structural analysis module will be further developed. The ultimate goal is to expand the GASFLOW-MPI code into an integral high-performance multi-physics simulation tool to cover the entire spectrum of phenomena involved in the mechanistic hydrogen safety analysis of large scale industrial facilities.