Materials for Fusion Applications

An overview of materials foreseen for use or already used in fusion devices is given. The operating conditions, material requirements and characteristics of candidate materials in several specific application segments are briefly reviewed. These include: construction materials, electrical insulation, permeation barriers and plasma facing components. Special attention will be paid to the latter and to the issues of plasma-material interaction, materials joining and fuctionally graded interlayers

A Solid breeder tokamak blanket designed for failure mode operation

Statement of responsibility on title-page reads: Franklin Chen, Peter Griffith, Thomas McManamy, and Gary Was"May 1977.""This study is basically an integration and extension of a doctor's thesis by Franklin Chen and a master's thesis by Gary Was."Includes bibliographical references (leaves 244-248)The objective of this study was to evaluate a new concept for a Tokamak type fusion reactor blanket. The design was based on using a packed bed of lithium aluminate as the breeding material with helium gas cooling. The unique aspect of the design was the assumption that small coolant leaks were inevitable and should not necessitate major maintenance. A modularized design was chosen with cylindrical breeder rods and graphite shim rods. Redundancy was provided by designing the blanket such that if a module failed it could be depressurized and its heat load shared by the neighboring operating modules. The thermal hydraulic analysis evolved analytical and computational methods for determining the temperature profiles of all components and the pumping power requirements. A computer program TRIPORT was developed to evaluate the tritium retention and transport. A one dimensional ANISN code was used to determine the breeding ratio for different configurations.!  The thermal hydraulic, neutronic and mechanical aspects of the Breeder Rod Shim Rod (BRSR) design were combined to determine a design window, that is the allowable range of system parameters. Unfortunately adequate breeding could not be demonstrated so that there was no open window. Basically the low breeding was caused by -he inherently poor breeding potential of LiAlO, combined with the additional structure required for failure mode operation. However, this conclusion is based on a specific design concept (BRSR) and further research in the area may prove more fruitful

Materials for Fusion Applications

An overview of materials foreseen for use or already used in fusion devices is given. The operating conditions, material requirements and characteristics of candidate materials in several specific application segments are briefly reviewed. These include: construction materials, electrical insulation, permeation barriers and plasma facing components. Special attention will be paid to the latter and to the issues of plasma-material interaction, materials joining and fuctionally graded interlayers

Experimental Study on Deuterium Extraction from Liquid Pb-Li with the Vacuum Sieve Tray Technique for the European DEMO Fusion Reactor

Das benötigte Tritium eines Fusionskraftwerks wird durch Neutronenbeschuss von Lithium im sogenannten Breeding Blanket (BB) erzeugt. Flüssige Konzepte von BB bestehen aus eutektischem Pb-Li. Das erzeugte Tritium wird aus dem flüssigen Metall bei dem Tritium Extraction and Removal System (TERS) extrahiert. Die Vacuum Sieve Tray (VST) Technologie wird für TERS für das europäische Demonstrationskraftwerk (DEMO) vorgeschlagen, welche eine Extraktionseffizienz von mindestens 80% erfordert. Diese Technik besteht in der Erzeugung kleiner oszillierenden Tröpfchen, die in eine Vakuumkammer fallen. Im Rahmen der vorliegenden Arbeit wurde eine mit Deuterium betriebene VST-Versuchsanlage aufgebaut. Um die Extraktioneffizienz zu bewerten wurden Versuche durchgeführt, die aus zwei Phasen bestehen. Zuerst wird Deuterium in das flüssige Metall (in einer oberen Kammer aus Edelstahl) gelöst und anschließend aus den fallenden Pb-Li-Tröpfchen (in einer unteren Edelstahlkammer unter Vakuum) extrahiert. Die Experimente wurden durch einen entwickelten fluiddynamischen Simulationscode und eine Hochgeschwindigkeitskamera, um die Größe und Bewegung der Flüssigmetalltröpfchen zu analysieren, unterstützt. Die gemessene Menge gelöstes Deuteriums im Pb-Li beträgt $(8.9\pm1.5)\!\times\!10^{-4}$ und $(4.4\pm1.4)\!\times\!10^ {-4}$ mol D$_2$ für Lösedrücke von 1000 bzw. 500 mbar. Diese Ergebnisse werden durch eine sorgfältige Auswertung des in die Struktur verlorenen Deuteriums bestimmt und entsprechen einer Sieverts-Konstanten von $(8.5\pm1.9)\!\times\!10^{-3}$ mol$_\text{D}$ m$^{-3}$ Pa$^{-0.5}$. Die Menge an D$_2$, die aus Tröpfchen mit einem Durchmesser von etwa $1.2\pm0.2$ mm innerhalb einer Fallhöhe von $\approx\!0.5$ m extrahiert wird, ist geringer als $8\!\times\!10^{ -6}$ mol. Dieses Ergebnis impliziert eine Extraktionseffizienz von $\leq\!1.2\%$, die wesentlich niedriger als der erwartete Wert ist, der auf der Diffusion von Deuterium zur Oberfläche der Tröpfchen beruht. Die erhaltenen Ergebnisse legen entweder einen Stoffübergangskoeffizienten von etwa $5\!\times\!10^{-12}$ m$^2$ s$^{-1}$ oder einen oberflächenbegrenzten Extraktionsprozess nahe

Technology Development Roadmap for the Advanced High Temperature Reactor Secondary Heat Exchanger

This Technology Development Roadmap (TDRM) presents the path forward for deploying large-scale molten salt secondary heat exchangers (MS-SHX) and recognizing the benefits of using molten salt as the heat transport medium for advanced high temperature reactors (AHTR). This TDRM will aid in the development and selection of the required heat exchanger for: power production (the first anticipated process heat application), hydrogen production, steam methane reforming, methanol to gasoline production, or ammonia production. This TDRM (a) establishes the current state of molten salt SHX technology readiness, (b) defines a path forward that systematically and effectively tests this technology to overcome areas of uncertainty, (c) demonstrates the achievement of an appropriate level of maturity prior to construction and plant operation, and (d) identifies issues and prioritizes future work for maturing the state of SHX technology. This study discusses the results of a preliminary design analysis of the SHX and explains the evaluation and selection methodology. An important engineering challenge will be to prevent the molten salt from freezing during normal and off-normal operations because of its high melting temperature (390°C for KF ZrF4). The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The need for efficiency, compactness, and safety challenge the capabilities of existing heat exchanger technology. The description of potential heat exchanger configurations or designs (such as printed circuit, spiral or helical coiled, ceramic, plate and fin, and plate type) were covered in an earlier report (Sabharwall et al. 2011). Significant future work, much of which is suggested in this report, is needed before the benefits and full potential of the AHTR can be realized. The execution of this TDRM will focuses research efforts on the near-term qualification, selection, or maturation strategy as detailed in this report. Development of the integration methodology feasibility study, along with research and development (R&D) needs, are ongoing tasks that will be covered in the future reports as work progresses. Section 2 briefly presents the integration of AHTR technology with conventional chemical industrial processes., See Idaho National Laboratory (INL) TEV-1160 (2011) for further detail

Hydrogen interaction with TiC-coated metals for fusion technology application

SIGLEAvailable from British Library Document Supply Centre- DSC:DX97146 / BLDSC - British Library Document Supply CentreGBUnited Kingdo