IAEA: Iran Has Enriched Uranium to Up to 63% Purity

Fluctuations at Iran's Natanz plant pushed the purity to which it enriched uranium to 63%, higher than the announced 60% that complicated talks to revive its nuclear deal with world powers, a report by the UN nuclear watchdog said on Tuesday.
Iran made the shift to 60%, a big step towards
nuclear weapons-grade from the 20% previously achieved, last month in response
to an explosion and power cut at Natanz that Tehran has blamed on Israel and
appears to have damaged its enrichment output at a larger, underground facility
there.
Iran's move rattled the current indirect talks
with the United States to agree conditions for both sides to return fully to
the 2015 nuclear deal, which was undermined when Washington abandoned it in
2018, prompting Tehran to violate its terms.
The deal says Iran cannot enrich beyond 3.67%
fissile purity, far from the 90% of weapons-grade. Iran has long denied any
intention to develop nuclear weapons.
"According to Iran,
fluctuations of the enrichment levels... were experienced," the
International Atomic Energy Agency (IAEA) said in the confidential report to
its member states, seen by Reuters.
"The agency's analysis
of the ES (environmental samples) taken on 22 April 2021 shows an enrichment
level of up to 63% U-235, which is consistent with the fluctuations of the
enrichment levels (described by Iran)," it added, without saying why the
fluctuations had occurred.
A previous IAEA report last month said Iran was
using one cascade, or cluster, of advanced IR-6 centrifuge machines to enrich
to up to 60% and feeding the tails, or depleted uranium, from that process into
a cascade of IR-4 machines to enrich to up to 20%.
Tuesday's report said Iran was now feeding the tails from the IR-4 cascade into a cascade of 27 IR-5 and 30 IR-6s centrifuges to refine uranium to up to 5%.