The drop in production, detailed in the International Atomic Energy Agency’s confidential report circulated Monday, gives the first substantive insight into the impact of the incident, which took out the power supply at Natanz and destroyed potentially hundreds of centrifuges, machines that enrich uranium. Israel has declined to comment on the incident, one of several at Iran’s nuclear facilities over the last 18 months. Tehran accused Israel at the time of orchestrating the attack to undermine the start of talks in Vienna involving Iran and the U.S. aimed at restoring the 2015 nuclear deal. Iran’s production of enriched uranium fell to an estimated 273 kilograms in the three months ending May 22, just over half the 525 kg in the previous quarter. The Natanz incident happened April 11, halfway through the reporting period.