The design of breeding blankets represents the major challenge for fusion reactor engineering because of performance requirements and severe operating conditions in terms of heat load and neutron flux. Liquid metal alloys such as lead-lithium, due to their lithium content, can be used to breed tritium, one of the plasma fuel components, and owing to their high thermal conductivity, they may serve as

In a large-scale helium cryogenic system, a tank is used to store liquid helium. To predict the cooling behaviour and thermal performance of the tank during liquid helium filling, a simple and efficient computational fluid dynamics methodology was used. The phase transition and temperature distribution in the tank were simulated through a two-dimensional thermal–fluid–structure coupling model. Based

According to the national fusion development strategy, China has determined to test the Helium-cooled Ceramic-Breeder Test Blanket Module (HCCB TBM) in one equatorial port of ITER specific for the TBM program. In the preliminary design (PD) phase, the design of CN HCCB TBM was updated based on the conceptual design (CD), but made a lot of changes and optimizations considering the manufacturing feasibility

In this study, a 5.8 MW high voltage power supply was developed for two 1.2 MW klystrons to operate the upgraded KSTAR helicon current drive system. The developed power supply was configured to connect 180 pulse step modulator (PSM) modules using semiconductor switches connected in series to produce an output with a rating of −92 kV and 64 A for 300 s. To operate the klystron individually, the output

On Experimental Advanced Superconducting Tokamak (EAST) several visible optical diagnostics are utilized to measure the operation parameters of the plasma, in order to obtain the high performance and steady-state of the plasma profile. The light beam spatial orientation of these optical diagnostics needs to be calibrated before plasma experiment. The calibration process is carried out manually in past

The linear mercury diffusion pump is proposed as the primary pump for sustaining the continuous working of KALPUREX (Karlsruhe liquid metal based pumping process for fusion reactor exhaust gases), which is considered as the exhaust pumping solution for reducing the tritium inventory in future fusion reactor with the fuel cycle based on the Direct Internal Recycling (DIR) concept. In this work, a preliminary

Tritium is essential for generating D-T reactions in a fusion reactor, which is expected to be used as a next power generation technology. If tritium is released into the environment due to unexpected accidents, it may transfer to human body through plants eventually. Therefore, it is needed to understand the behavior of tritium in plants from the viewpoint of radiation protection. In this study, an

The understanding of the neutron irradiation effects in tungsten is of significant importance for its use as a plasma facing material in future fusion devices. In this study, cold rolled tungsten is neutron irradiated at the Belgian BR2 fission reactor at the temperatures 600, 800, 900 and 1200 °C to a dose of 0.18 displacements per atom (dpa). The neutron induced changes in the microstructure are

When quench happens, the energy stored in the superconducting magnet is required to be transferred and consumed to fast discharge resistor (FDR) system in specific time by quench protection system (QPS). In the previous research, the design made of 1 mm SUS304 has a bad cooling effect due to the narrow wind channel. So, the updated design concerning the cooling problem as well as the stray inductance

The 500 W@4.5 K helium refrigeration system operated in HL-2M Tokamak is the first domestically made cryogenic system independently designed and manufactured in China. It is expected to cool down HL-2M cryousers for the first time around June 2021. In the requirement document of helium refrigeration system, the mean time between failures (MTTF) should be at least 8000 hours, and the inherent availability

The microstructure and corrosion resistance of FeCrCuTiV high entropy alloy prepared by vacuum arc melting and laser melting deposition were studied. The microstructure and phase composition of FeCrCuTiV high entropy alloy were characterized by SEM, XRD, EBSD, etc. It is found that both of them are composed of the FCC Cu-rich phase, BCC Fe-rich phase and, BCC V-rich phase. Comparing with FeCrCuTiV

China Fusion Engineering Test Reactor (CFETR) is the next device in the roadmap for the realization of fusion energy in China. Based on the current engineering design of CFETR, detailed activation analysis for the major components of CFETR has been performed by using the Monte Carlo transport code MCNP4C and the inventory code FISPACT-2007. The key radiological parameters, such as activity inventory

