What Fukushima Tells Us About Nuclear Power
Let's recap events.
- Fukushima I Nuclear Power Plant, a 40 year old reactor complex, was hit by a 9.0 Richter earthquake (the strongest ever reported in Japan) and a correspondingly enormous (14 m) tsunami.
- The reactors survived essentially unscathed, going into automatic shutdown despite ground accelerations well above nominal design limits..
- Grid power was lost, which, with the shutdown, threw the plant onto diesel generators to power cooling and control systems.
- The huge tsunami, more than twice what the seawall was designed to handle (5.7 m) flooded the generator building, knocking out the emergency power.
- The tsunami also flooded the electrical switching rooms in the basement of the reactor buildings.
- The control systems then switched to batteries, and additional batteries and generators were brought in to maintain control functions from other nuclear plants.
- Combined earthquake and tsunami damage limited access to the plant, making it difficult to get emergency crews, supplies, fuel and equipment in.
- With loss of all cooling due to failure of multiple power sources, overheating occurred in some of the spent fuel pools and reactor cores, with damage to some of the reactor fuel assemblies and some leakage of radioactive material.
- Hot zircaloy fuel rods reacted with steam to produce hydrogen which exploded, damaging three of the six reactor buildings, but apparently not the containment vessels.
So, with all this, what's the score so far? Two workers missing since the tsunami - it probably got them. Maybe thirty more injured, mostly by 'industrial accident' type stuff like hydrogen explosions. Three workers exposed to almost a year's limit of radiation, including two with radiation burns about equivalent to a sunburn. Note that they are in no danger of acute sickness, and very small danger of long term health risks - and they mainly got that way by ignoring their radiation monitoring equipment when it sounded a warning. They didn't even notice the 'burns' until they went off shift.
There's also been a minimal release of radiation into the general environment. The greatest damage is probably related to stress due to ignorance, fear mongering media, and grandstanding officials and politicians... oh, and also the people poisoning themselves to no end with self prescribed potassium iodide.
To put things in perspective, one airline flight from Toronto to Vancouver will expose you to more radiation - 400 times more - than living in the area of a nuclear plant for a year. A single dental x-ray is equivalent to 50 years living near a nuclear plant. For that matter, eating 1 bananas produces equivalent exposure to a year living near a nuclear power plant. One day on the Colorado plateau gives you 13 times the radiation of a year living near a nuclear plant. For that matter one year near a coal power plant is equivalent in radiation to three years near a nuclear plant.
It's pretty clear - nuclear power is the cleanest, safest form of base load power generation except for geothermal (limited application) and 'natural' hydro power - like Niagara Falls.
Hydro power that involves dams, weirs, canals, and the like has a much greater ecological impact than nuclear stations.
So, let's stop mucking about, and start building generation III and IV reactors. It's the clean, safe, responsible choice.
Oh, yes... and for a bit of perspective on the risks, look at xkcd.com/radiation
- Fukushima I Nuclear Power Plant, a 40 year old reactor complex, was hit by a 9.0 Richter earthquake (the strongest ever reported in Japan) and a correspondingly enormous (14 m) tsunami.
- The reactors survived essentially unscathed, going into automatic shutdown despite ground accelerations well above nominal design limits..
- Grid power was lost, which, with the shutdown, threw the plant onto diesel generators to power cooling and control systems.
- The huge tsunami, more than twice what the seawall was designed to handle (5.7 m) flooded the generator building, knocking out the emergency power.
- The tsunami also flooded the electrical switching rooms in the basement of the reactor buildings.
- The control systems then switched to batteries, and additional batteries and generators were brought in to maintain control functions from other nuclear plants.
- Combined earthquake and tsunami damage limited access to the plant, making it difficult to get emergency crews, supplies, fuel and equipment in.
- With loss of all cooling due to failure of multiple power sources, overheating occurred in some of the spent fuel pools and reactor cores, with damage to some of the reactor fuel assemblies and some leakage of radioactive material.
- Hot zircaloy fuel rods reacted with steam to produce hydrogen which exploded, damaging three of the six reactor buildings, but apparently not the containment vessels.
So, with all this, what's the score so far? Two workers missing since the tsunami - it probably got them. Maybe thirty more injured, mostly by 'industrial accident' type stuff like hydrogen explosions. Three workers exposed to almost a year's limit of radiation, including two with radiation burns about equivalent to a sunburn. Note that they are in no danger of acute sickness, and very small danger of long term health risks - and they mainly got that way by ignoring their radiation monitoring equipment when it sounded a warning. They didn't even notice the 'burns' until they went off shift.
There's also been a minimal release of radiation into the general environment. The greatest damage is probably related to stress due to ignorance, fear mongering media, and grandstanding officials and politicians... oh, and also the people poisoning themselves to no end with self prescribed potassium iodide.
To put things in perspective, one airline flight from Toronto to Vancouver will expose you to more radiation - 400 times more - than living in the area of a nuclear plant for a year. A single dental x-ray is equivalent to 50 years living near a nuclear plant. For that matter, eating 1 bananas produces equivalent exposure to a year living near a nuclear power plant. One day on the Colorado plateau gives you 13 times the radiation of a year living near a nuclear plant. For that matter one year near a coal power plant is equivalent in radiation to three years near a nuclear plant.
It's pretty clear - nuclear power is the cleanest, safest form of base load power generation except for geothermal (limited application) and 'natural' hydro power - like Niagara Falls.
Hydro power that involves dams, weirs, canals, and the like has a much greater ecological impact than nuclear stations.
So, let's stop mucking about, and start building generation III and IV reactors. It's the clean, safe, responsible choice.
Oh, yes... and for a bit of perspective on the risks, look at xkcd.com/radiation