Chennai, Dec 2 (IANS): Russian company JSC AEM-technology on Friday said it has started manufacturing two sets of steam generators for the third and fourth 1,000MW nuclear power units to be set up at Kudankulam in Tamil Nadu.

According JSC AEM-technology, blanks for two sets of steam generators have to date been delivered and machining work for steam generator body shells and large branch pipes have begun.

"After inspections of shell blocks being conducted in the presence of the customer's representative, it is planned to start the assembly of SG (steam generator) bodies," the company said.

The steam generator is an article of safety class 1. Its diameter is over 4 m, length 15 m, and weight 340 tonnes.

The SG body is a horizontally oriented vessel with two elliptical end heads, in the middle of which hot coolant supply and removal headers are located.

At the top of the vessel, there is steam room, while the bottom accommodates a heat exchange surface composed of 11,000 stainless steel tubes of 16 mm diameter and 10 to 15 m length.

The ends of the tubes are joined to the two headers. The set of equipment for one power unit of an nuclear power plant of this type includes four steam generators.

According to the company, the steam generators will be shipped to India in 2018.

India's nuclear power plant operator, Nuclear Power Corporation of India Ltd (NPCIL) is setting up 1,000 MW units at Kudankulam in Tirunelvelli district, around 650km from here.

The company has completed two units and construction activities for the third and fourth units have started.

The general agreement for the construction ofA Units 3 and 4 was signed with Russian atomic power company Rosatom in 2014.