On April 11, 2021, Iran’s Natanz enrichment complex suffered an electrical failure that Iranian officials described as sabotage. The incident came one day after Iran inaugurated advanced centrifuges at the site. Iranian officials later said an explosion had damaged both the main and emergency power supply. Israeli involvement was widely reported.
What happened on April 11
Iran’s Atomic Energy Organization spokesman Behrouz Kamalvandi announced a problem with Natanz’s electrical distribution network. The announcement followed a ceremony the previous day at which Iran presented new IR-6 and IR-5 centrifuges. Contemporaneous reporting recorded Iran’s initial description of an electrical incident and its statement that there were no injuries or radioactive pollution.
Two days later, former Iranian atomic energy chief Fereydoon Abbasi-Davani said an explosion had taken out the facility’s central and backup power. His remarks were carried by Iranian state television and quoted in The Times of Israel. The official said the blast had taken out both power systems.
Damage claims and attribution
Iran blamed an act of sabotage and accused Israel. Israeli officials hinted at Israeli involvement, while reports citing intelligence sources described severe damage to centrifuges and a delay in enrichment. Reports citing Israeli and U.S. intelligence sources described severe centrifuge damage and a delay in Iran’s enrichment program.
The International Atomic Energy Agency’s 2021 safeguards report records Iran’s centrifuge activity during that period. The outage disrupted a key part of Iran’s nuclear infrastructure. It followed the earlier Stuxnet operation.