China and Iran will sign the first commercial contract to redesign Iran's Arak heavy water reactor in Vienna on Sunday. Foreign Ministry spokesman Lu Kang said yesterday at a daily news briefing that China and Iran have reached initial agreement on the commercial contract. <br/><br/>Redesigning the Arak heavy water reactor is a core aspect of the Joint Comprehensive Plan of Action (JCPOA) on Iran's nuclear program. The JCPOA was reached in Vienna in July 2015 between Iran and the P5+1 group, namely Britain, China, France, Russia, the United States and Germany. <br/><br/>The signing will create a favorable condition for the progress of the redesign. The 7th Joint Commission between Iran and the P5+1 will convene in Vienna next Tuesday. Lu said the contract between China and Iran will inject positive impetus to the meeting.