International Atomic Energy Agency Information Circular (Unofficial electronic edition)

INFCIRC/254/Rev.1/Part 1*/ July 1992 GENERAL Distr. Original: ENGLISH and FRENCH

1. The Director General has received notes verbales dated 1 June 1992 from the Resident Representatives to the Agency of Australia, Austria, Belgium, Bulgaria, Canada, Czech and Slovak Federal Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, the United Kingdom of Great Britain and Northern Ireland, and the United States of America relating to the export of nuclear material, equipment or technology.

2. The purpose of the notes verbales is to clarify parts of the Trigger List which is incorporated in the Annex A to the Guidelines for Nuclear Transfers. A new part A of the Annex A and a revised Annex to it (new Annex B) have been incorporated in the Guidelines.

3. In the light of the wish expressed at the end of each note verbale, the text of the notes verbales is annexed hereto.

INFCIRC/254/Rev.1/Part 1
Annex

The Permanent Mission of [Member State] to the International Atomic Energy Agency presents its compliments to the Director General of the International Atomic Energy Agency and has the honour to refer to its letter of [date of previous communication] in which the Government of [Member State announced its decision to act in accordance with the guidelines for nuclear transfers annexed to that letter.

The Government of [Member State] has implemented these guidelines accordingly and hopes that other Governments, who have not yet done so, may decide to base their own nuclear export policies upon the guidelines.

As a member of the European Community, the Government of [Member State] has implemented these guidelines in accordance with the Declaration of Common Policy, communicated by the Resident Representative of Italy on behalf of the European Community, in his letter of 22 March 1985. The Government of [Member State] hopes that other governments, who have not yet done so, may decide to base their own nuclear export policies upon the said guidelines.^**/

In the aforementioned letter the Government of [Member State] pointed out the need to remove safeguards and non-proliferation assurances from the field of commercial competition. This need still exists.

In the years since the guidelines were formulated and published in INFCIRC/254 developments in nuclear technology have brought about the need further to clarify parts of the trigger list which is incorporated in Annex A to the guidelines. In the interest of clarity the resultant new Part A of the Annex A and a revised Annex to it (new Annex B) have been incorporated in the attached copy of the complete guidelines.

The Government of [Member State] requests that the Director General of the International Atomic Energy Agency should circulate the texts of this note and its enclosure to all member governments for their information and as a demonstration of support by the Government of [Member State] for the Agency's non-proliferation objectives and safeguards activities.

The Permanent Mission of [Member State] avails itself of this opportunity to renew to the Director General of the International Atomic Energy Agency the assurances of its highest consideration.

INFCIRC/254/Rev.1/Part 1
Annex
Attachment

1. The following fundamental principles for safeguards and export controls should apply to nuclear transfers to any non-nuclear-weapon State for peaceful purposes. In this connection, suppliers have defined an export trigger list and agreed on common criteria for technology transfers.

   Prohibition on nuclear explosives

2. Suppliers should authorize transfer of items identified in the trigger list only upon formal governmental assurances from recipients explicitly excluding uses which would result in any nuclear explosive device.

   Physical protection

3. 1. All nuclear materials and facilities identified by the agreed trigger list should be placed under effective physical protection to prevent unauthorized use and handling. The levels of physical protection to be ensured in relation to the type of materials, equipment and facilities, have been agreed by suppliers, taking account of international recommendations.

   2. The implementation of measures of physical protection in the recipient country is the responsibility of the Government of that country. However, in order to implement the terms agreed upon amongst suppliers, the levels of physical protection on which these measures have to be based should be the subject of an agreement between supplier and recipient.

   3. In each case special arrangements should be made for a clear definition of responsibilities for the transport of trigger list items.

   Safeguards

4. Suppliers should transfer trigger list items only when covered by IAEA safeguards, with duration and coverage provisions in conformance with the GOV/1621 guidelines. Exceptions should be made only after consultation with the parties to this understanding.

5. Suppliers will jointly reconsider their common safeguards requirements, whenever appropriate.

   Safeguards triggered by the transfer of certain technology

6. 1. The requirements of paragraphs 2, 3 and 4 above should also apply to facilities for reprocessing, enrichment, or heavy-water production, utilizing technology directly transferred by the supplier or derived from transferred facilities, or major critical components thereof.

   2. The transfer of such facilities, or major critical components thereof, or related technology, should require an undertaking (1) that IAEA safeguards apply to any facilities of the same type (i.e. if the design, construction or operating processes are based on the same or similar physical or chemical processes, as defined in the trigger list) constructed during an agreed period in the recipient country and (2) that there should at all times be in effect a safeguards agreement permitting the IAEA to apply Agency safeguards with respect to such facilities identified by the recipient, or by the supplier in consultation with the recipient, as using transferred technology.

   Special controls on sensitive exports

7. Suppliers should exercise restraint in the transfer of sensitive facilities, technology and weapons-usable materials. If enrichment or reprocessing facilities, equipment or technology are to be transferred, suppliers should encourage recipients to accept, as an alternative to national plants, supplier involvement and/or other appropriate multinational participation in resulting facilities. Suppliers should also promote international (including IAEA) activities concerned with multinational regional fuel cycle centres.

