In 2005, the Indira Gandhi Centre for Atomic Research made significant progress in the area mentioned in option 1, i.e., the reprocessing of uranium-plutonium mixed carbide fuel of the Fast Breeder Test Reactor. Fast Breeder Test Reactors are a type of nuclear reactor which produces more fissile material than it consumes, thus the `breeding` of fuel occurs. The reprocessing of uranium-plutonium mixed carbide fuel is a part of the fuel cycle of these reactors, where the used fuel is reprocessed for extraction of valuable elements and management of radioactive waste.

For the remaining options:

Option 2 refers to the application of radioisotopes in metallurgy, but the answer doesn`t specify this as the significant progress made in 2005.

Option 3 points to a new technology for the production of heavy water, but again there was no notable accomplishment in this area in the specified year.

Option 4 talks about new technology for high level nuclear waste management. Although an important field, it was not the area of significant progress in 2005 based on the correct answer provided.