With the removal of highly enriched uranium (HEU) fuel from Nigeria’s research reactor earlier this month, all 11 operational research reactors in Africa are now running on low enriched uranium (LEU). The conversion of reactor fuels around the world from HEU to LEU is part of international efforts, coordinated by the IAEA, to minimize civilian use of HEU and reduce associated security and proliferation risks.
Nigeria’s only operating research reactor, NIRR-1, is a Miniature Neutron Source Reactor (MNSR) designed and supplied by the China National Nuclear Corporation (CNNC) and used for scientific research, neutron activation analysis, education and training, operating since 2004. The project to convert the reactor from HEU to LEU was initiated by the Nigeria Atomic Energy Commission in 2016 and was supported by China, Norway, the United Kingdom, the United States and the IAEA. LEU fuel for NIRR-1 was manufactured and tested in China and delivered to Nigeria at the end of October 2018. After a month of testing, the reactor was commissioned and reached full power operation with the LEU core, and will continue to support education and research in the country. The HEU fuel was returned to China in early December.
“The IAEA has supported the design of LEU cores, the conversion of research reactors from HEU to LEU, and international HEU repatriation efforts for over 20 years,” said Christophe Xerri, Director of the IAEA’s Division of Nuclear Fuel Cycle and Waste Technology. “The IAEA stands ready to assist other Member States with future MNSR conversion and HEU removal efforts.”
Shen Lixin, Deputy Director General of the Department of Business Development and International Cooperation at CNNC, said: “This project manifests the determination and joint effort of several governments and organizations in preventing nuclear proliferation. This is also a demonstration of CNNC’s meeting its social responsibilities and the commitment to peaceful uses of nuclear energy. CNNC is more than willing to work together and cooperate whole heartedly with relevant parties to facilitate other MNSR conversion projects.”
Nigeria’s NIRR-1 is the second MNSR outside China converted to LEU, after a similar reactor in Ghana was converted in 2017.
Nigeria last week also hosted the 9th IAEA annual technical meeting to share lessons learned and discuss technical challenges related to MNSR conversion and HEU repatriation projects. Held in Abuja from 10 to 12 December, the meeting was attended by 21 participants from six countries.
MNSR type research reactors were designed and manufactured by the China Institute of Atomic Energy, and the original design had a compact core with 30 kW thermal power, containing about 1 kg of 90% enriched HEU.