   Special controls on export of enrichment facilities, equipment and technology

8. For a transfer of an enrichment facility, or technology therefor, the recipient nation should agree that neither the transferred facility, nor any facility based on such technology, will be designed or operated for the production of greater than 20 % enriched uranium without the consent of the supplier nation, of which the IAEA should be advised.

   Controls on supplied or derived weapons-usable material

9. Suppliers recognize the importance, in order to advance the objectives of these guidelines and to provide opportunities further to reduce the risks of proliferation, of including in agreements on supply of nuclear materials or of facilities which produce weapons-usable material, provisions calling for mutual agreement between the supplier and the recipient on arrangements for reprocessing, storage, alteration, use, transfer or retransfer of any weapons-usable material involved. Suppliers should endeavour to include such provisions whenever appropriate and practicable.

   Controls on retransfer

10. 1. Suppliers should transfer trigger list items, including technology defined under paragraph 6, only upon the recipient's assurance that in the case of:
       1. retransfer of such items,

          or

       2. transfer of trigger list items derived from facilities originally transferred by the supplier, or with the help of equipment or technology originally transferred by the supplier;

          the recipient of the retransfer or transfer will have provided the same assurances as those required by the supplier for the original transfer.

    2. In addition the supplier's consent should be required for: (1) any retransfer of the facilities, major critical components, or technology described in paragraph 6; (2) any transfer of facilities or major critical components derived from those items; (3) any retransfer of heavy water or weapons-usable material.
    SUPPORTING ACTIVITIES

    Physical security

11. Suppliers should promote international co-operation on the exchange of physical security information, protection of nuclear materials in transit, and recovery of stolen nuclear materials and equipment.

    Support for effective IAEA safeguards

12. Suppliers should make special efforts in support of effective implementation of IAEA safeguards. Suppliers should also support the Agency's efforts to assist Member States in the improvement of their national systems of accounting and control of nuclear material and to increase the technical effectiveness of safeguards.

    Similarly, they should make every effort to support the IAEA in increasing further the adequacy of safeguards in the light of technical developments and the rapidly growing number of nuclear facilities, and to support appropriate initiatives aimed at improving the effectiveness of IAEA safeguards.

    Sensitive plant design features

13. Suppliers should encourage the designers and makers of sensitive equipment to construct it in such a way as to facilitate the application of safeguards.

    Consultations

14. 1. Suppliers should maintain contact and consult through regular channels on matters connected with the implementation of these guidelines.

    2. Suppliers should consult, as each deems appropriate, with other Governments concerned on specific sensitive cases, to ensure that any transfer does not contribute to risks of conflict or instability.

    3. In the event that one or more suppliers believe that there has been a violation of supplier/recipient understandings resulting from these guidelines, particularly in the case of an explosion of a nuclear device, or illegal termination or violation of IAEA safeguards by a recipient, suppliers should consult promptly through diplomatic channels in order to determine and assess the reality and extent of the alleged violation.

       Pending the early outcome of such consultations, suppliers will not act in a manner that could prejudice any measure that may be adopted by other suppliers concerning their current contacts with that recipient.

       Upon the findings of such consultations, the suppliers, bearing in mind Article XII of the IAEA Statute, should agree on an appropriate response and possible action which could include the termination of nuclear transfers to that recipient.

15. In considering transfers, each supplier should exercise prudence having regard to all the circumstances of each case, including any risk that technology transfers not covered by paragraph 6, or subsequent retransfers, might result in unsafeguarded nuclear materials.

16. Unanimous consent is required for any changes in these guidelines, including any which might result from the reconsideration mentioned in paragraph 5.

1. Source and special fissionable material

   As defined in Article XX of the Statute of the International Atomic Energy Agency:

   1.1. "Source material"

   The term "source material" means 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; any other material containing one or more of the foregoing in such concentration as the Board of Governors shall from time to time determine; and such other material as the Board of Governors shall from time to time determine.

   1.2. "Special fissionable material"

   1. The term "special fissionable material" means plutonium-239; uranium-233; uranium enriched in the isotopes 235 or 233; any material containing one or more of the foregoing; and such other fissionable material as the Board of Governors shall from time to time determine; but the term "special fissionable material" does not include source material.

   2. The term "uranium enriched in the isotopes 235 or 233" means uranium containing the isotopes 235 or 233 or both in an amount such that the abundance ratio of the sum of these isotopes to the isotope 238 is greater than the ratio of the isotope 235 to the isotope 238 occurring in nature.

   However, for the purposes of the Guidelines, items specified in subparagraph (a) below, and exports of source or special fissionable material to a given recipient country, within a period of 12 months, below the limits specified in subparagraph (b) below, shall not be included:

   1. Plutonium with an isotopic concentration of plutonium-238 exceeding 80%.

      Special fissionable material when used in gram quantities or less as a sensing component in instruments; and

      Source material which the Government is satisfied is to be used only in non-nuclear activities, such as the production of alloys or ceramics;

   2. Special fissionable material	50 effective grams;
      Natural uranium	500 kilograms;
      Depleted uranium	1 000 kilograms; and
      Thorium	1 000 kilograms.