The development and demonstration of fusion power plant facilities require advancement of multiphysics modeling capabilities. These capabilities provide an integrated platform for design and analysis of a fusion engineering demonstration power plant. We present a state-of-the-art literature review of the status and needs of multiphysics modeling, including neutronics analysis, and thermal hydraulic/mechanical

In this work, the analysis of experimental results on the irradiation of lithium ceramics Li2TiO3 is presented. Lithium ceramics samples were irradiated at the WWR-K research reactor (Almaty, Kazakhstan) under continuous pumping conditions at a temperature of ~610°C for ~21 days with a thermal neutron flux of ~5•1013 n/(cm2•s). During the experiment, the release of tritium-containing molecules (HT

We have investigated ohmic plasma initiation for JA DEMO, a design concept of the tokamak demonstration fusion reactor examined in Japan. A calculation model describing the tokamak plasma initiation phase consisting of the two-dimensional analysis of the coil and eddy currents and the zero-dimensional plasma analysis is developed. It is revealed that the conducting shell does not necessarily hinder

In a solid breeder blanket as a functional material, the lithium ceramics are kept in the form of a pebble bed. Helium is used as a purge gas, which flows through the pebble bed. The flow characteristics are essential in designing and running the breeding blanket efficiently, depending on the pebble bed arrangement. In the present study, a computational model of unitary pebble bed was engineered using

In this paper we show an overview of the preliminary strategy planned for remote maintenance of neutron–activated and contaminated components of DTT machine, in the 2019 reference configuration. The remote maintenance of such a complex machine has impact on different aspects of the DTT machine: layout of the tokamak hall, vacuum vessel and cryostat structures, in–vessel components. To date, the number

As augmented and virtual reality technology is revolutionising the way products are designed and tested, many companies are expanding the range of use cases across their organisations. After 10 years using Virtual Reality (VR) & Augmented Reality (AR) technology during the life cycle of fusion components, the CEA IRFM has improved its skills developing immersive visualisation scenes for the WEST tokamak

Recent improvements in the superconducting performance and technical maturity of high-temperature-superconductors (HTS) lead to considerations of using HTS in future fusion magnets in addition to the presently used low-temperature superconductors (LTS). Compact high field magnet systems entirely made of HTS for compact tokamaks, hybrid HTS-LTS magnets for enhanced operational capabilities (e.g. larger

ITER Thermal Shield (TS) reduces radiation heat loads from vacuum vessel and cryostat to superconducting magnet structure. One of the key process among the fabrication of TS is the silver electroplating to reduce the emissivity. Requirement on emissivity of TS surface after silver coating is below 0.05 at the room temperature. In practice, inevitable non-coated areas exist due to the intrinsic geometry

Due to the nonlinear characteristic of the gas-discharge plasma and influenced of the gas pressure, outside magnetic field and state of cathode, the arc discharge process in ion sources for neutral beam injection(NBI) is difficult to be closed-loop controlled stably with the arc power supply (APS). A 5 MW-NBI APS for HL-2M tokamak based on super capacitor energy storage and switching power technology

The installation of a cryogenic circuit for a large-scale superconducting device such as a tokamak is quite complex. In the KSTAR tokamak, five cryogenic circuits are utilized to cool each type of the component (e.g., toroidal field magnets, poloidal field magnets, structures current leads, thermal shield, bus lines) independently. The circuit for the poloidal field magnets branches into hundreds of

New compact radiation shields have been designed to reduce the scattered neutrons and background gamma-rays for neutron and gamma-ray diagnostics in the EAST hall. The design focused on optimizing radiation shielding performance versus volume and weight to fit the small amount of available space outside the tokamak device. Based on the Monte Carlo method and using the Geant4 tool kit, three-dimensional

The magnetic field environment around tokamak devices is very strong, which affects the working characteristics of electrical and electronic devices. For the study of magnetic field interference problems and the qualification test of sensitive devices, an immunity test platform against both D.C. and power-frequency magnetic fields is designed in this paper, including the analysis and design of magnetic

