Tag Archives: nuclear reactors

Japan update 3/1/12

Today Hirono’s central government moved back to Hirono. I found out in early January from a friend of mine who works for Hirono city hall that they were planning to move back to Hirono in March, and it looks like they have done it:


Opinions seem to vary about the viability of folks moving back to Hirono. Some are hopeful and look forward to returning, while others are more pessimistic and believe that returning is not an option.

The article mentioned above states “A public Geiger counter near the town hall read 0.42 microsieverts per hour Thursday morning, a level several times higher than seen in Tokyo.”

And since I can’t keep track of microsieverts / millisieverts and what those numbers mean for radiation exposure, I thought I would try to figure it out and put it down here:

sievert = international unit of measure for an absorbed dose of radiation; measures the effect a dose of radiation will have on the cells of the body. 1 sievert (or “Sv”) = 100 rem (the measuring unit used in the U.S.). Receiving 1 Sv all at once will make you sick; receiving 6 Sv or more all at once is most likely fatal.

millisievert = 1/1000 of a Sievert (or 0.001 Sv). For example, a mammogram is 2 mSv, head CT scan 2 mSv, chest CT scan 8 mSv.

microsievert = 1/1,000,000 of a Sievert (or 0.000001 Sv). For example, an arm x-ray is 1 microsievert, a dental x-ray is 5 microsieverts, eating a banana is 0.1  microsieverts (weird, huh?), sleeping next to someone is 0.05 microsieverts.

For a point of reference, the background radiation dose we receive on a normal day is around 10 microsieverts (or 0.01 milliseiverts) The EPA yearly limit for radiation exposure to an average person (i.e. someone who doesn’t work with nuclear reactors) is 1 millisievert a year (or 1000 microsieverts).

For a chart that really provides perspective, check out http://xkcd.com/radiation/.

So if Hirono is currently reporting 0.42 microsieverts/hour, then the annual dosage would be 3.7 millisieverts. That’s equivalent to about a  head CT scan and a mammagram. Not that I would want to have both of those in a year, but that’s not too bad.

Maybe that trip to visit them in the fall will indeed happen.

Life at a Japanese evacuation center

Japan evacuees

Life in an evacuation center (you can forget privacy)

I just found these reports from a nuclear consultant who lives (well, lived) in Tomioka, a town near the Fukushima Daiichi Nuclear Power Plant. He and his family were evacuated, and he has reported his experiences in a 3-part series in English.

[Tomioka is about 10 miles north of Hirono, the town I lived in. – Andi]

Tohiro Kitamura reports frustration with the government and the lack of consideration for the evacuees, ranging from insufficient bathrooms (1 toilet for 500 people, in one case) and rations of expired food, to discrimination with ‘optional lodgings’ (if you have the money, then you can stay at a hotel or inn with some government compensation) and unclear directions (‘voluntary evacuation’ and radiation testing with nothing to show for it).

Take a look for yourself:

Kitamura’s evacuation experience – part 1 (PDF)

Kitamura’s evacuation experience – part 2 (PDF)

Kitamura’s evacuation experience – part 3 (PDF)

In his reports, Kitamura mentions people crossing the “No Entry” zones to get to their home, however to do so requires a car and fuel. One man traveled alone in the evacuation zone to take photos of homes for evacuees who couldn’t make the trek themselves:


[Visiting Yonomori Park for the cherry blossoms is one of my fondest memories of living in Japan. The park is filled with cherry trees, and the city would put in lights to shine up through the branches of the cherry trees for the evenings when people would sit under the trees and have picnics with the blossoms falling like snow. -Andi]

Reports provided by JAIF. News by Mainichi Daily News.

Japan update 5/2/2011

Work continues on the Fukushima Daiichi Nuclear Power Plant. They are in the process of installing air filters in the No. 1 reactor building, which should reduce the amount of radioactive materials by 95% when operated for 24 hours. Eight workers are set to enter the No.1 reactor building as early as Thursday. They will be the first to do so since a hydrogen explosion occurred one day after the March 11th earthquake and tsunami. Assuming that the air filters work, TEPCO will then install air filters in the No.2 and No. 3 reactor buildings.

