{"682969":{"#nid":"682969","#data":{"type":"news","title":"Why the US Bombed a Bunch of Metal Tubes \u2212 a Nuclear Engineer Explains the Importance of Centrifuges to Iranian Efforts to Build Nuclear Weapons","body":[{"value":"\u003Cdiv class=\u0022theconversation-article-body\u0022\u003E\u003Cp\u003EWhen U.S. forces \u003Ca href=\u0022https:\/\/theconversation.com\/us-bombs-irans-nuclear-sites-what-led-to-trump-pulling-the-trigger-and-what-happens-next-259519\u0022\u003Eattacked Iran\u2019s nuclear facilities\u003C\/a\u003E on June 21, 2025, the main target was metal tubes in laboratories deep underground. The tubes are centrifuges that produce highly enriched uranium needed to build nuclear weapons.\u003C\/p\u003E\u003Cp\u003EInside of a centrifuge, a rotor spins in the range of 50,000 to 100,000 revolutions per minute, 10 times faster than a Corvette engine\u2019s crankshaft. High speeds are needed to \u003Ca href=\u0022https:\/\/theconversation.com\/uranium-enrichment-a-chemist-explains-how-the-surprisingly-common-element-is-processed-to-power-reactors-and-weapons-259646\u0022\u003Eseparate lighter uranium-235 from heavier uranium-238\u003C\/a\u003E for further collection and processing. Producing this level of force means the rotor itself must be well balanced and strong and rely on high-speed magnetic bearings to reduce friction.\u003C\/p\u003E\u003Cp\u003EOver the years, \u003Ca href=\u0022https:\/\/www.iranwatch.org\/our-publications\/articles-reports\/explainer-irans-centrifuges\u0022\u003EIran has produced thousands of centrifuges\u003C\/a\u003E. They work together to enrich uranium to dangerous levels \u2013 close to weapons-grade uranium. Most of them are deployed in three enrichment sites: Natanz, the country\u2019s main enrichment facility, Fordow and Isfahan. Inside of these facilities, the centrifuges are arranged into cascades \u2013 series of machines connected to each other. This way, each machine yields slightly more enriched uranium, feeding the gas produced into its neighbor to maximize production efficiency.\u003C\/p\u003E\u003Cp\u003EAs a \u003Ca href=\u0022https:\/\/scholar.google.com\/citations?hl=en\u0026amp;user=m4uNFy0AAAAJ\u0026amp;view_op=list_works\u0026amp;sortby=pubdate\u0022\u003Enuclear engineer\u003C\/a\u003E who works on nuclear nonproliferation, I track centrifuge technology, including the Iranian enrichment facilities targeted by the U.S. and Israel. A typical cascade deployed in Iran is composed of 164 centrifuges, working in series to produce enriched uranium. The Natanz facility was designed to \u003Ca href=\u0022https:\/\/www.nti.org\/analysis\/articles\/visualizing-centrifuge-limits-under-iran-deal\/\u0022\u003Ehold over 50,000 centrifuges\u003C\/a\u003E.\u003C\/p\u003E\u003Cp\u003EIran\u2019s \u003Ca href=\u0022https:\/\/www.iaea.org\/sites\/default\/files\/documents\/gov2004-83.pdf\u0022\u003Eearly intentions\u003C\/a\u003E to field centrifuges on a very large scale were clear. At the peak of the program in the early 2010s it \u003Ca href=\u0022https:\/\/isis-online.org\/isis-reports\/the-iran-primer-centrifuges-key-to-final-nuclear-deal\/\u0022\u003Edeployed over 19,000 units\u003C\/a\u003E. Iran later scaled down the number of its centrifuges in part due to international agreements such as the since scrapped \u003Ca href=\u0022https:\/\/www.britannica.com\/question\/What-is-the-Iran-nuclear-deal-and-why-was-it-scrapped\u0022\u003EJoint Comprehensive Plan of Action\u003C\/a\u003E signed in 2015.\u003C\/p\u003E\u003Ch2\u003ELegacy of Enrichment\u003C\/h2\u003E\u003Cp\u003EIran has a long history of enriching uranium.