2. Equipment and Non-nuclear Materials

   The designation of items of equipment and non-nuclear materials (hereafter referred to as the "Trigger List") adopted by the Government is as follows (quantities below the levels indicated in the Annex B being regarded as insignificant for practical purposes):

   2.1. Reactors and equipment therefor (see Annex B, section 1.);

   2.2. Non-nuclear materials for reactors (see Annex B, section 2.);

   2.3. Plants for the reprocessing of irradiated fuel elements, and equipment especially designed or prepared therefor (see Annex B, section 3.);

   2.4. Plants for the fabrication of fuel elements (see Annex B, section 4.);

   2.5. Plants for the separation of isotopes of uranium and equipment, other than analytical instruments, especially designed or prepared therefor (see Annex B, section 5.);

   2.6. Plants for the production of heavy water, deuterium and deuterium compounds and equipment especially designed or prepared therefor (see Annex B, section 6.).

1. "Technology" means technical data in physical form designated by the supplying country as important to the design, construction, operation, or maintenance of enrichment, reprocessing, or heavy water production facilities or major critical components thereof, but excluding data available to the public, for example, in published books and periodicals, or that which has been made available internationally without restrictions upon its further dissemination.

2. "Major critical components" are:
   1. in the case of an isotope separation plant of the gas centrifuge type: gas centrifuge assemblies, corrosion-resistant to UF₆;

   2. in the case of an isotope separation plant of the gaseous diffusion type: diffusion barrier;

   3. in the case of an isotope separation plant of the jet nozzle type: the nozzle units;

   4. in the case of an isotope separation plant of the vortex type: the vortex units.

3. For facilities covered by paragraph 6 of the Guidelines for which no major critical component is described in paragraph 2 above, if a supplier nation should transfer in the aggregate a significant fraction of the items essential to the operation of such a facility, together with the knowhow for construction and operation of that facility, that transfer should be deemed to be a transfer of "facilities or major critical components thereof".

4. The definitions in the preceding paragraphs are solely for the purposes of paragraph 6 of the Guidelines and this Part B, which differ from those applicable to Part A of this Trigger List, which should not be interpreted as limited by such definition.

5. For the purposes of implementing paragraph 6 of the Guidelines, the following facilities should be deemed to be "of the same type (i.e. if their design, construction or operating processes are based on the same or similar physical or chemical processes)":

   Where the technology transferred is such as to make possible the construction in the recipient State of a facility of the following type, or major critical components thereof:	The following will be deemed to be facilities of the same type:
   (a) an isotope separation plant of the gaseous diffusion type	any other isotope separation plant using the gaseous diffusion process
   (b) an isotope separation plant of the gas centrifuge type	any other isotope separation plant using the gas centrifuge process.
   (c) An isotope separation plant of the jet nozzle type	any other isotope separation plant using the jet nozzle process.
   (d) an isotope separtion plant of the vortex type	any other isotope separation plant using the vortex process
   (e) a fuel reprocessing plant using the solvent extraction process	any other fuel reprocessing plant using the solvent extraction process
   (f) a heavy water plant using the exchange process	any other heavy water plant using the exchange process
   (g) a heavy water plant using the electrolytic process	any other heavy water plant using the electrolytic process
   (h) a heavy water plant using the hydrogen distillation process	any other heavy water plant using the hydrogen distillation process

   Note: In the case of reprocessing, enrichment, and heavy water facilities whose design, construction, or operation processes are based on physical or chemical processes other than those enumerated above, a similar approach would be applied to define facilities "of the same type" and a need to define major critical components of such facilities might arise.

6. The reference in paragraph 6(b) of the Guidelines to "any facilities of the same type constructed during an agreed period in the recipient's country" is understood to refer to such facilities (or major critical components thereof), the first operation of which commences within a period of at least 20 years from the date of the first operation of (1) a facility which has been transferred or incorporates transferred major critical components or of (2) a facility of the same type built after the transfer of technology. It is understood that during that period there would be a conclusive presumption that any facility of the same type utilized transferred technology. But the agreed period is not intended to limit the duration of the safeguards imposed or the duration of the right to identify facilities as being constructed or operated on the basis of or by the use of transferred technology in accordance with paragraph 6(b)(2) of the Guidelines.

1. Reactors and equipment therefor

   1.1. Complete nuclear reactors

   Nuclear reactors capable of operation so as to maintain a controlled self-sustaining fission chain reaction, excluding zero energy reactors, the latter being defined as reactors with a designed maximum rate of production of plutonium not exceeding 100 grams per year.

   EXPLANATORY NOTE

   A "nuclear reactor" basically includes the items within or attached directly to the reactor vessel, the equipment which controls the level of power in the core, and the components which normally contain or come in direct contact with or control the primary coolant of the reactor core.

   It is not intended to exclude reactors which could reasonably be capable of modification to produce significantly more than 100 grams of plutonium per year. Reactors designed for sustained operation at significant power levels, regardless of their capacity for plutonium production, are not considered as "zero energy reactors".

   EXPORTS

   The export of the whole set of major items within this boundary will take place only in accordance with the procedures of the Guidelines. Those individual items within this functionally defined boundary which will be exported only in accordance with the procedures of the Guidelines are listed in paragraphs 1.2 to 1.7. The Government reserves the right to apply the procedures of the Guidelines to other items within the functionally defined boundary.

   1.2. Reactor pressure vessels

   Metal vessels, as complete units or as major shop-fabricated parts therefor, which are especially designed or prepared to contain the core of a nuclear reactor as defined in paragraph 1.1. above and are capable of withstanding the operating pressure of the primary coolant.

