Chennai, Jun 14 (IANS): The Indian atomic energy establishment is mulling the option of going in for a higher capacity reactor powered by metallic fuel at Indira Gandhi Centre for Atomic Research (IGCAR) complex at Kalpakkam, a senior official said Friday.

"Setting up a fast reactor powered by metallic fuel is final. We are now discussing whether to go in for a higher capacity reactor than the 120 MW test reactor that was decided earlier," he told IANS, not wanting to be named.

He said there is not much of a difference in the reactor design of the 500 MW prototype fast breeder reactor (PFBR) that is under construction at Kalpakkam around 70 km from here, to be powered by mixed plutonium-uranium oxide (MOX) fuel, and the proposed metallic fuel reactor.

A fast-breeder reactor is one which breeds more material for a nuclear fission reaction than it consumes. It is the key to India's three-stage nuclear power programme.

The metallic fuel has better breeding ratio as compared to the MOX fuel, said an official.

The 120 MW reactor was thought of as the test bed for designing a 1,000 MW fast reactor to be powered by metallic fuel, a mix of 20 percent plutonium and 80 percent uranium.

According to an official, the research centre expects to receive the remaining sanctioned funds (total sanction Rs.25 crore) this year for carrying out preliminary studies.

He said the upward revision in the proposed reactor also changes many other aspects of the project like the entire fuel cycle of the reactor.

"The fuel assembly complex will be housed at the Kalpakkam complex instead of transporting it from some other place. The entire fuel systems will be co-located. Metallic fuel needs high preparation process," he said.

He said the existing 14 MW fast breeder test reactor (FBTR) is expected to serve the research needs for another 20 years and hence the question whether there is a need for another test reactor.

The proposed metallic fuel reactor will be the third reactor for IGCAR which already has a FBTR and a mini Kamini (Kalpakkam mini reactor) and the seventh one for the whole of Kalpakkam nuclear complex.

Two pressurised heavy water reactors (PHWR) of 220 MW capacity of Madras Atomic Power Station (MAPS) belonging to Nuclear Power Corporation India Ltd (NPCIL) are already functioning.

The 500 MW IGCAR designed PFBR is being built by Bharatiya Nabhikiya Vidyut Nigam Ltd (Bhavini).

A small light water reactor belonging to Bhabha Atomic Energy Centre (BARC) is also operational at the Kalpakkam nuclear complex.

With Bhavini planning to build two more 500 MW fast reactors sometime in the future, Kalpakkam nuclear complex will become one of the world's noted "island" of fast reactors, housing five units.

IGCAR officials expect the decision on the metallic fuel reactor to be taken soon, and construction is expected to begin in a couple of years.

Additional manpower would not be required for the proposed project as the existing resources would be sufficient.