We assess the effects of neutron irradiation on the deformation and stress evolution of large-scale fusion energy structures. This is accomplished through non-linear finite element structural analysis of the coupled thermal and mechanical fields at the Beginning-Of-Life (BOL), at 45 dpa, and at 90 dpa. Radiation effects include volumetric swelling and the influence of radiation on the mechanical properties

Oxide dispersion-strengthened (ODS) steel is one of the most prominent candidates as the fuel cladding or blanket component in advanced nuclear reactors. The stability and evolution of high-density nanoscale particles in ODS steels during irradiation are of considerable importance in influencing the mechanical properties and irradiation resistance. The microstructure, especially high-density nanoparticles

Deuterium (D) plasma-driven permeation (PDP) experiments for vanadium (V), niobium (Nb) and tantalum (Ta) membranes are performed between 573–873 K in the linear plasma facility PREFACE. The sample temperature, membrane thickness and ion incident energy effects on D permeation behavior through these three metals are studied. PDP fluxes of D through Ta and Nb decrease with decreasing sample temperature

The ITER Radial Neutron Camera is a diagnostic whose objective is measuring neutron emissivity and fusion power density through an array of detectors placed in collimating structures. The RNC is composed of two subsystems (In-Port RNC and Ex-Port RNC), located in the Equatorial Port 01 of the ITER tokamak. Although the measurements from the RNC are required for ITER D-T phase, its In-Port components

This paper presents the architecture and the implementation of the upgraded Experimental Advanced Superconducting Tokamak (EAST) Poloidal Field Power Supply (PFPS) monitoring system. To meet the requirements of EAST long pulse discharge, the monitoring system has been upgraded based on experimental physics and industrial control system (EPICS) and MDSplus. It provides an integrated management of supervision

The Divertor Tokamak Test (DTT) facility is an experimental facility under design and construction at ENEA C.R. Frascati. The aim of DTT is to investigate the power exhaust problem in a tokamak, providing possible alternative divertor solutions, with respect the conventional one, which can be extrapolated to DEMO fusion reactor. One of the main components of DTT facility is the Vacuum Vessel (VV),

To suppress the inrush current during the start of the rectifier circuit, the use of soft-start resistance is a conventional method, but the selection of its parameters lacks theoretical guidance. For the three-phase bridge uncontrollable rectifier circuit, combined with EAST (experimental advanced superconducting tokamak) fast control power supply, this paper analyzes the start-up process using soft-start

The tritium analysis in tritium/deuterium-containing zirconium thin films was performed using elastic backscattering spectrometry (EBS) and β-ray induced X-ray spectrometry (BIXS). The EBS energy spectra were simulated with the SIMNRA program to obtain the tritium depth profiles and the total tritium contents in the samples. Two stopping powers used in the SIMNRA program were compared and it was shown

This paper presents the design, simulation and characterization of a high temperature black body source for a target temperature of 873 K and frequency range of 70 to 143 GHz. The high temperature black body source has been designed using CST Microwave Studio. Different solvers in CST have been used to determine various black body parameters such as scattering, emissivity, reflectivity, radiation intensity

Corrosion of pure Cr and pure W in molten FLiNaK at 773 K was investigated to deeply understand the effect of the alloying elements on the corrosion mechanisms of reduced activation ferritic/martensitic (RAFM) steels. The molten salt blanket environment was simulated by hydrogen fluoride gas bubbling. Electrochemical polarization and weight change measurements were conducted to estimate corrosion rates

Accident analysis is an important part of the design of nuclear power reactor. It is a necessary step of nuclear safety review and a key requirement for the reactor operation permit. In the China Fusion Engineering Test Reactor (CFETR) preliminary design, the main contents of accident analysis include two aspects: verification of CFETR system and safety control function design to ensure that the consequences

The design of Chinese Fusion Engineering Test Reactor (CFETR) is being carried out. The neutronics analysis of the tritium-breeding blankets in CFETR is one of the essential tasks, and raises requirements for the neutronics-analysis codes such as the ability of simulating the neutron-photon-coupling transport and the ability of obtaining the accurate energy deposition of neutrons and photons. NECP-MCX