   EXPLANATORY NOTE

   A top plate for a reactor pressure vessel is covered by item 1.2. as a major shop-fabricated part of a pressure vessel.

   Reactor internals (eg support columns and plates for the core and other vessel internals, control rod guide tubes, thermal shields, baffles, core grid plates, diffuser plates, etc.) are normally supplied by the reactor supplier. In some cases, certain internal support components are included in the fabrication of the pressure vessel. These items are sufficiently critical to the safety and reliability of the operation of the reactor (and, therefore, to the guarantees and liability of the reactor supplier), so that their supply, outside the basic supply arrangement for the reactor itself, would not be common practice. Therefore, although the separate supply of these unique, especially designed and prepared, critical, large and expensive items would not necessarily be considered as falling outside the area of concern, such a mode of supply is considered unlikely.

   1.3. Reactor fuel charging and discharging machines

   Manipulative equipment especially designed or prepared for inserting or removing fuel in a nuclear reactor as defined in paragraph 1.1. above capable of on-load operation or employing technically sophisticated positioning or alignment features to allow complex off-load fuelling operations such as those in which direct viewing of or access to the fuel is not normally available.

   1.4. Reactor control rods

   Rods especially designed or prepared for the control of the reaction rate in a nuclear reactor as defined in paragraph 1.1. above.

   EXPLANATORY NOTE

   This item includes, in addition to the neutron absorbing part, the support or suspension structures therefor if supplied separately.

   1.5. Reactor pressure tubes

   Tubes which are especially designed or prepared to contain fuel elements and the primary coolant in a reactor as defined in paragraph 1.1. above at an operating pressure in excess of 5.1 MPa (740 psi).

   1.6. Zirconium tubes

   Zirconium metal and alloys in the form of tubes or assemblies of tubes, and in quantities exceeding 500 kg in any period of 12 months, especially designed or prepared for use in a reactor as defined in paragraph 1.1. above, and in which the relation of hafnium to zirconium is less than 1:500 parts by weight.

   1.7. Primary coolant pumps

   Pumps especially designed or prepared for circulating liquid metal as primary coolant for nuclear reactors as defined in paragraph 1.1. above.

2. Non-nuclear materials for reactors

   2.1. 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 as defined in paragraph 1.1. above in quantities exceeding 200 kg of deuterium atoms for any one recipient country in any period of 12 months.

   2.2 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/cm³ in quantities exceeding 3^. 10⁴ kg (30 metric tons) for any one recipient country in any period of 12 months.

3. Plants for the reprocessing of irradiated fuel elements, and equipment especially designed or prepared therefor

   INTRODUCTORY NOTE

   Reprocessing irradiated nuclear fuel separates plutonium and uranium from intensely radioactive fission products and other transuranic elements. Different technical processes can accomplish this separation. However. over the years Purex has become the most commonly used and accepted process. Purex involves the dissolution of irradiated nuclear fuel in nitric acid, followed by separation of the uranium, plutonium, and fission products by solvent extraction using a mixture of tributyl phosphate in an organic diluent.

   Purex facilities have process functions similar to each other, including: irradiated fuel element chopping, fuel dissolution, solvent extraction, and process liquor storage. There may also be equipment for thermal denitration of uranium nitrate, conversion of plutonium nitrate to oxide or metal, and treatment of fission product waste liquor to a form suitable for long term storage or disposal. However, the specific type and configuration of the equipment performing these functions may differ between Purex facilities for several reasons, including the type and quantity of irradiated nuclear fuel to be reprocessed and the intended disposition of the recovered materials, and the safety and maintenance philosophy incorporated into the design of the facility.

   A "plant for the reprocessing of irradiated fuel elements", includes the equipment and components which normally come in direct contact with and directly control the irradiated fuel and the major nuclear material and fission-product processing streams.

   These processes, including the complete systems for plutonium conversion and plutonium metal production, may be identified by the measures taken to avoid criticality (eg by geometry), radiation exposure (eg by shielding). and toxicity hazards (eg by containment).

   EXPORTS

   The export of the whole set of major items this within this boundary will take place only in accordance with the procedures of the Guidelines.

   The Government reserves to itself the right to apply the procedures of the Guidelines to other items within the functionally defined boundary as listed below.

   Items of equipment that are considered to fall within the meaning of the phrase "and equipment especially designed or prepared" for the reprocessing of irradiated fuel elements include:

   3.1. Irradiated fuel element chopping machines

   INTRODUCTORY NOTE

   This equipment breaches the cladding of the fuel to expose the irradiated nuclear material to dissolution. Especially designed metal cutting shears are the most commonly employed, although advanced equipment such as lasers, may be used.

   Remotely operated equipment especially designed or prepared for use in a reprocessing plant as identified above and intended to cut, chop or shear irradiated nuclear fuel assemblies, bundles or rods.

   3.2. Dissolvers

   INTRODUCTORY NOTE

   Dissolvers normally receive the chopped-up spent fuel. In these critically safe vessels, the irradiated nuclear material is dissolved in nitric acid and the remaining hulls removed from the process stream.

   Critically safe tanks (eg small diameter, annular or slab tanks) especially designed or prepared for use in a reprocessing plant as identified above, intended for dissolution of irradiated nuclear fuel and which are capable of withstanding hot, highly corrosive liquid, and which can be remotely loaded and maintained.