\u003C\/p\u003E\u003Cp\u003EIn the late 1990s, it acquired a Pakistani centrifuge design known as P-1. The blueprints and some components were supplied via the \u003Ca href=\u0022http:\/\/dx.doi.org\/10.5038\/1944-0472.9.1.1506\u0022\u003EA.Q. Khan black market network\u003C\/a\u003E \u2013 the mastermind of the Pakistani program and a serious \u003Ca href=\u0022https:\/\/carnegieendowment.org\/research\/2005\/09\/a-q-khan-nuclear-chronology?lang=en\u0022\u003Esource of nuclear proliferation\u003C\/a\u003E globally. Today, the P-1 design is known as IR-1. IR-1 centrifuges use aluminum and a high-strength alloy, known as \u003Ca href=\u0022https:\/\/mechanical-engineering.com\/maraging-steel\/\u0022\u003Emaraging steel\u003C\/a\u003E.\u003C\/p\u003E\u003Cp\u003EAbout \u003Ca href=\u0022https:\/\/www.iranwatch.org\/our-publications\/weapon-program-background-report\/irans-centrifuges-models-status\u0022\u003Eone-third of the centrifuges\u003C\/a\u003E that were deployed at the sites of the recent strike on June 21 are IR-1. Each one produces on the order of 0.8 \u003Ca href=\u0022https:\/\/energyeducation.ca\/encyclopedia\/Separative_work_unit\u0022\u003Eseparative work units\u003C\/a\u003E, which is the unit for measuring the amount of energy and effort needed to separate uranium-235 molecules from the rest of the uranium gas. To put this in perspective, one centrifuge would yield about 0.2 ounces (6 grams) of 60%-enriched uranium-235 per year.\u003C\/p\u003E\u003Cp\u003EA typical uranium-based weapon requires 55 pounds (25 kilograms) of 90%-enriched uranium. To get to weapons-grade level, a single centrifuge would produce only 0.14 ounces (4 grams) per year. It requires more work to go higher in enrichment. While capable of doing the job, the IR-1 is quite inefficient.\u003C\/p\u003E\u003Cfigure\u003E\u003Cp\u003E\u003Ciframe width=\u0022440\u0022 height=\u0022260\u0022 src=\u0022https:\/\/www.youtube.com\/embed\/Uul1xf9IXJk?wmode=transparent\u0026amp;start=0\u0022 frameborder=\u00220\u0022 allowfullscreen=\u0022\u0022\u003E\u003C\/iframe\u003E\u003C\/p\u003E\u003Cfigcaption\u003E\u003Cspan class=\u0022caption\u0022\u003EThe author explains the uranium enrichment process to CBS News.\u003C\/span\u003E\u003C\/figcaption\u003E\u003C\/figure\u003E\u003Ch2\u003EMore and Better Centrifuges\u003C\/h2\u003E\u003Cp\u003ESmall yields mean that over 6,000 centrifuges would need to work together for a year to get enough material for one weapon such as a nuclear warhead. Or the efficiency of the centrifuges would have to be improved. Iran did both.\u003C\/p\u003E\u003Cp\u003EBefore the strike by U.S. forces, Iran was operating close to 7,000 IR-1 centrifuges. In addition, Iran designed, built and operated \u003Ca href=\u0022https:\/\/www.iranwatch.org\/our-publications\/articles-reports\/explainer-irans-centrifuges\u0022\u003Emore efficient centrifuges\u003C\/a\u003E such as the IR-2m, IR-4 and IR-6 designs. Comparing the IR-1 with the latest designs is like comparing a golf cart with the latest electric vehicles in terms of range and payload.\u003C\/p\u003E\u003Cp\u003EIran\u2019s latest centrifuge designs contain carbon fiber composites with exceptional strength and durability and low weight. This is a recipe for producing light and compact centrifuges that are easier to conceal from inspections. According to the international nuclear watchdog International Atomic Energy Agency, before the strike \u003Ca href=\u0022https:\/\/www.iaea.org\/sites\/default\/files\/25\/06\/gov2025-24.pdf\u0022\u003EIran was operating\u003C\/a\u003E 6,500 IR-2m centrifuges, close to 4,000 IR-4 centrifuges and over 3,000 IR-6 centrifuges.