Earthquake and Tsunami in Japan
Earthquake and Tsunami in Japan
A Glimpse of Havoc That Nature Can Wreak
Man has made a lot of progress and marched on the ever-widening path of knowledge acquisition since he started making use of his brain. It is his power of thinking new ideas and getting at the truth behind every natural phenomenon that distinguishes him from other animals inhabiting this Earth.
But however enlightened and knowledgeable he might have grown, he feels at a loss for words and gasps for breath when some natural disasters occur about which he has knowledge, but are beyond his control. He remains silent spectator to every natural catastrophe and looks on almost helplessly and only looks after the areas which are man-made.
The earthquake that brought super-modern Tokyo to a standstill on March 11, 2011 paralysing almost all the activities was so devastating that all the world looked on almost like a palsy-stricken entity.
The 8.9-magnitude quake off Japan’s northeastern coast shook buildings in the Japanese capital, Tokyo, and left millions of homes across Japan without electricity, shut down mobile phone network and severely disrupted landline telephone service. It also brought the train system to a halt, choking a daily commuter flow of more than 10 million people.
The earthquake being the biggest on record in Japan triggered a devastating tsunami that reportedly killed thousands of people along the northeastern coast, sweeping away everything in its path. Three weeks after the disaster, the Japanese National Police Agency confirmed 11,532 deaths, adding that 2,873 people were injured and 16,441 were missing.
Tsunami was a big terror in itself, but its impact rose hundredfold due to the fact that Japan has several nuclear plants and the wall of water was likely to cause unfathomable damage to the third-biggest economy of the world.
Thousands of people were immediately evacuated from an area around a nuclear plant north of Tokyo after fears of a radiation leak, but officials said that problems with the reactor’s cooling system were not at a critical level.
The US leadership also underscored the grave concern about the plant and the US air force delivered coolant to the facility. A 10-metre high tsunami prompted offers of help from dozens of countries. Even in the country accustomed to earthquakes, the devastation was shocking.
Other Japanese nuclear power plants and oil refineries were shut down and one refinery was ablaze. There were also reports about an irrigation dam that had broken and swept away houses in Fukushima prefecture.
Two days after the devastating earthquake and ensuing tsunami ravaged Japan, the country mobilised a nationwide 390° Celsius ( 715°-735° Fahrenheit ).
According to him, the reactor was built to run at a temperature of302°C ( 575°F ). “Injecting more water is one option (to cool it),” he felt. Reuters had earlier reported that the Fukushima plant was storing more uranium than it was originally designed to hold, and that it had repeatedly missed mandatory safety checks over the past decade according to company documents and outside experts.
Questions have-also been raised about whether TBPCX ) officials waited too long to pump seawater into the reactors and abandon hope of saving the equipment in the aftermath of the earthquake and tsunami. But according to one expert, the smoke or steam seen over the reactors did not seem to be linked to rise in radiation levels.
Away from the plant, mounting evidence of radiation in vegetables, water and milk stirred concerns in Japan and abroad despite officials’ assurances that the levels were not dangerous.
TEPCO said that radiation was found in the Pacific Ocean nearby, not surprising given rain and the hosing of reactors with seawater.Radioactive iodine in the sea samples was 126.7 times the allowed limit, while caesium was 24.8 times according to the Kyodo News. That still posed no immediate danger, TEPCO perceived.
“It would have to be drunk for a whole year in order to accumulate to 1 millisievert,” a TEPCO official said, referring to the standard radiation measurement unit. People are generally exposed to 1 -10 millisieverts a year from background radiation caused by substances in the air and soil.
The Health Ministry said residents of five municipalities in Fukushima should not use tap water for baby powder milk after the water was found to have more than the standard level of radioactive iodine allowed for babies.
Authorities also stopped shipments of milk and some vegetables from the area. After the third explosion at the Fukushima nuclear facility, when the executives of the Tokyo Electric Power Company delayed the report to the Prime Minister Mr. Naoto Kan by nearly an hour, he was quite angry and asked them what they had been doing all the while. It has now come to light that the company has been storing 4,000 spent uranium fuel assemblies at its nuclear units at Fukushima Daiichi.
This is equivalent to almost the amount of highly radioactive uranium fuel produced in six years by the units and more than three times the amount of radioactive material present in the cores of all the six units.
For instance, Unit-4 had some 548 still-hot fuel assemblies stored in a pool of water in the upper floor. It was the lack of cooling water in this pool that ultimately led to an explosion of the roof of Unit-4. More than 60 percent of the spent fuel from the facility is stored in a separate pool built in 1997.
According to Reuters, constrained by space, TEPCO had the capacity of spent fuel inside the reactor buildings by “re-racking” the pools. There were other plans for increasing the storage capacity outside the reactor buildings.
But only the reactor buildings offered sufficient open space for any significant increase in storage capacity. The Guardian has reported that TEPCO had missed safety checks over a 10-year period up to two weeks before the March 11 quake.
For instance, the company had failed to carry out safety check on 33 pieces of equipment inside the plant’s cooling system of June 1992 that struck the town of Landers in California, set off jolts thousands of kilometres away.