And in other news: A group of Tohoku Electric Power Company (not the Tokyo Electric Power Company, which runs Fukushima Daiichi) shareholders will submit a motion calling for the closure of the company’s nuclear plants. 220 individual stockholders decided on the move ahead of the company’s annual shareholders’ meeting at the end of next month. The investors are demanding that the  utility state in its agreement with shareholders that it will close its nuclear power plants and end its investment in a reprocessing plant in Aomori Prefecture and similar projects. The shareholders say the problems at  the Tokyo Electric Power Company’s Fukushima Daiichi nuclear plant was a warning that accidents at any nuclear plant can lead to dangers that cannot be contained by any one company. They will deliver documents on the demand to the  company on Monday. The subject is expected to be discussed at this year’s shareholders’ meeting.

News courtesy NHK and JAIF 5/2/2011.

Update: Fukushima nuclear reactors 4/21/2011

It looks like it will take some time for the reactor situation to resolve.  On Monday TEPCO announced a 6-9 month containment plan. The first three months would attempt to achieve a steady reduction in radiation, then the next stage over the following three to six months would involve controlling the release of radioactive materials. Japanese government officials say that residents from the area around Fukushima Daiichi may be able to return to their homes in six months at the earliest, i.e. midway into the TEPCO containment plan timetable.

In other nuclear reactor news this week:

High radioactive levels detected in reactors
Robots have detected high levels of radioactivity inside the reactor buildings of the crippled Fukushima nuclear plant. The plant operator says the radioactivity must be reduced to allow work inside the buildings to bring the crisis under control.

Tokyo Electric Power Company surveyed the interiors of 3 reactor buildings on Sunday and Monday using robots equipped with dosimeters and cameras. TEPCO says that over 50 minutes the robots found 18.9 millisierverts of radioactivity in reactor Number 1 and 6.46 millisierverts in Number 2.

(NOTE: The maximum allowable amount of radiation that won’t show any clinical symptoms is 200 millisieverts per year.)

The levels are hazardous to humans even over a short period. Levels of radioactivity were not available in the Number 3 reactor.

TEPCO says it will need to install air conditioners to ventilate and clean the air of radioactivity before people can work there.

Levels of radioactive water rising despite efforts
The operator of the troubled Fukushima Daiichi Nuclear Plant continues to transfer highly radioactive water near a reactor to a storage facility. Tokyo Electric Power Company says work has been underway since Tuesday to move 10,000 tons of highly contaminated water accumulated in the turbine building of the Number 2 reactor to an on-site waste processing facility. The water has been pumped into the facility at a rate of 10 tons per hour.

TEPCO says the toxic water level in a tunnel near the turbine building was 2 centimeters lower as of 6 PM on Wednesday. But it says because there was no change in the water level in the basement of the turbine building, the leaking of toxic water into the basement appears to be continuing.

SDF may transfer people out of no-entry zone
Japan’s Self-Defense Forces are studying the possibility of helping transfer people out of the 20-kilometer zone around the crippled Fukushima Daiichi nuclear power plant.

Self-Defense Forces and local municipalities have found that several tens of people are still living in the area, which will be designated a legally-controlled, off-limits zone on Friday. They are people who are unable to evacuate by themselves such as the elderly or those in need of nursing care.

Self-Defense Forces are considering transferring these people out of the area with their vehicles if they are requested to do so by the local governments.

They are also considering taking people to their homes in the off-limit areas on temporary visits and then decontaminating them for radiation after the trip.

Evacuees visit their home before government no-entry zone in effect
Evacuees from near the Fukushima Daiichi nuclear power plant drove to their homes on Thursday before a no-entry zone covering their areas goes into operation at midnight on Thursday.

Police checked the driving licenses of car drivers at a checkpoint about 20 kilometers from the power plant and asked where they are going.

In the afternoon, people carrying clothes, appliances and other goods from their homes were seen driving through the checkpoint on their way back to evacuation centers.

Fukushima Governor dismayed at Government and TEPCO response
The Governor of Fukushima prefecture issued a statement on April 11 condemning TEPCO and the Japanese government for “betraying” the people by claiming nuclear power is safe:

“The Japanese Government and TEPCO have been saying that nuclear power generation is absolutely safe with multi-layered safety measures. I feel this was a betrayal.

