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Claims  |
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What is claimed is:
1. A method of separating from each other a portion of species from the
other species in a feedstock material comprising:
a. generating a product plasma that is composed principally of species of
elements of the feedstock material by injecting said feedstock material
into a volume plasma processor equipped with a toroidal containment vessel
and with at least one additional containment vessel having an exhaust
pipe, wherein said product plasma has a center and a surface,
b. maintaining said product plasma spaced from walls said toroidal
containment vessel by means of magnetic fields for a period of time over
which the species of elements of said feedstock material in the center of
the plasma diffuse to the surface of the plasma,
c. separating a first portion of the species from the other species by
repeatedly cycling all the species of the product plasma between said
plasma surface and deposition stage lining the toroidal containment vessel
walls such that a portion of species of elements which have high
ionization probability, accumulate on said deposition stages, while other
species, which have a lower ionization probability accumulate and remain
in said product plasma,
d. diverting said accumulated and remained product plasma, into said
additional containment vessel at the end of the period of time over which
the species of elements of the feedstock material from said center of the
plasma diffuse to the plasma surface,
e. causing the diverted plasma to move for an additional period of time
along parallel magnetic fields of said additional containment vessel, such
that species in the moved diverted plasma cools, recombines and lands on
deposition stages lining the walls of said additional containment vessel,
f. collecting landed species on deposition stages of said additional
containment vessel and on louvers terminating said exhaust pipe and,
g. removing from deposition stages of both vessels and louvers the
separated and collected species.
2. The method of claim 1 wherein the separating of the species from each
other is based on their differences in sputtering rates with different
materials, further comprising heating said deposition stages with heating
elements or cooling said deposition stages with cooling coils.
3. The method of claim 2 wherein the deposition stages lining said toroidal
containment vessel are maintained at a temperature of 800.degree. C. to
vaporize alkali metals.
4. The method of claim 1 wherein the separation of the species from each
other is based on their differences in sputtering rates with different
materials, further comprising coating the deposition stages with materials
that are chosen with sputtering coefficients that are higher than specific
species of species of elements such that those species collect in said
remainder product plasma.
5. The method of claim 1 wherein the separating of the species from each
other is based on their differences in chemisorption and physisorption
with different materials, further comprising coating the deposition stages
with materials selected to attach specific species of species of elements
more than others and accumulate those species so that they do not remain
in said remainder product plasma.
6. The method of claim 1 where the species of elements in said diverted
plasma cool and recombine as they move along the parallel magnetic fields
of said additional containment vessel and the species are collected
without further separations on cooled deposition stages.
7. The method of claim 6 where said deposition stages in said additional
containment vessel are cooled to at least room temperature to collect
species of alkali metals.
8. The method or claim 6 where said cooled louvers in the exhaust pipes are
cooled to cryogenic temperatures to collect species of oxygen, hydrogen
and nitrogen.
9. The method of claim 1 where the deposition stages are coated with glass,
quartz, sapphire, ceramics, or composites.
10. A method of separating from each other a portion of species from the
other species in a feedstock material comprising:
a. generating a product plasma that is composed principally of species of
elements of the feedstock material by injecting said feedstock material
into a volume plasma processor equipped with a toroidal containment vessel
and with at least one additional containment vessel having an exhaust pipe
with cooled louvers, wherein said product plasma has a surface,
b. diverting said product plasma containing species of the feedstock into
said additional containment vessel before any repeated cycling of the
species of said product plasma between the plasma surface and the
deposition stages lining the toroidal containment vessel,
c. causing the diverted product plasma to move along parallel magnetic
fields of said additional containment vessel,
d. controlling said diverted product plasma to a temperature range from
about 10,000.degree. C. to about 50,000.degree. C. by at least one means
of radiation cooling to lower the temperature and of raising the
temperature with electromagnetic wave heaters,
e. separating from the diverted plasma some of the species of elements from
each other on the basis of their differences in ionization potential, such
that species with ionization potentials below about 8 ev are maintained in
an ionized state and continue to be confined by said parallel magnetic
fields, while species with ionization potential above about 8 ev recombine
and lands on deposition stages lining wall of said additional containment
vessel or enter said exhaust pipe and strike said cooled louvers in said
exhaust pipe,
f. collecting landed species on deposition stages of said additional
containment vessel and on louvers terminating said exhaust pipe, and
g. removing from the deposition stages and louvers the separated collected
species.