The number of DNA double strand breaks (DSBs) of genome-sized DNA was quantitatively evaluated under several types of radiation sources. The characteristics of radiation damages by different linear energy transfer (LET) and the effect of radiation protection by tea catechins were also studied as a function of its concentration. After β-rays and γ-rays irradiation to samples, the length of genome size

Since 1991 radioactivity concentration of tritium (3H) in seawater has been monitored in the coastal waters off Rokkasho, Aomori Prefecture, where a commercial nuclear fuel reprocessing plant was in intermittent test operation beginning from 2006 and ending in 2008. Average 3H radioactivity concentrations, mainly derived from global fallout of atmospheric nuclear weapons tests in the 1950′s and early

The paper is focused on the optimal design of Fast Discharge Unit (FDU) for the quench protection of the Toroidal Field (TF) magnets of the Divertor Tokamak Test facility (DTT), an experimental facility under construction in ENEA Frascati Research Centre (Rome, Italy). The FDU is a safety key component that protects the superconducting magnets when a quench is detected through the fast extraction of

In high-power fusion gyrotrons, the maximum heat-load on the wall of the interaction section is in the order of 2 kW/cm2, which is the major limiting technological factor for output power and pulse-length of the tube. The ongoing gyrotron development demands a very effective cavity cooling system for optimum gyrotron operation. In this work, the experimental investigation of a mini-channel cavity cooling

W and W-5wt%Re alloy were irradiated by 50 keV helium ions at RT, 200 °C, 350 °C and 500 °C to investigate the influence of temperature on the microdefects and surface morphology in the sample. The microdefects in the subsurface region and the surface damage caused by irradiation were characterized by Doppler broadening spectroscopy (DBS) of slow positron beam, transmission electron microscope (TEM)

This paper presents a design study of a cryogenic distillation column for hydrogen isotope separation. The column was modeled as a theoretical equilibrium-based stage column. Thermodynamic properties were evaluated with the Peng–Robinson Twu equation of state model. The liquid holdup and pressure drop of each theoretical stage were modeled with a general packed column model. The models were implemented

Plasma disruptions are one of the major concerns in the design phase of fusion devices. The very high eddy and Halo currents, induced in the passive structures, crossing the electromagnetic field generate huge loads. A Vertical Displacement Event (VDE) begins with a loss of position control that could be triggered by a plasma perturbation (e.g. ELMs, L-H and H-L transitions, minor disruptions, etc

the Be-B films with B doping concentration in range of 0~20at.% were prepared by magnetron sputtering. The phase transition, density, electrical resistance and inner stress were investigated by XRD, SEM, TEM, balance, four-point probe and laser interferometer, respectively. The results suggested that the Be-B films gradually transformed from crystalline phase into amorphous phase, the grains in film

Achieving tritium self-sufficiency (tritium breeding ratio (TBR)≥1.1) is one of the most important missions of the Chinese Fusion Engineering Test Reactor (CFETR). The neutronics analysis shows that the global TBR of the CFETR water-cooled ceramic breeder (WCCB) blanket is 1.147 when the plasma is surrounded by blankets (without any windows), which can meet the tritium self-sufficiency requirement

Tritium breeding capability is one of the most important objectives for fusion reactor design, and the tritium self-sufficiency has been set as a crucial target for the China Fusion Engineering Test Reactor (CFETR). The first wall (FW) is the first component of the blanket facing plasma, which bears high heat flux and high neutron current. Due to the neutrons entering into the blanket pass through

A simple sampler using a brass bar and liquid nitrogen for measuring tritium in workplaces was designed, and the suitability of the device was evaluated. The brass bar was arranged to allow its end to touch liquid nitrogen in a stainless-steel bottle, and the water vapor in the air became saturated and condensed on the surface of the brass bar. The condensation was defrosted and the tritium in the

