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LIST OF ITEMS TO BE REPORTED TO IAEA
Items marked *
and shaded are prohibited to Iraq under Resolution
687.
The notation (SC II) or (SC IV)
indicates that items of the same type/category are also listed in
one of the Annexes (2 or 4, respectively) of the UN Special Commission
Plan.
NUCLEAR
MATERIALS
1. Source and special fissionable material as follows:
1.1. Uranium containing the mixture of isotopes occurring in
nature; uranium depleted in the isotope 235; thorium; any of the foregoing
in the form of metal, alloy, chemical compound or concentrate and any
other goods containing one or more of the foregoing. 1.2.
Low Enriched Uranium (LEU), or plutonium as follows:
Uranium
enriched to less than 20% of the isotopes 233, 235, or both; plutonium
with an isotopic concentration of Pu-238 exceeding 80%; any of the foregoing
in the form of metal, alloy, chemical compound or concentrate and any
other goods containing one or more of the foregoing. 1.3.
*Highly Enriched Uranium (HEU) or plutonium, as follows: Uranium
enriched to 20% or more in isotopes 233, 235, or both; plutonium containing
less than 80% plutonium 238; any of the foregoing in the form of metal,
alloy, chemical compound or concentrate and any other goods containing
one or more of the foregoing except for the following items which
are not prohibited, but are controlled:
(a) certified reference material; (b)
instrument calibration source; or
1.4.
*Irradiated nuclear fuel
Sub-gram amounts of the special fissionable material specified in 1.3
above in the form of:
(c) sensing components in instruments
EXPLANATORY NOTE:
The
prohibition applies only to the transfer of irradiated nuclear fuel
to Iraq.
NON-NUCLEAR MATERIALS
2. Zirconium (SC IV)
2.1. Zirconium metal and alloys in the form of tubes, or assemblies
of tubes, specially designed or prepared for use in a nuclear reactor
and in which the relation of hafnium to zirconium is less than 1:500
parts by weight. 2.2.
Zirconium as follows: metal, alloys containing more than 50%
zirconium by weight, and compounds in which the ratio of hafnium content
to zirconium content is less than 1 part to 500 parts by weight, and
manufactures wholly thereof; except zirconium in the form of foil having
a thickness not exceeding 0.10 mm (0.004 in). TECHNICAL
NOTE: This
applies to waste and scrap containing zirconium as defined here.
3. Aluminum alloys
Aluminum alloys capable of an ultimate tensile strength of 460 MPa (0.46 x 109 N/m2) or more at 293 K (20C), in the form of tubes or solid forms (including forgings) having an outside diameter or more than 75 mm (3 in).
TECHNICAL NOTE: The phrase "capable of" encompasses aluminum alloys before or after heat treatment.
4. Fibrous or filamentary materials (SC IV)
4.1. Carbon or aramid fibrous or filamentary materials
having a specific modulus of 12.7 x 10^6 m or greater or a
specific tensile strength of 23.5 x 10^4 m or greater; or
4.2. Glass fibrous or filamentary materials having a specific
modulus of 3.18 x 10^6 m or greater and a specific tensile
strength of 7.62 x 10^4 m or greater; 4.3.
*Composite structures in the form of tubes with an inside diameter of
between 75 mm (3 in) and 400 mm (16 in) made with fibrous or filamentary
materials described in 4.1 and 4.2 above.
TECHNICAL NOTE: "Specific
modulus" is the Young's modulus in N/m2 divided by the specific weight
in N/m3 when measured at a temperature of 23±2C and a relative humidity
of 50±5% "Specific
tensile strength" is the ultimate tensile strength in N/m2 divided
by the specific weight in N/m3 when measured at a temperature of 23±2C
and a relative humidity of 50±5%.
The term "fibrous or filamentary materials" includes continuous
monofilaments, continuous yarns, and tapes;
5. *Maraging steel (SC IV)
Maraging steel capable of an ultimate tensile strength of 2050 MPa (2.050 x 109 N/m2) (300,000 lb/in2) or more at 293 K (20C) except forms in which no linear dimension exceeds 75 mm (3 in).
TECHNICAL
NOTE:
The phrase "capable of" encompasses maraging steel before or after heat
treatment.
6. Titanium
Titanium alloys capable of an ultimate tensile strength of 900 MPa (0.9 x 109 N/m2) or more at 293 K (20C) in the form of tubes or solid forms (including forgings) with an outside diameter more than 75 mm (3 in).
TECHNICAL
NOTE:
The phrase "capable of" encompasses titanium alloys before or after heat
treatment.
7. Chlorine trifluoride (SC IV)
8. *Fast-reacting ion-exchange resins/adsorbents
Fast-reacting ion-exchange resins or adsorbents specially designed or prepared for uranium enrichment using the ion exchange process, including porous macroreticular resins, and/or pellicular structures in which the active chemical exchange groups are limited to a coating on the surface of an inactive porous support structure, and other composite structures in any suitable form including particles or fibers. These ion exchange resins/adsorbents have diameters of 0.2 mm or less and must be chemically resistant to concentrated hydrochloric acid solutions, as well as, physically strong enough so as not to degrade in the exchange columns. The resins/adsorbents are specially designed to achieve very fast uranium isotope exchange kinetics (exchange rate half-time of less than 10 seconds) and are capable of operating at a temperature in the range of 100C to 200C.
9. Beryllium (SC IV)
Beryllium as follows: metal, alloys containing more than 50% of beryllium by weight, compounds containing beryllium and manufactures thereof; except:
9.1. Metal windows for X-ray machines; 9.2.
Oxide shapes in fabricated or semi-fabricated forms specially
designed for electronic component parts or as substrates for electronic
circuits; 9.3.
Naturally occurring compounds containing beryllium.
TECHNICAL
NOTE:
This entry includes waste and scrap containing beryllium as defined
here.
10. Calcium
Calcium metal containing both equal to or less than 0.2% by weight of impurities other than magnesium and less than 20 ppm of boron.
11. Magnesium (SC IV)
Magnesium metal containing both equal to or less than 0.2% by weight of impurities other than calcium and less than 20 PPM of boron.
12. Tantalum (SC IV)
Tantalum sheets with a thickness of 2.5 mm or greater from which a circle of 200 mm diameter can be obtained.
13. Tungsten, as follows: (SC IV)
Parts made of tungsten, tungsten carbide, or tungsten alloys (greater than 90% tungsten) having a mass greater than 20 kg and a hollow cylindrical symmetry (including cylinder segments) with an inside diameter greater than 100 mm (4 in ) but less than 300 mm (12 in).
14. Hafnium
Hafnium as follows: metal, alloys, and compounds of hafnium containing more than 60% hafnium by weight and manufactures thereof.
15. Boron
Boron and boron compounds, mixtures and loaded materials in which the boron-10 isotope is more than 20% by weight of the total boron content.
16. Bismuth
High Purity (99.99% or greater) bismuth with very low silver content (less than 10 parts per million).
