In which one of the following areas did the Indira Gandhi Centre for Atomic Research make significant progress in the year 2005?

1. The Indira Gandhi Centre for Atomic Research (IGCAR) located at Kalpakkam, Tamil Nadu, is a premier research and development institution focused on fast breeder reactor (FBR) technology. 2. One of its key facilities is the Fast Breeder Test Reactor (FBTR). 3. A crucial aspect of the FBR fuel cycle is the reprocessing of spent fuel to recover fissile materials (like plutonium) and fabricate new fuel. 4. In the year 2005, IGCAR achieved significant progress in the area of reprocessing the uranium-plutonium mixed carbide fuel used in the Fast Breeder Test Reactor, demonstrating capabilities critical for the FBR program. 5. While IGCAR works on various nuclear technologies, this specific achievement in fuel reprocessing was a major milestone around that time.