The main container of the heavy - water reactor in the central Iran city of Arak has been installed in the presence of Iranian President Mahmoud Ahmadinejad.The installation took place on Sunday. The reactor, which uses natural uranium to produce radio medicines, is planned to replace the Tehran research reactor gradually. The United States, Israel, and some of their allies have repeatedly accused Iran of pursuing non-civilian objectives in its nuclear energy program. Over the false allegation, Washington and the European Union have imposed several rounds of illegal unilateral sanctions against the Islamic Republic. Iran refutes the allegation and argues that as a signatory to the nuclear Non-Proliferation Treaty and a member of the International Atomic Energy Agency, it is entitled to develop nuclear energy for peaceful purposes.