Frederik Arbeiter

Karlsruhe Institute of Technology | KIT · Institute of Neutron Physics and Reactor Technology

The first wall (FW) of DEMO is a component with high thermal loads. The cooling of the FW has to comply with the material's upper and lower temperature limits and requirements from stress assessment, like low temperature gradients. Also, the cooling has to be integrated into the balance-of-plant, in a sense to deliver exergy to the power cycle and...

During the Engineering Validation and Engineering Design Activities (EVEDA) phase (2007-2014) of the International Fusion Materials Irradiation Facility (IFMIF), an advanced engineering design of the High Flux Test Module (HFTM) has been developed with the objective to facilitate the controlled irradiation of steel samples in the high flux area dir...

This paper presents the engineering design of the IFMIF (International Fusion Materials Irradiation Facility) Tritium Release Test Module (TRTM). The objectives of the TRTM are: (i) in-situ measurements of the tritium released from lithium ceramics and beryllium pebble beds during irradiation, (ii) studying the chemical compatibility between lithiu...

As part of the Engineering Validation and Engineering Design Activities (EVEDA) for the International Fusion Materials Irradiation Facility (IFMIF) [1], it is foreseen to design and test a 1:1 scale prototype of the IFMIF High Flux Test Module (HFTM) [2]. The module has been designed to be cooled by a low pressure helium gas flowing through minicha...

The International Fusion Material Irradiation Facility (IFMIF) is designated to enable material testing for irradiation conditions relevant to future fusion reactors. The design process to optimize the High Flux Test Module (HFTM) containing the irradiation rigs for maximum utility to material research relies on dependable engineering tools for neu...

IFMIF-DONES is a facility under construction in Granada, whose main goal is the validation and characterization of materials under a fusion prototypic irradiation field. This field is created by the interaction of a high energy intense continuous deuteron beam and a flowing liquid lithium target. The requirements imposed on the beam at the interact...

IFMIF-DONES (International Fusion Materials Irradiation Facility-DEMO-Oriented Neutron Early Source)-a powerful neutron irradiation facility for irradiation of materials to be used in fusion reactors-is planned as part of the European roadmap to fusion electricity. Its main goal will be to characterize and qualify materials under a neutron field si...

Liquid metal heat transfer systems are a technical attractive option to increase the efficiency of CSP plants. Sodium as heat transfer medium is promising especially due to high heat transfer rates. In this paper, basic considerations are made to match the requirements of a small scale loop with sodium as heat transfer medium. The setup of the test...

The IFMIF-DONES Facility is a unique first-class scientific infrastructure whose construction is foreseen in Granada, Spain, in the coming years. Strong integration efforts are being made at the current project phase aiming at harmonizing the ongoing design of the different and complex Systems of the facility. The consolidation of the Diagnostics a...

The Helium Cooled Pebble Bed (HCPB) breeding blanket is one of the two driver-blanket candidates for the European fusion demonstration power plant (EU DEMO) within the framework of the EUROfusion Consortium. As the EU DEMO program is going, testing of mockups becomes increasingly important. In this article, the engineering design of a first-ever br...

Der Einsatz von Rippenstrukturen auf Wärmetauscheroberflächen führt zu einer erhöhten Wärmeübertragung zwischen Arbeitsfluid und Komponentenwand. Eine Möglichkeit lokale Wärmeübertragungsminima infolge von stationär auftretenden Staupunkt- und Rezirkulationsströmungen hinter den Rippen zu vermindern bzw. zu vermeiden, bietet das Anheben der Rippen...

In the IFMIF-DONES facility of the future, the back-plate behind the Li target will receive strong irradiation from high-energy neutrons. The potential use of the back-plate for material specimens is attractive with respect to providing complementary irradiation data for Eurofer. In this work, DPA (displacement per atom) and gas production rates as...

International Fusion Materials Irradiation Facility-DEMO-Oriented NEutron Source (IFMIF-DONES) is a high-intensity neutron irradiation facility for qualification of fusion reactor materials, which is being designed as part of the European roadmap to fusion-generated electricity. Its main purpose is to study the behavior of materials properties unde...

The scope of the EUFOfusion Work Package Breeding Blanket is to develop a blanket concept for the EU DEMO reactor; this includes the blanket segments inside the Vacuum Vessel and the related Tritium Extraction/Removal Systems. In the Pre-Concept Design (PCD) Phase, two concepts have been selected as candidates; a solid and a liquid breeder blanket...

