IGCAR successfully reprocesses carbide fuel
14 June 2005
Kalpakkam: The Indira Gandhi Centre for Atomic Research (IGCAR) has achieved a major breakthrough. It has successfully reprocessed the plutonium-uranium carbide fuel pins used at its Kalpakkam fast breeder test reactor (FBTR) indigenously and recovered an undisclosed quantity of pure plutonium and uranium for further use.
This is reportedly the first time in the world that carbide fuel has been successfully reprocessed in a fast breeder test reactor.
In fast breeder test reactors, large amounts of plutonium are generated while the reactor consumes Uranium 238. The spent fuel from the FBTR has 70 per cent plutonium. Normally in large fast breeder reactors, fresh plutonium produced from uranium 238 will be around 1.2kg for every kilogram of plutonium consumed.
In the fuel reprocessing plant, the fuel pins are dismantled from the subassembly. These are then "chopped" and dissolved in nitric acid. It then undergoes a solvent extraction process with tributyl phosphate being used as the solvent to separate uranium and plutonium and fission products. The radioactive fission products are fixed in suitable solid matrices such as glass and buried in deep underground chambers, while the irradiated fuel is reprocessed for recovering uranium and plutonium for reuse in the reactor.
Speaking about the achievement chairman, Atomic Energy Commission, Dr Anil Kakodkar said, "The carbide fuel is an advanced fuel to power nuclear reactors. The FBTR fuel was reprocessed after being put to cool for two years."
The indigenously developed carbide fuel has reached a peak "burn up" of 1,48,000mw day / tonne without any clad failure, close to the target value of 1,50,000mw day / tonne. Simply put, fuel "burn up" means the amount of energy that is extracted out of the fuel before the spent fuel is sent for storage / reprocessing.