The boss of the company behind the
devastated Japanese nuclear reactor today broke down in tears – as his
country finally acknowledged the radiation spewing from the over-heating
reactors and fuel rods was enough to kill some citizens
Nuclear and Industrial Safety Agency admitted that the disaster was a
level 5, which is classified as a crisis causing ‘several radiation
deaths’ by the UN International Atomic Energy.
said the rating was raised after they realised the full extent of the
radiation leaking from the plant. They also said that 3 per cent of the
fuel in three of the
reactors at the Fukushima plant had been severely damaged,
suggesting those reactor cores have partially melted down.
Tokyo Electric Power Company Managing Director Akio Komiri cried as he
left a conference to brief journalists on the situation at Fukushima, a
senior Japanese minister also admitted that the country was overwhelmed
by the scale of the tsunami and nuclear crisis.
Chief Cabinet Secretary Yukio Edano
said: ‘The unprecedented scale of the earthquake and tsunami that
struck Japan, frankly speaking, were among many things that happened
that had not been anticipated under our disaster management contingency
‘In hindsight, we
could have moved a little quicker in assessing the situation and
coordinating all that information and provided it faster.’
Nuclear experts have been saying for days that Japan was underplaying the crisis’ severity.
It is now officially on a par with the Three Mile
Island accident in Pennsylvania in 1979. Only the explosion at Chernobyl
in 1986 has topped the scale.
- At 9:20AM (JST) on March 17, radiation level at elevation of 1000ft
above Fukushima Daiichi Nuclear Power Station: 4,130 micro sievert.
- At 9:20AM on March 17, radiation level at elevation of 300ft above
Fukushima Daiichi Nuclear Power Station: 87,700 micro sievert. At
11:10AM on March 17, radiation level at main gate (approximately 3281
feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power
station: 646.2 micro sievert.
- At 7:50PM on March 17, radiation level outside main office building
(approximately 1,640 feet from Unit 2 reactor building) of Fukushima
Daiichi Nuclear Power Station: 3,599 micro sievert.
- For comparison, a human receives 2,400 micro sievert per year from
Natural radiation in the form of sunlight, radon, and other sources. One
Chest CT scan generates 6900 micro sievert per scan.
(One millirem = 10 microsievert, if you are used to the older system of radiation units.)
Let’s put this whole thing in perspective. The Health Physics Society states that radiation-induced health issues cannot be demonstrated in people who have received doses of radiation under 10,000 millirem (100,000 microsievert). Right now, the radiation level above the station is just under 88,000 microsievert, which is probably within the margin of error for a dangerous dosage. Considering the perfectionism and the obsession with safety that permeates Japanese engineering, it is no wonder that tears are being shed. Yet following the Trinity test in 1945,
radiation levels from blast fallout exceeding 15,000 millirem
(150,000 microsievert) were measured in populated areas (ranches, etc.)
surrounding the testing area — twice the amount of radiation being detected above the Fukushima plant.
Now let’s consider Three Mile Island. Three days after the partial meltdown in the No. 2 reactor on March 28, 1979, which caused the release of small quantities of radioactive cesium, iodine, and noble gas isotopes, the EPA established an intensive environmental monitoring program in the surrounding area. From Wikipedia:
An inter-agency analysis
concluded that the accident did not raise radioactivity far enough above
background levels to cause even one additional cancer death among the
people in the area. The EPA found no contamination in water, soil,
sediment or plant samples.
Researchers at nearby Dickinson College, which had radiation
monitoring equipment sensitive enough to detect Chinese atmospheric
atomic weapons testing, collected soil samples from the area for the
ensuing two weeks and detected no elevated levels of radioactivity,
except after rainfalls (likely due to natural radon plate out, not the accident). Also, white-tailed deer tongues harvested over 50 mi (80 km) from the
reactor subsequent to the accident were found to have significantly
higher levels of Cs-137 than in deer in the counties immediately
surrounding the power plant. Even then, the elevated levels were still
below those seen in deer in other parts of the country during the height
of atmospheric weapons testing. Had there been elevated releases of radioactivity, increased levels of
Iodine-131 and Cesium-137 would have been expected to be detected in
cattle and goat’s milk samples. Yet elevated levels were not found.
If “Three Mile Island” is as bad as the Fukushima accident gets, then it will be the least of Japan’s worries, as it struggles to rebuild itself from a devastating earthquake and tsunami.
The Nuclear Regulatory Comission currently defines the “safe” radiation
exposure level for the general public to be 2 millirem per hour, or
about 7 times the average environmental exposure we each receive over the course of a year, which is around 3.2 microsievert. In Japan, the evacuation of populations near the Fukushima plant (or for
that matter, the maneuvering of our Naval fleet away from detected
radiation) are simply measures designed to keep exposure levels below
the suggested 2 millirem per hour level. They are common sense safety
precautions, not signs of impending doom.
If you are interested seeing the radiation dosages that you regularly receive from the environment and from standard medical procedures such as x-rays and CT scans, another comprehensive chart of routine radiation exposures is available here.
Interestingly, cigarettes, concrete, and porcelain crowns each provide a
higher annual radiation exposure than one would receive living within
50 miles of a nuclear power plant.
Engineers at the
Fukushima plant are currently dealing with three
serious problems. The first is the complete destruction of the
electrical infrastructure of the plant by the earthquake and tsunami.
The availability of auxillary power is still a secondary concern at this
point, since workers have not finished repairing the wiring,
transformers, etc. to which any external power source can be connected.
The second problem involves the reservoirs that hold spend fuel rods.
Without the cooling system, these reservoirs have been steadily
increasing in temperature, and apparently the cooling reservoir within reactor #4 has boiled dry, exposing the rods. The third problem involves the damage to
the three operational reactors themselves, which still have the
potential to release large amounts of radiation if their
shielding fails. Problem one must be solved before problems two and
three can be adequately dealt with.
Herschel Smith’s article continues:
The main stream media (both print and television) continue to point
towards avoiding a core melt event, as if it will announce itself with
some sort of trumpet blast and melt through the earth. As I have
explained, it doesn’t happen that way. The corium, if it makes it
through the lower reactor vessel head, will disperse and cool from that
dispersal, not even making it through the lower basemat of concrete.
The cores for Units 1, 2 and 3 are already damaged. They are
partially melted, and partially shattered and rubblized, sitting in the
lower part of the reactor vessel. Most of the radiological source term (radioactive material released during an accident)
that can be expected to be released from the core to containment has
already been released. It is being held up inside hard containments and
depleted via radioactive decay, plateout, etc.
The work now has to do with mitigation of the radiological source
terms, from water injection into the reactor coolant system, water
washdown of plant components, and so on. If the semi-volatile fission
products and alkali metals are in effluent (dissolved in the water flowing out of the reactor area), they will likely not
re-evolve to the atmosphere in large quantities. Most importantly, for
now, the Spent Fuel Pools deserve attention, and hopefully the operators
will be able to mitigate zirconium fire events in the pools.
The Japanese are performing heroically, and the main stream media
will catch up in several days (or weeks). The current efforts are
focused on radiological source term and thus dose mitigation, not the
prevention of core melt events.
The mainstream media’s vernacular with respect to nuclear power is
severely limited — “radiation”, “fallout”, “meltdown” — and they have
demonstrated a very poor understanding of the actual meaning of these
terms. They are also incapable of providing clear explanations of
actual radiation levels and realistic exposure dangers associated with
those levels. Right now I would venture to guess that those in the
media who do understand the situation are being told to keep
quiet. Until the danger has subsided to a point where it can no longer
be hyped, sensationalism will continue to rule the airwaves.