The 700 MW-e Pressurised Heavy Water Reactor [PHWR] is the latest iteration of this indigenous Indian series. It's design evolution leverages the knowledge repository formed from the 530+ cumulative prior operating years of Nuclear Reactors in the country.
In the following video, the then Technical Director of the Nuclear Power Corporation of India Ltd. [NPCIL] gives an overview of the Design considerations & technological improvements that the 700 MW-e Reactor will incorporate.
Interestingly, he states that the 700 MW-e's Core's design remains same as the previous generation's 540 MW-e. Effort has gone into designing better heat extraction from the fuel bundles. Enhanced safety features include unmanned passive cooling for up to 8 hours. There is also studies ongoing, he informs, towards feeding it with Slightly Enriched Uranium [SEU] in place of the Natural Uranium it presently uses. If achieved, it would improve Steam generation & increase the mean time between fuel change, for the same volume of loading. While the design is 100% indigenous, the up to 93% of the hardware is sourced from within the country. Significantly, the Turbine Rotor assembly is imported, he stated.
The first 700 MWe Reactor went critical at the Kakrapar Atomic Power Station [KAPS 3] on July 20, 2020. It has yet to commence commercial production & has supplied around 402 MWe of infirm power to the National electricity grid.
Construction of another Reactor unit there, KAPS 4, is 93% complete. NPCIL has successfully completed Hydro Testing of it's Active Process Water [APW] circuit & End Shield Cooling System [ESCS]. Hydro Test of the Primary Heat Transport [PHT] circuit is set to start shortly. Originally conceived for completion in 2015, it is now set to go critical in December 2022.
The 700 MW-e design will be standardized across all sites. This will enable NPCIL to achieve Fleet Mode deployment for all 16 Reactors, thereby enjoying Economies of scale benefits.
Godspeed