Iran is using advanced machines at its underground Fordow plant to further escalate its uranium enrichment in a setup that can more easily change between enrichment levels, the UN atomic watchdog warned in a report on Saturday.
The presence of these so-called modified sub-headers this cascade, or cluster, of centrifuges, is equipped with has long concerned Western diplomats since its use means Tehran could more quickly and easily switch to enriching to higher purity levels.
Considering the current lag between Iran’s enrichment and the International Atomic Energy Agency (IAEA) inspectors’ verification of what is produced, Iran could easily escape detection of such a switch for some time although it is required to inform IAEA about such instances.
The confidential IAEA report to member states said Tehran informed them it had begun feeding the aforementioned centrifuges cascade with UF6 (uranium hexafluoride gas) enriched up to.
Months after, as the report points out, Iran had allegedly begun feeding UF6 into it for passivation – a process that comes before enrichment- the IAEA verified in July it had ended.
The report says that the agency verified on July 9 that Tehran had begun feeding 5% U-235 into the cascade of 166 IR-6 centrifuges with modified sub-headers whose declared purpose is producing UF6 enriched up to 20% U-235.
After its 2015 deal with major powers that capped its enrichment level at 3.67% failed, Iran began enriching uranium up to 60 percent in other locations. However, that’s well below roughly 90% of weapons-grade.