Chennai, Aug 14 - India's first fast breeder nuclear reactor, coming up at Kalpakkam near here to produce 500 MW of power, is facing a cost overrun of over 40 percent, but officials hope it will achieve criticality by September 2011 after a year's delay.

Escalation in material and labour costs, changes in component design and the tsunami of December 2004 pushed up costs from Rs.3,500 crore to Rs.5,000 crore, according to Nuclear Power Corp chairman S.K. Jain, who is also chairman and managing director of the state-owned Bharatiya Nabhikiya Vidyut Nigam (Bhavini), the company setting up the Kalpakkam project.

'The project report sent to the cabinet in 2002 was prepared like any other government department project; cost estimates were made without factoring taxes that are applicable for corporate entities like Bhavini. Between 2002 and 2009, the costs have escalated several times,' Jain told IANS.

Admitted project director Prabhat Kumar: 'The project faced several surprises.'

Apart from the tsunami that hit the Indian shores in 2004, Kumar said, construction of a tunnel under the sea got delayed on account of an unexpected soft patch of soil, which had to be reinforced before work could proceed.