   3.3. Solvent extractors and solvent extraction equipment

   INTRODUCTORY NOTE

   Solvent extractors both receive the solution of irradiated fuel from the dissolvers and the organic solution which separates the uranium, plutonium, and fission products. Solvent extraction equipment is normally designed to meet strict operating parameters, such as long operating lifetimes with no maintenance requirements or adaptability to easy replacement, simplicity of operation and control, and flexibility for variations in process conditions.

   Especially designed or prepared solvent extractors such as packed or pulse columns, mixer settlers or centrifugal contactors for use in a plant for the reprocessing of irradiated fuel. Solvent extractors must be resistant to the corrosive effect of nitric acid. Solvent extractors are normally fabricated to extremely high standards (including special welding and inspection and quality assurance and quality control techniques) out of low carbon stainless steels, titanium, zirconium, or other high quality materials.

   3.4. Chemical holding or storage vessels

   INTRODUCTORY NOTE

   Three main process liquor streams result from the solvent extraction step. Holding or storage vessels are used in the further processing of all these streams, as follows:

   1. The pure uranium nitrate solution is concentrated by evaporation and passed to a denitration process where it is converted to uranium oxide. This oxide is re-used in the nuclear fuel cycle.

   2. The intensely radioactive fission products solution is normally concentrated by evaporation and stored as a liquor concentrate. This concentrate may be subsequently evaporated and converted to a form suitable for storage or disposal.

   3. The pure plutonium nitrate solution is concentrated and stored pending its transfer to further process steps. In particular, holding or storage vessels for plutonium solutions are designed to avoid criticality problems resulting from changes in concentration and form of this stream.

   Especially designed or prepared holding or storage vessels for use in a plant for the reprocessing of irradiated fuel. The holding or storage vessels must be resistant to the corrosive effect of nitric acid. The holding or storage vessels are normally fabricated of materials such as low carbon stainless steels, titanium or zirconium, or other high quality materials. Holding or storage vessels may be designed for remote operation and maintenance and may have the following features for control of nuclear criticality:

   1. walls or internal structures with a boron equivalent of at least two per cent, or
   2. a maximum diameter of 175 mm (7 in) for cylindrical vessels, or
   3. a maximum width of 75 mm (3 in) for either a slab or annular vessel.

   3.5. Plutonium nitrate to oxide conversion system

   INTRODUCTORY NOTE

   In most reprocessing facilities this final process involves the conversion of the plutonium nitrate solution to plutonium dioxide. 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.

   Complete systems especially designed or prepared for the conversion of plutonium nitrate to plutonium oxide, in particular adapted so as to avoid criticality and radiation effects and to minimize toxicity hazards.

   3.6. Plutonium oxide to metal production system

   INTRODUCTORY NOTE

   This process, which could be related to a reprocessing facility, 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: fluorination (eg involving equipment fabricated or lined with a precious metal), metal reduction (eg employing ceramic crucibles), slag recovery, product handling, ventilation, waste management and process control.

   Complete systems especially designed or prepared for the production of plutonium metal, in particular adapted so as to avoid criticality and radiation effects and to minimize toxicity hazards.

4. Plants for the fabrication of fuel elements

   A "plant for the fabrication of fuel elements" includes the equipment:

   1. Which normally comes in direct contact with, or directly processes, or controls, the production flow of nuclear material, or

   2. Which seals the nuclear material within the cladding.

   EXPORTS

   The export of the whole set of items for the foregoing operations will take place only in accordance with the procedures of the Guidelines. The Government will also give consideration to application of the procedures of Guidelines to individual items intended for any of the foregoing operations, as well as for other fuel fabrication operations such as checking the integrity of the cladding or the seal, and the finishing treatment of the sealed fuel.

5. Plants for the separation of isotopes of uranium and equipment, other an analytical Instruments especially designed or prepared therefor

   Items of equipment that are considered to fall within the meaning of the phrase "equipment other than analytical instruments, especially designed or prepared" for the separation of isotopes of uranium include:

   5.1. Gas centrifuges and assemblies and components especially 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 unbalance. 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 especially 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.

   5.1.1. Rotating components

   1. Complete rotor assemblies:
      Thin-walled cylinders, or a number of interconnected thin-walled cylinders, manufactured from one 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 5.1.1.(c) following. The rotor is fitted with an internal baffle(s) and end caps, as described in section 5.1.1.(d) and (e) following, if in final form. However the complete assembly may be delivered only partly assembled.

   2. Rotor tubes:

      Especially 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 of the high strength to density ratio materials described in the EXPLANATORY NOTE to this Section.

   3. Rings or Bellows:

      Components especially 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 of the high strength to density ratio materials described in the EXPLANATORY NOTE to this Section.

   4. Baffles:

      Disc-shaped components of between 75 mm (3 in) and 400 mm (16 in) diameter especially 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 of the high strength to density ratio materials described in the EXPLANATORY NOTE to this Section.

   5. Top caps/Bottom caps:

      Disc-shaped components of between 75 mm (3 in) and 400 mm (16 in) diameter especially 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 NOTE to this Section.