Liquid metal heat transfer systems are a technically attractive option to increase the efficiency of CSP plants. Sodium as heat transfer medium is promising especially due to high heat transfer rates. In this paper, basic considerations are made to match the requirements of a small-scale loop with sodium as heat transfer medium. The setup of the te...

The main purpose of IFMIF-DONES facility is to provide a neutron source for irradiating small specimens and producing experimental data of material properties for the construction of DEMO fusion power plant. The Test Cell (TC) of the DONES is a confined and well-shielded room, where the strong irradiation environment is created. The biological shie...

Zusammenfassung In der vorliegenden Arbeit werden Ergebnisse von Laser-Doppler-Anemometrie(LDA)-Geschwindigkeitsmessungen in einem einseitig mit transversal orientierten Rippen-Rauheiten strukturierten quadratischen Kanal für die Strömung mit einer Reynolds-Zahl von Re H = 5 , 0 · 10 4 {\mathit{Re}_{H}}=5,0\cdot {10^{4}} vorgestellt. Das Rippenabst...

The velocity field of the fully developed turbulent flow in a one-sided ribbed square channel (rib-height-to-channel-height ratio of k/h = 0.0667, rib-pitch-to-rib-height ratio of p/k = 9) were measured at Reynolds numbers (based on the channel height h and the mean bulk velocity uB) of Reh = 50 000 and 100 000 by means of Laser-Doppler-Anemometry...

IFMIF-DONES is a powerful neutron irradiation facility for the study and qualification of materials planned as part of the European roadmap to fusion-generated electricity. Its main goal is to study properties of materials under severe irradiation in a neutron field similar to the one in a fusion reactor first wall. It is a key facility to prepare...

In this paper, we present experimental results for a non-isothermal vertical confined backward facing step conducted with a low-Prandtl number fluid. The eutectic alloy gallium–indium–tin is used as the working fluid. We conducted experiments for different Reynolds and Richardson numbers covering both forced and mixed convection regimes. Time-avera...

The International Fusion Materials Irradiation Facility (IFMIF), presently in its Engineering Validation and Engineering Design Activities (EVEDA) phase under the frame of the Broader Approach Agreement between Europe and Japan, accomplished in summer 2013, on schedule, its EDA phase with the release of the engineering design report of the IFMIF pl...

The goal of this paper is to introduce an analytical approach for the inversion of nxn solver matrices, which are typically used in Finite Difference Method approximations. In the present case, they are used to solve the Diffusion Equation numerically, since in many physics and engineering fields, partial differential equations cannot be solved ana...

In this work, the strategy for numerical solutions in transport processes is investigated. Permeation problems can be solved analytically or numerically by means of the Finite Difference Method (FDM), while choosing the Euler forward explicit or Euler backwards implicit formalism. The first method is the easiest and most commonly used, while the Eu...

Laser Doppler anemometry (LDA) measurements in the fully developed turbulent flow through a one-sided rib-roughened square channel with a rib-height-to-channel-height ratio of $$k/H = 0.0667$$ k / H = 0.0667 and a rib-pitch-to-rib-height ratio of $$p/k = 9$$ p / k = 9 were carried out at Reynolds numbers (based on the channel height H and the mean...

New Nuclear technologies require testing under conditions that are as close to real-life as possible. Usually, those are high temperature, specific atmosphere, and the high neutron flux. The research reactor can provide the latter, but the previous two require appropriate thermostatic equipment. Two such devices: ISHTAR and MAKARONI have been desig...

International Fusion Materials Irradiation Facility — DEMO–Oriented Neutron Source (IFMIF-DONES) is a planned powerful neutron source, which will generate an intense flux of neutrons (up to ~1015n/s/cm2) with a fusion-relevant energy spectrum. It will be an accelerator source based on deuteron beam - lithium target re-actions. The engineering desig...

The test cell (TC) serves as irradiation chamber in the IFMIF-DONES facility, which aims to irradiate material samples with a highly energetic deuterium-lithium based neutron source to contribute to the development of candidate materials to be used in the first wall components of future fusion reactors. The TC provides space for several sub-systems...

Recent analysis result in significant impact on the design of the Helium Cooled Pebble Bed (HCPB) Breeding Blanket (BB). Especially the main demanding sub-component of the BB in terms of fabrication, the First Wall (FW) is highly affected. As a matter of fact, the relevance of the developments made for the industrial fabrication of the FW used e.g....

In this paper the determination of material properties such as Sieverts' constant (solubility) and diffusivity (transport rate) via so-called gas release experiments is discussed. In order to simulate the time-dependent hydrogen fluxes and concentration profiles efficiently, we make use of an analytical method, namely we provide an analytical solut...