17. Lithium
Isotopically enriched in lithium-6; as follows:
17.1 *Metal, hydrides or alloys containing lithium enriched in the lithium-6 isotope (6Li) to a concentration higher that the one existing in nature (7.5% on an atom percentage basis):
17.2. *Any other materials containing lithium enriched in the lithium-6 isotope (including compounds, mixtures and concentrates):
17.3. 6Li incorporated in thermoluminescent dosimeters.
18. *Helium-3
Helium
in any form isotopically enriched in the helium-3 isotope, whether or
not mixed with other materials or contained in any equipment or device,
except for the following items which are not prohibited, but are controlled:
Products or devices containing less than 1 g of helium-3.
19. Tritium
19.1. *Tritium, including compounds and mixtures, containing
tritium in which the ratio of tritium to hydrogenby atoms exceeds 1
part in 1000. 19.2.
Tritium in luminescent devices (e.g. safety devices installed in aircraft,
watches, runway lights) containing more than 40 Ci of tritium in any
chemical or physical form. 19.3.
Tritium labeled organic compounds
20. Deuterium and heavy water
Deuterium, heavy water (deuterium oxide) and any other deuterium compound in which the ratio of deuterium to hydrogen atoms exceeds 1:5000 for use in a nuclear reactor.
21. Nuclear grade graphite
Graphite having a purity level better than 5 parts per million boron equivalent and with a density greater than 1.50 g/cm^3.
* PLANTS FOR THE SEPARATION OF ISOTOPES OF URANIUM AND EQUIPMENT, OTHER THAN ANALYTICAL INSTRUMENTS, SPECIALLY DESIGNED OR PREPARED THEREFOR
Items of equipment that are considered to fall within the meaning of the phrase "equipment other than analytical instruments, specially designed or prepared" for the separation of isotopes of uranium include:
22. *Gas centrifuges and assemblies and components specially designed or prepared for use in gas centrifuges
INTRODUCTORY NOTE
The gas centrifuge normally consists of a thin-walled cylinder(s) of between
75 mm (3 in) and 400 mm (16 in) diameter contained in a vacuum environment
and spun at high peripheral speed of the order of 300 m/s or more with
its central axis vertical. In order to achieve high speed, the materials
of construction for the rotating components have to be of a high strength
to density ratio and the rotor assembly, and hence its individual components
have to be manufactured to very close tolerances in order to minimize
the imbalance. In contrast to other centrifuges, the gas centrifuge for
uranium enrichment is characterized by having, within the rotor chamber,
a rotating disc-shaped baffle(s) and a stationary tube arrangement for
feeding and extracting the UF6 gas and featuring at least 3
separate channels, of which 2 are connected to scoops extending from the
rotor axis towards the periphery of the rotor chamber. Also contained
within the vacuum environment are a number of critical items which do
not rotate and which, although they are specially designed, are not difficult
to fabricate, nor are they fabricated out of unique materials. A centrifuge
facility, however, requires a large number of these components, so that
quantities can provide an important indication of end use.
22.1. *Rotating components
(a)
Complete rotor assemblies: Thin-walled cylinders (or a number
of interconnected thin-walled cylinders) manufactured from one or
more of the high strength to density ratio materials described in
the explanatory note to this section. If interconnected, the cylinders
are joined together by flexible bellows or rings as described in section
(c) following. The rotor is fitted with an internal baffle(s) and
end caps, as described in section (d) and (e) following, if in final
form. However, the complete assembly may be delivered only partly
assembled. (b)
Rotor tubes: Specially designed or prepared thin-walled cylinders
with thickness of 12 mm (0.5 in) or less, a diameter of between 75
mm (3 in) and 400 mm (16 in), and manufactured from one or more of
the high strength to density ratio materials described in the explanatory
note to this section. (c)
Rings or bellows: Components specially designed or prepared
to give localized support to the rotor tube or to join together a
number of rotor tubes. The bellows is a short cylinder of wall thickness
3 mm (0.12 in) or less, a diameter of between 75 mm (3 in) and 400
mm (16 in), having a convolute and manufactured from one or more of
the high strength to density ratio materials described in the explanatory
note to this section. (d)
Baffles: Disc-shaped components of between 75 mm (3 in) and
400 mm (16 in) in diameter specially designed or prepared to be mounted
inside the centrifuge rotor tube, in order to isolate the take-off
chamber from the main separation chamber and, in some cases, to assist
the UF6 gas circulation within the main separation chamber
of the rotor tube, and manufactured from one or more of the high strength
to density ratio materials described in the explanatory note to this
section. (e)
Top caps/Bottom caps: Disc-shaped components of between 75
mm (3 in) and 400 mm (16 in) in diameter specially designed or prepared
to fit to the ends of the rotor tube, and so contain the UF6
within the rotor tube, and in some cases to support, retain, or contain
as an integrated part an element of the upper bearing (top cap) or
to carry the rotating elements of the motor and lower bearing (bottom
cap), and manufactured from one of the high strength to density ratio
materials described in the explanatory notes to this section. EXPLANATORY
NOTE:
The materials used for centrifuge rotating components are: Maraging
steel capable of an ultimate tensile strength of 2.05 x 109
N/m2 (300,000 psi) or more; Aluminum alloys capable of
an ultimate tensile strength of 0.46 x 109 N/m2
(67,000 psi) or more; Filamentary materials suitable for use in composite
structures and having a specific modulus of 12.3 x 106
m or greater and a specific ultimate tensile strength of 0.3 x 106
m or greater ('Specific Modulus' is the 'Young Modulus in N/m2
divided by the specific weight in N/m3; 'Specific
Ultimate Tensile Strength' is the ultimate tensile strength in N/m2
divided by the specific weight in N/m3.)
22.2. *Static components
(a) Magnetic suspension bearings: (b)
Bearings/Dampers:
Specially designed or prepared bearings comprising a pivot/cup assembly
mounted on a damper. The pivot is normally a hardened steel shaft
with a hemisphere at one end with a means of attachment to the bottom
cap described in Section 22.1.(e) at the other. The shaft may, however,
have a hydrodynamic bearing attached. The cup is pellet-shaped with
a hemispherical indentation in one surface. These components are often
supplied separately to the damper. (c)
Molecular pumps:
Specially designed or prepared cylinders having internally machined
or extruded helical grooves and internally machined bores. Typical
dimensions are as follows: 75 mm (3 in) to 400 mm (16 in) internal
diameter, 10 mm (0.4 in) or more wall thickness, with the length equal
to or greater than the diameter. The grooves are typically rectangular
in cross-section and 2 mm (0.08 in) or more in depth. (d)
Motor stators:
Specially designed or prepared ring-shaped stators for high-speed
multiphase AC hysteresis (or reluctance) motors for synchronous operation
within a vacuum in the frequency range of 600-2000 Hz and a power
range of 50 -1000 VA. The stators consist of multi-phase windings
on a laminated low loss iron core comprised of thin layers typically
2.0 mm (0.08 in) thick or less. (e)
Centrifuge housing/recipients:
Components specially designed or prepared to contain the rotor tube
assembly of a gas centrifuge. The housing consists of a rigid cylinder
of wall thickness up to 30 mm (1.2 in) with precision machined ends
to locate the bearings and with one or more flanges for mounting.
