OKBM Afrikantov participated in the construction of China Experimental Fast Reactor. Mercury was used in the first fast reactor. The project is also known as Xiapu fast reactor pilot project. The fast reactor related research in India, originated at BARC, Mumbai. The Dounreay Fast Reactor is an example. Design is called the Molten Chloride Salt, Fast Reactor (MCSFR). The Russian MBIR is a planned 150 MWt, sodium-cooled fast reactor. During his visit, Iyengar was impressed by the plutonium-fueled pulsed fast reactor. Therefore a fast reactor cannot run on natural uranium fuel. The power plant for the boat was a lead-bismuth cooled fast reactor (LCFR). As such, no true gas-cooled fast reactor design has ever been brought to criticality. A fast reactor directly uses the fast neutrons emitted by fission, without moderation. A sodium-cooled fast reactor, the CFR-600, is under construction. A fast reactor is more efficient for using plutonium and higher actinides as fuel. A sodium-cooled fast reactor is a fast neutron reactor cooled by liquid sodium.