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2017年11月 4日 (土)

Inquiries and answers about keeping Japanese nationals secure from risks of Nuclear power plants such as losing security functions after a big earthquake. 2006

I am sure that these documents of inquiries by the diet member Hidekatsu Yoshii and of answers by the prime minister Shinzo Abe about a security of Nuclear power plants hit by big earthquakes, issued in 2006, are very important historical documents in an our human society.

So, I am sure that it should be shared widely and I dare to translate them into English here despite of my poor ability of using this language.
I hope someone who find this page in future will correct my mistakes and use the information for study, research and so on.




提出者  吉井英勝

Submitted on December 13 of 2006
Inquiry No.256
Inquiries about keeping Japanese nationals secure from risks of Nuclear power plants such as losing security functions after a big earthquake.
Submitted by Hidekatsu Yoshii

Inquiries about keeping Japanese nationals secure from risks of Nuclear power plants such as losing security functions after a big earthquake.



The Japanese government admitted that there were nuclear power plants which would be unable to get cooling water for nuclear reactors and for the system to cool nuclear fuel rods that are not being used for making electricity when the sea level went down because of backwash of Tsunami caused by big earthquake



Losing power sources for equipment of nuclear power plants caused by big earthquake is also a great problem. Furthermore, there seems to be a movement to permit setting up new nuclear power plants in which film boiling envelope nuclear fuel rods for a short time to result in insufficient cooling. Credibility of Japanese nuclear power plants has been deteriorating because of successions of forgeries of data and false reports, though accuracy of data and those reports are necessary to assess whether the plants clear the safety standards. It is necessary to make clear these matters, to guarantee safety of residents from risks inherent to nuclear power plants,.



Wherefore as above, I ask as follows,


一 大規模地震時の原発のバックアップ電源について
1   Backup power supply of nuclear power plants in a case of big earthquakes


 1 原発からの高圧送電鉄塔が倒壊すると、原発の負荷電力ゼロになって原子炉停止(スクラムがかかる)だけでなく、停止した原発の機器冷却系を作動させるための外部電源が得られなくなるのではないか。


When high-voltage power transmission towers fall, the loss of load power does cause not only reactors shutdown but also impossibility of getting electricity from external power sources to function cooling system of the reactors, does not it?



Are there any nuclear power plants that have multiple routes to external power supply even in the above cases? If there were, show the list of the plants.



In Japan, there was a case in which a high-voltage power transmission tower for nuclear power plants fell down. Show the case and clarify the cause of the accident.


 2 落雷によっても高圧送電線事故はよく起こっていると思われるが、その結果、原子炉緊急停止になった実例を示されたい。


I guess that falling of the thunderbolt often causes accidents of high-voltage power transmission cable. Show the cases of nuclear reactor emergent shut down caused by falling of the thunderbolt.


 3 外部電源が取れなくても、内部電源、即ち自家発電機であるディーゼル発電機と無停電電源であるバッテリー(蓄電器)が働けば、機器冷却系の作動は可能になると考えられる。


Without any external power supply, cooling system can function if internal power supplies, those are, a diesel power generator as an independent power generator and a storage battery as an uninterruptible battery system, work.



It is absolutely indispensable for nuclear power plants to maintain power supply for cooling system in order to remove decay heat from nuclear fuel rods in reactors which are shut down because of a large scale earthquake. In the past, there must be nuclear power plants accidents in which backup power supply did not work. Show the cases of the past.


 4 スウェーデンのフォルクスマルク原発1号(沸騰水型原発BWRで出力一〇〇・八万kw、運転開始一九八一年七月七日)の事故例を見ると、バックアップ電源が四系列あるなかで二系列で事故があったのではないか。


In the accident case of number 1 power reactor of Forsmark nuclear power plants in Sweden (Boiling water reactor, 1008000 kw. Operation started on July 7 of 1981), two of four backup electricity supply systems had trouble, did not they?



Furthermore, each of the backup supply systems of the plants had both a diesel generator and a battery. In the two troubled system, both the diesel generators and the batteries couldn’t work, could they?


