TIRUNELVELI: The fifth 1,000-MW unit of the Kudankulam Nuclear Power Project (KKNPP), constructed in India under the Russian WWER-1000 reactor-type NPP design, saw the installation of the first component of the nuclear reactor core melt localisation device (CMLD, core catcher) in the design position on Friday. The 1,000-MW unit is an essential part of the prevention system ensuring the safety of the beyond-design-basis accidents, read a statement.
In a statement, the Rosatom said the core melt localisation device is a Russian invention, and a part of the passive safety system, which is intended to prevent radioactive substances from entering the environment in case of a severe accident followed by the reactor vessel destruction.
"The core catcher, installed on supports under the reactor vessel, has been made as a globe-bottom container that weighs more than 156 metric tonnes. The total weight of the entire device exceeds 800 metric tonnes. Apart from a casing, the main CMLD components include cartridge units filled with special non-metallic materials, a maintenance platform, a cantilever truss, and a bottom plate. As a part of the preparations for the device installation, a significant scope of work has been completed, especially placing the second concrete layer and sealing liners in the melt localisation pit. An embedded part has been installed in the pit while the reactor cavity has been concreted. Direct catcher installation work started after a permit from the Indian regulator was obtained," it added.
"It brought us an exceptional pleasure when the Indian Party invited all participants to come to a large window to observe the catcher being raised before the installation," informed Mikhail Novikov, Director of Indian Projects, Atomstroyexport JSC.
He added that such moments vividly display the results of our activities and the progress of the Kudankulam NPP construction. The power unit 5 core catcher was delivered by the Russian Party to the KKNPP by a cargo vessel in January 2023.
"The core catcher has the ability to contain liquid and solid fragments of the core and structural materials of the reactor for an indefinitely long time, keeping a nuclear power plant safe for the environment and people. The core catcher installation operation is one of the critical path activities in the schedule, the completion of which makes it possible to construct the reactor cavity further," Rosatom's statement read.