India's fast breeder reactor operator Bharatiya Nabhikiya Vidyut Nigam Ltd (Bhavini) has started preliminary work for the construction of two more units at Kalpakkam in Tamil Nadu.
'The government has released Rs.250 crore to carry out preliminary activities towards setting up of two more 500 MW fast reactors at Kalpakkam (around 80 km from here). We have started the site preparatory work where the two units are likely to be located,' Prabhat Kumar, project director at Bhavini, told IANS.
The funds will be utilised for preparation of detailed project report (DPR) and other pre-project activities such as levelling the site, laying of roads, setting up assembly shops and other activities.
The project site got approval from the site selection committee last year.
The government has sanctioned construction of four more 500 MW fast reactors, of which two will be housed inside the existing nuclear island at Kalpakkam, and are expected to be ready by 2020.
Decision on locating the remaining two fast reactors is yet to be taken.
A breeder reactor is one that breeds more material for a nuclear fission reaction than it consumes. The reaction produces energy that is used in the form of electricity. The Indian fast reactors will be fuelled by a blend of plutonium and uranium oxide.
While the reactor will break up (fission) plutonium for power production, it will also breed more plutonium than it consumes. The original plutonium comes from natural uranium.
The surplus plutonium from each fast reactor can be used to set up more such reactors and grow the nuclear capacity in tune with India's energy needs.
According to Kumar, environmental approvals have to be obtained for the project.
He said orders for some equipment needed for the pre-project works will also be ordered.
Meanwhile, the Rs.5,600 crore ($1.25 billion) prototype fast breeder reactor (PFBR) under construction at Kalpakkam, is expected to get its fourth critical component, the inner vessel, this week.
The sodium-cooled PFBR designed by the Indira Gandhi Centre for Atomic Research (IGCAR) has three vessels - a safety vessel, a main vessel and an inner vessel.
Outer-most is the stainless steel safety vessel (200 tonnes, 13 metres in diameter and 13 metres in depth) which was lowered into the reactor vault in June 2008.
The main vessel - 12.9 metres in diameter and 12.94 metres in height, weighing 206 tonnes - was lowered into the safety vessel December 2009, and is termed as the second milestone.
The project achieved its third milestone in May this year when another critical component, thermal baffle, a cylindrical safety vessel weighing 60 tonnes, and measuring 12 metre in diameter and more than six metres in height, was lowered into the main vessel.
The 11-metre tall conical shaped inner vessel will be lowered into the main vessel to support reactor components like pumps, heat exchangers and others.
'We hope to lower the inner vessel Wednesday. However, it depends on the rain gods as the weather department has predicted rains over the next 48 hours,' Kumar said.
The PFBR is expected to start operations next September.
After erecting the inner vessel, the top opening will be covered with a component called 'roof slab' and the main vessel will be welded to it, said Kumar.
Other reactor components will be inserted into the main vessel through the opening in the roof slab.
Kumar is confident that 95 percent of the reactor components would be received by the end of this year.