 5 日本の原発の約六割はバックアップ電源が二系列ではないのか。仮に、フォルクスマルク原発1号事故と同じように、二系列で事故が発生すると、機器冷却系の電源が全く取れなくなるのではないか。


60% of nuclear power plants in Japan have dual backup power supply systems, do not they? If accidents occurred in both backup systems just as in the Forsmark case, no electricity can be supplied to cooling system. Is it right?


 6 大規模地震によって原発が停止した場合、崩壊熱除去のために機器冷却系が働かなくてはならない。津波の引き波で水位が下がるけれども一応冷却水が得られる水位は確保できたとしても、地震で送電鉄塔の倒壊や折損事故で外部電源が得られない状態が生まれ、内部電源もフォルクスマルク原発のようにディーゼル発電機もバッテリーも働かなくなった時、機器冷却系は働かないことになる。


When a nuclear power plants shut down occurred because of a large scale earthquake, cooling system should function to remove decay heat. Even when sea level was enough to get water for a cooling system fortunately, the cooling system could not work if an internal power supply was lost just as in the Forsmark case and if external power supply form diesel generators and batteries was lost because of a falling or breakage accident of transmission tower caused by the earthquake.



In such a case, what would happen to nuclear reactors? Has the Nuclear Safety Commission examined safety of each nuclear power plant all over Japan one by one?



What kind of examinations has the Nuclear and Industrial Safety Agency done on each nuclear power plant about these problems? Show details of the examinations.


 7 停止した後の原発では崩壊熱を除去出来なかったら、核燃料棒は焼損(バーン・アウト)するのではないのか。その場合の原発事故がどのような規模の事故になるのかについて、どういう評価を行っているか。


If we cannot remove decay heat after nuclear reactors shut down, will not the nuclear fuel rods burn out? After nuclear fuel rods burn out, what level of nuclear accident is estimated to follow?


 8 原発事故時の緊急連絡網の故障という単純事故さえ二年間放置されていたというのが実情である。ディーゼル発電機の冷却水配管の減肉・破損が発生して発電機が焼きつく事故なども発生した例が幾つも報告されている。一つ一つは単純な事故や点検不十分などのミスであったとしても、原発の安全が保障されないという現実が存在しているのではないか。


The Nuclear and Industrial Safety Agency had neglected for two years even a simple breakdown of emergency contact network. Reported are some accidents in which thinning or breakage of pipes for cooling water of diesel electric generators resulted in the generators burnt out. Though these were simple accidents or results of merely incomplete inspections, it is enough to say that there is a reality nobody can secure safety of nuclear power plants in Japan, isn’t it?


二 沸騰遷移と核燃料棒の安全性について
2  Boiling transition and safety of nuclear fuel rods


 1 原発運転中に、膜沸騰状態に覆われて高温下での冷却不十分となると、核燃料棒の焼損(バーン・アウト)が起こる。焼損が発生した場合に、放射能汚染の規模がどのようなものになるのかをどう評価しているか。原子炉内に閉じ込めることができた場合、大気中に放出された場合、さらに原子炉破壊に至る規模の事故になった場合まで、それぞれの事故の規模ごとに、放射能汚染の規模や内容がどうなるかを示されたい。


If nuclear fuel rods were covered with film boiling and cooling of the rods in high temperature became insufficient inside an operating nuclear power plant, the nuclear fuel rods would burn out. In the case of nuclear fuel rods burn out, what level of radiation contamination is supposed to happen? Show estimation of each case below. 1) the case in which there is no emission of radiation. 2) the case in which radiation emitted. 3) the case in which a nuclear reactor is destroyed.


 2 経済産業省と原発メーカは、コストダウンの発想で、原発の中での沸騰遷移(Post Boiling Traditional)を認めても「核燃料は壊れないだろう」としているが、この場合の安全性の証明は実験によって確認されているのか。


Both the Ministry of Economy, Trade and Industry and manufacturers of nuclear power plants, thinking of cost reduction, assume that “nuclear fuel rods will not be destroyed” even when Post Boiling Transition occurred in nuclear power plant. Has their assumption been proved by experimentations?



