Taro Yamamoto of the Liberal Party, member of the House of Councilors, accused the double standard of the the public radioprotection policy during his questions at the Special Commission of Reconstruction of the House of Deputies on March 21, 2017. He compared the health examination scheme introduced by Ibaraki prefecture to its population after the JCO* criticality accident to that currently available to Fukushima residents. The result shows the utter deficiency of the latter in spite of the fact that the Fukushima accident is classified as level 7, much more severe than the JCO level 4 accident.

We are publishing here the transcription of Taro Yamamoto’s questions** as well as the soil contamination map of Kashima and Haramachi districts of Minamisoma where the evacuation order was lifted in July 2016. The map is provided by the civil measurement group called “Fukuichi*** Area Environmental Radiation Monitoring Project”**** composed mainly of residents of Minamisoma which has been taking measurements of soil contamination in the vicinity of the members’ neighborhoods and in residential areas since 2012. Taro Yamamoto has already used their maps during another session of the Special Commission of Reconstruction. Let us note that in the map uploaded here, there are only two rectangles where the contamination density is lower than 40,000Bq/m2, and that for the rest of Kashima and Haramachi districts, the density is amazingly higher. As Taro Yamamoto indicated during his questions on November 18 last year, according to the Ordinance on Prevention of Ionizing Radiation Hazards a zone is called a Radiation Control Zone when the surface density is over 40,000Bq/m2. In a Radiation Control Zone, following the Ordinance, it is prohibited to drink, eat or stay overnight. Even adults are not allowed to stay more than 10 hours. To leave the zone, one has to go through a strict screening. The map shows that most of the two districts of Minamisoma city are in this situation. But it is not classified as Radiation Control Zone. On the contrary, people are told to go back there to live, including children.


Measurement devices : scintillation radiometers
Hitachi Aloka TCS172B
Dose rate of airborn radiation at 1 m, 50 cm, 1 cm from the ground. Unit : µSv/h
Hitachi Aloka TGS146B
Calculation of the rate of surface contamination, 1 cm from the ground. Unit : cpm
Procedure for measuring soil samples
Ram a tube in the ground (diam. : 80 mm, h : 50 mm), collect the soil and measure.
For TCS172B/TGS146B, wait for stabilisation, measure 5 times,then take the average value.
Insert ★ where the soil was collected.
Analysis device:
Canberra NaI Scintillation Detector (10 or 20 min)
According to the Ordinance on Prevention of Ionizing Radiation Hazards and Industrial Safety and Health Law, places where the effective dose reaches 1.3mSv in 3 months (approximately 0.6µSv/h of airborne radioactivity) or 40,000Bq/m2, in terms contamination density, are designated as a ‘’Radiation Control Zone’’ and public entry must be severely restricted.


Transcription of the questions of Taro Yamamoto

Taro Yamamoto

In Japanese history, except for the TEPCO Fukushima accident, are there other cases of population evacuation due to a nuclear accident?

Ÿ Government expert (Hiromu KATAYAMA)

Here is the answer. According to our understanding, as for the case of population evacuation due to a nuclear disaster in Japan, except for the cases of TEPCO Fukushima Daiichi and Daini that you pointed out, there is the case of the criticality accident of the JCO Tokai plant.


Thank you.

That was 18 years ago, on September 30, 1999. The criticality accident occurred in a uranium reprocessing facility for the experimental fast breeder reactor fuel, operated by JCO, in the village of Tokai, Ibaraki Prefecture. The nuclear fission chain reaction continued for about 20 hours. The radiation went through the walls, reaching the surrounding environment. 150 people within a 350-meter radius were evacuated and the confinement recommendation was given to inhabitants and shops within a 10km radius. On the spot, since the central government delayed to react, the village mayor at the time decided to evacuate the residents upon his responsibility. This is the first case of population evacuation due to a nuclear accident in Japan. It was a severe accident where two workers died, and the rescue members as well as residents in the neighborhood area were irradiated.