11. The method of claim 10 where the electromagnetic wave heaters maintain
the temperature of said product plasma between 1 and 50 ev.
12. The method of claim 10 wherein the separating of the species from each
other is based on their differences in charge exchange cross sections with
different atomic and molecular species comprising directing beams of said
atomic and molecular species through said product plasma to cause specific
species to become neutral and unconfined by the magnetic field and to
strike the deposition stages in the proximity of the atomic or molecular
beam.
13. The method of claim 10 wherein the separating of the species from each
other is based on their different charge to mass ratios comprising using
rf ponderomotive force applicators to stop parallel motion of specific
species that strike the deposition stages in a proximity of the rf
ponderomotive force applicator.
14. The method of claim 13 where the rf ponderomotive force applicator is
an antenna.
15. A method of separating from each other a portion of species from the
other species in feedstock material comprising:
a. generating a product plasma that is composed principally of species of
elements of the feedstock material by injecting said feedstock material
into a volume plasma processor equipped with a toroidal containment vessel
and with more than one additional containment vessel, having an exhaust
pipe with louvers equipped with means to separate specific species of
elements from each other, wherein said product plasma has a center and a
surface,
b. maintaining most of said product plasma separated from said walls of
said said toroidal containment vessel by magnetic fields while identifying
the species of elements and their location in the product plasma by means
of a spectrometer,
c. choosing one of said additional containment vessels for collecting the
specific species identified in an edge region of the plasma, then,
d. diverting a portion of said product plasma in the edge region into at
least one said additional containment vessel equipped to separate the
species identified in the edge region,
e. causing the diverted product plasma to move along said magnetic fields
of the chosen said additional containment vessel,
f. separating species in the diverted product plasma from the other species
as the plasma moves along said magnetic fields of said additional
containment vessel wherein the separating of the species from each other
is based on their different ionization potentials, interactions, rf
ponderomotive forces, or charge exchange neutralization,
g. collecting said other species of said product plasma that lands on
deposition stages lining walls of said additional containment vessel, and
on said louvers terminating said exhaust pipes, and
h. removing from the deposition stages and louvers separated collected
species.
16. The method of claim 15 where the portion of said product plasma surface
is diverted into said additional containment vessel at any time between 1
millisecond and the time over which species of elements of said feedstock
material in the center of the plasma diffuse to the surface of the plasma.
17. The method of claim 15 where the feedstock material is inhomogeneous
radioactive waste and where the spectrometer identifies regions of the
product plasma initially containing levels of radioactive species content.
18. The method of claim 15 where the volume plasma processor includes at
least two additional confinement vessels and when the product plasma has
high concentrations of radionuclides, further comprising diverting the
product plasma into one of said additional confinement vessels and when
the product plasma has low concentrations of radionuclides, diverting said
product plasma into the other containment vessel.
19. Apparatus which is a large volume plasma processor for separating from
each other a portion of species from the other species in a feedstock
material comprising:
a. a toroidal containment vessel with walls,
b. a gas inlet, to supply a generating gas,
c. means to create ionization in the generating gas,
d. means for generating a magnetic field substantially parallel to the
walls of said toroidal containment vessel and substantially filling said
toroidal containment vessel,
e. means for generating a toroidal current which is substantially parallel
to said toroidal magnetic field and generates a magnetic field, a poloidal
field, perpendicular to the toroidal field,
f. means for heating the generating gas to produce a high temperature, low
density ionized gas plasma with a temperature of at least 500,000.degree.