I have, therefore, strongly demanded the Japanese Government and TEPCO to come up with solutions to this incident. However, there has yet to be any sign of improvement in terms of restoration of the facilities.”

As a sidenote, Japanese culture places an emphasis on being vague and using ‘softening’ words when making a request of any sort. Strong language is avoided because it could cause more harm than good.

The fact that the Governor used the word ‘betrayal’ reflects just how strong his feelings are. And then to make those words public? That demonstrates a lot of strong emotion. It shocked me to read his statement because you just don’t talk like that in Japan. You don’t.


More news updates next week.

About the Fukushima nuclear reactors

nuclear sign

The nuclear situation is a "sideshow." The real concern is the aftermath of the tsunami.

Update: For more information about radiation see the post for 3/1/2012 here.

Update: See the post for 4/21/2011 here.

Between the mainstream news and questions I’ve been getting from folks, I’ll try to help clarify the status of the Fukushima nuclear power plants, and hopefully relieve some people’s concerns.

Q: What is the current status of the Fukushima nuclear reactors?
A: According to the Nuclear Energy Institute as of 3/17/2011:

The reactors at Fukushima Daiichi are in stable condition and are being cooled with seawater. They are in the process of restoring off-site electricity to provide power to the control rod drive pump, instrumentation, batteries, and the control room.

The reactors at Fukushima Daini are shutdown with normal cooling being maintained using residual heat removal systems.

Q: Could the reactors blow up and have a ‘meltdown’?
A: Technically they could, however it would only affect the local area (30km around the reactors).

According to the Chief Scientist for the U.K.:

Reasonable worst case scendario: If the Japanese fail to keep the reactors cool and fail to keep the pressure in the containment vessels at an appropriate level, you could get the dramatic word “meltdown” where the basic reactor core melts, and as it melts, nuclear material falls through to the floor of the container. There it reacts with concrete and other materials. In this reasonable worst case you get an explosion. You get some radioactive material going up to about 1600 feet into the air. That is serious only for the local area (30km around the plant).

Q: How would a ‘meltdown’ affect Tokyo? Other parts of Japan? The West Coast of the U.S.?
A: Again from the Chief Scientist for the U.K.:

Even if there were an explosion and then the worst possible weather situation (i.e. prevailing weather taking radioactive material in the direction of Greater Tokyo and rainfall bringing the radioactive material down), there would still be absolutely no impact on Tokyo or anywhere outside of the 30km radius surrounding the reactors. [ed. note: That includes the West Coast.]

Q: How would this compare to Chernobyl?
A: With Chernobyl, the top of the reactor blew off and then they had a massive fire at the graphite core which lasted for a long time, causing the heat to push the material up 30,000 feet. It lasted for months, putting nuclear radioactive material up into the upper atmosphere for a very long period of time.

With the Fukushima reactors, there would be a single explosion, not a continued explosion, so the material would be sent up only 1600 feet.

In the case of Chernobyl, they established an exclusion zone of 30 kilometers, just like in Fukushima. Outside of that exclusion zone, there is no evidence whatsoever to indicate people had problems from the radiation. The problems with Chernobyl were people continued to drink the contaminated water and eat contaminated food. That’s not going to be the case here. The Japanese are already testing food for contaminants.

Radiation level chart

Radiation level effects on the human body

Q: What about radiation?
A: According to this chart by the National Institute of Radiological Sciences, the maximum allowable amount of radiation that won’t show any clinical symptoms is 200 millisieverts/year. This translates to a sustained amount of 22.83 microsieverts/hour.

[1 millisievert = 1000 microsieverts]

Please note that this would need to be a SUSTAINED dosage, meaning you should get 22.83 microsieverts/hour continuously for ONE YEAR for it to be cause for concern. Any sudden spike should be okay if it does not last for several hours (or days).

Take a look at the these charts of radiation levels in Ibaraki and Fukushima prefectures.  See the numbers for yourself – there is a spreadsheet of hourly recorded radiation leves in Fukushima.

Q: How can we trust what you’re saying?
A: The Japanese authorities are providing information to the appropriate international agencies, which are watching the situation closely. Besides,
the radiation levels can’t be concealed because they are being monitored throughout the world.

KEEP IN MIND: The news we receive in the U.S. is generally 36-48 hours behind what is currently happening in Japan.

I will post more updates as I can.