Nuclear reactor vessels contain core internals and coolant. They are designed to withstand high temperature and high pressure.
Calandria is reactor core vessel of CANDU type reactors, made from Stainless Steel, contains heavy water, a moderator used to moderate neutrons to achieve nuclear fission.The pressure tubes inside calandria contains heavy water as coolant which carries the heat from the reactor core.
L&T has a track record of manufacturing the Calandria since, 1969 (RAPP-II). The manufacturing of reactors more than 10m diameter involves precision fabrication with stringent tolerances.
L&T delivered the main vessel and safety vessel with highest accuracy level (i.e. within ±12mm for ~13 meter diameter vessels), manufactured from Stainless Steel at Kalpakkam for India’s First commercial Fast Breeder Reactor on schedule.
The main vessel of reactor assembly houses hot and cold sodium pools separated by an inner vessel. To contain the sodium in the unlikely event of leak in the main vessel, a Safety Vessel is provided surrounding the main vessel.