受辐照研究快堆的燃料已经从法国返运到美国爱达荷国家实验室，它将完成最后一阶段的研究。该研究已经持续了超过8年时间。

The shipping cask is opened ready to transfer the irradiated fuel to INL's Hot Fuels Examination Facility (Image: INL)

A consignment of irradiated experimental fast reactor fuel has returned to the Idaho National Laboratory (INL) in the USA from France for the final stages of a study that has been ongoing for over eight years.

The fuel elements contain advanced metallic and nitride fuels fabricated by INL and Los Alamos National Laboratory in 2006 under the Futurix-FTA project, a collaboration between the US Department of Energy (DOE) and the French Atomic Energy Commission (CEA). Four fuel pins were sent to France for irradiation in the Phenix fast breeder reactor. At the same time, a similar set of fuel elements was placed in INL's own Advanced Test Reactor (ATR) to see if INL's reactor could successfully simulate the same conditions. Phenix shut down in 2009 after operating for over 30 years.

The fuel was stored in a hot cell in France for several years before beginning its journey back to the USA in July. According to Areva TN, which performed the shipment using a TN-106 nuclear transport package, the operation required several months of preparatory engineering and coordination work involving the CEA, DOE, regulators and other stakeholders. The TN-106 is extensively used in Europe for transporting experiments between labs, but had not previously been used in the USA.

INL researchers will now examine both sets of fuel elements to confirm whether the ATR can adequately recreate fast reactor fuel behaviour. This would enable INL researchers to continue to use the ATR in studies of new fuels under its Transmutation Fuels Program.

As part of efforts to look at ways of using uranium resources more efficiently and reducing the amounts of used fuel for ultimate disposal, the Transmutation Fuels Program is researching different fuel compositions for recycling used nuclear fuel in a fast breeder reactor. However the USA does not have a fast breeder reactor, so the will confirm whether ATR can be successfully used to test the fuels developed by the program.

（原标题：Journey's end for fast reactor fuel）