   EXPLANATORY NOTE

   The materials used for centrifuge rotating components are:

   1. Maraging steel capable of an ultimate tensile strength of 2.05^. 10⁹ N/m² (300,000 psi) or more;

   2. Aluminium alloys capable of an ultimate tensile strength of 0.46^. 10⁹ N/m² (67,000 psi) or more;

   3. Filamentary materials suitable for use in composite structures and having a specific modulus of 12.3^. 10⁴m or greater and a specific ultimate tensile strength of 0.3^. 10⁴m or greater ("Specific Modulus is the Young's Modulus in N/m² divided by the specific weight in N/m²; "Specific Ultimate Tensile Strength" is the ultimate tensile strength in N/m² divided by the specific weight in N/m³).

   5.1.2. Static components

   1. Magnetic suspension bearings:

      Especially designed or prepared bearing assemblies consisting of an annular magnet suspended within a housing containing a damping medium. The housing will be manufactured from a UF₆-resistant material (see EXPLANATORY NOTE to Section 5.2.). The magnet couples with a pole piece or a second magnet fitted to the top cap described in Section 5.1.1.(e). The magnet may be ring-shaped with a relation between 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.

   2. Bearings/Dampers:

      Especially designed or prepared bearings comprising a pivot/cup assembly mounted on a damper. The pivot is normally a hardened steel shaft polished into a hemisphere at one end with a means of attachment to the bottom cap described in section 5.1.1 .(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.

   3. Molecular pumps:

      Especially 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, 1 to 1 length to diameter ratio. The grooves are typically rectangular in cross-section and 2 mm (0.08 in) or more in depth.

   4. Motor stators:

      Especially 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.

   5.2. Especially 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 plant needed to feed UF₆ to the centrifuges, to link the individual centrifuges to each other to form cascades (or stages) to allow for progressively higher enrichments and to extract the "product" and "tails" UF₆ from the centrifuges, 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 centrifuges by way of cascade header pipework. The "product" and "tails" UF₆ gaseous streams flowing from the centrifuges are also passed by way of cascade header pipework to cold traps (operating at about 203 K (-70^oC)) 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.

   5.2.1. Feed systems/product and tails withdrawal systems

   Especially designed or prepared process systems including:

   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;

   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 (-70^oC) and heated to 343 K (70^oC);

   "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 to this section) and is fabricated to very high vacuum and cleanliness standards.

   5.2.2. Machine header piping systems

   Especially 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 to this section) and is fabricated to very high vacuum and cleanliness standards.

   5.2.3. UF₆ mass spectrometers/ion sources

   Especially 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:

   1. Unit resolution for atomic mass unit greater than 320;

   2. Ion sources constructed of or lined with nichrome or monel or nickel plated;

   3. Electron bombardment ionization sources;

   4. Having a collector system suitable for isotopic analysis.

   5.2.4. Frequency changers

   Frequency changers (also known as converters or invertors) especially designed or prepared to supply motor stators as defined under 5.1 .2.(d), or parts, components and sub-assemblies of such frequency changers having all of the following characteristics:

   1. A multiphase output of 600 to 2000 Hz;

   2. High stability (with frequency control better than 0.1%);

   3. Low harmonic distortion (less than 2%); and

   4. An efficiency of greater than 80%.

   EXPLANATORY NOTE

   The items listed above 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, aluminium, aluminium alloys, nickel or alloys containing 60% or more nickel.

   5.3. Especially 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 values, 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.

   5.3.1. Gaseous diffusion barriers

   1. Especially designed or prepared thin, porous filters, with a pore size of 100 - 1,000 A (angstroms), 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

   2. especially prepared compounds or powders for the manufacture of such filters. Such compounds and powders include nickel or alloys containing 60 per cent or more nickel, aluminium oxide, or UF₆-resistant fully fluorinated hydrocarbon polymers having a purity of 99.9 per cent or more, a particle size less than 10 microns, and a high degree of particle size uniformity, which are especially prepared for the manufacture of gaseous diffusion barriers.

   5.3.2. Diffuser housings

   Especially designed or prepared hermetically sealed cylindrical vessels greater then 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 UF-₆ resistant materials and designed for horizontal or vertical installation.

   5.3.3. Compressors and gas blowers

   Especially 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.

   5.3.4. Rotary shaft seals

   Especially 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 cm³/min (60 in³/min).

   5.3.5. Heat exchangers for cooling UF₆

   Especially 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).

   5.4. Especially 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 especially their shutdown, leads to serious consequences. Therefore, a strict and constant maintenance of vacuum in ail technological systems, automatic protection from accidents, and 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 of piping systems are fabricated to very high vacuum and cleanliness standards.

   5.4.1. Feed systems/product and tails withdrawal systems

   Especially designed or prepared process systems, capable of operating at pressures of 300 kPa (45 psi) or less, including:

   Feed autoclaves (or systems), used for passing UF₆ to the gaseous diffusion cascades; Desublimers (or cold traps) used to remove UF₆ from diffusion cascades;

   Liquefaction stations where UF₆ gas from the cascade is compressed and cooled to form liquid UF₆;

   "Product" or "tails" stations used for transferring UF₆ into containers.

   5.4.2. Header piping systems

   Especially designed or prepared piping systems and header systems for handling UF₆ within the gaseous diffusion cascades. This piping network is normally of the "double" header system with each cell connected to each of the headers.

