Chennai, Sep 16 (IANS) India’s fast breeder reactor operator Bharatiya Nabhikiya Vidyut Nigam Limited (Bhavini) is awaiting a clear sky report from the India Meteorological Department (IMD) to install a critical component – inner vessel – in its upcoming 500 megawatt prototype fast breeder reactor (PFBR).
‘We need at least ten hours to complete installation of the giant inner vessel. The process involves removing the top cover of the reactor vault, lifting and lowering the inner vessel by a crane and closing the top again,’ Bhavini project director Prabhat Kumar told IANS.
The component was ready for installation last week itself but the rains made the officials postpone the work-schedule.
Even though it didn’t rain Wednesday, contrary to IMD predictions, Bhavini officials didn’t want to take a chance as the sky was cloudy and the whole process would take around ten hours.
According to Kumar, the top opening of the reactor vault has been covered long back and a clean room environment created.
‘The process of removing and replacing the reactor vault cover (now temporary) would take around five hours. Then the inner vessel has to be slowly lowered and alignment properly fixed. We cannot risk rain water inside the already erected huge main and safety vessels,’ Kumar added.
A breeder reactor is one that breeds more material for a nuclear fission reaction than it consumes.
The Rs.5,600 crore ($1.25 billion) sodium cooled PFBR under construction at Kalpakkam, around 80 km from here, 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 – 206 tonnes, 12.9 metres in diameter and 12.94 metres in height – was lowered into the safety vessel December 2009, and is termed as the second milestone.
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.
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.