Until now, when a manufacturer submitted an application for permission of installation of a nuclear reactor in which Post Boiling Transition may occur, the government has required a confinement function and has set a condition that Post Boiling Transition must not occur. From now on, when manufacturers apply for permission of new nuclear power plants, will you change the former policy and permit a nuclear reactor in which Post Boiling Transition may occur?


 3 アメリカのNRC(原子力規制委員会)では、TRACコードでキチンと評価して沸騰遷移(PBT)は認めていないとされているが、実際のアメリカの扱いはどういう状況か、またアメリカで認められているのか、それとも認められないのか。


The Nuclear Regulatory Commission of the United States of America is said not to permit Post Boiling Transmission in accordance with an accurate evaluation under TRAC code. How is the real situation in the United States? Is Post Boiling Transmission permitted in the United States?



How do other countries, such as European countries, deal with this matter?


 4 東通原発1、2号機(着工準備中、改良型沸騰水型軽水炉ABWR、電気出力一三八・五万kw)については、「重要電源開発地点の指定に関する規程」(二〇〇五年二月一八日、経産省告示第三一号)に基づいて、〇六年九月一三日に経済産業大臣から指定され、九月二九日に原子炉規制法第二三条に基づいて東通原発1号機の原子炉設置許可申請が国に出された。この中では、沸騰遷移が想定されているのではないのか。


Regarding to No.1 plant and No.2 plant of Higashidori Nuclear Power Plants (preparing construction. Advanced Boiling Water Reactors. Generating power; 1,385,000 kw), the plants were designated by the minister of Economy, Trade and Industry under the official rules by “the Rule of an important point for developing sources of electricity (announced on February 18 of 2005, METI’s 31st announcement of 2005 )” on September 13 of 2006, and on September 29 of 2006 an application for permission to install a nuclear reactor into the No. 1 plant of Higashidori Nuclear Power Plants was submitted to the government under the article 23 of the Nuclear Reactor Regulation Act. In this application, Post Boiling Transmission is supposed to occur, isn’t it?


 5 ABWRでは、浜岡5号機や志賀2号機などタービン翼の破損事故が頻発している。ABWRの東通原発が、沸騰遷移を認めて作られた場合に、核燃料が壊れて放射性物質が放出される事態になる可能性は全くないと実証されたのか。安全性を証明した実証実験があればその実例も併せて示されたい。


Breakage accidents of turbine blades have occurred very frequently in No.5 plant of Hamaoka Nuclear Power Plants and No.2 plant of Shiga Nuclear Power Plants those are equipped with Advanced Boiling Water Reactors. Higashidori nuclear power plants also will be installed with Advance Boiling Water Reactors. Is it proved through experimentations that there is no possibility of emitting radiation caused by damages of nuclear fuel rods in Higashidori Nuclear Power Plants even if occurrence of Post Boiling Transmission was allowed in its reactors? If there were experimentations that demonstrate safety, show those cases.



Is it a view of the government that there are no problems to be concerned?


三 データ偽造、虚偽報告の続出について
3. Succession of forged data and false reports


 1 水力発電設備のダム測定値や、火力・原発の発電設備における冷却用海水の温度測定値に関して測定データの偽造と虚偽報告が電力各社で起こっていたことが明らかになった。総ての発電設備について、データ偽造が何時から何時までの期間、どういう経過で行われたのか明らかにされたい。


It has been brought to light that electric power companies have forged and reported mendacious data of temperatures of cooling seawater for generators of steam or nuclear power plants, and measurements of hydroelectric dams.
Disclose information of all power plants respectively about periods of the forgeries, when started and when ended, and how the forgeries went on.

 2 こうしたデータ偽造と虚偽報告は、繰り返し行われてきた。使用済核燃料の輸送キャスクの放射線遮蔽データ偽造、原発の溶接データ偽造、原子炉隔壁の損傷データ偽造とデータ隠し、配管減肉データ偽造、放射線量データ偽造など数多く発生してきた。日本の原子力発電が始まって以来の、こうした原発関連機器の測定データや漏洩放射線量のデータについての偽造や虚偽報告について年次的に明らかにされたい。


Forging data and reporting falsehood have occurred repeatedly, such as forging data of radiation shielding of casks for transportation of a spent nuclear fuel, forging data about welding in nuclear power plants, forging and hiding data about damage on a partition wall of nuclear reactor, forging data of thinning of piping, forging data of radiation dose, and so on. Show all the information about forgery and the false reports related to nuclear power plants and about leakage of radiation since the beginning of history of nuclear power generation in Japan annually.

