The nuclear crisis at the Daiichi Nuclear Power Plant in Fukushima, 250 km from Tokyo, has been getting a lot of attention in the media lately but fears expressed for dangerous levels of radiation reaching areas further than 30km from the stricken nuclear facilities are unfounded and need to be put into perspective.
First of all this map will give you some idea of the distances involved.
It shows the proximity of three major US Cities, New York City, Baltimore, and Washington DC to Three Mile Island.
Clicking on a colored line will give you approximate distances in miles and kilometers.
View The distance from Three Mile Island to Major US Cities in a larger map
I chose to use Three Mile Island as a reference point to show that in America’s worst nuclear accident to date these THREE major US cities were closer to the incident than Tokyo is to Fukushima.
Daiichi compared to Three Mile Island.
At the moment, the incident at the Daiichi Nuclear Power Plant in Fukushima resembles a more serious version of the 1979 nuclear accident at the Three Mile Island Nuclear Power Plant in Dauphin County, Pennsylvania near Harrisburg, United States.
It currently has the same accident rating of 5 (out of 1-7) on the International Nuclear and Radiological Event Scale (INES) – see chart below..
There are major differences of course –
According to Harold Denton, a senior official with the U.S. Nuclear Regulatory Commission at the time of the TMI accident, and the man put in charge of the situation:
– At Three Mile Island there were no injuries and only minor amounts of radiation released into the atmosphere. At Daiichi, at least two workers are missing and many other workers are risking heavy doses of radiation.
– There was only one troubled reactor at Three Mile; in Daiichi there are six.
– His teams could work close to the reactor. In Japan it may well be too dangerous to do so because of high levels of radiation.
– The power was working at Three Mile. In Japan, it was knocked out by the earthquake and tsunami.
(src: Reuters Full Article Here)
The seriousness stems from the amount of damage sustained to the reactors and their buildings from the combination of an Earthquake (the largest in Japan’s recorded history) the Tsunami that followed (the largest in Japan’s recorded history), the spate of large aftershocks that continued to hit the area (equal to news worthy quakes in and of themselves), and a series of explosions that damaged the structures from the inside.
Three Mile Island had no such calamity of course, issues at the TMI facility were caused and compounded by a number of factors, chief among them human error, confusing and ambiguous controls and design flaws within the reactor itself.
The similarities between the two events are in the danger posed to the surrounding environment and population by radiation and fallout – i.e. very little.
That is to say at this point the radiation is highly localised even if there was to be an explosion (possible but unlikely) it would not send debris more than 500 meters into the air and would hardly pose a major risk to areas outside the evacuation zone of 30km.
“What a meltdown involves is the basic reactor core melts, and as it melts, nuclear material will fall through to the floor of the container. There it will react with concrete and other materials … that is likely… remember this is the reasonable worst case, we don’t think anything worse is going to happen. In this reasonable worst case you get an explosion. You get some radioactive material going up to about 500 metres up into the air. Now, that’s really serious, but it’s serious again for the local area. It’s not serious for elsewhere even if you get a combination of that explosion it would only have nuclear material going in to the air up to about 500 metres. If you then couple that with the worst possible weather situation i.e. prevailing weather taking radioactive material in the direction of Greater Tokyo and you had maybe rainfall which would bring the radioactive material down do we have a problem? The answer is unequivocally no. Absolutely no issue. The problems are within 30 km of the reactor.”
– Chief Scientific Adviser to the UK Government Sir John Beddington on the situation at the Daiichi Nuclear Power Plant – March 15th.
(src: UK Embassy Japan)
In comparison TMI’s evacuation zone was around 10 Kilometres (5 Miles) and President Carter was even able to tour the control room on the fourth day of the accident.
Daiichi compared to Chernobyl.
The Fukushima incident though is in no way near the intensity of the Chernobyl incident in Ukraine (former USSR) which had a fire that sent highly radioactive particles 30 000ft into the atmosphere and was a full 7 on the INES.
It is physically impossible (i.e. the physics are different) for that kind of accident to occur at Fukushima.
1. Chernobyl’s reactor had no containment structure.
2. Chernobyl’s reactors had several design flaws that made the crisis harder to control. Most crucially, their cooling system had a “positive void coefficient,” which means that as coolant water is lost or turns into steam, the reaction speeds up and becomes more intense, creating a vicious feedback loop.
3. The carbon in Chernobyl’s reactor fueled a fire that spewed radioactive material further into the atmosphere. Fukushima’s reactors do not contain carbon, which means that the contamination from an explosion would remain more localized.
4. Unlike Chernobyl, however, a meltdown at Daiichi could end up contaminating the water table.
5. Much of the public health impact of Chernobyl was the result of the Soviet government’s attempt to cover up the crisis, rather than moving quickly to inform and protect the public.
6. Emergency workers at Chernobyl took few precautions, and may not have been fully informed about the risks they were taking.
(src: ProPublica Full Article Here.)
Only number 4 on the above list is a real major issue for areas outside the 30km evacuation zone around Daiichi and that is why they are working so hard to keep the stricken reactors and containment pools cool.
At the time of this posting the situation, as reported by the IAEA, has not deteriorated.
At this point if you are anywhere in the world further from Daiichi than the 30km evacuation area you will probably get more radiation from eating several bananas with your breakfast while watching the US media flop about on TV.