\u003C\/p\u003E\u003Cp\u003EWith each new generation, the separative work unit efficiency increased significantly. IR-6 centrifuges, with their carbon fiber rotors, can achieve \u003Ca href=\u0022https:\/\/www.iranwatch.org\/our-publications\/weapon-program-background-report\/irans-centrifuges-models-status\u0022\u003Eup to 10 separative work units\u003C\/a\u003E per year. That\u2019s about 2.8 ounces (80 grams) of 60%-enriched uranium-235 per year. The International Atomic Energy Agency verified that the IR-6 cascades have been actively \u003Ca href=\u0022https:\/\/www.iaea.org\/sites\/default\/files\/25\/06\/gov2025-24.pdf\u0022\u003Eused to ramp up production\u003C\/a\u003E of 60%-enriched uranium.\u003C\/p\u003E\u003Cp\u003EThe most recent and advanced centrifuges developed by Iran, known as IR-9, \u003Ca href=\u0022https:\/\/www.iranwatch.org\/news-brief\/iran-testing-advanced-ir-9-centrifuges-aeoi-spokesperson\u0022\u003Ecan achieve 50 separative work units\u003C\/a\u003E per year. This cuts down the time needed to produce highly enriched uranium for weapon purposes from months to weeks. The other aspect of IR-9 advanced centrifuges is their compactness. They are easier to conceal from inspections or move underground, and they require less energy to operate.\u003C\/p\u003E\u003Cp\u003EAdvanced centrifuges such as the IR-9 drive up the risk of nuclear weapons proliferation significantly. Fortunately, the International Atomic Energy Agency \u003Ca href=\u0022https:\/\/www.iaea.org\/sites\/default\/files\/25\/06\/gov2025-24.pdf\u0022\u003Ereports that only one exists\u003C\/a\u003E in testing laboratories, and there is no evidence Iran has deployed them widely. However, it\u2019s possible more are concealed.\u003C\/p\u003E\u003Ch2\u003EBombs or Talks?\u003C\/h2\u003E\u003Cp\u003EUranium enrichment of 60% is far beyond the needs of any civilian use. The International Atomic Energy Agency confirmed that Iran \u003Ca href=\u0022https:\/\/www.iaea.org\/newscenter\/pressreleases\/update-on-developments-in-iran-6\u0022\u003Estockpiled about 880 pounds (400 kilograms)\u003C\/a\u003E of highly enriched uranium before the attack, and it \u003Ca href=\u0022https:\/\/www.theguardian.com\/us-news\/2025\/jun\/24\/jd-vance-trump-iran-nuclear-program\u0022\u003Emight have escaped intact\u003C\/a\u003E. That\u2019s enough to make 10 weapons. The newer centrifuges \u2013 IR-2m, IR-4 and IR-6 \u2013 would need a bit over eight months to produce that much.\u003C\/p\u003E\u003Cp\u003EIt\u2019s \u003Ca href=\u0022https:\/\/www.nytimes.com\/interactive\/2025\/06\/27\/world\/middleeast\/iran-us-nuclear-weapons.html\u0022\u003Enot clear\u003C\/a\u003E what the U.S. attack has accomplished, but destroying the facilities targeted in the attack and hindering Iran\u2019s ability to continue enriching uranium might be a way to slow Iran\u2019s move toward producing nuclear weapons. However, based on my work and research on preventing nuclear proliferation, I believe a more reliable means of preventing Iran from achieving its nuclear aims would be for diplomacy and cooperation to prevail.\u003C!-- Below is The Conversation\u0027s page counter tag. Please DO NOT REMOVE. --\u003E\u003Cimg style=\u0022border-color:!important;border-style:none;box-shadow:none !important;margin:0 !important;max-height:1px !important;max-width:1px !important;min-height:1px !important;min-width:1px !important;opacity:0 !important;outline:none !important;padding:0 !important;\u0022 src=\u0022https:\/\/counter.theconversation.com\/content\/259883\/count.gif?distributor=republish-lightbox-basic\u0022 alt=\u0022The Conversation\u0022 width=\u00221\u0022 height=\u00221\u0022 referrerpolicy=\u0022no-referrer-when-downgrade\u0022\u003E\u003C!