Fukushima Nuclear Disaster

The Fukushima Daiichi Nuclear Disaster (福島第一原子力発電所事故) was a nuclear disaster that affected the the Fukushima I Nuclear Power Plant in the wake of th 2011 Tohokutsunami. For this reason, the 2011 series of incidents is often known as a "triple disaster" - earth, water and nuclear.

Four of the six reactors in the plant were catastrophically affected by the earthquake and tsunami that hit Japan's northeast coast. The nuclear meltdown resulted in radioactive contamination near the plant’s area with widespread and catastrophic damages to the environment. The nuclear disaster ranked 7 (the most sever level for a nuclear power plant) based on the International Nuclear Event Scale, the first since the Chernobyl disaster in the former USSR, now Ukraine, on 26 April 1986.

Cause
Though the Fukushima Nuclear Power Plant escaped the earthquake that occured in the Tōhoku region, it was near the Pacific Ocean and thus, was severely hit by the Tōhoku tsunami, which was a direct result of the earthquake. The plant did have a sea wall to protect it but, as it had been drastically reduced in height, the sea wall failed to protect the complex from the tidal wave. Four reactors were badly damaged and began to leak contaminated water. The Japanese government evacuated residents within a 20 km radius and sent in workers to try and repair the site.

Structural Integrity
The Fukushima Nuclear Accident Independent Investigation Commission concluded that the damage was "manmade" and that the damage caused was generated largely due to the lack of countermeasures for such an event.

There were 11 operating nuclear reactors at four plants in the region, when the earthquake struck, with another 3 that weren't currently operational. The reactors at, Fukushima Daiichi 1, 2, and 3, Fukushima Daini 1, 2, 3, and 4, Tohoku's Onagawa 1, 2, 3, and Japco's Tokai reactor all shut down automatically when the earthquake hit. Fukushima Daiichi has 3 other reactors that weren't currently operating at the time, listed as 4, 5, and 6.

All the reactors listed weathered the earthquake without major incident. However, the reactors (all 11 of them) were vulnerable, and consequently, affected by the tsunami following the earthquake. Eight of the 11 units managed to, either by accessing the grid, or backup generators, to run Residual Heat Removal system cooling pumps and managed to achieve a cold shutdown

However, reactors 1, 2, 3, and later on, 4 at Fukushima Daiichi failed to weather the tsunamis that were to hit the station. The earthquake disconnected the reactors, all 6, from the main external power source, resulting in the backup diesel generators located in the basements of the reactors starting up in order to keep the cooling system functional. The tsunamis hit approximately 41, and 49 minutes after the earthquake. The resulting waves inundated the cooling circuits, notably, the RHR system that kept the other reactors in the region from overheating and breaching containment. Reactors 5&6 were left out because they still had a single air-cooled system between the two which kept the temperatures there relatively low.

The following reactors and stations had countermeasures against tsunamis which were considered acceptable in relation to the scientific knowledge avaliable in 1960, with run-up heights for the coastline which it was built upon being recorded as relatively low. Such data had long become outdated by the time of the 2011 disaster, with new information indicating the possibility of a large earthquake and associated tsunami hitting the plant.

Underlying problems
There were multiple factors which may, or may not have contributed to the category 7 nuclear disaster].

The Earthquake and following Tsunami's were definitely the way in which the reactors were first incapacitated, but it's more about why the reactors didn't manage to weather the disaster, than being hit by the earthquake that's generating discussion, and consequently, criticism about both the design, miantenance, regard for (or lack thereof) of information concerning new infromation that might've prevented such destruction, and the age of the mostly antiquated nuclear reactors.

The reactors at that site were allegedly already in a bad condition before the earthquake and tsunami struck. It appears that workers asserted that, during the earthquake, although the plant was structurally sound on the outside, it appears that the pipes inside were not. reports indicate that recirculation and cooling pipes, and the plumbing within the plant in general was seriously compromised by the earthquake. If these claims were to be true, then the plant would have been in serious trouble before the tsunami struck.

There is evidence to support this, stemming from as far back as 2000. Katsunobu Onda, who wrote TEPCO: The Dark Empire, notes that, during his research about the plants, when he interviewed the engineers working at the plant, one stated that the blueprints did not always match up with the actual position of the pipes, forcing them to use heavy machinery to bend, and weld the pipes together. That being said, Onda described the inside of the power plant as "a web of pipes". Inspections were lackluster, and were done via simple visual checks,and the backs of pipes, where they were harder to reach, were often ignored. The pipes carrying the coolant were cracked, old, and a liability.

Impact


97,000 people were displaced by the Nuclear Disaster, as ongoing radiation means it is still deemed unsafe for people to return to their homes - especially around the Miyagi, Iwate and Fukushima regions. Resettlement back to the affected areas has been postponed by a nervous government. About 1000 deaths may be attributed to the extended period these people spent displaced from their original settlements.

All 48 of the nation’s commercial reactors are now offline, but the government wants to restart those that clear newly established safety regulations despite strong public opposition. The resulting blackout, as 47% of Japan's power supply comes from nuclear power, has resulted i more than 4.4 million buildings affected by the blackout and left 1.5 million buildings out of water for days.

Anti-Nuclear Sentiment
Though the fate of the Fukushima Daiichi plant is yet to be decided, the vulnerability it displayed to the combined effects of the earthquake and tsunami, particularly dangerous in an area prone to such disasters, aroused anti-nuclear sentiment. Protests in Japan and other countries aim to shut down the plant, and others in other countries with nuclear power. Japan's reactors are still offline as of August 2, 2014, but there are plans to restart many of them.

Criticism
During the aftermath of the nuclear disaster, both the Japanese government and Tepco, have come under heavy sustained criticism. The Japanese government was criticised and unsatisfactory and lacklustre in their response to the disaster. The New York Times critized saying "“Never has postwar Japan needed strong, assertive leadership more—and never has its weak, rudderless system of governing been so clearly exposed." Tepco has admitted to falsifying its records of nuclear inspections and hiding the facts for more than a decade, and it's response immediately following the disaster was "confusing, contradictory and downright mysterious."

The government and Tepco's lack of communication has also been criticized. Following the tragedy, the Japanese Ambassador appeared on CNN with Wolf Blitzter and sought to reassure the world that everything was fine, and claimed there was no meltdown. But, within minutes, the ambassador was contradicted by the head of Japan’s Nuclear and Industrial Safety agency, which told CNN that a meltdown actually “might be under way.”