   5.4.3. Vacuum systems

   1. Especially designed or prepared large vacuum manifolds, vacuum headers and vacuum pumps having a suction capacity of 5 m³/min (175 ft³/min) or more.

   2. Vacuum pumps especially designed for service in UF₆-bearing atmospheres made of, or lined with, aluminium, 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.

   5.4.4. Special shut-off and control valves

   Especially 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.

   5.4.5. UF₆ mass spectrometers/ion sources

   Especially 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:

   1. Unit resolution for atomic mass unit greater than 320;

   2. Ion sources constructed of or lined with nichrome or monel or nickel plated;

   3. Electron bombardment ionization sources;

   4. Collector system suitable for isotopic analysis.

   EXPLANATORY NOTE

   The items listed 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, aluminium, aluminium alloys, aluminium oxide, nickel or alloys containing 60% or more nickel and UF₆-resistent fully fluorinated hydrocarbon polymers

   5.5. Jet nozzle separation units

   5.6. Vortex separation units

6. Plants for the production of heavy water, deuterium and deuterium compounds and equipment especially designed or prepared therefor

   INTRODUCTORY NOTE

   Heavy water can be produced by a variety of processes. However, the two processes that have proven to be commercially viable are the water-hydrogen suphide exchange process (GS process) and the ammonia-hydrogen exchange process.

   The GS process is based upon the exchange of hydrogen and deuterium between water and hydrogen sulphide within a series of towers which are operated with the top section cold and the bottom section hot. Water flows down the towers while the hydrogen sulphide gas circulates from the bottom to the top of the towers. A series of perforated trays are used to promote mixing between the gas and the water. Deuterium migrates to the water at low temperatures and to the hydrogen sulphide at high temperatures. Gas or water, enriched in deuterium, is removed from the first stage lowers at the junction of the hot and cold sections and the process is repeated in subsequent stage towers. The product of the test cage, water enriched up to 30% in deuterium, is sent to a distillation unit to produce reactor grade heavy water; i.e., 99.75% deuterium oxide.

   The ammonia-hydrogen exchange process can extract deuterium from synthesis gas through contact with liquid ammonia in the presence of a catalyst. The synthesis gas is fed into exchange towers and to an ammonia converter. Inside the towers the gas flows from the bottom to the top while the liquid ammonia flows from the top to the bottom. The deuterium is stripped from the hydrogen in the synthesis gas and concentrated in the ammonia. The ammonia then flows into an ammonia cracker at the bottom of the tower while the gas flows into an ammonia converter at the top. Further enrichment takes place in subsequent stages and reactor grade heavy water is produced through final distillation. The synthesis gas feed can be provided by an ammonia plant that, in turn, can be constructed in association with a heavy water ammonia-hydrogen exchange plant. The ammonia-hydrogen exchange process can also use ordinary water as a feed source of deuterium.

   Many of the key equipment items for heavy water production plants using GS or the ammonia-hydrogen exchange processes are common to several segments of the chemical and petroleum industries This is particularly so for small plants using the GS process. However, few of the items are available "off-the-shelf". The GS and ammonia-hydrogen processes require the handling of large quantities of flammable, corrosive and toxic fluids at elevated pressures. Accordingly, in establishing the design and operating standards for plants and equipment using these processes, careful attention to the materials selection and specifications is required to ensure long service life with high safety and reliability factors. The choice of scale is primarily a function of economics and need. Thus, most of the equipment items would be prepared according to the requirements of the customer.

   Finally, it should be noted that, in both the GS and the ammonia-hydrogen exchange processes, items of equipment which individually are not especially designed or prepared for heavy water production can be assembled into systems which are especially designed or prepared for producing heavy water. The catalyst production system used in the ammonia-hydrogen exchange process and water distillation systems used for the final concentration of heavy water to reactor-grade in either process are examples of such systems.

   The items of equipment which are especially designed or prepared for the production of heavy water utilizing either the water-hydrogen suphide exchange pro cess or the ammonia-hydrogen exchange process include the following:

   6.1. Water-Hydrogen Sulphide Exchange Towers

   Exchange towers fabricated from fine carbon steel (such as ASTM A516) with diameters of 6 m (20 ft) to 9 m (30 ft), capable of operating at pressures greater than or equal to 2 MPa (300 psi) and with a corrosion allowance of 6 mm or greater, especially designed or prepared for heavy water production utilizing the water-hydrogen sulphide exchange process.

   6.2. Blowers and Compressors

   Single stage, low head (i.e., 0.2 MPa or 30 psi) centrifugal blowers or compressors for hydrogen sulphide -gas circulation (i.e., gas containing more than 70% H₂S) especially designed or prepared for heavy water production utilizing the water-hydrogen sulphide exchange process. These blowers or compressors have a throughput capacity greater than or equal to 56 m³/second (120,000 SCFM) while operating at pressures greater than or equal to 1.8 MPa (260 psi) suction and have seals designed for wet H₂S service.

   6.3. Ammonia-Hydrogen Exchange Towers

   Ammonia-hydrogen exchange towers greater than or equal to 35 m (114.3 ft) in height with diameters of 1.5 m (4.9 ft) to 2.5 m (8.2 ft) capable of operating at pressures greater than 15 MPa (2225 psi) especially designed or prepared for heavy water production utilizing the ammonia-hydrogen exchange process. These towers also have at least one flanged, axial opening of the same diameter as the cylindrical part through which the tower internals can be inserted or withdrawn.