The machined ends are parallel to each other and perpendicular to
the cylinder's longitudinal axis to within 0.05 degrees or less. The
housing may also be a honeycomb type structure to accommodate several
rotor tubes. The housings are made of, or protected by, materials
resistant to corrosion by UF6. (f)
Scoops:
Specially designed or prepared tubes of up to 12 mm (0.5 in) internal
diameter for the extraction of UF6 gas from within the
rotor tube by a Pitot tube action (that is, with an aperture facing
into the circumferential gas flow within the rotor tube, for example
by bending the end of a radially disposed tube) and capable of being
fixed to the central gas extraction system. The tubes are made of,
or protected by, materials resistant to corrosion by UF6.
Specially designed or prepared bearing assemblies consisting of an
annular magnet suspended within a housing containing a damping medium.
The housing is manufactured from a UF6-resistant material
(see explanatory note to Section 23). The magnet couples with a pole
piece or a second magnet fitted to the top cap described in Section
22.1.(e). The magnet may be ring-shaped with a relation between the
outer and inner diameter smaller or equal to 1.6:1. The magnet may
be in a form having an initial permeability of 0.15 H/m (120,000 in
CGS units) or more, or a remanence of 98.5% or more, or an energy
product of greater than 80 kJ/m3 (107 gauss-oersteds).
In addition to the usual material properties, it is a prerequisite
that the deviation of the magnetic axes from the geometrical axes
is limited to very small tolerances (lower than 0.1 mm or 0.004 in)
or that homogeneity of the material of the magnet is specially called
for.
23. *Specially designed or prepared auxiliary systems, equipment and, components for gas centrifuge enrichment plants
INTRODUCTORY NOTE
The auxiliary systems, equipment, and components for a gas centrifuge
enrichment plant are the systems of the plant needed to feed UF6
to the centrifuges, to link the individual centrifuge to each other to
form cascades (or stages) to allow for progressively higher enrichments
and to extract the 'product' and 'tails' UF6 from the centrifuge
together with the equipment required to drive the centrifuges or to control
the plant. Normally, UF6 is evaporated from the solid using
heated autoclaves and is distributed in gaseous form to the centrifuge
by way of cascade header pipework. The 'product' and 'tails' UF6
gaseous streams flowing from the centrifuge are also passed by way of
cascade header pipework to cold traps (operating at about 203 K (-70oC))
where they are condensed prior to onward transfer into suitable containers
for transportation or storage. Because an enrichment plant consists of
many thousands of centrifuges arranged in cascades there are many kilometers
of cascade header pipework, incorporating thousands of welds with a substantial
amount of repetition of layout. The equipment, components and piping systems
are fabricated to very high vacuum and cleanliness standards.
23.1. *Feed systems/'product' and 'tails' withdrawal systems
Specially
designed or prepared process systems including: (a)
Feed autoclaves (or stations) used for passing UF6
to the centrifuge cascades at up to 100 kPa (15 psi) and at a rate
of 1 kg/h or more; (b)
Desublimers (or cold traps) used to remove
UF6 from the cascades at up to 3 kPa (0.5 psi) pressure.
The desublimers are capable of being chilled to 203 K (-70C) and heated
to 343 K (70C); and (c)
'Product' and 'tails' stations used for trapping UF6
into containers
This plant, equipment, and pipework is wholly made of or lined with
UF6-resistant materials (see explanatory note at the end
of this section) and is, fabricated to very high vacuum and cleanliness
standards.
23.2. *Machine header piping systems
Specially designed or prepared piping systems and header systems for handling UF6 within the centrifuge cascades. The piping network is normally of the 'triple' header system with each centrifuge connected to each of the headers. There is, thus, a substantial amount of repetition in its form. It is wholly made of UF6-resistant materials (see explanatory note at the end of this section) and is fabricated to very high vacuum and cleanliness standards.
23.3. *UF6 Mass spectrometers/mass ion sources
Specially designed or prepared magnetic or quadrupole mass spectrometers,
capable of taking 'on-line' samples of feed, 'product' or 'tails',
from UF6 gas streams and having all of the following characteristics: (a)
Unit resolution for atomic mass unit greater than 320; (b)
Ion sources constructed of or lined with nichrome or monel
or nickel plated; (c)
Electron bombardment ionization sources; and
(d) A collector system suitable for isotopic analysis.
23.4
*Frequency
changers
Frequency changers (also known as converters or invertors) specially
designed or prepared to supply motor stators as defined under 22.2.(d),
or parts, components, and sub-assemblies of such frequency changers
having all of the following characteristics: (a)
A multiphase output of 600 to 2000 Hz; (b)
High stability (with frequency control better than 0.1%);
and (c)
Total harmonic distortion less than 2%.
EXPLANATORY
NOTE:
The items listed in section 23 either come into direct contact with the
UF6 process gas or directly control the centrifuges and the
passage of the gas from centrifuge to centrifuge and cascade to cascade.
Materials resistant to corrosion by UF6 include stainless steel,
aluminum, aluminum alloys, nickel, or alloys containing 60% or more nickel.
24. *Specially designed or prepared assemblies and components for use in gaseous diffusion enrichment
INTRODUCTORY
NOTE
In the gaseous diffusion method of uranium isotope separation, the main
technological assembly is a special porous gaseous diffusion barrier,
heat exchanger for cooling the gas (which is heated by the process of
compression), seal valves and control valves, and pipelines. In as much
as gaseous diffusion technology uses uranium hexafluoride (UF6 ),
all equipment, pipeline and instrumentation surfaces (that come in contact
with the gas) must be made of materials that remain stable in contact
with UF6 . A gaseous diffusion facility requires a number of
these assemblies, so that quantities can provide an important indication
of end use.
24.1. * Gaseous diffusion barriers
(a) Specially designed or prepared thin, porous filters, with
a pore size of 100 - l000 Å (ångstroms), a thickness
of 5 mm (0.2 in) or less, and for tubular forms, a diameter of 25
mm (1 in) or less, made of metallic, polymer or ceramic materials
resistant to corrosion by UF6, and (b) Specially
prepared compounds or powders for the manufacture of such filters.
Such compounds and powders include nickel or alloys containing 60%
or more nickel, aluminum oxide, or UF6-resistant fully
fluorinated hydrocarbon polymers having a purity of 99.9% or more,
a particle size less than 10 microns, and a high degree of particle
size uniformity, which are specially prepared for the manufacture
of gaseous diffusion barriers.
24.2. *Diffuser housings Specially
designed or prepared hermetically sealed cylindrical vessels greater
than 300 mm (12 in) in diameter and greater than 900 mm (35 in) in length,
or rectangular vessels of comparable dimensions, which have an inlet
connection and two outlet connections all of which are greater than
50 mm (2 in) in diameter, for containing the gaseous diffusion barrier,
made of or lined with UF6-resistant materials and designed
for horizontal or vertical installation. 24.3.
