China and Iran have signed the first agreement on reconfiguration of Iran's Arak reactor. The deal was concluded between the Atomic Energy Organization of Iran (AEOI) and a Chinese company at the official ceremony in the Austrian capital Vienna yesterday, the Mehr News Agency reported. <br/><br/>In 2016, the AEOI deputy atomic chief Ali Asghar Zarean said China would help to modify the design of Iran's IR-40 heavy-water reactor, which is under construction at the Arak nuclear facility. The reconstruction of the Arak heavy-water reactor is a part of the Joint Comprehensive Plan of Action (JCPOA) deal, which Tehran signed with international mediators in July 2015 in return for sanctions easing.<br/><br/>According to the JCPOA, Tehran vowed not to produce weapons-grade plutonium at its Arak facility and not to build new heavy-water reactors for 15 years as part of a mid-2015 deal to curb its nuclear program.