This work continues the development of a numerical model to simulate transient tritium transport on the breeder zone (BZ) level for the EU helium-cooled pebble bed (HCPB) concept for DEMO. The basis of the model is the open-source field operation and manipulation framework, OpenFOAM. The key output quantities of the model are the tritium concentrat...

In preparation for determining material properties such as Sieverts’ constant (solubility) and diffusivity (transport rate) we give a detailed discussion on a model describing some gas release experiment. Aiming to simulate the time-dependent hydrogen fluxes and concentration profiles efficiently, we provide an analytical solution for the diffusion...

Helium flow at low pressure (0.3 MPa) is used to cool the specimen capsules and the structure of the neutron irradiated High Flux Test Module (HFTM) of the IFMIF-DONES (International Fusion Materials Irradiation Facility- DEMO Oriented NEutron Source). The flow path includes mini-channels with gap-widths less than 1 mm where a high velocity low Rey...

Our research group is currently investigating a new kind of thermal desorption experiment (TDE), which uses a hydrogen isotope by loading-unloading process yielding transport parameters. Safety issues are limiting the hydrogen loading content to 3 % at 10 ⁵ Pa, while former experiments are using pure hydrogen for the loading process at nearly same...

The need of a high-intensity, 14 MeV neutron source for the qualification of materials under fusion-relevant conditions has been recognized in the European fusion programme as an essential step towards the design and licensing of DEMO and future commercial fusion power plants. This need has pushed the EU to support the development of a Li(d,nx) neu...

A maintainable test cell (TC) concept, which targets replacing TC key components in case of damages, for the IFMIF-DONES (International Fusion Materials Irradiation Facility – Demo Oriented NEutron Source) facility is proposed to facilitate the maintenance of key containment and biological shielding components, i.e. the liner and the surrounding co...

IFMIF-DONES (International Fusion Material Irradiation Facility- DEMO Oriented NEutron Source) is an accelerator based irradiation facility which is aimed to provide the irradiation data needed for the construction of DEMO. The Test Cell (TC) is the central room of IFMIF-DONES enclosing the target and the test module. This work presents the neutron...

Helium flows at low pressure (3 bar) are used to cool the specimen capsules and the structure of the neutron irradiated High Flux Test Module (HFTM) of the DEMO-Oriented Neutron Source (DONES). The flow path includes inlet and outlet ducts with large cross sections, but also mini-channels with gap widths less than 1 mm, where a high velocity low Re...

Periodic boundary conditions in streamwise direction are commonly applied for scale-resolving numerical simulations of turbulent flow and heat transfer in cooling channels structured with periodically repeated rib-turbulators, as an approach to approximate fully developed conditions with limited computational effort. The number of rib-pitch section...

The capsules of the IFMIF-DONES High Flux Test Module (HFTM)are packed densely with Eurofer specimens. A filling material (previously NaK-78 and currently sodium)is needed to fill any empty volume to improve the heat conduction and obtain uniform temperature distribution. NaK-78 is replaced by sodium because potassium, in NaK-78, generates argon is...

The High Flux Test Module (HFTM) carries the specimens to be irradiated with the Early Neutron Source. The knowledge of the total neutron fluence on the specimen will be necessary for analysis. Neutron activation is a widely used method for neutron fluence measurement. We have tested a set of activation materials which seem to be suitable for appli...

The thermal hydraulics of helium-gas cooled channels for the First Wall of DEMO structured by fully attached and semi-detached upward directed V-shaped ribs and spherical dimples in a staggered array were investigated. Large-Eddy-Simulations with the dynamic Smagorinsky sub-grid scale model were performed. The global and local heat transfer coeffic...

Different manufacturing routes are investigated at the KIT INR for the realization of First Walls (FW) for nuclear fusion components, such as the ITER Test Blanket Module (TBM) and DEMO Breeding Blankets (BB) for the Helium Cooled Pebble Bed (HCPB) Breeding concept. One conventional manufacturing route mainly basing of Electrical Discharge Machinin...

Currently available diffusion constant and Sieverts constant experimental results are based on time dependent permeation experiments. The common principle is an analysis which is expecting that the permeating hydrogen is “transported” from the retentate chamber to the permeate chamber through the connecting membrane, with a vanishing hydrogen parti...

Abstarct The Q-PETE (Hydrogen Permeation and Transport Experiment) at KIT is set up to investigate hydrogen isotopes permeation through structural materials with specific relevance to the HCPB (helium cooled pebble bed) DEMO blanket breeder zone. The results are intended to provide validation data for simulation codes. A second objective is the dir...