*Compressors and gas blowers Specially
designed or prepared axial, centrifugal, or positive displacement compressors,
or gas blowers with a suction volume capacity of 1 m3/min
or more of UF6, and with a discharge pressure of up to several
hundred kPa (100 psi), designed for long-term operation in the UF6
environment with or without an electrical motor of appropriate power,
as well as separate assemblies of such compressors and gas blowers.
These compressors and gas blowers have a pressure ratio between 2:1
and 6:1 and are made of, or lined with, materials resistant to UF6.
24.4.
*Rotary shaft seals Specially
designed or prepared vacuum seals, with seal feed and seal exhaust connections,
for sealing the shaft connecting the compressor or the gas blower rotor
with the driver motor, so as to ensure a reliable seal against in-leaking
of air into the inner chamber of the compressor or gas blower which
is filled with UF6. Such seals are normally designed for
a buffer gas in-leakage rate of less than 1000 cm^3/min (60
in^3/min). 24.5.
*Heat exchangers for cooling UF6 Specially
designed or prepared heat exchangers made of or lined with UF6-resistant
materials (except stainless steel) or with copper or any combination
of those metals, and intended for a leakage pressure change rate of
less than 10 Pa (0.0015 psi) per hour under a pressure difference of
100 kPa (15 psi).
25. *Specially designed or prepared auxiliary systems, equipment and components for use in gaseous diffusion enrichment
INTRODUCTORY
NOTE
The auxiliary systems, equipment and components for gaseous diffusion
enrichment plants are the systems of plant needed to feed UF6
to the gaseous diffusion assembly, to link the individual assemblies to
each other to form cascades (or stages) to allow for progressively higher
enrichments and to extract the 'product' and 'tails' UF6 from
the diffusion cascades. Because of the high inertial properties of diffusion
cascades, any interruption in their operation, and specially their shut-down,
leads to serious consequences. Therefore, a strict and constant maintenance
of vacuum in all technological systems, automatic protection from accidents,
the precise automated regulation of the gas flow is of importance in a
gaseous diffusion plant. All this leads to a need to equip the plant with
a large number of special measuring, regulating and controlling systems.
Normally, UF6 is evaporated from cylinders placed within autoclaves
and is distributed in gaseous form to the entry point by way of cascade
header pipework. The 'product' and 'tails' UF6 gaseous streams
flowing from exit points are passed by way of cascade header pipework
to either cold traps or to compression stations where the UF6
gas is liquefied prior to onward transfer into suitable containers for
transportation or storage. Because a gaseous diffusion enrichment plant
consists of a large number of gaseous diffusion assemblies arranged in
cascades, there are many kilometers of cascade header pipework, incorporating
thousands of welds with substantial amounts of repetition of layout. The
equipment, components and piping systems are fabricated to very high vacuum
and cleanliness standards.
25.1. *Feed systems/'product' and 'tails' withdrawal systems
Specially designed or prepared process systems, capable of operating at pressures of 300 kPa (45 psi) or less, including:
(a) Feed autoclaves, or systems used for passing UF6 to the gaseous diffusion cascade;
(b) Desublimers (or cold traps)used to remove UF6 from diffusion cascades;
(c) Liquefaction stations where UF6 gas from the cascade is compressed and cooled to form liquid UF6; and
(d) 'Product' or 'tails' stations used for transferring UF6 into containers.
25.2. *Header piping systems
Specially designed or prepared piping systems and header systems, for handling UF6 within the gaseous diffusion cascade. This piping network is normally of the 'double' header system with each stage or group of stages connected to each of the headers.25.3. *Vacuum systems
(a) Specially designed or prepared large vacuum manifolds, vacuum headers and vacuum pumps having a suction capacity of 5 m3/min (175 ft3 / min) or more; and
(b) Vacuum pumps specially designed for service in UF6-bearing atmospheres made of, or lined with, aluminum, nickel, or alloys bearing more than 60% nickel. These pumps may be either rotary or positive, may have displacement and fluorocarbon seals, and may have special working fluids present.
25.4. *Special shut-off and control valves
Specially designed or prepared manual or automated shut-off and control bellows valves made of UF6-resistant materials with a diameter of 40 to 1500 mm (1.5 to 59 in) for installation in main and auxiliary systems of gaseous diffusion enrichment plants.
25.5. *UF6 mass spectrometers/ion sources
Specially designed or prepared magnetic or quadrupole mass spectrometers capable of taking "on-line" samples of feed, 'product' or 'tails', from UF6 gas streams and having all of the following characteristics:
(a) Unit resolution for atomic mass unit greater than 320;
(b) Ion sources constructed of or lined with nichrome or monel or nickel plated;
(c) Electron bombardment ionization sources; and
(d) Collector system suitable for isotopic analysis.
EXPLANATORY NOTE:
The items listed in section 25 above either come into direct contact with the UF6 process gas or directly control the flow within the cascade. All surfaces which come into contact with the process gas are wholly made of, or lined with, UF6-resistant materials. For the purposes of the sections relating to gaseous diffusion items, the materials resistant to corrosion by UF6 include stainless steel, aluminum, aluminum alloys, aluminum oxide, nickel or alloys containing 60% or more nickel and UF6-resistant fully fluorinated hydrocarbon polymers.
26. Specially designed or prepared systems, equipment and components for use in aerodynamic enrichment plants
INTRODUCTORY
NOTE
In aerodynamic enrichment processes, a mixture of gaseous UF6
and light gas (hydrogen or helium) is compressed and then passed through
separating elements wherein isotopic separation is accomplished by the
generation of high centrifugal forces over a curved-wall geometry. Two
processes of this type have been successfully developed: the separation
nozzle process and the vortex tube process. For both processes, the main
components of a separation stage include cylindrical vessels housing the
special separation elements (nozzle or vortex tubes), gas compressors,
and heat exchangers to remove the heat of compression. An aerodynamic
plant requires a number of these stages, so that quantities can provide
an important indication of end use. Since aerodynamic processes use UF6
, all equipment, pipeline and instrumentation surfaces (that come
in contact with the gas) must be made of materials that are stable in
contact with UF6.
EXPLANATORY
NOTE:
The items listed in this section either come into direct contact with
the UF6 process gas or directly control the flow within the
cascade. All surfaces which come into contact with the process gas are
wholly made of, or protected by, UF6-resistant materials. For
the purposes of the section relating to aerodynamic enrichment items,
the materials resistant to corrosion by UF6 include copper,
stainless steel, aluminum, aluminum alloys, nickel or alloys containing
60% or more nickel and UF6-resistant fully fluorinated hydrocarbon
polymers.
26.1. *Separation nozzles
Specially designed or prepared separation nozzles and assemblies thereof. The separation nozzles consist of slit-shaped, curved channels having a radius of curvature less than 1 mm (typically 0.1 to 0.05 mm), resistant to corrosion by UF6 and having a knife-edge within the nozzle that separates the gas flowing through the nozzle into two fractions.