C.,
g. means for controlling a space between said high temperature, low density
ionized gas plasma and the walls of the containment vessel,
h. means for injecting a portion of the feedstock material at a velocity
into said high temperature, low density ionized gas plasma, which is
identified as a product plasma,
i. means for rapidly increasing the heating means to overcome radiation
losses,
j. means for rapidly stabilizing said product plasma, to initially maintain
the space between the plasma anti the containment vessel walls,
k. means for moving a portion of said product plasma, across said space
between the plasma and the containment vessel walls to deposit the ionized
and unionized species of elements in the feedstock material on deposition
stages lining the walls of the containment vessel,
l. means for modifying the magnetic field by the addition of diverting
magnetic fields to move the plasma into more than one additional
containment vessels lined with deposition stages, and
m means for removing the deposited species from deposition stages.
20. The apparatus of claim 19 where the other containment vessel is an
elongated evacuated container and is surrounded by magnetic field
generating coils which produce magnetic fields that are parallel to the
long axis or said elongated evacuated container and substantially guide
the diverted said product plasma species of the elements of the feedstock
material said product plasma the walls of said elongated evacuated
container.
21. The apparatus of claim 19 where the additional containment vessels are
equipped with means for heating the plasma with electromagnetic wave
heaters, with means for stopping parallel motion of some species with rf
ponderomotive force applicators, with molecular beam projectors means and
with bead projectors means.
22. The apparatus of claim 19 wherein the toroidal containment vessel has a
major radius of between 60 cm and 300 cm and a minor radius of between 20
cm and 200 cm. |
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Claims |
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Description |
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DESCRIPTION
1. Technical Field
This invention relates to a plasma processor which is a species separation
device that converts substances included in toxic materials such as
nuclear wastes or chemical warfare agents into a fully ionized plasma and
separates from each other a portion of species of elements from the other
species of elements and collects them on deposition stages.
2. Background Art
High level nuclear waste tank remediation is a severe problem because
hundreds of storage tanks located at Hanford, and at Savannah River have
been used to process and store radioactive and mixed waste generated from
weapons material production. The waste takes several forms including
sludge, solids and liquids. Complex chemicals include nitrate and nitrate
salts, hydrated metal oxides, phosphate precipitate and ferrocyanides. The
radioactive species include the actenides and fission fragments. This
material is not only difficult to handle, it is difficult to characterize
initially before remediation efforts can even begin. Retrieval and
conveyance to processing apparatus is a problem. Separation of species of
elements one from the other is a complex task and one in which existing
chemical and high temperature plasma torch based technologies can create
additional problems due to contamination and emissions associated with the
process streams. See for example, "Radioactive Waste Tank Remidiation
Focus Area", Technology Summary, DOE Office of Environmental Management,
Jun., 1995.
Arc plasma torches have been applied to low level nuclear wastes derived
from maintenance work at nuclear power stations, hospitals and Research
and Development facilities. These plasma torch systems include filters to
scrub radionuclides and particulates containing radionuclides and are
subject to upsets that can require extensive cleaning and refurbishing.
The problem arises partly because plasma torches are unable to completely
convert solids into gaseous ionized states. See for example, "Plasma
Technology for Rapid Oxidation, Melting, and Vitrification of Low/Medium
Level Radioactive Waste", W. Hoffelner et al, Nuclear Engineering
International, Oct., 1992.
Plasma torches operate from 5,000 to about 15,000 degrees Celsius and
pressures of 100 torr to 3000 torr or more. For a more detailed
understanding of the inability of the technology of commercial plasma
torches to completely vaporize and ionize solids see "Plasma Spray
Coatings", Herman, Scientific American, Sept. 1988 and "A Quarter of a
Century of Plasma Spraying", Zaat, in "Annual Review of Materials
Science," Huggins, Bube and Vermilyea, Annual Reviews Inc., Palo Alto,
Calif., Vol. 13, 1988.
Westinghouse has been a prime leader in applying plasma torches to toxic
wastes. See for example, "Putting a Torch to Toxic Wastes", by John
Holusha, New York Times. Jun. 21, 1989. Again, these plasma torch systems
include filters to scrub particulates and are subject to upsets that can
require extensive cleaning and refurbishing.