The need of a neutron source for the qualification of materials to be used in future fusion power reactors has been recognized in the European Union (EU) fusion programme for many years. The construction and exploitation of this facility is presently considered to be critical to the construction of the DEMOnstration Power Plant (DEMO). This issue h...

IFMIF-DONES (International Fusion Materials Irradiation Facility - DEMO-oriented Neutron Source) is currently being developed in the frame of the EUROfusion Early Neutron Source work package (WPENS), based on the results achieved in the ongoing IFMIF/EVEDA (Engineering Validation and Engineering Design Activities) project by Japan and Europe in the...

In the framework of the EUROfusion’s Power Plant Physics and Technology, the Working Package Breeding Blanket aims at investigating 4 different Breeding Blanket (BB) concepts for a EU demonstration fusion reactor (DEMO). One of these concepts is the Helium Cooled Pebble Bed (HCPB) BB, which is based on the use of pebble beds of lithiated ternary co...

The IFMIF-DONES (International Fusion Materials Irradiation Facility-Demo Oriented NEutron Source) test cell (TC) biological shielding is responsible of providing sufficient protection for the surrounding rooms and cells from intensive neutron irradiation and gamma radiation from inside of the TC. The TC biological shielding is composed of surround...

IFMIF-DONES (International Fusion Materials Irradiation Facility- DEMO Oriented NEutron Source) is a neutron irradiation facility aiming at providing material irradiation data for the construction of DEMOnstration fusion power plants. This work presents nuclear analyses and associated neutronics modeling conducted on an updated design of the High F...

An experiment termed "Q-PETE" representative for the situation in the Helium Cooled Pebble Bed (HCPB) breeding zone and suitable for the validation of relevant tritium transport codes has been devised. In a temperature controlled setup a hydrogen loaded gas is directed over a steel membrane (several millimeter thickness) into which it can permeate....

This work describes the development of a numerical model to simulate transient tritium transport on the breeder unit (BU) level for the EU helium cooled pebble bed (HCPB) concept for DEMO. The key output quantities of the model are the tritium concentration in the purge gas and in the coolant and the tritium inventory inside the BU structure. The m...

In the DONES (DEMO-Oriented Neutron Source) neutron source a single accelerator line delivers 125 mA of deuterons at 40 MeV to a flowing liquid lithium target with a free (vacuum) surface facing the deuteron beam. Neutrons with fusion-relevant spectrum are generated by a stripping reaction and used for material samples irradiation. The Quench Tank...

As part of the engineering validation and engineering design activities (EVEDA) phase for the international fusion materials irradiation facility IFMIF, major elements of a lithium target facility and the test facility were designed, prototyped and validated. For the lithium target facility, the EVEDA lithium test loop was built at JAEA and used to...

Heat transfer and pressure drop measurements were conducted to study the thermal-hydraulics in a square, round-edged channel roughened by ribs (e/Dh = 0.0638, p/e = 10) on one wall at Reynolds numbers ranging from 5.0 E4 to 2.5 E5. Three variously shaped ribs were investigated: Transverse ribs with square cross sections, transverse ribs, and upstre...

Delayed Detached Eddy Simulations with the k-ω-SST turbulence model were conducted for 8.0 MPa pressurized helium-gas flow in cooling channels with rib arrays on one wall at a Reynolds number of Re = 1.05 E5. Turbulent flow and heat transfer were determined for arrays of eight variously configured V-shaped and transverse ribs. The relative roughnes...

IFMIF, the International Fusion Materials Irradiation Facility, is presently in its engineering validation and engineering design activities (EVEDA) phase under the Broader Approach Agreement. The engineering design activity (EDA) phase was successfully accomplished within the allocated time. The engineering validation activity (EVA) phase has focu...

Helium is considered as coolant in the plasma facing first wall of several blanket concepts for DEMO fusion reactors, due to the favorable properties of flexible temperature range, chemical inertness, no activation, comparatively low effort to remove tritium from the gas and no chemical corrosion. Existing blanket designs have shown the ability to...

During the EVEDA phase of the International Fusion Materials Irradiation Facility (IFMIF), the High Flux Test Module (HFTM) was developed as dedicated irradiation device for Small Scale Testing Technique (SSTT) material specimens in the intensive IFMIF neutron radiation field. The specimens are contained in temperature controlled irradiation rigs....

Rib-roughening the helium-gas cooling channels in the plasma facing components of DEMO (First Wall, limiters or the divertor) enhances heat transfer and reduces structural material temperatures. In the present study the applicability of six different surface-attached rib-arrays and of two different detached rib-arrays was examined for increasing th...

