Israel attacked Iran’s nuclear development sites with a wave of airstrikes on Thursday, seeking to decimate the country’s nuclear program.

Israel’s air force bombed Iran’s Arak Nuclear Complex on Thursday morning. The facility is known as IR-40 and is used as a heavy-water nuclear reactor, according to the Missile Defense Advocacy Alliance. Heavy water helps cool nuclear reactors, and this process produces plutonium, which can be used to develop a nuclear weapon. It is considered a vital component of Iran’s nuclear programs. This facility began operating in 2003.