A theoretical concept described as "The Fusion Torch" has been proposed by
the inventor to use the high energy flux plasmas typical of controlled
fusion research devices as a "universal solvent" to vaporize, dissociate
and ionize any substance. See for example, "The Fusion Torch-Closing the
Cycle From Use to ReUse", by Bernard J. Eastlund and William C. Gough,
WASH-1132, U.S.A. E. C., May 15, 1969 and "Near Term Recycling Options
Using Fusion-Grade Plasmas", Eastlund and Gough, Fusion Technology,
December, 1991. These papers, and other papers on the "Fusion Torch" cited
in these references were in general terms, did not address high atomic
number radiation loss containment problems and did not specify how to
build such devices for separation purposes.
Boeing Company, Seattle, Wash. initiated studies on separation of one
species, aluminum, from other species, oxygen and silicon in aluminum ore
as a result of a lecture given at Boeing Research Labs by Bernard J.
Eastlund in 1970, and received a patent entitled "Method and Apparatus for
Reducing Matter to Constituent Elements and Separating One of the Elements
from the Other Elements," by James E. Drummond, U.S. Pat. No. 3,942,975,
Mar. 9, 1976. This method was not pursued because the apparatus could not
reliably convert all the solid particulates into ionized gas plasma and
because the density was too high for separations to occur without
interference from multiple collisions.
TRW Inc. of Redondo Beach, Calif. received three patents relating to the
separation of one species of isotopes of elements from other species of
isotopes of elements. These patents are "Separation of Isotopes by Time of
Flight", John Dawson, U.S. Pat. No. 4,059,761, Nov. 22, 1977; "Isotope
Separation by Magnetic Fields", John Dawson, U.S. Pat. No. 4,081,677; and
"Isotope Separation by Ion Waves", U.S. Pat. No. 4,066,893, by John
Dawson, Jan. 3, 1978. These devices were built and tested but were found
to be limited by plasma instabilities that debated efforts to collect the
separated species efficiently. Also, the devices were limited to working
with gaseous feed materials and could not utilize solids.
For a brief description of controlled fusion research devices, see "Fusion
Research", Dolan, Pergamon Press, New York, N.Y., 1982. This, and other
similar articles and books on fusion research are written with emphasis on
the physics necessary to achieve electricity producing controlled fusion
devices and do not emphasize specific descriptions of how to build such
devices for process applications
To operate properly, the Tokamak research devices that have been built need
to prevent high atomic number atoms, such as atoms of tungsten, molybdenum
and iron from sputtering from containment vessel walls and radiating away
the power applied to heat the plasma. See, "The Prospects of Fusion
Power", W. C. Gough and B. J. Eastlund, Scientific American, Feb. 1971,
and "Fusion", Furth, Scientific American, Sept. 1995. Plasma processing
techniques using gas phase feedstock have been used to clean the vacuum
chamber walls and to deposit coatings of low atomic number (Z) materials
such as boron, carbon, lithium and silicon on all parts exposed to the
high temperature plasmas produced in such devices. For example, see
"Physics of Plasma-Wall Interactions in Controlled Fusion", Post et al,
NATO ASI Series, Series B: Physics Vol. 131, Plenum Press, N.Y., 1984.
Solid materials injected into the high energy flux research plasmas have
been used as feedstock for similarly coating the walls. Wall coatings have
been successfully achieved with pellets of low atomic number elements such
as lithium, lithium deuteride, boron and carbon. The carbon pellets have
been difficult to use because they can occasionally cause the high energy
flux research plasmas to become unstable and extinguish. See for example,
"Wall Conditioning Experiments on TFTR Using Impurity Pellet Injection",
Strachan et al, Journal of Nuclear Materials 217, 145-153, 1994. Pellets
of tungsten, molybdenum and other high Z materials immediately extinguish
the plasmas in Tokamak devices as presently built and operated. For
descriptions of how to build a Tokamak device, see "The Texas Experimental
Tokamak, A Fusion Plasma Research Facility", Proposal to The Energy
Research and Development Administration, by The Fusion Research Center of
the University of Texas at Austin, Jun., 1976.