26.2. *Vortex tubes
Specially designed or prepared vortex tubes and assemblies thereof. The vortex tubes are cylindrical or tapered, made of, or protected by, materials resistant to corrosion by UF6, having a diameter of between 0.5 cm and 4 cm, a length to diameter ratio of 20:1 or less and with one or more tangential inlets. The tubes may be equipped with nozzle-type appendages at either or both ends.
EXPLANATORY NOTE:
The feed gas enters the vortex tube tangentially at one end or through swirl vanes or at numerous tangential positions along the periphery of the tube.26.3. *Compressors and gas blowers
Specially designed or prepared axial, centrifugal or positive displacement compressors or gas blowers made of, or protected by, materials resistant to corrosion by UF6 and with a suction volume capacity of 2 m3/min or more of UF6/carrier gas (hydrogen or helium) mixture.
EXPLANATORY NOTE:
These compressors and gas blowers typically have a pressure ratio between 1.2:1 and 6:1.26.4. *Rotary shaft seals
Specially designed or prepared rotary shaft seals, with seal feed and seal exhaust connections, for sealing the shaft connecting the compressor rotor or the gas blower rotor with the driver motor so as to ensure a reliable seal against out-leakage of process gas or in-leakage of air or seal gas into the inner chamber of the compressor or gas blower which is filled with a UF6/carrier gas mixture.
26.5. *Heat exchangers for gas cooling
Specially designed or prepared heat exchangers made of, or protected by, materials resistant to corrosion by UF6.
26.6. *Separation element housings
Specially designed or prepared separation element housings, made of, or protected by, materials resistant to corrosion by UF6, for containing vortex tubes or separation nozzles.
EXPLANATORY NOTE:
These housings may be cylindrical vessels greater than 300 mm in diameter and greater than 900 mm in length or may be rectangular vessels of comparable dimensions, and may be designed for horizontal or vertical installation.26.7. *Feed systems/'product' and 'tails' withdrawal systems
Specially designed or prepared process systems or equipment for enrichment plants made of, or protected by, materials resistant to corrosion by UF6, including:
(a) Feed autoclaves, ovens, or systems used for passing UF6 to the enrichment process;
(b) Desublimers (or cold traps) used to remove UF6 from the enrichment process for subsequent transfer upon heating;
(c) Solidification or liquefaction stations used to remove UF6 from the enrichment process by compressing and converting UF6 to a liquid or solid form; and
(d) 'Product' or 'tails' stations used for transferring UF6 into containers
26.8. *Header piping systems
Specially designed or prepared header piping systems, made of, or protected by, materials resistant to corrosion by UF6, for handling UF6 within the aerodynamic cascades. This piping network is normally of the 'double' header design with each stage or group of stages connected to each of the headers.
26.9. *Vacuum systems and pumps
(a) Specially designed or prepared vacuum systems having a suction capacity of 5 m^3/min or more, consisting of vacuum manifolds, vacuum headers and vacuum pumps, and designed for service in UF6 bearing atmospheres; and
(b) Vacuum pumps specially designed or prepared for service in UF6-bearing atmospheres and made of, or protected by, materials resistant to corrosion by UF6. These pumps may use fluorocarbon seals and special working fluids.
26.10. *Special shut-off and control valves
Specially designed or prepared manual or automated shutoff and control bellows valves made of, or protected by, materials resistant to corrosion by UF6 with a diameter of 40 to 1500 mm for installation in main and auxiliary systems of aerodynamic enrichment plants.
26.11. *UF6 mass spectrometers/ion sources
Specially designed or prepared magnetic or quadrupole mass spectrometers capable of taking 'on-line' samples of feed, 'product' or 'tails', from UF6 gas streams and having all of the following characteristics:
(a) Unit resolution for mass greater than 320;
(b) Ion sources constructed of or lined with nichrome or monel or nickel plated;
(c) Electron bombardment ionization sources; and
(d) Collector system suitable for isotopic analysis.
26.12. *UF6/carrier gas separation systems
Specially designed or prepared process systems for separating UF6 from carrier gas (hydrogen or helium).
EXPLANATORY NOTE:
These systems are designed to reduce the UF6 content in the carrier gas to 1 PPM or less, and may incorporate equipment such as:
cryogenic heat exchangers and cryoseparators capable of temperatures of -120oC or less, or
cryogenic refrigeration units capable of temperatures of -120oC or less, or
separation nozzle or vortex tube units for the separation of UF6 from carrier gas, or
UF6 cold traps capable of temperatures of -20oC or less.
27. *Specially designed or prepared systems, equipment and components for use in chemical exchange or ion exchange enrichment plants.
INTRODUCTORY
NOTE
The slight difference in mass between the isotopes of uranium causes small
changes in chemical reaction equilibria that can be used as a basis for
separation of the isotopes. Two processes have been successfully developed:
liquid-liquid chemical exchange and solid-liquid ion exchange.
In the liquid-liquid chemical exchange process, immiscible liquid phases (aqueous and organic) are countercurrently contacted to give the cascading effect of thousands of separation stages. The aqueous phase consists of uranium chloride in hydrochloric acid solution. The organic phase consists of an extractant containing uranium chloride in an organic solvent. The contactors employed in the separation cascade can be liquid-liquid exchange columns (such as pulsed columns with sieve plates) or liquid centrifugal contactors. Chemical conversions (oxidation and reduction) are required at both ends of the separation cascade in order to provide for the reflux requirement at each end. A major design concern is to avoid contamination of the process streams with certain metal ions. Plastic, plastic-lined (including use of fluorocarbon polymers) and/or glass-lined columns and piping are therefore used.
In the solid-liquid ion-exchange process, enrichment is accomplished by uranium adsorption/desorption on a special very fast-acting, ion-exchange resin or adsorbent. A solution of uranium in hydrochloric acid and other chemical agents is passed through cylindrical enrichment columns containing packed beds of the adsorbent. For a continuos process, a reflux system is necessary to release the uranium from the adsorbent back into the liquid flow so that 'products' and 'tails' can be collected. This is accomplished with the use of suitable reduction/oxidation chemical agents that are fully regenerated in separate external circuits and that may be partly regenerated within the isotopic separation columns themselves.. The presence of hot concentrated hydrochloric acid solutions in the process requires that the equipment be made of, or protected by, special corrosion-resistant materials.
27.1.
*Liquid-liquid exchange columns (Chemical exchange) Countercurrent
liquid-liquid exchange columns having mechanical power input (i.e.,
pulsed columns with sieve plates, reciprocating plate columns, and columns
with internal turbine mixers), specially designed or prepared for uranium
enrichment using the chemical exchange process. For corrosion resistance
to concentrated hydrochloric acid solutions, these columns and their
internals are made of, or protected by, suitable plastic materials (such
as fluorocarbon polymers) or glass. The stage residence time of the
columns is designed to be short (30 seconds or less). 27.2.
