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Saturday, 21 September 2013

Can Japan Contain The Fukushima Disaster? - Facts & Infographic

Can Japan Contain The Fukushima Disaster?


Fukushima Daiichi Power Plant
The combined power generating capacity of the power plants at Fukushima is 4.7 GWe Located in the Fukushima prefecture of Japan, about 95 kilometers to the south east of the city of Sendai, Fukushima, the plant was initially commissioned in 1971 to generate nuclear power that would help meet Japan’s increasing industrial needs as there is a lack of other fuel resources in Japan. The plant had six Boiling Water Reactors (BWRs). The Fukushima plant was affected by the March 2011 earthquake and tsunami that hit Japan. Damage to the reactors made it impossible to restart them. The accident also led to a major release of radioactive elements into the environment - a challenge the government of Japan is still grappling with. The government of Japan has declared an evacuation zone of 20 kilometer radius, surrounding the plant. In April 2012, Units 1-4 of the Fukushima plant were decommissioned permanently.

What Went Wrong?
On March 2011, a huge earthquake with the magnitude of 9.0 (Mw) hit Japan, wreaking much damage along the coast of Honshu, the largest island in Japan. The earthquake triggered a tsunami with waves as high as 40.5 meters (133 feet) in Miyako. The tsunami damaged some of the equipment at about four nuclear power stations in Japan. At the Fukushima Daiichi Nuclear Power Plant it led to the loss of the power supply to the cooling system of the reactors; the backup generators were flooded too and failed to function normally. At the time of the earthquake and tsunami, the plant had six boiling water reactors which had been designed by General Electric (GE) and were maintained by the Tokyo Electric Power Company (TEPCO). Japan declared a nuclear emergency. Of the six reactors, 5 and 6 were in cold shut down. On March 12, 2011, pressure started to build up in reactors 1, 2, and which lost their coolant systems leading to overheating of the reactor core. Unit 1 exploded damaging the spent fuel pool and necessitating an evacuation of residents 20 kilometers around Fukushima. The next day Unit 3 exploded as well and within the next two days Units 1-3 had been flooded with seawater to cool them despite the risk of ruining them. On March 15, 2011, Unit 2 suffered a hydrogen explosion like Units 1 and 3. The next few days were spent by emergency crews in spraying seawater and freshwater mixed with boric acid on the reactors and the spent fuel pools. About 200,000 people were forced to evacuate the region. Radiation (radioactive iodine-131 and cesium-137) was soon detected in milk, tap water, and spinach near the Fukushima plant. By April 2011, the accident at the plant was escalated to Level 7 INES (International Nuclear Event Scale) rating by the Nuclear and Industrial Safety Agency of Japan (NISA), indicating that it was a serious accident with significant radioactive releases.

The Risks
Even as early as March 15, 2011, the International Atomic Energy Agency declared that the radiation levels at the Fukushima plant were recorded at 167 times the average annual dose of radiation. This was, however, expected to go down with remedial measures being taken by TEPCO. TEPCO had initially said the radiation emitted by the leaking water at the plant was estimated to be about 100 millisieverts an hour. In August 2013, it was discovered that the radiation was about 1,800 millisieverts an hour - enough to kill a person within four hours of exposure. In addition, another leak in a pipe has been found to emit radiation levels of 220 millisieverts.
While there have been no reported deaths due to radiation exposure at the plant, TEPCO has revealed that a number of employees were exposed to high levels of radiation. According to a study, the risks of thyroid cancer among the girls exposed as infants to the radiation in the Fukushima region could be as high as 70%.The Sixth Report of Fukushima Prefecture Health Management Survey (June 2012) says that about 35.3% of the children in the region were found to have growths such as cysts or nodules on their thyroids. Authorities, however insist that this has no link to radiation exposure in the region. The Institute of Radiological Sciences in Japan fears that some children in the region may have been exposed to radiation close to "lifetime doses" to their thyroid glands.
According to a health report by the World Health Organization (WHO), though the health risks stemming from the accident for the people of Japan were relatively low, the residents of the Fukushima Prefecture would suffer from elevated risks of certain types of cancers and were in need of regular health checks through their lives. The lack of information about the highest levels and durations of exposure make accurate assessments impossible, said the WHO.

Since March 2011, the Tokyo Electric Power Company (TEPCO) has been struggling to contain nuclear contamination of groundwater in the region and subsequent leaks into the Pacific Ocean. The greatest challenge faced by TEPCO is handling the huge volume of radioactive water accumulated at the site and the build-up from the constant need to cool the damaged reactors.
In July 2012, the Fukushima Nuclear Accident independent Investigation Commission reported to the Japanese National Diet (parliament) that the Fukushima Nuclear Plant had not been adequately protected against the tsunami and the ensuing disaster. In October 2012, TEPCO admitted that it had failed to adequately insulate the plant against disaster for fear of inviting criticism and protests.
Initially TEPCO had announced that there was no risk of leaks of the contaminated waters of the nuclear plant. In August 2013, however, much to the horror of the Japanese people it became evident that water from the coolant was mixing with groundwater. The contaminated groundwater was flowing into the sea at the rate of 300 tons each day. TEPCO announced in August 2013 that the storage tanks containing contaminated water had sprung a leak.
By early September 2013, it was estimated that there was already over 330,000 tons of toxic water held in about 1,000 storage tanks. TEPCO will soon run out of tanks to store the contaminated water in and will be left no alternative but to discharge the waters into the sea.
TEPCO administration came under severe criticism when it was discovered that the company had hired only two workers to inspect all the storage tanks twice daily. To add to its woes TEPCO is now struggling to hire workers to inspect and maintain its operations onsite since the existing employees are forced to leave due to prolonged radiation exposure related health conditions. In 2012, TEPCO was saved from a complete collapse by being nationalized and given a boost of public funds.

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