Fukushima NPP Meltdown
I saw this coming at about 4am, when I heard the NHK English news anchor saying that "All of the regions nuclear power plants are safe, however Fukushima Power Plant has experienced a state of emergency with the cooling system. The backup diesel generators are all inoperable..." Then she quickly moved onto other news. Deductive logic and a bit of knowledge about nuclear reactions led me to quickly deduct that this was not good at all, and that it would likely escalate to a more serious situation if they couldn't get coolant pumps working quickly.
Add the fact that the media was also saying that all the other plants were safe, and this plant had no radiation leaks detected 'outside'. The use of the word outside led me to believe that there were leaks inside the plant. Add the fact that the plant was also suffering from a major fire. Another telltale sign that things aren't really going all that well.
Well now it seems that radiation levels outside the plant have jumped up 8 times higher then normal readings. And the containment pressure has risen 50% higher then normal, which has forced them to vent some radioactive gasses to relieve the pressure. At the moment, it doesn't like it will be as bad as Chernobyl, but it will likely be worse then Three Mile Island. We shall see...
More predictions from experts say that this could turn into a Chernobyl scale event. And more then one reactor may be involved, not just one!
6:20 PM EST: Main gate reading is now 20 times normal radiation. Control room is 1000 times normal.
6:30 PM EST: 45,000 People Evacuated around Plant.
6:45 PM EST: Preliminary reports of 15,000 times normal radiation now reported. Uranium tempature has reached critical levels. (From the BBC)
6:50 PM EST: Venting still hasn't happened, as there is no power to open the vents to vent the buildup of gasses. This is starting to look more like a Chernobyl.
7:01 PM EST: 3 workers confirmed dead at Fukushima.
7:06 PM EST: Evacuation radius raised to 20 km, from the previous 10km.
7:11 PM EST: Five reactors now under Emergency Conditions at both Fukushima No. 1 and No. 2 plants. (http://blogs.aljazeera.net/live/asia/live-blog-japan-earthquake#update-10551)
7:31 PM ET: Venting has apparently begun to prevent an explosion. Crews rushed in emergency generators, to power the vent systems. Coolant that the US promised has apparently not been delivered.
3:36: Explosion at Fukushima Daiichi No. 1. Roof blown off building for Reactor 1. Containment chamber for reactor appears undamaged.
7:00: 90 people who were exposed to radiation at Fukushima have been taken to the hospital for radiation exposure.
A March 12 explosion at the earthquake-damaged Fukushima Daiichi nuclear power plant in Okuma, Japan, appears to have caused a reactor meltdown.
The key piece of technology in a nuclear reactor is the control rods. Nuclear fuel generates neutrons; controlling the flow and production rate of these neutrons is what generates heat, and from the heat, electricity. Control rods absorb neutrons — the rods slide in and out of the fuel mass to regulate neutron emission, and with it, heat and electricity generation.
A meltdown occurs when the control rods fail to contain the neutron emission and the heat levels inside the reactor thus rise to a point that the fuel itself melts, generally temperatures in excess of 1,000 degrees Fahrenheit, causing uncontrolled radiation-generating reactions and making approaching the reactor incredibly hazardous. A meltdown does not necessarily mean a nuclear disaster. As long as the reactor core, which is specifically designed to contain high levels of heat, pressure and radiation, remains intact, the melted fuel can be dealt with. If the core breaches but the containment facility built around the core remains intact, the melted fuel can still be dealt with — typically entombed within specialized concrete — but the cost and difficulty of such containment increases exponentially.
However, the earthquake in Japan, in addition to damaging the ability of the control rods to regulate the fuel — and the reactor’s coolant system — appears to have damaged the containment facility, and the explosion almost certainly did. There have been reports of “white smoke,” perhaps burning concrete, coming from the scene of the explosion, indicating a containment breach and the almost certain escape of significant amounts of radiation.
At this point, events in Japan bear many similarities to the 1986 Chernobyl disaster. Reports indicate that up to 1.5 meters (4.9 feet) of the reactor fuel was exposed. The reactor fuel appears to have at least partially melted, and the subsequent explosion has shattered the walls and roof of the containment vessel — and likely the remaining useful parts of the control and coolant systems.
And so now the question is simple: Did the floor of the containment vessel crack? If not, the situation can still be salvaged by somehow re-containing the nuclear core. But if the floor has cracked, it is highly likely that the melting fuel will burn through the floor of the containment system and enter the ground. This has never happened before but has always been the nightmare scenario for a nuclear power event — in this scenario, containment goes from being merely dangerous, time consuming and expensive to nearly impossible.
Radiation exposure for the average individual is 620 millirems per year, split about evenly between manmade and natural sources. The firefighters who served at the Chernobyl plant were exposed to between 80,000 and 1.6 million millirems. The Nuclear Regulatory Commission estimates that exposure to 375,000 to 500,000 millirems would be sufficient to cause death within three months for half of those exposed. A 30-kilometer-radius (19 miles) no-go zone remains at Chernobyl to this day. Japan’s troubled reactor site is about 300 kilometers from Tokyo.
The latest report from the damaged power plant indicated that exposure rates outside the plant were at about 620 millirems per hour, though it is not clear whether that report came before or after the reactor’s containment structure exploded.
Thanks to Stratfor.com for some of this article.
7:50 AM: FLASH: Japan's nuclear safety agency says Fukushima Daiichi Nuclear Plant No. 3 reactor's emergency cooling system not functioning (Reuters)
8:00 AM: Evacuation area possibly spread to 20km, 170,000 people evacuated.
Authors Note: Please note that despite this, I am still highly in favour of Nuclear Power. This plant was 40 years old, and from the sounds of things was allowed to operate when it really shouldn't of been operating. If they knew they had problems with the backup cooling systems, why were those reactors online?
7:30 AM: Second explosion at the plant rumored.
This image is actually a fake, however it is still fairly accurate. Just ignore the intensity. It will be much less.
7:40 AM: Meltdown may be under way at Fukushima Daiichi's nuclear power reactor, an official w/ Japan's safety agency says
7:42 AM: Officials say that current exposure to high levels of radiation at Fukushima may reach upwards of 160.
8:00 AM: Total reactors involved now at 6 (http://www.latimes.com/news/science/la-sci-japan-quake-sixth-reactor-20110313,0,3146984.story)
8:30 AM: IEEE describes this event as Worse then Worst. (http://spectrum.ieee.org/energywise/energy/nuclear/japan-nuclear-accident-worse-than-worst-again)
"There is the possibility of an explosion in the third reactor, as in the case of the first reactor," he said, adding there would be no effect on the health of nearby residents. - (http://blogs.aljazeera.net/live/asia/japans-twin-disasters-march-13-live-blog)