When on Monday next week delegations of Iran and world powers resume their talks in Vienna, the previous three weeks have seen much clarification already. Iran’s offer (or request) to further enrich most of its 1500 kg of 3.5% or so low enriched uranium (LEU) with the help of Russia or France to the desired 19.75% (for fueling the Tehran’s research reactor which is entirely used for producing the medical isotope technetium 99) has come by many as a surprise.

One reason for Iran’s turn may be contamination of the UF₆ with molybdenum which could damage the centrifuges in Natanz if it is further enriched. Joshua Pollack at ArmsControlWonk.com points to the long-known facts today that the contamination has its origin in Esfahan’s Uranium Conversion Facility (UCF). Only early in 2007 centrifuges in Natanz have been fed by UF₆, which had been produced in Esfahan, then leading to the contamination problem. Before, they relied on stuff which had been delivered by China.

According to Pollack, purification of contaminated LEU is not really a problem for the Iranians. The material has only to be transported back to Esfahan, re-processed and returned to Natanz. Tehran has, therefore, already stressed that, given the Vienna talks failed or did not yield, for Iran, constructive results one would definitely go ahead with enriching in the country. One should not underestimate Tehran’s first aim: mastering the entire nuclear fuel cycle.

Given Iran’s bad experience with western collaboration for decades, becoming independent of external sources may be of utmost importance for the country. Western powers may be well-advised of eventually building trust and confidence in offering honest and constructive international cooperation. So are the rulers in Tehran.