Iran has no plan to change its Arak heavy water reactor into a light water facility, the spokesman for the Atomic Energy Organization of Iran (AEOI) said on Saturday. "The Arak heavy water reactor is unalterable and will remain a heavy water reactor," Behrouz Kamalvandi was quoted by lRAN Daily as saying on Friday, adding that the Islamic republic will not relinquish its nuclear rights. Last month AEOI head Ali-Akbar Salehi said that the dispute with the six world powers over Iran's Arak heavy water reactor had almost been solved during their latest nuclear negotiations. "As for Arak heavy water reactor, we had negotiations with the P5+1 group. We proposed to redesign the core of the reactor and to reduce plutonium output to one fifth (of the plant's capacity) which was welcomed by the P5+1 group," Salehi told Al-Alam Arabic- language TV station. Iran's uranium enrichment capacity and Arak heavy water reactor comprise a major part of Iran and world powers' negotiations for a comprehensive nuclear deal. They clinched an interim deal last November, in which Iran agreed to cap its nuclear program in exchange for easing some financial sanctions against it.