*Liquid-liquid centrifugal contactors (Chemical exchange) Liquid-liquid
centrifugal contactors specially designed or prepared for uranium enrichment
using the chemical exchange process. Such contactors use rotation to
achieve dispersion of the organic and aqueous streams and then centrifugal
force to separate the phases. For corrosion resistance to concentrated
hydrochloric acid solutions, the contactors are made of or are lined
with suitable plastic materials (such as fluorocarbon polymers) or are
lined with glass. The stage residence time of the centrifugal contactors
is designed to be short (30 seconds or less). 27.3.
*Uranium reduction systems and equipment (Chemical exchange)
(a) Specially designed or prepared electrochemical reduction
cells to reduce uranium from one valence state to
another for uranium enrichment using the chemical exchange process.
The cell materials in contact with process solutions must be corrosion
resistant to concentrated hydrochloric acid solutions. EXPLANATORY
NOTE:
(b)
Specially designed or prepared systems at the product end
of the cascade for taking the U+4 out of the organic stream,
adjusting the acid concentration and feeding to the electrochemical
reduction cells. EXPLANATORY
NOTE:
27.4.
*Feed preparation systems (Chemical exchange) Specially
designed or prepared systems for producing high-purity uranium chloride
feed solutions for chemical exchange uranium isotope separation plants. EXPLANATORY
NOTE:
27.5.
*Uranium oxidation systems (Chemical exchange) Specially
designed or prepared systems for oxidation of U+3
to U+4 for return to the uranium isotope separation cascade
in the chemical exchange enrichment process. EXPLANATORY
NOTE:
Equipment for contacting chlorine and oxygen with the aqueous effluent
from the isotope separation equipment and extracting the resultant
U+4 into the stripped organic stream returning from the
product end of the cascade; and. Equipment
that separates water from hydrochloric acid so that the water and
the concentrated hydrochloric acid may be reintroduced to the process
at the proper location. 27.6.
*Ion exchange columns (Ion exchange) Cylindrical
columns greater than 1000 mm in diameter for containing and supporting
packed beds of ion exchange resin/adsorbent, specially designed or prepared
for uranium enrichment using the ion exchange process. These columns
are made of, or protected by, materials (such as titanium or fluorocarbon
plastics) resistant to corrosion by concentrated hydrochloric acid solutions
and are capable of operating at a temperature in the range of 100C to
200C and pressures above 0.7 MPa (102 psi). See also item 8 for
ion exchange resins/adsorbents. 27.7.
*Ion exchange reflux systems (Ion exchange)
(a) Specially designed or prepared chemical or electrochemical
reduction systems for regeneration of the chemical reducing agent(s)
used in ion exchange uranium enrichment cascades; and (b)
Specially designed or prepared chemical or electrochemical
oxidation systems for regeneration of the chemical oxidizing agent(s)
used in ion exchange uranium enrichment cascades. EXPLANATORY
NOTE:
The
process may use for example trivalent iron (Fe+3) as an oxidant
in which case the oxidation system would regenerate Fe+3
by oxidizing Fe+2.
The cell cathodic compartment must be designed to prevent re-oxidation
of uranium to its higher valence state. To keep the uranium in the
cathodic compartment, the cell may have an impervious diaphragm membrane
constructed of special cation exchange material. The cathode consists
of a suitable solid conductor such as graphite.
These systems consist of solvent extraction equipment for stripping
the U+4 from the organic stream into an aqueous solution,
evaporation and/or other equipment to accomplish solution pH adjustment
and control, and pumps or other transfer devices for feeding to the
electrochemical reduction cells. A major design concern is to avoid
contamination of the aqueous stream with certain metal ions. Consequently
for those parts in contact with the process stream, the system is
constructed of equipment made of, or protected by, suitable materials
(such as glass, fluorocarbon polymers, polyphenyl sulfate, polyether
sulfone, and resin-impregnated graphite).
These systems consist of dissolution, solvent extraction and/or ion
exchange equipment for purification and electrolytic cells for reducing
the uranium U+6 or U+4 to U+3. These
systems produce uranium chloride solutions having only a few parts per
million of metallic impurities such as chromium, iron, vanadium, molybdenum
and other bivalent or higher multi-valent cations. Materials of construction
for portions of the system processing high-purity U+3 include
glass, fluorocarbon polymers, polyphenyl sulfate or polyether sulfone
plastic-lined and resin-impregnated graphite
These systems may incorporate equipment such as:
The ion exchange enrichment process may use, for example, trivalent
titanium (Ti+3) as a reducing action in which case the reduction
system would regenerate Ti+3 by reducing Ti+4.
28. * Specially designed or prepared systems, equipment and components for use in laser based enrichment plants
INTRODUCTORY
NOTE
Present systems for enrichment processes using laser fall into two categories:
those in which the process medium is atomic uranium vapor and those in
which the process medium is the vapor of a uranium compound. Common nomenclature
for such processes include:
first category - atomic vapor laser isotope separation (AVLIS or SILVA); second
category - molecular laser isotope separation (MLIS or MOLIS); and chemical
reaction by isotope selective laser (CRISLA).
The systems, equipment and components for laser enrichment plants embrace:
devices to feed uranium metal vapor (for selective photo ionization)
or devices to feed the vapor of a uranium compound (for photo-dissociation
or chemical activation); devices
to collect enriched and depleted uranium metals as 'product' and 'tails'
in the first category, and devices to collect dissociated or reacted
compounds as 'products' and unaffected material as 'tails' in the second
category; (i)
process laser systems to selectively excite the uranium-235 species;
and feed
preparation and product conversion equipment.
The complexity of the spectroscopy of uranium atoms and compounds may require incorporation of any of a number of available laser technologies.
EXPLANATORY
NOTE:
Many of the items listed in this section come into direct contact with
uranium metal vapor or liquid or with process gas consisting of UF6
or a mixture of UF6 and other gases. All surfaces that come
into contact with the uranium or UF6 are wholly made of, or
protected by, corrosion-resistant materials. For the purposes of the section
relating to laser-based enrichment items, the materials resistant to corrosion
by vapor or liquid uranium metal or uranium alloys include yttria-coated
graphite and tantalum; and the materials resistant to corrosion by UF6
include copper, stainless steel, aluminum, , aluminum alloys, nickel or
alloys containing 60% or more nickel and UF6-resistant fully
fluorinated hydrocarbon polymers.
28.1. *Uranium vaporization systems (AVLIS)
Specially designed or prepared uranium vaporization systems which contain high-power strip or scanning electron beam guns with a delivered power on the target of more than 2.5 kW/cm.
28.2. *Liquid uranium metal handling systems (AVLIS)
Specially designed or prepared liquid metal handling systems for molten uranium or uranium alloys, consisting of crucibles and cooling equipment for the crucibles.