If the Alaskan quake triggered tremors as far as 3,200 km away in the Yellowstone National Park in the US, the Landers quake led to smaller ones, again, in the Yellowstone National Park. Scientists found that the 2004 Sumatra earthquake triggered quakes even on the opposite side of the Earth in licuador.
In fact, according to a study published in May 2008 in the Nature Geoscience journal, 12 of the 15 major tremors ( between 1992 and 2006 ) greater than 7 magnitude caused quakes even thousands of kilometres away.
If places far away from major quakes are jolted, there is plenty of evidence to show that quakes come in clusters following a giant tremor. For instance, the 9.1 -magnitude Sumatra quake of 2004 set off a series of nearby quakes, including one five years later. These are distinctly different from aftershocks.
But do giant quakes come in clusters ? Though statistically significant evidence of a number of giant quakes occurring in clusters is not available, it is a fact that within an interval of less than seven years there have been three giant quakes—December 2004 Sumatra quake of 9.1 magnitude, February 2010 Chile quake of 8.8 magnitude, and now the 9-magnitude quake off Sendai.
It is well known that release of stress during an earthquake can in turn load up the same fault or adjacent faults with stress. Clustering has been seen even when the initial quake has not been a giant one. A 2009 paper in Nature cites how a series of quakes in 1992 shook California’s Mojave Desert in quick succession. It started with the 6.2-magnitude
Joshua Tree quake of April 1992 followed by two quakes in June 1992—the 7.3-magnitude Landers quake and the 6.5-magnitude Big Bear quake, and finally die 7.1-magnitude Hector Mine earthquake in 1999. Are cartons safer? : Cratons, the old and stable parts of the continental crust, which are far away from the plate margins, are generally considered to be free from big quakes.
But the late 1811 and early 1812 quakes of more than 8 magnitude that jolted the New Madrid region in Mississippi, US, defied that assumption. So will the 9-magnitude quake that rocked Japan on March 11,2011 lead to minor jolts in far away places, big quakes in the neighbouring regions, and giant quakes in other regions of the world in the coming years ?
India has, however, not been directly hit by the recent tsunami. But everybody who prides himself / herself on it being a nuclear power has started asking whether India’s nuclear reactors can survive any disaster of such a devastating scale.
India has got world’s oldest operating Boiling Water Reactors (BWRs) at Tarapur. It is a coincidence that the company which built Tarapur, i.e.
General Electric also supplied the BWRs that were at the heart of the Fukushima crisis. Pressures are likely to be exerted with regard to the closure of the 1969-vintage Tarapur.
Though on March 11, 2011 itself the Central Government assured that there was no immediate threat to the Indian coast in the wake of recent tsunami, the people living in the coastal areas are quite apprehensive. They thought that the Japan earthquake might affect countries in the Indian Ocean-range as well. Though India, fortunately, has not witnessed many major earthquakes, it has to lost several thousand lives these natural disasters.
Some theories suggest that the Indian landmass, which rests on a plate called the Indo-Australian Plate, is sliding along another massive structure, the Asian Plate which includes China and Japan.
The energy released from this friction is said to have created the Himalayas. Spread along a line, there is a 2,500-km long zone—the Main Central Thrust—that stretches from Bhutan to India’s western border. It has several tectonic rocks that are most likely to trigger earthquakes. The Indian Government has closed ranks to protect the nuclear industry.
Prime Minister Dr. Man Mohan Singh announced a safety review of all the nuclear projects even as members of the atomic energy establishment emphasised the safety of the Indian reactors. According to the Chairman of Atomic Energy Commission Mr. Srikumar Banerjee, Indian nuclear reactors are capable of handling the worst natural disasters.
Indian scientists have a system where all the safety measures are reviewed every five years. All the recommendations from the safety audit are followed strictly, according to him. But the facts present somewhat contradictory views. There have been a number of minor accidents over the past twenty years.
They could have built up into major catastrophes – Heavy water leaks at the Kota nuclear plant and a Tarapur in 1992; a heavy water leak in Kalpakkam in 1999; radiation contamination at the Kaiga atomic power plant in 2009. As regards the impact of tsunamis on nuclear plants, it has not been considered even in the least.
Union Environment Minister Mr. Jairam Ramesh has clearly said that he does not recall that tsunamis were factored into the environment clearance process of Jaitapur nuclear plant. But the safety issue has been left to the Atomic Energy Regulatory Board and Nuclear Energy Council.
In fact, there is no clear understanding of the impact of seismic activity on nuclear power plants. Hardly a decade ago, the 2001 Bhuj earthquake measuring 6.9 on the Richter scale and the 2004 tsunami, which hit Tamil Nadu occurred quite close to nuclear plants.
In both cases, Gujarat’s Kakrapar atomic plant and the Kalpakkam nuclear reactor in Tamil Nadu shut down safely. The Indian nuclear scientists cite these two examples as testimony to the fact that the Indian nuclear plants are safe.
They also say that at Kalpakkam, the generators that supply the water for cooling are located at a height of 25 feet and that is why the sea water that came into the plant could not touch them.
People are, however, not sure whether an Indian nuclear plant can survive a catastrophe like an earthquake measuring 9 on the Richter scale or not. They are also apprehensive about the fate of the Indian nuclear plants in the event of any tsunami with 23-foot-high waves like one witnessed by Fukushima.