Here is my question. How many people were recognized as being irradiated in this accident.

Ÿ Government expert (Hiromu KATAYAMA)

Here is the answer. According to the report dated March 2000 by the Health Management Committee established by the Nuclear Safety Commission at the time, as for the civil population, there are 7 people for who we have a real value of irradiation, and 200 people for who the dose of radiation is estimated. Among these people, 119 people received more than 1mSv either measured or estimated.


According the central government, it is 119 people. But Ibaraki prefecture, following the radio security administration of Ibaraki prefecture, reported 666 irradiated people including those who received less than 1mSv. This is more than 5 times of the figure reported by the central government. I suppose that the central government does not want to recognize as many. However, Ibaraki prefecture, recognizing that the local government caused the damaged to its population, reported this figure.

Thereafter, Ibaraki prefecture created a fund of ¥300,000,000 to allow the irradiated population or those who were in doubt to be irradiated access to a heath examination. It concerns around 500 people. Its characteristic consists of the fact that it covers those who are born in 1999, the year of the accident, until they reach 82 years old. In other words, it is conceived to assure free health exminations through their entire life.

Please look at page 2 of document A to see what kind of health examinations the neighboring population can take since the JCO accident. They are quite extensive. It has been the accepted Ibaraki prefectural policy after the JCO accident. Even cancer examinations have been added. These examinations are accessible to those who are not recognized as irradiated, and who were exposed to the additional radiation of under 1mSv. They are open to those who stayed there temporarily because of their work or school, or those who have evacuated from Ibaraki prefecture since the accident.

Please show the next Figure.

Please don’t talk about the circumstances. Please answer in terms of the accident level. In which level is the JCO accident classified? Likewise, in which level is TEPCO Fukushima nuclear plant accident classified?

Ÿ Government expert (Hiromu KATAYAMA)

Here is the answer. As for the JCO criticality accident, the Science and Technology Agency at the time evaluated the accident as level 4. Concerning the accident of the Fukushima Daiichi nuclear power plant, the Nuclear and Industrial Safety Agency as well as the Nuclear Safety Commission at the time evaluated the emission of radioactive substances and consequently rated the accident as level 7.


Let’s go over this again. JCO is classed as level 4, it was a level 4 accident. The TEPCO Fukushima nuclear power plant accident is a level 7 accident. With the JCO accident of level 4, with the additional radiation of 1mSv, the authority promised a lifetime access to health examinations including cancer examinations. Yet, in the case of the TEPCO Fukushima nuclear power plant accident of level 7, the population is told to return to the region when the annual dose of radioactivity becomes lower than 20mSv/year, since it is then considered as safe. The housing aid is cut, since there is no necessity of evacuation.

To those who would say that they are not comparable, I would like to ask the following. Currently, in Japan, after a nuclear accident, with 1mSv of additional irradiation, are health examinations offered free during a lifetime? With an accident of level 4, you can have lifetime free examinations including cancer examinations. Yet, with level 7 accident, there aren’t. Look here! Which of these two accidents is more severe?

What is the reason, in the case of the TEPCO Fukushima Daiichi accident, not to offer free lifetime health examinations including cancer examinations with additional radiation of 1mSv? Is it because of financial reasons? Is it because it can be installed for a small number of the concerned population of Tokai village, but not in the case of TEPCO nuclear power plant accident, because there will be too many people to be examined and thus will cause financial problems, or even financial breakdown? Is it because it is not practically feasible? Is that why? Then, it is not a scientifically based judgment. This is a financially, efficiency based judgment.

After the dispersion of contamination due to the nuclear accident, Japan has adopted a new standard. It considers it normal to live an everyday life in the area if the dose of radioactivity is under 20mSv/year. The government says that it will make efforts to lower the level to 1mSv/year. Then I asked: how long does it take to lower the level of airborne radioactivity of the contaminated area to 1mSv/year? They are not even embarrassed to answer that they are not supposed to carry out such a calculation.