 3 原発の危険から住民の安全を守るうえで、国の安全基準や技術基準に適合しているのかを判断する基礎的なデータが偽造されていたことは重大である。そこで国としては、データ偽造が発覚した時点で、データが正確なものか偽造されたものかを見極める為に、国が独自に幾つかのデータを直接測定するなど検査・監視体制を強化することや、データ測定に立ち会って測定が適正かどうかのチェックをすることが必要である。国は、検査・監視体制を強化したのか、またデータ測定を行う時に立ち会ったのか。


It is crucial that fundamental data which were essential to judge plants conformity with national safety and technical standards, concerning protection of residents from risks of nuclear power plants. If forgery of data were revealed, it is necessary for the government to strengthen checking and monitoring system, taking an accurate measurement of data independently by itself, or standing by measurement of data to check whether it is done properly or not. Has the government strengthen checking and monitoring system? Have the government officers stood by measurement of data?


Why has the government over looked those repeating forgery for such a long time?



As above I inquire.


Received on December 22, 2006
Reply No. 256



December 22, 2006


内閣総理大臣 安倍晋三
Prime Minister Shinzo Abe


       衆議院議長 河野洋平 殿
To the Chairperson of the House of Representatives, Yohei Kohno



I send an annexed reply paper to the inquiries by the diet member Hidekatsu Yoshii, about keeping Japanese nationals secure from risks of Nuclear power plants such as losing security functions after a big earthquake.


Reply paper to inquiries by a diet member Hidekatsu Yoshii keeping Japanese nationals secure from risks of Nuclear power plants such as losing security functions after a big earthquake.


To 1-1


In my nation Japan, facilities with nuclear reactor related to practical power generation, hereinafter referred to as ‘nuclear reactor facilities’, are designed to be connected to external power supply system via at least two power lines. Furthermore, as to structures, systems and machines which need electricity to fulfil their highly important safety functions, they are designed to get electricity from both external power sources and internal emergency power sources inside nuclear reactor facilities. So, even when it became impossible to get electricity from external power sources, it is possible to cool down nuclear reactors which were shutdown using electricity from inside nuclear reactor facilities.



To speak of nuclear reactor facilities which can get electricity from external power supply even when one of high-voltage power transmission towers falls, it is exemplified with No.1 reactor of Tomari power plants of Hokkaido Electric Power Company Inc.



Though I am not sure what you meant by ‘a case in which a high-voltage power transmission tower for nuclear power plants fell down’, an accident in which a power transmission tower connected to nuclear reactor facilities fell down occurred in Hakui City of Ishikawa prefecture on April 1 of 2005. In that case, one of transmission towers of main line named Noto Kansen that was connected to Shiga nuclear power plants of Hokuriku Electric Power Company and other facilities, fell down because of a landslide.


To 1-2


The recent case of nuclear reactor emergent shut down caused by an accident of power transmission cable resulted from falling of the thunderbolt was a case of No. 1 reactor of Tsuruga electric power plants of the Japan Atomic Power Company on December 19 of 2003..


To 1-3


In my nation Japan, there was no case in which troubles of diesel power generators for emergency use have resulted in nuclear reactor shut down. There was no case in which cooling functions of nuclear power plants had got lost due to a loss of necessary electricity sources.


To 1-4


I recognize as below; In No.1 power reactor of Forsmark nuclear power plants in Sweden at around 13:19 on July 25 of 2006 (local time), an operation error occurred when maintenance work was conducted, then a generator was disconnected from transmission lines and a supply of electricity got lost. After that, they could not switch to another external power supply and a safeguard of batteries started to function because of a set up error. Therefore 2 of 4 diesel generators for emergency use connected to the safeguard did not boot up automatically.


To 1-5


In my nation Japan, though only 33 of 55 operating nuclear reactor facilities have 2 diesel power generators for emergency use, all the nuclear reactor facilities in my nation Japan respectively have multiple storage batteries and multiple diesel power generators for emergency use, multiple lines to external power supply.



In addition, as nuclear reactor facilities in my nation Japan are designed differently from No.1 reactor of Forsmark nuclear power plants. So, it is unthinkable that the same situation of the Forsmark nuclear power plants occur in Japan.


To 1-6


On each application for installation or change of nuclear reactor, the safety of nuclear reactors including countermeasures against natural disasters such as earthquakes and tsunami has been examined by METI (Ministry of Economy, Trade and Industry) referring to guidelines such as ‘Examination Guideline of safety design related to light-water nuclear reactor facilities for power generation’ (decided by Nuclear Safety Commission on August 30 of 1990), and the appropriateness of those examinations by METI have been confirmed by Nuclear Safety Commission. I take all the possible measures to ensure safety in order to prevent the occurrence of the situations you pointed out.


To 1-7


Though METI has not estimated what you asked, it takes all the possible measures to ensure safety in order to prevent the occurrence of the situations where nuclear reactors cannot be cooled down.


To 1-8


Regarding to equipment which are important for aiming safety of nuclear reactor facilities, examinations and inspections by laws and regulations are done strictly. Through such procedures, I will take all the possible measures to ensure safety of nuclear power.


To 2-1


Though METI has not estimated what you asked, it takes  all the possible measures to ensure safety in order to prevent the occurrence of the situations where nuclear reactors cannot be cooled down.


To 2-2


To talk about an estimation of safety of Post Boiling Transition of fuel inside nuclear reactors, Special Sectional Meeting for Nuclear Safety Standard and Guideline inside Nuclear Safety Commission produced a report (‘Report of the sectional meeting to Estimate fuel’s soundness after Post Boiling Transition’. Hereinafter, ‘the Report.’) which was based on the results of various experimentations and other things on May 19 of 2006, and Nuclear Safety Commission acknowledged it on June 29 of 2006.


With regard to an application for permission of installation of a nuclear reactor in which Post Boiling Transition may occur, the application will be examined under various guidelines of Nuclear Safety Commission including the Report mentioned above to confirm safety.


To 2-3


Although the government does not grasp in detail the treatment of Post Boiling Transmission of fuel in nuclear reactors in other countries, it is written in the Report that a document of safety assessment of Advanced Boiling Water Reactor (ABWR) by the Nuclear Regulatory Commission of the United States of America has a description saying soundness of fuel rods is kept in Post Boiling Transmission under a certain condition. It is also written in the Report that in Germany electric power companies and others are proposing a technical standards to permit Post Boiling Transmission.


To 2-4


I recognize that, in an application document for a permission of installation of nuclear reactor into Higashidori Nuclear Power Plants of Tokyo Electric Power Company, it is designed to permit an occurrence of a temporary Post Boiling Transmission compliant to the standard of soundness of fuel after Post Boiling Transmission written in the Report


To 2-5


Safety of nuclear reactor facilities related to Higashidori Nuclear Power Plants of Tokyo Electric Company is being examined by various guidelines including the Report.


To 3-1 and 3-2


It is difficult to answer the question because enormous works such as investigation and data filing are needed. I can say that METI is now requiring general electric enterprises, the Japan Atomic Power Company and Electric Power Development Co., Ltd. to check whether there are forgeries of data and deficiencies or defect of necessary procedures.


To 3-3


Electricity enterprises are obliged to be inspected by the government periodically about their compliance to the safety regulations. In 2003 quality assurance was clearly stipulated by law as a matter that the enterprises should define in their safety regulations.


As what you call ‘Measurement of data’ may include various contents, it is difficult to answer generally. For example, on periodic inspection under the article 54 of the Electricity Business Act , electric facility inspectors should stand by during a Periodic Operator's Inspection or should confirm a report of the inspection.



As it is not entirely clear what it means by “over looked … for such a long time”, it is difficult to answer. Regarding to equipment which are important to guarantee safety of nuclear reactor facilities, examinations and inspections by laws and regulations are done strictly. Through such procedures, I will take all the possible measures to ensure safety of nuclear power.