Japan reactor meltdown drivers#

Japan reactor meltdown drivers#

We were also told that people who remained in the 'shelter-in-place' region close to Fukushima were having problems finding food at the stores because truck drivers were reluctant to enter the area. When I was there, about a month after the accident, I heard daily radio announcements in Tokyo (in English!) informing people of the radioactivity concentrations in the drinking water. Japan also banned produce from the area around the reactor site to reduce radioactivity entering the food supply. Some of these pockets exploded in the days to come, damaging the support buildings.Īs a result of these radioactivity releases to the environment, the Japanese government ordered the evacuation of everyone living within 20 km (12 miles) of the site this included a number of hospitals. Over the next several days, the hydrogen escaped the reactor plant and collected in the support buildings. High-temperature chemical reactions between the zirconium fuel cladding and water created hydrogen. That wasn't the end of the immediate danger. Portraits of Devastation: Japan After the Tsunami Once seawater has been introduced into a reactor plant, it will never operate again. By the time this was accomplished, the core had already been damaged beyond repair. Ultimately, the answer was to bring in power barges to allow pumping seawater into the reactor plant to keep the core cooled. Lacking cooling water, the fuel-including the radioactive fission products-heated up and began to melt.Īs crews raced to contain the disaster, one of their biggest challenges was to add cooling water to the reactors and find a way to power pumps needed to circulate this water through the reactor cores and spent fuel pools. Seawater climbed over the seawall and inundated the diesel generators, shutting them down. With the electrical grid busted by the earthquake, Fukushima's emergency diesel generators kicked on and powered the site including cooling water pumps-again, as they were designed to do. The quake itself caused the operating reactors to scram (shut down) as they were designed to do. Units 4, 5, and 6 were shut down, albeit with spent reactor fuel sitting in pools that required cooling. When the earthquake hit there were three operating reactors (units 1, 2, and 3). Near the city of Fukushima was a complex of six nuclear reactors capable of producing more than 4500 MW of electrical energy. This was among the worst natural disasters to hit a nation known for natural disasters, and that was only the start. The tsunami slammed into the coast of Japan, killing more than 15,000 people and destroying or damaging more than a million buildings. The seafloor began rising towards the surface, and as the water ran into the shallower depths it piled up to a height of more than 40 meters (140 feet) before it swept over the land. The moving rocks shoved a wall of water across the Pacific Ocean. The quake shifted the Earth's axis by somewhere between 4 and 10 inches, altering the length of a day by nearly 2 microseconds. It was the fourth-strongest earthquake recorded since 1900 and the strongest earthquake to strike Japan in recorded history. The earth moved more than 20 meters over a 500-mile zone and the resulting earthquake released as much energy as a 45-megaton hydrogen bomb (to put this in perspective, this is 30,000 times more powerful as the bomb that leveled Hiroshima). When it released, that stress caused one of the most damaging quakes on record.

But to really understand what happened at the nuclear plant that day, you need to know a little more.Īt the site of the earthquake, stress had been building up in the Earth's crust for decades. You know the outline of the disaster by now: A powerful earthquake caused a massive tsunami that crashed into Fukushima Daiichi Nuclear Power Plant and caused multiple nuclear reactor meltdowns.

With the fifth anniversary of the Fukushima accident upon us this month, let's take a look at where things stand today with recovering from this calamity, and what might be happening next. Yet it's the part that still engenders so much fear. But the nuclear part of this horrible day was, if the longest-lasting, certainly the least lethal event. Mawas a day of unimaginable tragedy in northern Japan, a tragedy exacerbated by the reactor meltdowns and release of contamination. Nuclear reactor accidents are so devastating and world-changing that you know them by one name: Three Mile Island (1979), Chernobyl (1986), and Fukushima.