Chennai, Sep 25 (IANS): Concreting work for turbine building for the seventh unit at Rajasthan Atomic Power Station (RAPS) belonging to the Nuclear Power Corporation of India Ltd. (NPCIL), India's atomic power plant operator, started Wednesday.

NPCIL is building two 700 MW pressurised heavy water reactors (PHWR) at RAPS at an outlay of around Rs.12,300 crore.

The first pour of concrete took place July 2011 and September 2011 for the upcoming 7th and 8th units.

"The concreting work for turbine building for the seventh unit has begun today (Wednesday). Around 60 percent of the civil construction work relating to the seventh unit at RAPS is complete. If one takes into account the eighth unit also, then civil work completion will be around 44 percent," B.C.Pathak, project director for the 7th and 8th units at RAPS, told IANS over phone from the project site.

According to Pathak, the main component the cylindrical shaped calandria weighing around 35 tonnes, with around eight-metre diametre is ready at the site.

The NPCIL already has six units with a total capacity of 1,180 MW (4x220 MW and one each of 100 MW and 200 MW) at RAPS.

"We will be sending our application to install the major components in the 7th unit to AERB (Atomic Energy Regulatory Board). But our application will be sent after KAPS (Kakrapar Atomic Power Station) where two 700 MW units are being built," Pathak said.

A senior AERB official earlier told IANS that the construction of the two new units at KAPS has progressed well, and NPCIL would seek the regulator's permission to erect major nuclear reactor equipment.

"We expect AERB's approval to begin erection of major equipment. Nearly 70 percent of the civil works have been completed," Lokesh Kumar, project director for the 3rd and 4th units of KAPS told IANS over phone from Kakrapar in Gujarat Tuesday.

For tghe NPCIL that has been building 220 MW and 540 MW pressurised heavy water reactors (PHWRs), it is a major jump to go in for 700 MW PHWRs.

Interestingly, Pathak has the experience in setting up the above reactors and also the 1,000 MW reactor at Kudankulam Nuclear Power Project (KNPP) at Tirunelveli district in Tamil Nadu.

Pathak said as the NPCIL is setting up four units of 700 MW, two each at RAPS and KAPS, there are economies of volume as vendor quotes are very competitive. "There are common vendors for both the projects," he added.

Pathak is confident that the first unit will start fission process June 2016 and the second unit December 2016.