prev
next
Japan nuclear reactor has fatally high radiation
The No. 2 reactor building of the crippled Fukushima Dai-ichi nuclear power plant is seen Sept. 29, 2011, in Okuma, Japan, in this picture released by Tokyo Electric Power Co. / AP Photo/Tokyo Electric Power Co.
(AP) TOKYO - One of Japan's crippled nuclear reactors still has fatally high radiation levels and hardly any water to cool it, according to an internal examination Tuesday that renews doubts about the plant's stability.
A tool equipped with a tiny video camera, a thermometer, a dosimeter and a water gauge was used to assess damage inside the No. 2 reactor's containment chamber for the second time since the tsunami swept into the Fukushima Dai-ichi plant a year ago. The probe done in January failed to find the water surface and provided only images showing steam, unidentified parts and rusty metal surfaces scarred by exposure to radiation, heat and humidity.
The data collected from the probes showed the damage from the disaster was so severe, the plant operator will have to develop special equipment and technology to tolerate the harsh environment and decommission the plant, a process expected to last decades.
Complete coverage: Disaster in Japan
Tuesday's examination with an industrial endoscope detected radiation levels up to 10 times the fatal dose inside the chamber. Plant officials previously said more than half of melted fuel has breached the core and dropped to the floor of the primary containment vessel, some of it splashing against the wall or the floor.
Particles from melted fuel have probably sent radiation levels up to dangerously high 70 sieverts per hour inside the container, said Junichi Matsumoto, spokesman for Tokyo Electric Power Co.
"It's extremely high," he said, adding that an endoscope would last only 14 hours in that condition. "We have to develop equipment that can tolerate high radiation" when locating and removing melted fuel during the decommissioning.
The probe also found the containment vessel - a beaker-shaped container enclosing the core -- had cooling water up to only 60 centimeters (2 feet) from the bottom, far below the 10 meters (yards) estimated when the government declared the plant stable in December.
Finding the water level was important to help locate damaged areas where radioactive water is escaping.
He said that the actual water level inside the chamber was way off the estimate, which had used data that turned out to be unreliable. But the results don't affect the plant's "cold shutdown status" because the water temperature was about 50 degrees Celsius (122 Fahrenheit), indicating the melted fuel is cooled.
Three Dai-ichi reactors had meltdowns, but the No. 2 reactor is the only one that has been examined because radiation levels inside the reactor building are relatively low and its container is designed with a convenient slot to send in the endoscope.
The exact conditions of the other two reactors, where hydrogen explosions damaged their buildings, are still unknown. Simulations have indicated that more fuel inside No. 1 has breached the core than the other two, but radiation at No. 3 remains the highest.
The high radiation levels inside the No. 2 reactor's chamber mean it's inaccessible to the workers, but parts of the reactor building are accessible for a few minutes at a time -- with the workers wearing full protection.
Last year's massive earthquake and a tsunami set off the worst nuclear accident since Chernobyl, sending three reactor cores to melt and causing massive radiation leaks. The government said in December that the reactors are safely cooled and the plant has stabilized, while experts have questioned its vulnerability.
During a recent visit by a group of journalists including The Associated Press, the head of the plant said it remains vulnerable to strong aftershocks and tsunami and containing contaminated water and radiation is a challenge. Radioactive water had leaked into the ocean several times already.
Workers found the fresh leak of 120 tons from a water treatment unit this week from one of its hoses, with estimated 80 liters (20 gallons) escaping into the ocean, Matsumoto said. Officials are still investigating its impact.
Fukukushima's accident has instilled public distrust and concerns about nuclear safety, making it difficult for the government to start up reactors even after regular safety checks. All but one of Japan's 54 reactors are now offline, with the last one scheduled to stop in early May.
Popular on CBSNews.com
- Mexico's drug war 20 Photos
- U.K. official: London attack suspects probed before
- Tokyo's rockabilly scene 16 Photos
- Graphic video: Man dead in "truly shocking" London attack Play Video
- Muslim hard-liners ID suspect in London attack
- Man dead in "truly shocking" London attack 253 Comments
- Slain London soldier was 25-year-old drummer, father
- London soldier slaying homegrown Islamic extremism?
Most Popular
-
01
-
02
-
03
-
04
-
05
Most Shared
Most Discussed
Highly toxic radionuclides like Strontium 90, Plutonium 239, and Cesium 137 are not "natural" elements, you idiot. They are the waste byproducts of man-made nuclear fission.
_______________________________
Guess again, gruven. That was disproven by them looking at soil samples taken back in the 1890's to 1940's (before nuclear power) and finding those things in very small amounts.
Yes, they are natural though we don't understand in the slightest yet HOW when they are only supposed to be created by nuclear fission that they have been created.
All cesium-137 existing today is unique in that it is totally anthropogenic (man-made). Unlike most other radioisotopes, cesium-137 is not produced from its non-radioactive isotope but as a byproduct of nuclear fission, meaning that until now, it has not occurred on Earth for billions of years.
From the Wiki quoting well-referenced academic peer reviewed research.
"Experiments with dogs showed that a single dose of 3800 microCi/kg (140 MBq/kg, or approximately 44 micrograms/kg) is lethal within three weeks."
This stuff is very dangerous (despite what the nuclear industry promoters will say). And, a few hundred micrograms is 100 percent lethal.
Perhaps it's time to stop calling it the worst nuclear accident since Chernobyl, and start calling it the worst since ever.
How's that new reactor design coming along? You know, the one where when cooling power is lost, the building doesn't just explode.
Another big problem for nuclear power is that renewables provide cheaper alternatives that are available now.
Nuclear power plants WHEN DONE CORRECTLY are our best source of clean energy (or as close to absolutely clean as we are going to get).
A design that is guaranteed to meltdown if it's not constantly cooled.
Does that make any sense, what so ever, to anybody?
There are newer, safer designs out there that don't require constant cooling.
But, the deeper problem is that the nuclear industry is corrupt and dishonest, and fail to take into account the consequences of their actions.
The new designs have new problem - but, the nuclear industry will do everything possible to cover-up the flaws.
The nuclear industry does not have even have to worry about paying for insurance in the U.S. - most clean-up and disaster management costs have been shifted to the taxpayers. They can destroy your land, contaminate your family, and then make you pay for it.
While it was happening we saw a stream of blatant lies from TEPCO.
Now we are see the harsh reality of what has actually happened, and what will affect much of Japan for generations.
And, we still do not know the full consequences of the significant plume of contamination that was detected over much of the western U.S..