MOX Fuel and Managing Spent MOX Fuel
24 February 2011 | Most of the spent fuel accumulating from power reactors is currently stored and only about 30% of fuel discharged each year from nuclear power reactors is reprocessed, although spent fuel reprocessing facilities would have the capacity to cope with double the amount.
"Through reprocessing, plutonium - and to some extent uranium - in spent fuel can be recovered", explains Zvonko Lovasic of the IAEA’s Nuclear Fuel Cycle and Materials Section. "The plutonium can then be used to manufacture mixed oxide - or MOX - nuclear fuel, and provide energy through electricity generation", he adds.
There is a substantial amount of knowledge and experience in the manufacture, use and management of MOX fuel in thermal reactors. "The developments of new generation reactors and fuel cycles may also facilitate the use of MOX fuel with fast reactors and other fuel cycle technologies" says Mr. Lovasic. However, these applications with novel fuel cycles may not be realized in the near future, and it is therefore important to bear in mind that safe and reliable long term storage is also an essential prerequisite for the use of MOX fuel.
Therefore, the IAEA brought together a group of international experts to discuss the current status of MOX fuel applications and related developments in advanced reactors and fuel cycles. The Technical Meeting (TM) on MOX Fuel and MOX Spent Fuel Management was held on 21-24 February 2011 at the IAEA Headquarters in Vienna.
"This meeting has helped us to compile the latest information on the current status of MOX fuel development and use, and consider potential future applications with advanced reactor systems and fuel cycles" says John Killeen, a nuclear fuel specialist in the IAEA’s Nuclear Fuel Cycle and Materials Section. "Our aim is to provide IAEA Member States with the understanding of the key issues in utilizing MOX fuel and to provide a basis for them to update their spent fuel management strategies" Mr. Killeen adds.
The following topics were covered at the meeting:
- Strategic considerations for implementing a MOX fuel programme;
- Design and manufacturing of MOX fuel for thermal reactors;
- Licensing and safeguarding a MOX fuel programme;
- In-reactor experiences with MOX fuel;
- Management of spent MOX fuel including storage, disposal and reprocessing;
- Application of MOX in advanced fuel cycles; and
- Potential timing of MOX use and long term storage of spent MOX fuel.
There are good reasons for utilizing reprocessing and MOX fuel in a thermal reactor programme: MOX fuel use can enhance the utilisation of the uranium resource and reduce the burden of plutonium for final disposal, thus improving the sustainability of the fuel cycle. "Dealing with spent nuclear fuel from thermal reactors is a challenging issue. The use of reprocessing and MOX fuel is a mature technology that can help minimise waste disposal, and international cooperation can allow newcomer countries to consider it as an option" says Mr Killeen.
The operation of MOX fuel in thermal reactors has been excellent, with no specific problems associated with the use of plutonium in the fuel, and MOX fuel is now used as equivalent to normal uranium oxide fuel.
The IAEA document "Status and Advances in MOX Fuel Technology" (TRS 415) was reviewed by the participants. The document will be revised to take into account the discussion and the new information on MOX fuel that was presented at the meeting.