A paper has appeared in which a Tokamak fusion research device was
suggested as a means of pyrolysis of toxic wastes, but, like "The Fusion
Torch", this work did not address key issues of how to construct a device
that could handle disruptions caused by toxic materials with high Z
content. See "Pyrolysis in Tokamak Plasmas", McNeil, Industrial
Applications of Plasma Physics, ISPP-13, edited by Bonizzoni, Hooke and
Sindoni, SIF, Bologna, 1993.
Thus, present technologies for remediation of toxic or radioactive wastes
are limited by problems associated with the complexity and inhomogeneity
of the substances and by contamination and emissions associated with
process streams, especially as a consequence of malfunctions. The waste
tanks at Hanford are so dangerous and difficult to deal with, that it is a
major problem to identify or characterize the waste materials in
sufficient detail to facilitate conventional remediation steps. The plasma
torch approaches to date are limited in ability to handle substances with
high atomic numbers.
DISCLOSURE OF INVENTION
This invention has been made in order to solve problems associated with
remediation of toxic or radioactive waste tanks. In particular, it
provides a means of using the high temperature plasma of a large volume
plasma processor to ionize any feedstock material such as radioactive
wastes and for separation of some of the elements from the other elements.
The invention allows real time characterization of the elemental
constituants of the waste, separates the most dangerous radioactive
elements from the benign elements of the waste, and minimizes residual
contaminant release by carrying out all processing within a closed vacuum
environment. The principal object of this invention is to provide three
principal novel methods of separating from each other a portion of species
from the other species in any feedstock material, such as radioactive
wastes. For further description of the Large Volume Plasma Processor see
the U.S. Pat. No. 5,630,880 entitled "Method and Apparatus for a Large
Volume Plasma Processor That Can Ionize Any Material" by Bernard John
Eastlund, submitted simultaneously with this patent application.
One principal method in accordance with this invention is to utilize a
large volume plasma processor to separate some of the elements from the
other elements in a series of seven steps. The first step is to generate a
product plasma that is composed principally of the ionized and unionized
species of elements of the feedstock material by means of injecting the
feedstock material, such as radioactive wastes into a large volume plasma
processor equipped with a toroidal containment vessel and with at least
one additional containment vessel. The second step is to maintain the
product plasma spaced from the toroidal containment vessel walls by means
of magnetic fields for the period of time over which the ionized and
unionized species of elements of the feedstock material in the center of
the plasma diffuses to the surface of the plasma. Next a first portion of
the species is separated from the other species by repeatedly cycling all
of the species of the product plasma between the plasma surface and
deposition stages lining the toroidal containment vessel walls, whereby a
portion of the elements which have high ionization probabilities, such as
metals, preferentially accumulate on the deposition stages, while other
species such as oxygen, nitrogen and hydrogen, which have lower ionization
probabilities accumulate in the remainder of the confined product plasma.
The fourth step is to divert the remainder of the species of the product
plasma, containing species such as oxygen, nitrogen and hydrogen into the
additional containment vessel at the end of the time over which the
ionized and unionized species of elements of the feedstock material from
the center of the plasma diffuse to the plasma surface. The fifth step is
to cause these remaining species to move for an additional period of time
along the parallel magnetic fields of the additional containment vessel.
The sixth step is to collect the species moving along the additional
containment vessel as they cool and recombine and land on the deposition
stages lining the walls of the additional containment vessel. The seventh
and final step is to remove the deposition stages with the collected
material from the large volume plasma processor.
Another object of this invention is a method of separating the species of
elements from each other on the basis of their differential sputtering
rates with specially prepared materials.
Another object of this invention is a method of separating the species of
elements from each other on the basis of their differential physisorption
and chemisorption rates of interaction with specially prepared materials.
A second principal method in accordance with this invention differs from
the first principal method by carrying out the separation of the species
of elements from each other entirely in an additional confinement vessel
The crucial step of this method is to separate the species of elements
from each other based on their differences in ionization potential.
Another object of this invention is a method of separating the species of
elements from each other on the basis of their differences in charge
exchange cross sections with different atomic and molecular species.
Another object of this invention is a means of separating the species of
elements from each other on the basis of their differences in charge to
mass ratios.
