AREVA has extracted all of the solid uranium hexafluoride from Eurodif's George Besse I gaseous diffusion enrichment facility at the Tricastin nuclear site in France.
The milestone, also known as 'rising', was completed on 5 October and has significantly reduced the quantity of nuclear and chemical materials present within the facility.
AREVA says they next stage of the decommissioning process will involve the cleanup of the gaseous diffusion equipment in 2016.
The George Besse enrichment plant started winding down in mid-2011 as its replacement George Besse II, which uses centrifuge technology, ramped up. The plant finally ceased production in June 2012, after 33 years of operation.