EXPLANATORY NOTE:
The crucibles and other parts of this system that come into contact with molten uranium or uranium alloy are made of, or protected by, material of suitable corrosion and heat resistance. Suitable materials include tantalum, yttria-coated graphite, graphite coated with other rare earth oxides or mixtures thereof.28.3. *Uranium metal 'product' and 'tails' collector assemblies (AVLIS)
Specially designed or prepared 'product' and 'tails' collector assemblies for uranium metal in liquid or solid form.
EXPLANATORY NOTE:
Components for these assemblies are made of, or protected by, materials resistant to the heat and corrosion of uranium metal vapor or liquid (such as yttria-coated graphite or tantalum) and may include pipes, valves, fittings, 'gutters', feed-throughs, heat exchangers and collector plates for magnetic, electrostatic (or other) separation methods.28.4. *Separator module housings (AVLIS)
Specially designed or prepared cylindrical or rectangular vessels for containing the uranium metal vapor source, the electron beam gun and the 'product' and 'tails' collectors.
EXPLANATORY NOTE:
These housings have multiplicity of ports for electrical and water feed-throughs, laser beam windows, vacuum pump connections and instrumentation diagnostics and monitoring. They have provisions for opening and disclosure to allow refurbishment of internal components.28.5. *Supersonic expansion nozzles (MLIS)
Specially designed or prepared supersonic expansion nozzles for cooling mixtures of UF6 and carrier gas to 150 K or less and which are corrosion resistant to UF6.
28.6. *Uranium pentaflouride product collectors (MLIS)
Specially designed or prepared uranium pentafluoride (UF5) solid product collectors consisting of filter, impact or cyclone-type collectors, or combinations thereof, and which are corrosion resistant to the UF5/UF6 environment.
28.7. *UF6/carrier gas compressors (MLIS)
Specially designed or prepared compressors for UF6 carrier gas mixtures, designed for long term operation in a UF6 environment. The components of these compressors that come into contact with process gas are made of, or protected by, materials resistant to corrosion by UF6.
28.8. *Rotary shaft seals (MLIS)
Specially designed or prepared rotary shaft seals, with seal feed and seal exhaust connections, for sealing the shaft connecting the compressor rotor with the driver motor so as to ensure a reliable seal against out-leakage of process gas or in-leakage of air or seal gas into the inner chamber of the compressor which is filled with a UF6 carrier gas mixture.
28.9. *Flourination systems (MLIS)
Specially designed or prepared systems for fluorinating UF5 (solid) to UF6 (gas).
EXPLANATORY NOTE:
These systems are designed to fluorinate the collected UF5 powder to UF6 for subsequent collection in 'product' containers or for transfer as feed to MLIS units for additional enrichment. In one approach the fluorination reaction may be accomplished within the isotopic separation system to react and recover directly off the 'product' collectors. In another approach, the UF5 powder may be removed/transferred from the 'product' collectors into a suitable reaction vessel (e.g., fluidized-bed reactor, screw reactor or flame tower) for fluorination. In both approaches, equipment for storage and transfer of fluorine (or other suitable fluorinating agents) and for collection and transfer of UF6 are used.28.10. *UF6 mass spectrometers/ion sources (MLIS)
Specially designed or prepared magnetic or quadrupole mass spectrometers capable of taking 'on-line' samples of feed, 'product' or 'tails', from UF6 gas streams and having all the following characteristics:
(a) Unit resolution for mass greater than 320;
(b) Ion sources constructed of or lined with nichrome or monel or nickel plated;
(c) Electron bombardment ionization sources; and; and;;;;;;;;;;l;
(d) Collector system suitable for isotopic analysis.
28.11 *Feed systems/'product' and 'tails' withdrawal systems (MLIS)
Specially designed or prepared process systems or equipment for enrichment plants made of, or protected by, materials resistant to corrosion by UF6 including:
(a) Feed autoclaves, ovens, or systems used for passing UF6 to the enrichment process;
(b) Desublimers (or cold traps) used to remove UF6 from the enrichment process for subsequent transfer upon heating;
(c) Solidification or liquefaction stations used to remove UF6 from the enrichment process by compressing and converting UF6 to a liquid or solid form; and
(d) 'Product' or 'tails' stations used for transferring UF6 into containers.
28.12. *UF6/carrier gas separation systems
Specially designed or prepared process systems for separating UF6 from carrier gas. The carrier gas may be nitrogen, argon, or other gas.
EXPLANATORY NOTE:
These systems may incorporate equipment such as:
Cryogenic heat exchangers or cryoseparators capable of temperatures of -120C or less, or
Cryogenic refrigeration units capable of temperatures of -120C or less, or
UF6 cold traps capable of temperatures of -20C or less.
28.13. *Laser systems (AVLIS, MLIS and CRISLA) as follows:
Laser systems specially designed or prepared for the separation of uranium isotopes.
EXPLANATORY NOTE:
The laser system for the AVLIS process usually consists of two lasers: a copper vapor laser and a dye laser. The laser system for MLIS usually consists of a CO2 or excimer laser and a multi-pass optical cell with revolving mirrors at both ends. Laser or laser systems for both processes require a spectrum frequency stabilizer for operation over extended periods of time.28.14. Lasers, as follows:
(a) Copper vapor lasers with 40 W or greater average output power operating at wavelengths between 500 nm and 600 NM;
(b) Argon ion lasers with greater than 40 W average output power operating at wavelengths between 400 NM and 515 NM;
(c) Neodymium-doped (other than glass) lasers as follows:
(i) Having an output wavelength between 100 NM and 1100 NM, being pulse-excited and Q-switched with a pulse duration equal to or greater than 1 ns, and having either of the following:
(A) A single-transverse mode output having an average output exceeding 40 W; or
(B) A multiple-transverse mode output having an average output power exceeding 50 W;
(ii) Operating at a wavelength between 1000 NM and 1100 NM incorporating frequency doubling giving an output wavelength between 500 NM and 550 NM with an average power at the doubled frequency (new wavelength) of greater than 40 W;
(d) Tunable pulsed single-mode dye oscillators capable of an average power output of greater than 1 W, a repetition rate greater than 1 kHz, a pulse width less than 100 Ns, and a wavelength between 300 NM and 800 NM;
(e) Tunable pulsed dye amplifiers and oscillators, except single-mode oscillators, with an average power output of greater than 30 W, a repetition rate greater than 1 kHz a pulse width less than 100 Ns, and a wavelength between 300 NM and 800 NM;
(f) Alexandrite lasers with a bandwidth of 0.005 NM or less, a repetition rate of greater than 125 Hz, and an average power output greater than 30 W operating at wavelengths between 720 NM and 800 NM;
(g) Pulsed carbon dioxide lasers with a repetition rate greater than 250 Hz, an average power output of greater than 500 W, and a pulse of less than 200 Ns operating at wavelengths between 9000 NM and 11,000 NM;
NOTE:
This specification is not intended to control the higher power (typically 1 to 5 kW) industrial CO2 lasers used in applications such as cutting and welding, as these latter lasers are either continuous wave or are pulsed with a pulse width more than 200 Ns(h) Pulsed excimer lasers (XeF, XeCl, KrF) with a repetition rate greater than 250 Hz, an average power output of greater than 500 W, and a pulse of less than 200 Ns operating at wavelengths between 240 and 360 NM;
(i) Para-hydrogen Raman shifters designed to operate at 16 NM output wavelength and at a repetition rate greater than 250 Hz; and
(j) Free electron lasers.