Another object of this invention is a means of separating the species of
elements from each other on the basis of their difference in attachment to
ceramic, glass or other non-metallic beads.
A third principal method in accordance with this invention utilizes
spectrometer obtained information that identifies the species and their
spatial location in the product plasma to make decisions to divert the
identified species into at least one of more than one additional
containment vessels, one of which has means to separate the species from
each other of high level nuclear waste and the other has means to separate
the species from each other of low level nuclear waste.
These methods provide a unique new method for characterization, separation
and preparation for either permanant storage or transmutation of high
level nuclear wastes.
Another object of this invention is to provide a novel large volume plasma
processor apparatus for converting any feedstock material, such as high
level nuclear waste, into a product plasma composed of the species of
elements in the feedstock material
Another object of this invention is to provide additional confinement
vessels and means to divert the product plasma into those vessels.
Another object of this invention is to provide apparatus in the additional
confinement vessels with means for heating the plasma with electromagnetic
wave heaters, with rf ponderomotive force applicators, with atomic and
molecular beam projectors and with bead projectors.
This invention is a unique new method and apparatus for characterization,
separation and preparation for either permanant storage or transmutation
of high level nuclear wastes. The methods described herein can be used for
reactor fuel element reprocessing, for elimination of chemical toxic
wastes and can eliminate chemical or germ warfare weapons.
Other objects, features, and advantages of the invention will be apparent
from the drawings, from the specifications and embodiments, and the
claims,
BRIEF DESCRIPTION OF THE DRAWINGS
The actual construction, operation and apparant advantages of this
invention will be better understood by referring to the drawings in which
like numerals identify like parts and in which:
FIG. 1 is a top view, partly in blocks, showing the construction details of
a large volume plasma processor.
FIG. 2 is a cross section, partly in blocks, through the line 2 in FIG. 1,
that shows internal construction details of the large volume plasma
processor.
FIG. 3 is a top view, partly in blocks, that shows an injector portion and
an antenna attached to the large volume plasma processor.
FIG. 4 is a cross section, partly in blocks, through the line 3 in FIG. 3,
that shows additional construction details of the large volume plasma
processor.
FIG. 5 is a detailed block diagram of a driving power source for the
toroidal field coils shown in FIG. 1.
FIG. 6 is a detailed block diagram of a driving power source for the ohmic
heating coils shown in FIG. 1.
FIG. 7 is a detailed block diagram of a driving power source for the
vertical field coils shown in FIG. 1.
FIG. 8 is a detailed block diagram of a driving power source for the iron
core bias field coils shown in FIG. 1.
FIG. 9 is a detailed block diagram of an enhanced driving power source for
the ohmic heating coils.
FIG. 10 is a detailed block diagram of the driving power source for the
additional ohmic heating coils.
FIG. 11 is a detailed block diagram of a driving power source for the lower
hybrid heating system. in FIG. 10.
FIG. 12 is a top view and cross section, partly in blocks, showing the
addition of magnetic field coils for diverting the plasma from the
toroidal containment vessel into an additional containment vessel.
FIG. 13 is a schematic depicting the magnetic fields puckered out by the
diverting magnetic field coils of FIG. 12.
FIG. 14 is a detailed block diagram of a driving power source for the
diverting field coil shown in FIG. 12.
FIG. 15 is a detailed block diagram of a driving power source for the
toroidal field nulling coils shown in FIG. 12.
FIG. 16 is a detailed block diagram of a driving power source for the
expander field coils shown in FIG. 12.
FIG. 17 is a schematic depicting the electric current and magnetic field
structure in the toroidal containment vessel.
FIG. 18a is a waveform diagram showing the time dependence of the loop
voltage which causes ohmic heating current to flow in the toroidal
direction in the toroidal containment vessel.
FIG. 18b is a waveform diagram showing the time dependence of the electric
current.
FIG. 18c is a waveform diagram showing the time dependence of electron
number density.
FIG. 18d is a waveform showing the time dependence of the electron
temperature.
FIG. 19a is a waveform diagram showing the time dependence of loop voltage
during low atomic number pellet injection.
