C.4. Nuclear components for an explosive device
31. For use in a nuclear device, HEU retrieved from the enrichment process is first converted to metal. The metal is then cast and machined into suitable components for a nuclear core.
32. As indicated in paragraph 5 above, Iran has acknowledged that, along with the handwritten onepage document offering assistance with the development of uranium centrifuge enrichment technology, in which reference is also made to a reconversion unit with casting equipment, Iran also received the uranium metal document which describes, inter alia, processes for the conversion of uranium compounds into uranium metal and the production of hemispherical enriched uranium metallic components.
33. The uranium metal document is known to have been available to the clandestine nuclear supply network that provided Iran with assistance in developing its centrifuge enrichment capability, and is also known to be part of a larger package of information which includes elements of a nuclear explosive design. A similar package of information, which surfaced in 2003, was provided by the same network to Libya.35 The information in the Libyan package, which was first reviewed by Agency experts inJanuary 2004, included details on the design and construction of, and the manufacture of components for,a nuclear explosive device.36
34. In addition, a Member State provided the Agency experts with access to a collection of electronic files from seized computers belonging to key members of the network at different locations. That collection included documents seen in Libya, along with more recent versions of those documents,including an up-dated electronic version of the uranium metal document.
35. In an interview in 2007 with a member of the clandestine nuclear supply network, the Agency wastold that Iran had been provided with nuclear explosive design information. From information provided tothe Agency during that interview, the Agency is concerned that Iran may have obtained more advanced design information than the information identified in 2004 as having been provided to Libya by thenuclear supply network.
36. Additionally, a Member State provided information indicating that, during the AMAD Plan, preparatory work, not involving nuclear material, for the fabrication of natural and high enriched uraniummetal components for a nuclear explosive device was carried out.
37. As the conversion of HEU compounds into metal and the fabrication of HEU metal componentssuitable in size and quality are steps in the development of an HEU nuclear explosive device, clarification by Iran is needed in connection with the above.
C.5. Detonator development
38. The development of safe, fast-acting detonators, and equipment suitable for firing the detonators, is an integral part of a programme to develop an implosion type nuclear device. Included among the alleged studies documentation are a number of documents relating to the development by Iran, during the period2002–2003, of fast functioning detonators, known as “exploding bridgewire detonators” or “EBWs” as safe alternatives to the type of detonator described for use in the nuclear device design referred to inparagraph 33 above.
39. In 2008, Iran told the Agency that it had developed EBWs for civil and conventional military applications and had achieved a simultaneity of about one microsecond when firing two to three detonators together,37and provided the Agency with a copy of a paper relating to EBW development work presented by two Iranian researchers at a conference held in Iran in 2005. A similar paper was publishedby the two researchers at an international conference later in 2005.38 Both papers indicate that suitablehigh voltage firing equipment had been acquired or developed by Iran. Also in 2008, Iran told the Agency that, before the period 2002–2004, it had already achieved EBW technology. Iran also provided the Agency with a short undated document in Farsi, understood to be the specifications for a detonator development programme, and a document from a foreign source showing an example of a civilian application in which detonators are fired simultaneously. However, Iran has not explained to the Agency its own need or application for such detonators.
40. The Agency recognizes that there exist non-nuclear applications, albeit few, for detonators likeEBWs, and of equipment suitable for firing multiple detonators with a high level of simultaneity.Notwithstanding, given their possible application in a nuclear explosive device, and the fact that there arelimited civilian and conventional military applications for such technology, Iran’s development of such detonators and equipment is a matter of concern, particularly in connection with the possible use of the multipoint initiation system referred to below.