Learning From Fukushima Power Plant

There was not a single Television news channel that did not cover the news of Fukushima power plant. Suddenly the questions on safety of such plants have been raised after the devastation in Japan. Everyone is suddenly talking about how and what went wrong. Going on a little bit different way, we may like to have a relook at our future nuclear power plants. Have our designers accounted for such a thing while designing for the future power plants?



The current reactors are from the 2^nd generation. The construction of a better breed of nuclear reactors Generation III plus is ongoing in a few countries. Four AP1000 type (Gen III) reactors are being constructed in China and one of them is scheduled to be energized in 2013. The officials of Areva say that they are constructing enormous 1,650 megawatt EPRs (evolutionary power reactor) in Finland, France and two of them in China. These reactors are said to have much lesser probabilities of occurrence of any kind of fault. The designers of these power plants have made amendments in the design keeping in mind the Three Mile Island and Chernobyl incidents.

IT is now clear that it was the cooling system that went down after the earthquakes and produced a whole train of difficulties for the engineers (and general public too) in Japan. The smarter plants that are coming now have some kind of arrangements for this difficulty. Here are a few design changes or rather arrangements in the new reactors (Gen III) that are based on our previous bitter experiences-

[*]The smarter plants are equipped with arrangements regarding the cooling systems.  They are said to have passive cooling systems contrary to the active cooling systems used in 40 year old Fukushima plant.
[*]The AP1000 (Gen III) reactors can be shut down for as long as three days without any power supply to it. The above said passive cooling technology makes use of pressure changes, gravity and natural air flow to aid to cooling of the reactor core.
[*]The new reactors are also having double containment dome which was not there in the older plants.
[*]The plants provide a technology named as core - catcher. The nuclear fuel is directed into an underground pit in case of a complete meltdown situation.

While the designers have come forward with these innovations, the critics are doubtful about the robustness of the newer designs. The already working reactors that constitute about 20% of USA’s power demand have lived their life now and need to be replaced in near future. Now, after the Japan tragedy, the designs of to-be-installed-soon power plants may have to be re-examined for all the possibilities of fault. This may take some time but looking at the devastation in Japan, it would be worth. With the new core-catcher and other technologies, we can definitely expect safer and more robust nuclear power plants in near future.