FIG. 19b is a waveform diagram showing the time dependence of electric
current during low atomic number pellet injection.
FIG. 19c is a waveform diagram showing the time dependence of electron
number density during low atomic number pellet injection.
FIG. 19d is a waveform diagram showing the time dependence of electron
temperature during low atomic number pellet injection.
FIG. 20a is a waveform diagram showing the time dependence of loop voltage
during high atomic number pellet injection.
FIG. 20b is a waveform diagram showing the time dependence of electric
current during high atomic number pellet injection.
FIG. 20c is a waveform diagram showing the time dependence of electron
number density during high atomic number pellet injection.
FIG. 20d is a waveform diagram showing the time dependence of electron
temperature during high atomic number pellet injection.
FIG. 21a is a waveform diagram showing the time dependence of loop voltage
during high atomic number pellet injection with stabilization.
FIG. 21b is a waveform diagram showing the time dependence of electric
current during high atomic number pellet injection with stabilization.
FIG. 21c is a waveform diagram showing the time dependence of electron
number density during high atomic number pellet injection with
stabilization.
FIG. 21d is a waveform diagram showing the time dependence of electron
temperature during high atomic number pellet injection with stabilization.
FIG. 22 is a waveform diagram for repetitively pulsed operation.
FIG. 23a is a waveform diagram of the time dependence of the loop voltage
during stabilized high atomic number pellet injection.
FIG. 23b is a graph of the species concentration versus radius.
FIG. 24 is a block diagram of the separation of species using the first
principal method.
FIG. 25 is a cross section of an additional confinement vessel equipped
with various separation devices.
FIG. 26 is a block diagram of the separation of species using the second
principal method.
PREFERRED EMBODIMENTS OF THE INVENTION
Now, embodiments of this invention will be described in detail with
reference to the accompanying drawings.
FIGS. 1 and FIG. 2 describe the system components required to build a large
volume plasma processor that can generate a product plasma composed
principally of the ionized and unionized species of elements of any
feedstock material such as uncharacterized high level nuclear waste.
FIG. 1 is a top view, partly in blocks, that shows construction details of
a large volume plasma processor that produces a high temperature, low
density plasma with a high energy flux that is called a process plasma.
comprising a process plasma generation portion 10 with a toroidal
containment vessel 11, a gas inlet 12 for supplying a generating gas, such
as hydrogen, helium or neon, for the generation of the process plasma,
toroidal magnetic field generation cells 13, a driving power source 14 for
the toroidal field generation coils, an iron core yoke 15 to link the
current in the ohmic heating cells with the toroidal current in the
toroidal containment vessel.
FIG. 2 is a cross section, partly in blocks, through the line 2 in FIG. 1,
that shows internal construction details of the large volume plasma
processor, with a plasma ignitor 20, ohmic heating cells 21 for heating
the process plasma, a driving power source 22 for the ohmic heating cells,
vertical field coils 23 for positioning the process plasma within the
toroidal containment vessel 11, a driving power source 24 for the vertical
field coils, iron cora bias field cells 25, a driving power source 26 for
the iron core bias field coils, limiters 27 to define the shape of the
high energy flux plasma, and an exhaust pipe 28.
FIG. 3 and FIG. 4 describe the system components that are used to inject
feedstock material and to heat and stabilize the interacting mixture of
process plasma and feedstock material, referred to as the "combination
plasma" in the disclosure above.
FIG. 3 is a top view, partly in blocks, that shows an injector portion 30
and an antenna 31 attached to the toroidal containment vessel 11.
FIG. 4 is a cross section, partly in blocks, through the line 3 in FIG. 3,
that shows internal details that include additional ohmic heating coils
41, driving power source 42 for the additional ohmic heating coils,
enhanced driving power source 43 for the ohmic heating coils 15, an
antenna 31 and a driving power source 44 which is a lower hybrid frequency
generator for the antenna 31 and deposition stages 45.
By way of example, a set of typical parameters for component sizes and
power supplies suitable for a pulsed mode of operation are described in
detail.