The quench tank (QT) location in the test cell is an open issue for IFMIF-DONES (International Fusion Material Irradiation Facility- DEMO Oriented NEutron Source) design. Neutronics assessments have been carried out on two QT location options. A parametric study of the neutron streaming in the lithium chute shows a quasi-linear dependence of the ne...

The High Flux Test Module (HFTM) of the International Fusion Materials Irradiation Facility (IFMIF) is a device to enable irradiation of Small Scale Testing Technique (SSTT) specimens by neutrons up to a structural damage of 50 displacements per atom (dpa) in an irradiation campaign of 1 year. The IFMIF source generates neutrons with a D-T-fusion-r...

Detached Eddy Simulations were conducted for pressurized helium-gas flow in cooling channels with rib-arrays detached from one wall at a Reynolds number of Re = 1.05E5. Turbulent flow fields and conjugated heat transfer were predicted. The rib-arrays consisted of 60° (with respect to the centerline) V-shape or 90° transverse ribs with a rib-height...

For several reasons the challenge to keep the loads to the first wall within engineering limits is substantially higher in DEMO compared to ITER. Therefore the pre-conceptual design development for DEMO that is currently ongoing in Europe needs to be based on load estimates that are derived employing the most recent plasma edge physics knowledge. A...

The so called High Flux Test Module (HFTM) represents the component of IFMIF (International Fusion Irradiation Facility) in which material specimens are being placed that accumulate high neutron induced damage rates (≥20 dpa/fpy). Damage rates of this magnitude are limited to a volume of ∼500 cm³ (attenuation in beam direction) behind a beam footpr...

The hydrogen isotopes tritium and deuterium as fuel of future fusion power plants will be in contact with several plant components: Reduced Activation Ferritic Martensitic (RAFM) steel parts of the blanket and austenitic steels used for pipelines and process equipment. Temperatures range from ambient up to 550 °C. Since both steel kinds can store a...

The test cell (TC) in IFMIF-DONES (International Fusion Material Irradiation Facility – Demo Oriented NEutron Source) is the meeting area of the three major systems (test systems, lithium systems, and accelerator systems) to host the irradiation test module, lithium target assembly and the end section of the accelerator line. Although the design of...

Small specimen test technology or technique (SSTT) towards design of fusion DEMO reactors was investigated and evaluated in the related studies of the International Fusion Materials Irradiation Facility / Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) project under Broader Approach (BA) Agreement. The main results were descr...

As part of the Engineering Validation and Engineering Design Activities (EVEDA) phase for the International Fusion Materials Irradiation Facility IFMIF, major elements of Lithium Target Facility and the Test Facility were designed, prototyped and validated. For the Lithium Target Facility, the ELTL lithium loop was built and used to test the stabil...

Detached-Eddy-Simulations (DES) were performed for investigating the thermal-hydraulics of a one-sided heated and rib-roughened cooling channel at Reynolds numbers ranging from 2.5E4 to 1.58E5. Heat transfer and flow characteristics for three different types of centrally positioned, transversally oriented rib-elements with a rib-height and rib-top-...

In the frame of the EUROfusion Consortium activities were launched in 2014 to develop a concept of a DEMO reactor including a large R&D program and the integrated design of the tokamak systems. The integration of the in-vessel components (IVCs) must accommodate numerous constraints imposed by their operating environment, the requirements for precis...

The necessity of a neutron source for fusion materials research was identified already in the 70s. Though neutrons induced degradation present similarities on a mechanistic approach, thresholds energies for crucial transmutations are typically above fission neutrons spectrum. The generation of He via 56Fe (n,α) 53Cr in future fusion reactors with a...

Several validation activities were dedicated to the High Flux Test Module (HFTM) of the International Fusion Materials Irradiation Facility (IFMIF) at the Karlsruhe Institute of Technology (KIT) in Germany. The HFTM contains 24 capsules packed densely with Eurofer specimens to facilitate their irradiation in the high flux zone directly behind the I...

The hydraulic and thermal testing of two different irradiation rig models A and B, differing in the inlet nozzle design, bottom reflector length and steps inside a mock-up container is part of the HFTM validation activities which support the engineering design of the High Flux Test Module. The pressure drops for all models in the test section are m...

Improved cooling channel designs of helium cooled first wall (FW) applications focus on efficient heat transfer enhancement and reduced material temperatures, even for high incident heat flux densities of more than 0.5 MW/m2. To this end, thermohydraulics of turbulent flow in a one-sided heated, one-sided rib-roughened channel with squared, round-e...