I asked if this was considered permissible before the accident, if it was allowed by the scientific standards before the accident. The bureaucrats’ answer was: “ this is a new challenge “. I think it is not a very elaborated approach for revitalization. It seems like the authorities have started cleaning up the damage to turn the page, to deny the accident. I suppose that there are people who say “that is not correct”. Some people might consider that the public support after the TEPCO accident is as solid as the support of the Tokai village aftermath, to make the people feel safe and secure.

Let us then see now what kind of medical support is available in Fukushima.

In the case of the Fukushima resident health investigations, only the thyroid cancer examination for those under 18 years old at the time of the accident, and a questionnaire survey for pregnant women are available to the population of Fukushima prefecture. Other than these two, health examinations are available only to those from evacuation zones. This includes a usual obesity examination offered to those over 40 years old all over Japan, plus blood tests including leukocyte fraction analysis.

Isn’t this health examination scheme too poor compared to the one of Tokai village? Besides, it is limited to those who are from the areas that have been classified as evacuation zones. In other words, if you are living in Fukushima prefecture, you can hardly have sufficient medical support, except for in limited areas. In the case of the JCO level 4 accident, one has a guarantee of a lifetime health examination at 1mSv of additional irradiation, and you still can have access to health examinations even if you are exposed to radiation under 1mSv. Yet in the case of the level 7 TEPCO Fukushima Daiichi accident, the support is so much inferior. Mr Minister, it seems to me that the difference of treatment is too much.

There are other things I would like to ask. So please give me a short answer. I think that the gap is too much. In terms of the accident level, Fukushima is more severe. But Tokai village offers a significantly more extensive support. On the other hand, the Fukushima support seems to be too feeble.

Sorry, I am running out of the time. I am going to skip that question, and go forward to other questions.

I would like to ask the following to the Minister. Who is responsible for this situation? The minimum compensation that the State and TEPCO, – who left the cause of the severe accident unattended -, should offer to the population should at least equal to the one offered in the Tokai village case. The central government should suggest it to Fukushima prefecture.

Besides, in the countries where there have been severe nuclear disasters, sanitary vacations are common practice. Their purpose is to reduce the internal irradiation. At least, we should invest in sanitary vacation programs open to the population of Fukushima prefecture.

Lastly, the end of the housing support for the auto-evacuees from the areas outside of the evacuation zones, which is in two weeks time, is the same as the order of forced return. It shouldn’t be just ‘’return’’ and ‘’should return’’. People ought to have the right to choose. The options are: remain or evacuate. In both cases, the State should give compensation and support.

Please give me your answer on the three points.

Minister (Masahiro Imamura)

You mentioned the levels. I suppose that I don’t have to answer. I think it covers different viewpoints including the accident scale.

Concerning the health problem, Fukushima prefecture is carrying out the Fukushima resident health investigation using the allocation. We have the intention to guide the prefecture to use this efficiently so that we can avoid the health hazards.

About the housing aid, as I have already answered, in spite of specific circumstances, the big majority of people have already returned to Fukushima. As for those who have not returned yet, I suppose that they have their specific situations. We will back up the prefecture to listen to them and carry out the program.

  • Chairman (Mitsuru Sakurai)

Your time is up.


Yes, I conclude.

There are more than 25,000 empty apartments for public servants in Japan. I strongly suggest that they are offered to those who would like to continue the evacuation. Please maintain the housing aid. Mr Minister, I sincerely hope you do. I count on you. Thank you very much.


* formerly Japan Nuclear Fuel Conversion Co.

** Published in Taro Yamamoto’s official site :
参議院議員山本太郎オフィシャルサイト :

Footage of the question :
質問ビデオ :

***Fukuichi is short for Fukushima Daiichi

**** Fukuichi shûhen kankyôhôshasen monitoring project