-- End of code. If you don\u0027t see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https:\/\/theconversation.com\/republishing-guidelines --\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis article is republished from \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\u0022\u003E\u003Cem\u003EThe Conversation\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E under a Creative Commons license. Read the \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/why-the-us-bombed-a-bunch-of-metal-tubes-a-nuclear-engineer-explains-the-importance-of-centrifuges-to-iranian-efforts-to-build-nuclear-weapons-259883\u0022\u003E\u003Cem\u003Eoriginal article\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E.\u003C\/em\u003E\u003C\/p\u003E\u003C\/div\u003E","summary":"","format":"full_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EWhen U.S. forces attacked Iran\u2019s nuclear facilities on June 21, 2025, the main target was metal tubes in laboratories deep underground. The tubes are centrifuges that produce highly enriched uranium needed to build nuclear weapons.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"When U.S. forces attacked Iran\u2019s nuclear facilities on June 21, 2025, the main target was metal tubes in laboratories deep underground. The tubes are centrifuges that produce highly enriched uranium needed to build nuclear weapons."}],"uid":"27469","created_gmt":"2025-07-01 15:48:25","changed_gmt":"2025-07-02 19:54:22","author":"Kristen Bailey","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2025-07-01T00:00:00-04:00","iso_date":"2025-07-01T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"677327":{"id":"677327","type":"image","title":"An image from Iranian television shows centrifuges lining a hall at Iran\u2019s Natanz uranium enrichment facility in 2021. IRIB via APPEAR","body":"\u003Cp\u003EAn image from Iranian television shows centrifuges lining a hall at Iran\u2019s Natanz uranium enrichment facility in 2021. \u003Ca href=\u0022https:\/\/newsroom.ap.org\/detail\/IranNuclear\/b33a4cafe0cc4c65a9befae76240b7ea\/photo\u0022\u003EIRIB via APPEAR\u003C\/a\u003E\u003C\/p\u003E","created":"1751385183","gmt_created":"2025-07-01 15:53:03","changed":"1751385183","gmt_changed":"2025-07-01 15:53:03","alt":"An image from Iranian television shows centrifuges lining a hall at Iran\u2019s Natanz uranium enrichment facility in 2021. IRIB via APPEAR","file":{"fid":"261214","name":"file-20250630-56-2lv66g.jpg","image_path":"\/sites\/default\/files\/2025\/07\/01\/file-20250630-56-2lv66g.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2025\/07\/01\/file-20250630-56-2lv66g.jpg","mime":"image\/jpeg","size":249918,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2025\/07\/01\/file-20250630-56-2lv66g.jpg?itok=FcYdZyxH"}}},"media_ids":["677327"],"related_links":[{"url":"https:\/\/theconversation.com\/why-the-us-bombed-a-bunch-of-metal-tubes-a-nuclear-engineer-explains-the-importance-of-centrifuges-to-iranian-efforts-to-build-nuclear-weapons-259883","title":"Read This Article on The Conversation"}],"groups":[{"id":"660369","name":"Matter and Systems"},{"id":"1188","name":"Research Horizons"}],"categories":[],"keywords":[{"id":"187915","name":"go-researchnews"}],"core_research_areas":[{"id":"193652","name":"Matter and Systems"}],"news_room_topics":[{"id":"71901","name":"Society and Culture"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Ch5\u003EAuthors:\u003C\/h5\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/profiles\/anna-erickson-2420881\u0022\u003EAnna Erickson\u003C\/a\u003E, professor of Nuclear and Radiological Engineering, \u003Ca href=\u0022https:\/\/theconversation.com\/institutions\/georgia-institute-of-technology-1310\u0022\u003EGeorgia Institute of Technology\u003C\/a\u003E\u003C\/p\u003E\u003Ch5\u003EMedia Contact:\u003C\/h5\u003E\u003Cp\u003EShelley Wunder-Smith\u003Cbr\u003E\u003Ca href=\u0022mailto:shelley.wunder-smith@research.gatech.edu\u0022\u003Eshelley.wunder-smith@research.gatech.edu\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}