Wednesday, March 16, 2011

Lessons from the Japan nuclear crisis


The operators at Japan’s Fukushima nuclear plants are fighting the most deadly battles in hazardous circumstances trying to bring the nuclear plants under control. After an earthquake followed by a tsunami, Japan is now facing the biggest threat – a possibility of a nuclear meltdown.  After a series of explosions at the reactors, latest reports say “that a second reactor unit at the stricken Fukushima Daiichi plant in northeastern Japan may have ruptured and appeared to be releasing radioactive steam”. ‘Radioactive steam’ indicates that a meltdown of the fuel rods inside the reactor is already in progress. While radiation from Xenon and cesium are expected to be detected, experts say they decay quickly and that may avert big casualties.

Japan’s rich disaster mitigation and prevention 
Even as the 5 day ordeal seems to unravel, it is noteworthy that Japan, due to its history with natural calamities, sitting as it is in a seismic zone, consistently spent big money and efforts on disaster mitigation and prevention.  According to FEMA, Japan routinely spent around 5-8% (about 0.8% of GDP) of its national budget since 1950s. It is technologically well-equipped, well-trained to handle earthquakes and tsunamis. But all that fell short to take on an earthquake measuring 8.9 quickly followed by a tsunami of 13-14 foot wall of water. The quake is fifth largest ever recorded. The tsunami too was too big to handle for the protective walls build on Japan’s coast to stop the tides. However, with its preparedness Japan could mitigate to some extent the damages due to these calamities. What is glaring now dangerously at Japan more than the above natural calamities is the nuclear threat from the nuclear reactor that rests on an outdated safety mechanism. 

The design issue Fukushima-Daiichi nuclear power plant 
Soon after the earthquake on 11 March, Fukushima-Daiichi nuclear power plant, as per its security procedures, slowed down and shut down it’s fission reactions in about 10 minutes. The tsunami too struck in about the same time and interfered with the plant’s post-shutdown process. Apparently, even after the fission reactions cease, the fission products continue to emit huge amounts of heat and these are supposed to be cooled. Only when this is done, the nuclear fuel’s temperatures are controlled. The cooling was being done through water being pumped by diesel generators through water chambers around the nuclear container. The fuel resides within the container. The tsunami washed away the generators and the water supply stopped circulating into and out of the reactor. The static water got heated and the temperatures rose in the container resulting in steam with radioactivity flowing out of it. In addition, the chemical reactions resulted in hydrogen gas that blew the tops out of the nuclear installations.The reactors within, the nuclear containers, did not seem to be disrupted for now. But the melting fuel rods seem to leak out radiation.

Experts now say the boiling water reactors (BWR) built by G.E. in 1960s are not up to safety standards followed today. Firstly, the external cooling system powered by diesel pumps is considered a design flaw that didn’t take into consideration how extreme calamities can occur and disrupt the external cooling systems, let the nuclear reactor get heated, and result in a radiation leak. Secondly, the very use of plutonium in nuclear reactors is an offshoot of nuclear weaponisation program of cold war era. While use of Thorium through Liquid Fluoride Thorium Reactor (LFTR) is said to be far less dangerous and less prone to the meltdown scenario we are seeing now, not much headway is made in commercial use of LFTR. Incidents like in Japan can happen elsewhere and it is imperative we look at making nuclear reactors safe to operate, drawing lessons from Japans’ catastrophe.

Lessons for India 
India is a pioneer in LFTR technology as it spent considerable time and resources building thorium reactors after the west refused to supply it Uranium as fuel for its nuclear power plants. India developed an experimental thorium reactors like Kamini through Indira Gandhi Centre for Atomic Research (IGCAR) at Kalpakkam. India should build on this foundation to see if it can commercially make use of the technology instead of limiting the exercise to research.

India can learn well that it shouldn’t plan its nuclear sites should not be located on geological fault lines. The Jaitapur nuclear plant has evoked concerns on this front as its is prone to earthquakes and is located right on coast. While the altitude of the coast on western ghats is quite high and affect in case of tsunami is unlikely, It can not be overruled.

The Jaitapur nuclear reactor is of Pressurised water reactor (PWR) type which again depends on water to cool the reactor in case of a shutdown. Using fluoride salts as coolant is said to be less prone to risk. With water supply disrupted at Fukushima, Japanese are even trying to pour from the sky – through helicopters! But in vain. The radiation at the plant is too dangerous for the helicopters to go nearer.

Japan's disaster management system, despite its preparedness, is seen wanting in view of the big quake and tsunami. Countries like India with far poorer disaster mitigation systems should wake up for the possibility of calamities of this magnitude.

8 comments:

Karan said...

Nuclear plants should be scrapped altogether. They are dangerous and not safe. After seeing so many accidents we should decide.

Anna said...

finally something about a non-telangana issue. :) i saw agree to the above comment. reading yesterday of the 50 people who are staying behind to manage the crisis, is too horrifying to think

jshanthkumar said...

Japan always teaches lessons to the world, self development and self destroy. It always stood first in the developments which is appreciable. Today world need to learn from Japan 'not to stop such technology developments rather search for better disaster management and also to analyze the importance of such implementations before taking initiatives against nature’.

Anonymous said...

@jshanthkumar

Problem now is due to technology, why should we not stop it? If your house is near the nuclear plant you also will demand to stop it. Think honestly brother

Amar said...

@Karan, Anna, Anon

The one in Japan is not a nuclear accident. It was a result of an earthquake and Tsunami. Even a dam burst because of the quake. We can't say no to dams on that basis. We have instead debate about designs of the reactors that could go wrong in these kind of extreme natural calamities.i agree with Shanth on that count.

Green Star said...

@Amar

You are right, when you can not stop the mother nature, dams may be broken and distinction may happen. But we can rebuild in few years from such destructions. But nuclear disaster is not such easy, this will hunt for generations and very hard to recover from it. At the same time we can not deny this technology as our power requirements are growing every day, we do not have any alternate for this currently. What we have to do is, to research about how to avoid such destructions in future.

Amar said...

@Green Star

I was only pointing that while we can rebuild dams, we can't undo the damage caused by their collapse. In that way, there is no difference between their failure or those of nuclear plants when nature strikes.

I agree with what you say about seriousness of a nuclear accident and the limitations of usage with renewable sources of energy at present. The Govts have to encourage research to overcome design faults in nuclear reactors and very seriously focus on making commercial use of renewable energy viable. After all, we are piling up radioactive waste out of nuclear plants with each passing day. That is the most dangerous aspect which is yet to be addressed by any Govt across the world. How to dispose it?

Venu said...

You dont actually see the effect of the radiation which got released from the reactors in few days. It takes years to leave some mark.

I think geographically india is in better location, not like Japan where the earth quakes and tsunamis are normal. So keeping this in mind we are safe.

Lessons to India: Indians always overlook the safety concerns/protocols. This is the right time for the Govt to take the necessary steps to review our disaster management system.