29. *Systems, equipment and components for use in plasma separation enrichment plants.
INTRODUCTORY
NOTE
In the plasma separation process, a plasma of uranium ions passes through
an electric field tuned to the 235U ion resonance frequency
so that they preferentially absorb energy and increase the diameter of
their corkscrew-like orbits. Ions with a large-diameter path are trapped
to produce a product enriched in 235U. The plasma, which is
made by ionizing uranium vapor, is contained in a vacuum chamber with
a high-strength magnetic field produced by a superconducting magnet. The
main technological systems of the process include the uranium plasma generation
system, the separator module with superconducting magnet, and metal removal
systems for the collection of 'product' and 'tails'.
29.1. *Microwave power sources and antennae
Specially designed or prepared microwave power sources and antennae for producing or accelerating ions and having the following characteristics:
(a) greater than 30 GHz frequency; and
(b) greater than 50 kW mean power output for ion production.
29.2. *Ion excitation coils
Specially designed or prepared radio frequency ion excitation coils for frequencies of more than 100 kHz and capable of handling more than 40 kW mean power.
29.3. *Uranium plasma generation systems
Specially designed or prepared systems for the generation of uranium plasma, which may contain high-power strip or scanning electron beam guns with a delivered power on the target of more than 2.5 kW/cm.
29.4. *Liquid uranium metal handling systems
Specially designed or prepared liquid metal handling systems for molten uranium or uranium alloys, consisting of crucibles and cooling equipment for the crucibles.
EXPLANATORY NOTE:
The crucibles and other parts of this system that come into contact with molten uranium or uranium alloys are made of, or protected by, materials of suitable corrosion and heat resistance. Suitable materials include tantalum, yttria-coated graphite, graphite coated with other rare earth oxides or mixtures thereof.29.5. *Uranium metal 'product' and 'tails' collector assemblies
Specially designed or prepared product and 'tails' collector assemblies for uranium metal in solid form. These collector assemblies are made of, or protected by, materials resistant to the heat and corrosion of uranium metal vapor, such as yttria-coated graphite or tantalum.
29.6. *Separator module housings
Cylindrical vessels specially designed or prepared for use in plasma separation enrichment plants for containing the uranium plasma source, radio-frequency drive coil and the 'product' and 'tails' collectors.
EXPLANATORY NOTE:
These housings have a multiplicity of ports for electrical feed-throughs, diffusion pump connections and instrumentation diagnostics and monitoring. They have provisions for opening and closure to allow for refurbishment of internal components and are constructed of a suitable non-magnetic material such as stainless steel.29.7. *Superconducting electromagnets
Superconducting solenoidal electromagnets with all of the following characteristics:
(a) Capable of creating magnetic fields of more than 2 teslas (20 kilogauss);
(b) With a L/D (length divided by inner diameter) greater than 2;
(c) With an inner diameter of more than 300 mm; and
(d) With a magnetic field uniform to better than 1% over the central 50% of the inner volume.
NOTE:
This item does not cover magnets specially designed for and used as parts of medical nuclear magnetic resonance (NMR) imaging systems.
30. *Systems, equipment and components for use in electromagnetic enrichment plants.
INTRODUCTORY
NOTE
In the electromagnetic process uranium metal ions produced by ionization
of a salt feed material (typically UCl4) are accelerated and
pass through a magnetic field that has the effect of causing the ions
of different isotopes to follow different paths. The major components
of an electromagnetic isotope separator include: a magnetic field for
ion-beam diversion/separation of the isotopes, an ion source with its
acceleration system, and a collection system for the separated ions. Auxiliary
systems for the process include the magnet power supply system, the ion
source high-voltage power supply system, the vacuum system, and extensive
chemical handling systems for recovery of product and cleaning/recycling
of components.
30.1. *Electromagnetic isotope separators
Electromagnetic isotope separators specially designed or prepared for the separation of uranium isotopes and equipment and components therefor, including:
(a) Ion sources:
Specially designed or prepared single or multiple uranium ion sources consisting of a vapor source, ionizer and beam accelerator, constructed of suitable materials such as graphite, stainless steel, or copper and capable of providing a total ion beam current of 50 mA or greater.(b) Ion collectors:
Collector plates consisting of two or more slits and pockets specially designed or prepared for collection of enriched and depleted uranium ion beams and constructed of suitable materials such as graphite or stainless steel.(c) Vacuum housings:
Specially designed or prepared vacuum housings for uranium electromagnetic separators constructed of suitable nonmagnetic materials such as stainless steel and designed for operation at pressures of 0.1 Pa or lower.EXPLANATORY NOTE:
The housings are specially designed to contain the ion sources, collector plates and water-cooled liners and have provision for diffusion pump connections and openings and closures for removal and reinstallation of these components.(d) Magnet pole pieces:
Specially designed or prepared magnet pole pieces having a diameter greater than 2 m used to maintain a constant magnetic field within an electromagnetic isotope separator and to transfer the magnetic field between adjoining separators.30.2. *Electromagnetic isotope separators other than those specified in 30.1 above, designed for or equipped with single or multiple ion sources capable of providing a total ion beam current of 50 ma or greater.
30.3. *High voltage power supplies
Specially designed or prepared high-voltage power supplies for ion sources,capable of continuously producing, over a time period of 8 hours, the following:
(a) Output voltage of 20,000 V or greater;
(B) Output current of 1 A or greater; and
(C) Voltage regulation of better than 0.1%.
30.4. *High current power supplies
Direct current high-power supplies capable of continuously producing, over a period of 8 hours, the following:
(a) Output voltage of 100 V or greater, with a current output of 500 A or greater; and
(b) Current or voltage regulation better than 0.1%.
30.5. Vacuum pumps
Vacuum pumps with an input throat size of 380 mm or greater with a pumping speed of 15,000 liters/second or greater and capable of producing an ultimate vacuum better than 10-4 Torr (0.76 x 10-4 mbar).
TECHNICAL NOTE:
The ultimate vacuum is determined at the input of the pump with the input of the pump blocked off.
ANALYTICAL INSTRUMENTS AND PROCESS CONTROL SYSTEMS USED IN URANIUM ENRICHMENT
31. Mass spectrometers
Mass spectrometers capable of measuring ions of 230 atomic mass units or greater and having a resolution of better than 2 parts in 230, as follows, and ion sources therefor;
31.1 Inductively coupled plasma mass spectrometers (ICP/MS); 31.2.
Glow discharge mass spectrometers (GDMS); 31.3.
Thermal ionization mass spectrometers (TIMS); 31.4.
*Electron bombardment mass spectrometers which have a source chamber
constructed from or lined with or plated with materials resistant to
UF6. 31.5.
Molecular beam mass spectrometers as follows: