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7 years after Fukushima N-plants Disaster

- Reality of 7 years after the accident -

Cat: ENE
Pub: 2108/2
#: 1802

Hiroaki Koide (小出裕章)

7 years after Fukushima N-plants Disaster 福島原発事故後7年
  1. Introduction:
  2. Birth and use of nuclear bombs:
  3. How the radioactive materials polluted the environment:
  4. Radiation that we couldn't feel by our five senses:
  5. Responsibility of the present generation:
  6. History of N-plants development:
  7. Q&A:
  1. 序:
  2. 原子爆弾の誕生と使用:
  3. 放射能のよる環境汚染:
  4. 五感で感じない放射能:
  5. 現世代の責任:
  6. 原子力開発の歴史:
  7. Q&A:

; 1-20 mSv/y; 7th grade; 47 tons of Pu; Alchemical solution; BEIR; Cs-134; Cs-137 by Fukushima; Exposure allowance; ICRP; LNT model; Nuclear Emergency Situation; Radiation Controled Area;

  • 2018/Feb/14: This is a summary of two-hour special lecture held by Dr. Yasuaki Koide, nuclear specialist, former resercher at Reserch Reactor Institute of Kyoto Univercity held at Kita-ku, Tokyo.
  • Seven years seem substantially long for usual persons since Mar. 2011, but it is only beginning of the disater story; Dr. Koide emphasized the accident is still in the process; noboby knows when it could be settled down.
  • 小出裕章元京大原子力実験所助教による福島事故後7年目を語る
  • 福島原発事故は未だ進行中。

>Top 0. Introduction:

  • The special lecture was held at Tokyo by Dr. Yasuaki KoideFukushima Nuclear accident happened on 2011/Mar./11, with 7th grade of major accident.

0. 序:

  • 2011/3/11: 福島原発事故レベル7

>Top 1. Birth and use of Nuclear bombs:

  • 1945/Mar/10; US 340 B29 bombers firebombed in Tokyo (Great Tokyo Air Raid) and burned down 40% of Tokyo .
  • 1945/Jul/16, 08:15; the first nuclear bomb, named Trinity, exploded Alamogordo at New Mexico, which was instantly reported to President Truman; who is about to start the important negotiation in Potsdam preparing 'Potsdam Declaration.
  • 1945/Aug/6; A-bomb, named Little Boy, was actually and firstly used in the war; a B29 (Enola Gay) dropped A-bomb in Hiroshima, and burned almost all in the center of city. The number of victim was 160K people.
    • 16Kton (of TNT equivalent)
    • Cf: Total 1.8Kton bombs were dropped in Tokyo on 1945/Mar/10.
  • 1954/Jul/2: Newspaper reported the plan promoting nuclear power generation in Japan.
    • Uranium reserves actually exist 1/N of oil reserve, or 1/10N of coal reserve.
    • The news advertised that the cost of electricity would be 1/2000, if generated by nuclear energy.
    • But, the nuclear power generation was not actually cost effective; Japanese electricity charge is about 3 time higher than that of US. From now, enormous extra fee for demobilization of Fukushima is to be needed for a century or more.
    • Furthermore, the news advertised that the size of n-plant could be much smaller, even available under a city building; unlike large plant site such as conventional power generation. The forecast proved to be an illusion; nuclear power plant needs much larger plant site, which could not be built in populated urban areas.
      • Actually 42 plants were constructed in depopulated area in Japan, and newly three more plants are scheduled (Ohma, Totsu, and Shimane-3).
        • These are part from megalopolis zone like Tokyo, Nagoya, Osaka.
        • It is unreasonable that electricity consuming areas have enforced the site of N-plants in most depopulated areas.
        • 2017/Dec/22: Saitama, located adjacent to Tokyo, the prefectural assembly rudely required re-operation of Kashiwazaki-Kariha N-plant, though it has no N-plant.
      • In addition, there is a dangerous nuclear fuel reprocessing plant (Rokkasho), which produces nuclear waste every day as much as a year volume produced by a N-plant.
  • 20111/Mar/11: The Fukushima Daiichi N-plants (1/2/3 plants were operating and 4 was not then) disaster happened.
    • Demobilization works of these 4 plants may require several ten or even hundred years.

1. 原子爆弾の誕生と使用:

  • Pollution by Cs-137:



>Top 2. How the radioactive materials polluted the environment:

  • The amount of radioactive materials emitted:
    • Japanese government reported to IAEA (International Atomic Energy Agency) the amount of Cs-137, most sensitive nuclear fuel product to human body, emitted in the air by the accident:
      • Hiroshima A-bomb emitted: $8.9\times 10^{13}$ Bq (Becquerel, decays/sec)
      • >Top Polluted Cs-137 by Fukushima N-plants disaster:
        total $1.5\times 10^{16}$; 168 times of Hiroshima A-bomb.
        (#1: $5.9\times 10^{14}$; #2: $1.4\times 10^{16}$; #3: $7.1\times 10^{14}$)
      • The northern temperate westerlies blows out these nuclear fall-outs to the Pacific Ocean; more amounts of fall-out polluted not only the Pacific Ocean, but west coast of US, or almost around the earth.
      • Rain which washed away and contained radioactive materials is called 'Black Rain'; also the same title of famous Japanese movie describing fear of the black rain in 1989.
      • The same scene was repeated in Fukushima disaster, because it rained and snowed in the mostly contaminated area, particularly NW of Fukushima N-plants.
      • More than 100K people were forced to evacuate from that area.
      • After six years decontamination activities, J-government announced deregulation of yellow and blue painted areas and called the evacuators to return to their home, truncating support for evacuation; except the highly contaminated red zone.
      • The center street, called 'Nakadori' penetrates Fukushima prefecture from north to south along the valley between Abukuma mountains westward and Ohu mountains eastward; The polluted area painted blue runs along this valley; along which there are such cities as Date, Fukushima, Nihonmatsu, Koriyama city, Sukagawa, and Shirakawa are located.
      • The polluted area extends to Tochigi and Gunma prefectures, up to part of Saitama, and Tokyo. Most of these areas are similar or more polluted than the Radiation Controlled Area.
      • >Top 2011/Mar/11:Special measures law of 'Declaration of Nuclear Emergency Situation' was announced. But after 7 years, this special measures law has not yet terminated. (just like under the martial law situation) Or even after 100 years this law will not be terminated. Half life of Cs-137 is 30 years, which means it takes 100 years to make Cs-137 decrease in 1/10.
        • Even new born babies today will have to endure the continuation of declaration of nuclear emergency situation until 100 years future.
        • Ordinary people: 1 mmSV/y.

2. 放射性物質による環境を汚染:


  • Cesium-137 content: Bq per sq.m
  • Red zone:
  • Yellow zone:
  • Light green zone:
  • Light blue zone: 300-600K
  • Dark Blue zone: 100-300K
  • Violet blue zone: 60-100K
  • Gray green zone: 30-60K
  • >Top Cf: Radiation Controlled Area: (no water, no food, no toilet, no bed in the area) 40K

>Top 3. Radiation that our five senses could not feel:

  • Actual fall-out Cs-137 is estimated (by Nobuhiro Sawano): $2.4\times 10^{15}$ Bq.; 16% (weighted only 0.75 Kg)of all emitted Cs-137 from the disaster (weighted 4.7 Kg); the remained 84% is dropped in the Pacific Ocean.
  • Even a slight weight of radioactive material has polluted such wide area of east Japan.
  • If the radioactive materials had existed such amount as to be felt by human senses, it should have killed the person instantly.
  • >Top BEIR (Biological Effects of Ionizing Radiation), a committee of the National Research Council of USA. The BEIR Committee published a series of reports on the effects of ionizing radiation: BEIR III 1980, BEIR IV 1988, BEIR V 1990, BEIR Vi 1999, BEIR VII, Phase-1 1998, and BEIR VII, Phase-2 2006.
    • A comprehensive review of available biological and bio-physical data led the committee to conclude that the risk would continue in a linear fashion at lower doses without a threshold and that the smallest dose has the potential to cause a small increase in risk to humans. This assumption is termed the “linear-no-threshold” (LNT) model.
  • >Top ICRP (International Commission on Radiological Protection) of UK; 2007 recommendation:
    • ICRP considered possible challenges to its linear non-threshold model but concluded that for the purposes of radiological protection, it is scientifically plausible to assume that the incidence of cancer or hereditary disorders will rise in direct proportion to an increase in the equivalent dose in the relevant organs and tissues, below about 100 mSv.
  • >Top Historical Exposure Allowance (1900-2000):
    • The allowance constantly decreasing according to accumulation of scientific data.
    • In 1845, Wilhelm Röntgen, German physicist discovered X-ray and was awarded Nobel prize in 1901; but the knowledge of radiation was very poor, and not a few physicists were irradiated; Röntgen himself was died in 1923 due to cancer.
  • Dose limits recommended by ICRP Publication 103 Table 6:
    • Limit on dose from occupational exposure: 20 mSv/year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv.
      • After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy.
    • Limit on dose from public exposure: 1 mS/year. In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year.
  • Cesium may actually shift by weather; thus $\gamma$ radiation may shift accordingly.
  • >Top Existing exposure: (現存被爆)

3. 五感で感じない放射能:

Picture: by Misato Yuki

  • BEIR VII: 被爆のリスクは低線量に至るまで直線的に存在し続け、閾値はない。
  • ICRP:100mSv以下の線量では癌の疫学研究が放射線リスクの証拠を提供している。100mSvを下回る低線量域での癌・遺伝的影響の発生率は、組織の被爆量に比例して増加すると仮定するのが科学的に妥当。
  • 放射線許容量の変遷:


>Top 4. Responsibility of the present generation:

  • Most of the general public, including even participants to this forum, have not seriously faced with the truth of nuclear issue. The present adult generation should have some substantial responsibility about the Fukushima N-plants accident. But it is clear there is no responsibility for children; in addition such children are very sensitive to radiation exposure. (>Fig: Radiation Age dependency: rate of death by cancer caused by radiation)
    • Elder generation, who are responsible in promoting nuclear power, are ironically insensitive to radiation; they have less risk of becoming cancer due to radiation.
    • Younger generation, whose somatic cells division (mitosis) is quite active, have much more risk to become cancer due to radiation.
  • >Top Cs-134 (half life: 2.07y) and Cs-137 (half year: 30.17y:
    • Early period after the accident, radiation by Cs-134 is
  • Wide area of living people, everywhere such as land, forest, houses, food, and water, have been polluted by fall-out more than 40K Bq. per sq.m (=Radiation Controlled Area). Ordinary people are enforced to live in such area.
    • In Fukushima, there are many posters saying; 'Protect Fukushima from harmful rumors!'; But I wonder from what they are protecting.
    • But J-government decided to promote evacuators to return to their homes which are polluted less than 20 mSv/y with terminating support for evacuation (by Mar/2017). It is too risky to make people including younger generation return in the area of the level of Radiation Controlled Area.
    • Kosuke Hino, journalist of Mainichi Shimbun, wrote a book titled, "Abandoned people by the nuclear plants" in 2016.


4. 現世代の責任:


Picture: by Misato Yuki

cesiumdose cesiumshiftdose cesiumcumudose cancerdeath

>Top 5. History of nuclear development:

  • Dr. Hideki Yukawa of Kyoto University (!907-1981):
    • It is true that he had actively cooperated the N-bomb development project during WWII, though he participated anti-nuclear movement after WWII.
    • The general tidal current of militarism before 1945 was so strong that almost anyone could not resist it. Even general public expelled conscientious minorities who were against the war of being unpatriotic or ostracize them from the community.
  • After WWII, nationalistic Japan was totally changed; and chose to subordinate to US, remaining Japanese Emperor system by US strategic convenience.
  • Korea had been annexed by Japan for 35 years (1910/Aug/29 - 1945/Sep/9); Japan should have primary responsibility to terminate the vestiges of the Cold War ages after tragic Korean war between 1950-53; which is still unstable, or state of war continuing under Korean Armitice Agreement.
    • >Top Pu for N-bomb is made by operating a nuclear reactor. Japan has made 47 tons of Pu, which is equivalent to 4000 Pu bombs of Nagasaki.
  • The size of nuclear reactors and N-bombs:
    • Research Reactor Institute, Kyoto University: 5MWt (thermal)
    • Standard size of N-plant: 1MkWh=1GWh=3GWt; 40 N-plants total 40GWh
    • North Korean Nyeongbyeon reactor: 25-30Mt
    • N-bombs is bad, all the more reason, which should not be allowed to use.
  • Japan is a nation of obedient to the stronger (typically under N-umbrella), while domineering to the weak.
    • Nuclear village comprised of major nuclear industry and related industries.
    • No one takes responsibility of the Fukushma N-plants accidents.
  • Last message: "As I've been involved in nuclear research, it is my responsibility to send the message what I've known about the status of nuclear development... I don't want to be called a prewar generation. Each one of us should recognize his or her own responsibility and take proper actions. I don't want to make children experience a war."

5. 文字的矛盾:


>Top 6. Q&A:

  • Q: Japanese Nuclear Regulatory Commission proclaims that Japanese regulatory requirements for nuclear restriction is the severest one in the world. Is this correct?
    • A: It is not the world severest one. They want to make 'Safety guideline' instead. After the Fukushima accident, they could say 'safety of N-plant' any more. Regulatory requirement is a kind of criterion of abiding. J-NRC says that the acceptance criterion of the guideline does not mean that the reactor is safe. (2015/Jul/16)
    • Europe has severer guideline which requires a core catcher to catch the meltdown debris, second container covering the containment reactor, as well as establishing evacuation plan.
  • Q: Is the present food or tap water is safe to intake? What about the agriculture products made in Fukushima?
    • A: Unfortunately contamination has already widely spread worldwide by the continuous atmospheric nuclear tests (accumulating 60 times of Fukushima's emission), and some part of Tohoku and Kanto area were seriously contaminated due to the accident. It is a very difficult issue how to treat the product of Fukushima. At the case of Chernobyl accident, many Japanese called for ban on imports from Chernobyl area. In my opinion, I wonder wheather Japan could ban the import while continues to operate N-plants. After all the contaminated product may be exported to poorer countries. I rather insisted to import the products from Chernobyl, and to consider seriously contaminated foods and discuss how to treat them as a country promoting nuclear energy actively. And this time the Fukushima accident happened. Farmers of Fukushima have no option but to continue to farm there. I'd propose that the contaminated food should be eaten by the people who have promoted nuclear energy. Then, I'd propose a certain age prohibited food like the adult movie; foods with 60 age prohibited, 50 age prohibited, and so on subject to strict radiation monitoring.
  • Q: How do you think an opinion claiming not to inflame public anxiety about radioactive contamination?
    • All data shown today is not made by me, which is the published data by J-government. And all criteria shown are all Japanese laws. Is it an act of inflaming an unnecessary anxiety to explain the fact made by J-government? I believe we should face to the fact straight which sounds even the severest one, than to neglect them.
  • Q: >Top What is the possibility to control the nuclear and radiation by ourselves?
    • We couldn't control the nuclear, because the accidents happened. Regarding radiation, it is the capability material emitting radiation. It is a physical property of some unstable nuclei which tend to convert to other atoms by radioactive decay. It is the essential scientific subject to control, eliminate, or detoxicate such radioactive decay; since 1942, various challenges of detoxication research have done, aiming to explore new alchemical solution; but not successful yet spending almost 75 years.
    • Nuclear waste was globally banned to launch it to space or bury it in the Antarctica. The site for the underground disposal plan for so many years (100K years or more) could not be accepted by any local governments in Japan.

6. Q&A:

N-plant capacity:


Neucreal arsenal:nbombcapacity

  • >Top It is our duty for us to review and reflect the situation of Fukushima accident time to time. It became a new peccatum originale for humans like opening the Pandora's Box.
  • There had been possibility of debate of pros & cons about N-plant, at least before Mar. 2011; but all debates were subject to perfect confinement of nuclear materials within the container, which should not be leaked or broken out. But it did! It became a homework which could be solved spending nearly 100K years.
  • 福島事故を時折レビューすることは我々の義務だと思う。パンドラの箱を開けてしまった以上は..
  • 2011年3月以前は、原発に関する功罪を議論する可能はあったが、全ての議論は格納容器に完璧に封じ込めることが可能であるという前提での議論だった。しかし実際にはそうならなかった。核物質の完璧な閉じ込めが前提の議論だった。そうはならず、10万年かけて解決しなければならない宿題を残した。

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