My colleague, Barbara Slavin, writes:
A report today by the Associated Press that nuclear inspectors have found traces of uranium enriched beyond 20 percent at Iran’s Fordow enrichment plant appears to reflect changes in the design of centrifuge cascades rather than a deliberate Iranian effort to get closer to weapons-grade uranium.
David Albright, a former arms inspector and president of the Institute for Science and International Security, a Washington-based organization that closely tracks nuclear proliferation, told Al-Monitor in an email that the higher level of enrichment “is likely due to improved cascade design. The cascades at Fordow making 19.7 percent LEU [low-enriched uranium] have 17 stages instead of 15 as in the old cascade design. An effect is to overshoot 20 percent when 3.5 percent LEU is fed into the tandem cascades at the old feed rate for 15 stage cascades.”
According to the AP, which cited “several diplomats,” “the International Atomic Energy Agency has found traces of uranium enriched up to 27 percent” at Fordow, which is built into the side of a mountain near the holy city of Qom and whose existence was hidden by Iran until the plant was discovered by Western intelligence in 2009.
Albright said the discovery of uranium enriched beyond 20 percent “is an embarrassment for Iran but it is not a sign of Iran moving to higher enrichments. Nonetheless, its deployment of a 17 stage cascade reflects a reconfiguration of the cascades that can make breakout faster and more efficient.”
Weapons-grade uranium is enriched to 90 percent of the isotope U-235 and it would take Iran only a few months to turn 20 percent uranium into potential bomb fuel. Friday’s news suggests, however, that inspectors would detect any such diversion.
According to the latest IAEA report, Iran has produced 6197 kilograms of uranium enriched up to 5 percent and 145.6 kilograms of 20-percent uranium – 45.6 kilograms of the latter at the Fordow plant. Asked by the IAEA about the traces of 27 percent uranium at Fordow, Iran told the IAEA that “the production of such particles ‘above the target value’ may happen for technical reasons beyond the operator’s control.”
Iran, which just concluded two days of “intense” talks in Baghdad over its nuclear program, insists that its activities are purely peaceful in nature. Iran says it needs 20 percent-enriched uranium to fuel a reactor in Tehran that makes medical isotopes for cancer patients. The United States and its negotiating partners have offered to provide fuel for that reactor if Iran stops enriching uranium beyond the 3.5 percent needed for most civilian uses. Iran, however, appears to be seeking more incentives before signing any deal.