Related Topic in KAS Prelims Syllabus:
Science and Technology [Paper-II]: India’s energy resources and dependence, Renewable and Non renewable energy resources
- Rosatom State Corporation Engineering Division has announced that it had installed a core melt localisation device (CMLD) or “core catcher” at Unit 3 of Tamil Nadu’s Kudankulam Nuclear Power Plant (KKNPP).
- The device is designed to localise and cool the molten core material in case of a meltdown accident.
What is the protective “core catcher” device?
- Molten core material, or corium, is lava-like material that gets formed in the core of a nuclear reactor in the event of a meltdown accident.
- Such an accident occurs when the nuclear fission reaction taking place inside a reactor is not sufficiently cooled, and the buildup of heat causes fuel rods to melt down.
- The corium so formed can remain radioactive for several decades, even centuries.
- In the past, meltdown accidents have occurred at Chernobyl in Russia in 1986 and at Fukushima in Japan in 2011.
- According to the Rosatom website, the core catcher is a cone shaped metal structure that weighs about 800 tonnes.
- The structure is double walled, with the gap between the two walls filled with FAOG (ferric and aluminium oxide granules).
- The core catcher is filled with a ceramic mixture also including ferric oxide and aluminium oxide, called ‘sacrificial material’.
- The sacrificial material prevents the corium from trickling through and also acts as a cooling mechanism.
- The core catcher device is installed at the bottom of the nuclear station’s protective shell, and is designed to save the latter as well as exude radioactive emission in the environment in case of a serious accident.
- At Kudankulam, it has been installed in the design position under the reactor pit of Unit 3, and has been adapted to the relevant site conditions and safety requirements.
- The device has improved seismic resistance, hydro-dynamic and shock strength as well as equipped with flood protection and simplified installation and assembly technology.
[Source: Indian Express]