   6.4. Tower Internals and Stage Pumps

   Tower internals and stage pumps especially designed or prepared for towers for heavy water production utilizing the ammonia-hydrogen exchange process. Tower internals include especially designed stage contactors which promote intimate gas/liquid contact. Stage pumps include especially designed submersible pumps for circulation of liquid ammonia within a contacting stage internal to the stage towers.

   6.5. Ammonia Crackers

   Ammonia crackers with operating pressures greater than or equal to 3 MPa (450 psi) especially designed or prepared for heavy water production utilizing the ammonia- hydrogen exchange process.

   6.6. Infrared Absorption Analyzers

   Infrared absorption analyzers capable of "on-line" hydrogen/deuterium ratio analysis where deuterium concentrations are equal to or greater than 90%.

   6.7. Catalytic Burners

   Catalytic burners for the conversion of enriched deuterium gas into heavy water especially designed or prepared for heavy water production utilizing the ammonia-hydrogen exchange process.

1. The purpose of physical protection of nuclear materials is to prevent unauthorized use and handling of these materials. Paragraph 3(a) of the Guidelines document calls for agreement among suppliers on the levels of protection to be ensured in relation to the type of materials, and equipment and facilities containing these materials, taking account of international recommendations.

2. Paragraph 3(b) of the Guidelines document states that implementation of measures of physical protection in the recipient country is the responsibility of the Government of that country. However, the levels of physical protection on which these measures have to be based should be the subject of an agreement between supplier and recipient. In this context these requirements should apply to all States.

3. The document INFCIRC/225 of the International Atomic Energy Agency entitled "The Physical Protection of Nuclear Material" and similar documents which from time to time are prepared by international groups of experts and updated as appropriate to account for changes in the state of the art and state of knowledge with regard to physical protection of nuclear material are a useful basis for guiding recipient States in designing a system of physical protection measures and procedures.

4. The categorization of nuclear material presented in the attached table or as it may be updated from time to time by mutual agreement of suppliers shall serve as the agreed basis for designating specific levels of physical protection in relation to the type of materials, and equipment and facilities containing these materials, pursuant to paragraph 3(a) and 3(b) of the Guidelines document.

5. The agreed levels of physical protection to be ensured by the competent national authorities in the use, storage and transportation of the materials listed in the attached table shall as a minimum include protection characteristics as follows:

   CATEGORY III

   Use and Storage within an area to which access in controlled.

   Transportation under special precautions including prior arrangements among sender, recipient and carrier, and prior agreement between entities subject to the jurisdiction and regulation of supplier and recipient States, respectively, in case of international transport specifying time, place and procedures for transferring transport responsibility.

   CATEGORY II

   Use and Storage within a protected area to which access is controlled, i.e. an area under constant surveillance by guards or electronic devices, surrounded by a physical barrier with a limited number of points of entry under appropriate control, or any area with an equivalent level of physical protection.

   Transportation under special precautions including prior arrangements among sender, recipient and carrier, and prior agreement between entities subject to the jurisdiction and regulation of supplier and recipient States, respectively, in case of international transport, specifying time, place and procedures for transferring transport responsibility.

   CATEGORY I

   Materials in this category shall be protected with highly reliable systems against unauthorized use as follows:

   Use and Storage within a highly protected area, i.e. a protected area as defined for Category II above, to which, in addition, access is restricted to persons whose trustworthiness has been determined, and which is under surveillance by guards who are in close communication with appropriate response forces. Specific measures taken in this context should have as their objective the detection and prevention of any assault, unauthorized access or unauthorized removal of material

   Transportation under special precautions as identified above for transportation of Category II and III materials and, in addition, under constant surveillance by escorts and under conditions which assure close communication with appropriate response forces.

6. Suppliers should request identification by recipients of those agencies or authorities having responsibility for ensuring that levels of protection are adequately met and having responsibility for internally co-ordinating response/recovery operations in the event of unauthorized use or handling of protected materials. Suppliers and recipients should also designate points of contact within their national authorities to co-operate on matters of out-of-country transportation and other matters of mutual concern.

   Table: Categorization of Nuclear Material
   		Category
   Material	Form	I	11	111
   1. Plutonium[a]	Unirradiated[b]	2 kg or more	Less than 2 kg but more than 500 g	500 g or less[c]
   2. Uranium-235	Unirradiated[b]
   	uranium enriched to 20% 235U or more	5 kg or more	Less than 5 kg but more than 1 kg	1 kg or less[c]
   	uranium enriched to 10% 235U but less than 20%	-	10 kg or more	Less than 10 kg[c]
   	uranium enriched above natural, but less than 10% 235U[d]			10 kg or more
   3. Uranium-233	Unirradiated[b]	2 kg or more	Less than 2 kg but more than 500 g	500 g or less[c]
   4. Irradiated fuel			Depleted or natural uranium, thorium or low-enriched fuel (less than 10% fissile content)[e],[f]

^[f] Other fuel which by virtue of its original fissile material content is classified as Category I or II before irradiation may be reduced one category level while the radiation level from the fuel exceeds 100 rads/hour at one metre unshielded.