The typical dimensions for the toroidal containment vessel 11 of FIG. 1 are
a major radius, R.sub.M, of 100 cm and a minor radius, r.sub.m, of about
50 cm. A typical material for the containment vessel 11 is stainless steel
with a ceramic gap to allow transient magnetic fields to enter the
containment vessel. The cross section of the toroidal containment vessel
can be square as shown in FIG. 2, in which case r.sub.m is a mean of the
dimensions. The cross section can be circular, octaganal or any continuous
shape.
The toroidal magnetic field generation coils 13 as shown in FIG. 1 are made
with 6 turns of copper wire that have a resistance of 1.2 milliohms and an
inductance of 2 millihenry's. The outer dimensions of each coil are 150
cm.times.150 cm.times.90 cm. The bore is a rectangle with dimensions of 80
cm.times.90 cm.
A detailed block diagram of the driving power source 14 for the toroidal
field coils is shown in FIG. 5. By way of example, this driving power
source for the toroidal field coils is constructed with a power source 50
of 500 volts with single phase current capability of 157 kiloamperes, with
a total power capability of 65 Megawatts, a voltage controller 52 which
controls the output power of the power source 50, a rectifier circuit 52,
which rectifies the controlled output current, a trigger circuit 53, which
generates firing signals, and a switching circuit 54 to turn the system on
and off.
The ohmic heating coils 21 of FIG. 4 are made with copper coils of from 90
to 180 cm in diameter with conducting cross sections of about 2.times.5
cm.
A detailed block diagram of the driving power source 22 for the ohmic
heating coils 21 of FIG. 2 is shown in FIG. 6. By way of example, this
driving power source for the ohmic heating coils is constructed with a
power source 60 of up to 2000 volts with single phase current capability
of 10 kiloamperes, with a total power capability of 2 Megawatts, a voltage
controller 61 which controls the output power of the power source 60, a
rectifier circuit 62, which rectifies the controlled output current, a
trigger circuit 63, which generates firing signals, and a switching
circuit 64 to turn the system on and off.
The vertical field coils 23 of FIG. 2 are for positioning the high energy
flux within the toroidal containment vessel 11 are made of copper and
encircle the torus in the same fashion as the ohmic heating coils 2t but
are configured so that the net vertical field current circulating around
the iron core is zero. Residual mutual inductance is cancelled out by
raising the mutual inductance in the power feed circuits. An active
feedback system from sensors that determine the position of the toroidal
high energy flux plasma quickly change the current in the vertical field
coils 23 to maintain position within the toroidal chamber.
A detailed block diagram of the driving power source 24 for the vertical
field coils is shown in FIG. 7. By way of example, this driving power
source for the vertical field coils is constructed with a power source 70
of up to 180 volts with single phase current capability of 10 kiloamperes,
with a total power capability of 2 Megawatts, a voltage controller 71
which controls the output power of the power source 70, a rectifier
circuit 72, which rectifies the controlled output current, a trigger
circuit 73, which generates firing signals, and a switching circuit 74 to
turn the system on and off.
The iron core bias field coils 25 of FIG. 2 consist of 40 turns of copper
conductor 2.times.5 cm in cross section. these are wrapped around the
center of the iron core.
A detailed block diagram of the driving power source 26 for the iron core
bias field coils is shown in FIG. 8. By way of example, this driving power
source for the iron core bias field coils is constructed with a power
source 80 of up to 180 volts with single phase current capability of 10
kiloamperes, with a total power capability of 2 Megawatts, a voltage
controller 81 which controls the output power of the power source 80, a
rectifier circuit 82, which rectifies the controlled output current, a
trigger circuit 83, which generates firing signals, and a switching
circuit 84 to turn the system on and off.
The injector portion 30 of FIG. 3 is for injecting pellets of feedstock
material into the process plasma formed with the equipment described
above. The injector technology assumed for this example is a a gas fired
pellet gun. For detailed discussion of pellet injection equipment options
see "Pellet Injection Technology", Combs, Rev. Sci. Instrum., Vol 64, No.
7, July, 1993. The injector is designed to shoot pellets of fee | | |
