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.

AIM has a track record of manufacturing the Calandria and involves precision fabrication with stringent tolerances. Reactor Vessel for Prototype Fast Breeder Reactor AIM delivered the main vessel and safety vessel with highest accuracy level. 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.