First plasma operation in ITER will start after completing the assembly of the tokamak vessel and the installation of the main sub-systems, but prior to the installation of the blanket modules and the divertor cassettes. Utilization of temporary limiters and divertor replacement structures will provide a poloidal and toroidal reference side position to the plasma edge to protect the vacuum vessel and

Determining the distribution of plasma current in the equilibrium state is one of the most important steps to realize effective and safe operation of tokamak. In this study, a novel reconstruction code based on Bayesian inference is developed to infer the plasma current distribution for experiment analysis of EAST. Without iteratively solving Grad-Shafranov (G-S) equation to find an optimal fit for

Generally, the accuracy of the key-values extraction algorithm of experimental data will affect the adjustment of the operating parameters of the experimental device, especially when the NBI (Neutral Beam Injector) ion source breakdown occurs. The instability of the internal plasma of the ion source caused by the mismatch of operating parameters is the main cause of breakdown of the NBI ion source

Aiming to efficiently enrich heavier hydrogen isotope on a large scale, a process named Dual-Column Vacuum Pressure and Temperature Swing Adsorption (DC-VPTSA) was proposed and experimentally tested. The process has the following characteristics: 1) two identical separation columns work together; 2) Pressure Swing Adsorption (PSA) process and Temperature Swing Adsorption (TSA) process are coupled;

Sensor technologies will play a key role in the success of Remote Maintenance (RM) systems for future fusion reactors. In this paper, three key types of sensor technologies of particular interest in the robotics field at the moment are evaluated, namely: Colour-Depth cameras, LIDAR (Light Detection And Ranging), and Millimetre-Wave (mmWave) RADAR. The evaluation of the sensors is performed based on

The paper presents the results of reactor experiments with lithium ceramic Li2TiO3 performed at the WWR-K research reactor (Almaty, Kazakhstan). A qualitative analysis of the experimental results is presented. The following general results are obtained from the experiments performed by the vacuum extraction method: • Almost no tritium is released in the form of tritium water vapor, and the processes

Cabling the ReBCO conductor on a round core (CORC) has potential of application for future fusion magnets to carry high current and generate high magnetic field. However, the tape needs to experience the combined tension, compression, bending and torsion stresses during magnet manufacturing. In order to understand the stress effect on the critical current of ReBCO tape with a substrate thickness of

To measure plasma potential in toroidal magnetically confined fusion plasma, the Heavy Ion Beam Diagnostic (HIBD) employs of the electrostatic energy analyzer. The 90° cylindrical energy analyzer (CEA) developed for the HIBD on the ISTTOK tokamak due to compactness and multislit operation capability, is characterized by large angular aberrations, if operated in conventional mode. A new operation regime

The accurate prediction of tritium inventory and permeation fluxes in the breeding blanket of a D-T fusion reactor is a key aspect for future thermonuclear power plants licensing. Tritium permeation into structural materials could give rise to potential issues concerning the fuel self-sufficiency and can be lost into the environment with resulting radiological risks for the population. In the frame

The neutron production in ASDEX Upgrade (AUG) neutral beam injection (NBI) heated discharges is dominated by beam-target fusion reactions. Hence, the neutron rate (NR) and energy distributions are footprints of the fast ion distribution. This motivates to establish a reliable neutron rate calibration. Comparisons at AUG between the experimental NR and the one predicted by the TRANSP code show systematic

We report our study of stress relaxation of Viton™ A hexafluoropropylene-vinylidene fluoride co-polymer fluoroelastomer compressed 25% and irradiated at room temperature in air to nominal absorbed doses of 10 – 106 Gy with 1.17 and 1.33 MeV gammas from a cobalt-60 source. Our data show that the true stresses at room temperature in ring samples of Viton™ A fluoroelastomer compressed 25% decline slightly

The improved thermal desorption diagnostics has been manufactured, installed and tested in the Uragan-2M (U-2M) stellarator [1], [2], [3], [4], [5] for in-situ characterisation a stainless steel (SS) wall outgassing rate and a number of molecular layers of residual gases on its surface in four different positions. The detailed description of this diagnostics, the location of thermal desorption stainless