NOEL-A no-leak fusion blanket concept

Thermal analysis and tests of a non-leak fusion blanket concept (NOEL-No External Leak) are presented. The NOEL blanket module operates with a material A that is present in both its solid and liquid phases. The solid phase zone of material A is maintained as a thick lining on the inside of blanket module shells (which are made of stainless steel, aluminum or any other structural metal and serve as the first wall) by cooling tubes embedded in the solid zone. These metal tubes carry a liquid or gas coolant B at a temperature below the melting point of A. Most of the 14 MeV neutron energy is deposited as heat in the module interior, and the temperature increase from the shell to the interior due to heat flow is sufficient to keep the interior liquid. Pressure on the liquid A interior is maintained at a higher level than the pressure on B, so that B can not leak out if failures occur in the coolant tubes embedded in the frozen layer

HYFIRE: a tokamak-high-temperature electrolysis system

Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400/sup 0/C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700/sup 0/ to 800/sup 0/C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constituents, H/sub 2/ and O/sub 2/, electrical input is required. Fourteen hundred degree steam coupled with 40% power efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

Fusion-Fission Hybrid Reactors

to the design of hybrid reactors and to inform the new generation of hybrid reactor researchers of the hybrid reactor data base developed in the seventies and early eighties

Galileo`s relativity principle, the concept of pressure, and complex characteristics, for the six-equation, one-pressure model

We have studied various formulations of the concept of pressure, in the context of the usual Six-Equation Model of thermal-hydraulics. A different concept of pressure, than the usual one, has been used. This new pressure concept is Galilean Invariant, and results for the One-Pressure Model with the same complex characteristic roots as the ``Basic III-Posed Model,`` discussed in the literature for the cases we have investigated. We have also examined several Two-Pressure formulations and shown that two pressures are a necessary but not sufficient condition for obtaining a Well-Posed system. Several counter examples are presented. We have shown that the standard theory is not Galilean Invariant and suggested that the origin of III-Posedness is due to our closure relationships. We also question whether the current theory can satisfy conservation principles for mass, energy, and momentum

Study of limiter damage in a magnetic-field error region of the ZT-40M experiment

A study has been initiated of material plasma interactions on the ZT-40M, Reversed Field Pinch (RFP) plasma physics confinement experiment at Los Alamos National Laboratory. Observations of the evaporation and cracking to TiC coatings, initially placed on an AXF-5Q Graphite mushroom limiter, installed in a high field error region (e.g. an experimental vacuum vessel/liner port) were investigated. A parametric study was performed of the thermal and stress behavior of the limiter and coating materials undergoing plasma material heat exchange processes, in order to infer the magnitude of heat flux necessary to explain the observed material damage. In addition the vacuum (liner) wall material behavior was studied parametrically using the same heat flux values as the limiter study. A one-dimensional conduction model was used with applied heat and radiation boundary conditions, for predicting temperature distributions in space and time, where the thermal stress was calculated using a restrained in bending only plate model. Wall loadings corresponding to first wall, limiter energy fluxes ranging between 1 x 10/sup 2/ W/cm/sup 2/ and 1 x 10/sup 5/ W/cm/sup 2/ were used as parameters with plasma material interaction times (tau/sub QO) between 0.5 ms and 10 ms. Short plasma energy deposition time (tau/sub QO/ > 10 ms) spacial and time histories of temperature and stress were calculated for SS-304, Inconel-625, TiC and AXF -5Q Graphite materials

Review of melting and evaporation of fusion-reactor first walls

The most severe thermal loading on the first wall will occur when the plasma becomes unstable resulting in a hard plasma disruption or at the end of a discharge when the plasma is dumped on the wall in a very short period of time. Hard plasma disruptions are of particular concern in future fusion reactors where the thermal energy of the plasma may reach values on the order of 300 MJ. Sufficiently high heating rates can occur to melt the first wall surface, and the temperature can increase resulting in vaporization. Thermal models are reviewed which treat these problems

Aspects of microwave-heating uniformity

Interest has been shown in the field of nuclear reactor safety in the use of microwave heating to simulate the nuclear heat source. The objective of the investigation reported here was to evaluate the usefulness of microwave dielectric heating as a simulator of the nuclear heat source in experiments which simulate the process of boiling of molten mixtures of nuclear fuel and steel. This paper summarizes the results of studies of several aspects of energy deposition in dielectric liquid samples which are exposed to microwave radiation

Heat transfer modelling of first walls subject to plasma disruption

A brief description of the plasma disruption problem and potential thermal consequences to the first wall is given. Thermal models reviewed include: a) melting of a solid with melt layer in place; b) melting of a solid with complete removal of melt (ablation); c) melting/vaporization of a solid; and d) vaporization of a solid but no phase change affecting the temperature profile

Microwave heating simulations of fission energy generation in volume-boiling pool systems

The transition phase of the (hypothetical) loss-of-flow accident in LMFBR's may be characterized by the temporary entrapment of boiling pools of molten fuel and steel within the original core boundaries. Experiments to investigate the multiphase flow and heat transfer characteristics of such systems have been performed and are planned in which simulant fluids are volume-heated by microwave electromagnetic radiation. It has been assumed that the microwave radiation provides a spatially uniform energy source per unit volume of liquid in multiphase flow geometries. It is known, however, that energy absorption by dielectrics in a microwave electromagnetic field is a function of geometry, dielectric properties, and wavelength of the radiation. At high power density, volume-heated boiling pools exhibit a complex two-phase, liquid-vapor, geometric structure. Dispersed droplets, with diameters less than 1 mm, in a vapor continuum may coexist with continuous liquid structures of centimeter scale or greater. This study was performed to: (i) investigate the uniformity of microwave heating in boiling pool systems as a function of liquid geometry; and (ii) design an experimental system employing microwave heating in which the heat generation rate per unit volume of liquid is independent of geometric structure. The results of the study are presented

Fast power cycle for fusion reactors

The unique, deep penetration capability of 14 MeV neutrons produced in DT fusion reactions allows the generation of very high temperature working fluid temperatures in a thermal power cycle. In the FAST (Fusion Augmented Steam Turbine) power cycle steam is directly superheated by the high temperature ceramic refractory interior of the blanket, after being generated by heat extracted from the relatively cool blanket structure. The steam is then passed to a high temperature gas turbine for power generation. Cycle studies have been carried out for a range of turbine inlet temperatures (1600/sup 0/F to 3000/sup 0/F (870 to 1650/sup 0/C)), number of reheats, turbine mechanical efficiency, recuperator effectiveness, and system pressure losses. Gross cycle efficiency is projected to be in the range of 55 to 60%, (fusion energy to electric power), depending on parameters selected. Turbine inlet temperatures above 2000/sup 0/F, while they do increase efficiency somewhat, are not necessarily for high cycle efficiency