Appendix J to Part 110 - Illustrative List of Uranium Conversion Plant Equipment and Plutonium Conversion Plant Equipment Under NRC Export Licensing Authority
10:2.0.1.1.20.11.139.7.31 : Appendix J
Appendix J to Part 110 - Illustrative List of Uranium Conversion
Plant Equipment and Plutonium Conversion Plant Equipment Under NRC
Export Licensing Authority Note:
Uranium conversion plants and systems may perform one or more
transformations from one uranium chemical species to another,
including: conversion of uranium ore concentrates to UO3,
conversion of UO3 to UO2, conversion of uranium oxides to UF4 or
UF6, conversion of UF4 to UF6, conversion of UF6 to UF4, conversion
of UF4 to uranium metal, and conversion of uranium fluorides to
UO2. Many key equipment items for uranium conversion plants are
common to several segments of the chemical process industry,
including furnaces, rotary kilns, fluidized bed reactors, flame
tower reactors, liquid centrifuges, distillation columns and
liquid-liquid extraction columns. However, few of the items are
available “off-the-shelf”; most would be prepared according to
customer requirements and specifications. Some require special
design and construction considerations to address the corrosive
properties of the chemicals handled (HF, F2, CLF3, and uranium
fluorides). In all of the uranium conversion processes, equipment
which individually is not especially designed or prepared for
uranium conversion can be assembled into systems which are
especially designed or prepared for uranium conversion.
(a) Uranium Conversion Plant Equipment.
(1) Especially designed or prepared systems for the conversion
of uranium ore concentrates to UO3.
Conversion of uranium ore concentrates to UO3 can be performed
by first dissolving the ore in nitric acid and extracting purified
uranyl nitrate using a solvent such as tributyl phosphate. Next,
the uranyl nitrate is converted to UO3 either by concentration and
denitration or by neutralization with gaseous ammonia to produce
ammonium diuranate with subsequent filtering, drying, and
calcining.
(2) Especially designed or prepared systems for the conversion
of UO3 to UF6.
Conversion of UO3 to UF6 can be performed directly by
fluorination. The process requires a source of fluorine gas or
chlorine trifluoride.
(3) Especially Designed or Prepared Systems for the conversion
of UO3 to UO2.
Conversion of UO3 to UO2 can be performed through reduction of
UO3 with cracked ammonia gas or hydrogen.
(4) Especially Designed or Prepared Systems for the conversion
of UO2 to UF4.
Conversion of UO2 to UF4 can be performed by reacting UO2 with
hydrogen fluoride gas (HF) at 300-500 °C.
(5) Especially Designed or Prepared Systems for the conversion
of UF4 to UF6.
Conversion of UF4 to UF6 is performed by exothermic reaction
with fluorine in a tower reactor. UF6 is condensed from the hot
effluent gases by passing the effluent stream through a cold trap
cooled to −10 °C. The process requires a source of fluorine
gas.
(6) Especially Designed or Prepared Systems for the conversion
of UF4 to U metal.
Conversion of UF4 to U metal is performed by reduction with
magnesium (large batches) or calcium (small batches). The reaction
is carried out at temperatures above the melting point of uranium
(1130 °C).
(7) Especially designed or prepared systems for the conversion
of UF6 to UO2.
Conversion of UF6 to UO2 can be performed by one of three
processes. In the first, UF6 is reduced and hydrolyzed to UO2 using
hydrogen and steam. In the second, UF6 is hydrolyzed by solution in
water, ammonia is added to precipitate ammonium diuranate, and the
diuranate is reduced to UO2 with hydrogen at 820 °C. In the third
process, gaseous UF6, CO2, and NH3 are combined in water,
precipitating ammonium uranyl carbonate. The ammonium uranyl
carbonate is combined with steam and hydrogen at 500-600 °C to
yield UO2. UF6 to UO2 conversion is often performed as the first
stage of a fuel fabrication plant.
(8) Especially Designed or Prepared Systems for the conversion
of UF6 to UF4. Conversion of UF6 to UF4 is performed by reduction
with hydrogen.
(9) Especially designed or prepared systems for the conversion
of UO2 to UCl4 as feed for electromagnetic enrichment.
Note:
Plutonium conversion plants and systems may perform one or more
transformations from one plutonium chemical species to another,
including: conversion of plutonium nitrate to PuO2, conversion of
PuO2 to PuF4 and conversion of PuF4 to plutonium metal. Plutonium
conversion plants are usually associated with reprocessing
facilities, but may also be associated with plutonium fuel
fabrication facilities. Many of the key equipment items for
plutonium conversion plants are common to several segments of the
chemical process industry. For example, the types of equipment
employed in these processes may include the following items:
furnaces, rotary kilns, fluidized bed reactors, flame tower
reactors, liquid centrifuges, distillation columns and
liquid-liquid extraction columns. Hot cells, glove boxes and remote
manipulators may also be required. However, few of the items are
available off-the-shelf; most would be prepared according to the
requirements and specifications of the customer. Particular care is
essential in designing for the special radiological, toxicity and
criticality hazards associated with plutonium. In some
circumstances, special design and construction considerations are
required to address the corrosive properties of some of the
chemicals handled (e.g., HF). Finally, it should be noted that, for
all plutonium conversion processes, items of equipment which
individually are not especially designed or prepared for plutonium
conversion can be assembled into systems that are especially
designed or prepared for use in plutonium conversion.
(b) Plutonium Conversion Plant Equipment
(1) Especially designed or prepared systems for the conversion
of plutonium nitrate to oxide.
The main functions involved in this process are: process feed
storage and adjustment, precipitation and solid/liquor separation,
calcination, product handling, ventilation, waste management, and
process control. The process systems are particularly adapted so as
to avoid criticality and radiation effects and to minimize toxicity
hazards. In most reprocessing facilities, this process involves the
conversion of plutonium nitrate to plutonium dioxide. Other
processes can involve the precipitation of plutonium oxalate or
plutonium peroxide.
(2) Especially designed or prepared systems for plutonium metal
production.
This process usually involves the fluorination of plutonium
dioxide, normally with highly corrosive hydrogen fluoride, to
produce plutonium fluoride, which is subsequently reduced using
high purity calcium metal to produce metallic plutonium and a
calcium fluoride slag. The main functions involved in this process
are the following: fluorination (e.g., involving equipment
fabricated or lined with a precious metal), metal reduction (e.g.,
employing ceramic crucibles), slag recovery, product handling,
ventilation, waste management and process control. The process
systems are particularly adapted so as to avoid criticality and
radiation effects and to minimize toxicity hazards. Other processes
include the fluorination of plutonium oxalate or plutonium peroxide
followed by reduction to metal.
(c) Any other components especially designed or prepared for use
in a uranium conversion plant or plutonium conversion plant or in
any of the components described in this appendix.
[61 FR 35606, July 8, 1996, as amended at 65 FR 70291, Nov. 22,
2000; 79 FR 39298, July 10, 2014]