Design features of reactor assembly and structures of Indian 500 MWe PWHR stations

The first phase of the Indian Nuclear Power Programme is based on construction of a series of nuclear power stations of the PHWR (Pressurised Heavy Water Reactor) type of 235 MWe and 500 MWe capacities. This paper describes the design evolution and salient design features of some of the key equipment of the reactor assembly and structures of the Indian 500 MWe PHWR stations viz. calandria, end shields, coolant channel assemblies, reactivity control devices and reactor vault. Safety aspects have been enhanced. The efforts towards standardisation would result in considerable saving in manufacturing and installation time and this, with other steps being taken would help in reducing the gestation period to set up the nuclear power station. (orig.)