End shield is vital part of pressurised heavy water reactor
Nuclear Power Corporation of India Ltd (NPCIL) said a major milestone has been achieved in the construction of the Kaiga-5 and - 6 nuclear power plants in Karnataka state, southwest India, with the successful unloading of the first end shield.
The state company said the critical reactor component, manufactured by L&T Heavy Engineering, the manufacturing arm of Larsen & Toubro, at its Hazira facility, north of Mumbai in western India, weighs 107 tonnes and measures approximately 9.3 metres in height and width with a thickness of 0.92 metres.
The end shield is a vital component of a pressurised heavy water reactor (PHWR). It provides structural support to coolant channel assemblies, facilitates on-power refuelling and forms an integral part of the calandria vault enclosure.
Larsen & Toubro has already manufactured and dispatched four of the eight steam generators for the units.
Kaiga-5 and -6 belong to the IPHWR-700 reactor class, a Generation III+ evolution of India’s earlier 220-MW and 540-MW PHWR designs. These designs use natural uranium oxide fuel and heavy water as both coolant and neutron moderator.
The Kaiga units will be part of a series of 10 Indian-designed PHWRs to be built in “fleet mode”, designed to bring economies of scale and maximise efficiency.
The 10 plants are Kaiga-5 and Kaiga-6, Mahi Banswara-1, -2, -3 and -4 in Rajasthan state, Gorakhpur-3 and -4 in Haryana state, and Chutka-1 and -2 in Madhya Pradesh state.
There are four smaller 202-MW PHWR units in commercial operation at Kaiga. Kaiga-1 and -2 began operation in 2000, while Kaiga-3 and -4 started in 2007 and 2011.
According to the International Atomic Energy Agency’s reactor database, India has 23 commercial plants in operation and eight under construction.
