Science,English,and math １１th
I will start from now on
パート⑧になります。よろしくお願いします。
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Continuation on the last response of Science, math and English 10th. ありがとう、メイちゃん
【Absorbing radioactive material with sunflower】
《Taking advantage of bacteria and decreasing the cubic volume on the radioactive waste》
…so we have to collect the plant and to dispose of it. The expert has a plan of making bacteria dismantle the collected plant, so the plant in which hydrogen, carbon, and oxygen almost account for is dismantled quickly, and is changed into water and carbon dioxide. Mineral which was in the plant remains.
Cesium 137 could has been included in the mineral, so making the…
- << 3 I am glad I was of help to you.😉
【Absorbing the radioactive material with sunflower】
《Making use of bacteria and reducing the cubic volume on the radioactive waste》
…so making the cesium with concrete and disposing of it safely as radioactive waste.
But there are still lots of problem actually.
For example, there are the people who are engaged in the series of work and they are forced to be exposing to radiation, and lawful regulation on the radioactive waste which occurs finally isn’t done yet.
The expert says as time passes, the radioactive material in the soil spreads, so the pollution circulates, so we have to…
＞＞2
…so we have to move forward with the plan quickly.
【An instrument on measuring radioactivity】
《Survey meter》
The instrument measuring radioactivity has began to paid attention due to the accident in the atomic power plant. Inspection against workers who are engaged in the atomic power plant or agricultural products. Lots of people must have looked at it on TV.
How do they measure the invisible radioactivity? Let’s look at the mechanism on the instrument measuring radioactivity.
Survey meter which is the instrument measuring the radioactivity has some kinds, according to the way of
【An instrument measuring radioactivity】
《Survey meter》
Survey meter has some kinds, according to the way of detecting radioactivity.
The ones which are frequently adopted is four, GM, scintillation, ionization container, and semi conductor.
The kind and strength on the radioactivity is different on each of four instruments, and applying for the goal of measuring pollution on the surface, or the amount of radiation on individual, and an appropriate instrument is adopted.
Those instruments measuring radioactivity is changing the radiation into electric flow and measuring. It’s common in…
【An instrument measuring radioactivity】
《Survey meter》
Four instruments measuring radioactivity are in common on changing the radioactivity into electric current and measuring, but the way of changing is different.
GM and scintillation have appeared in a news report sometimes, so lots of people may have looked at them. Each of shape looks alike, but it’s structure is different so much.
Radiation makes the air in the measuring instrument ionize. Ionization is something electric neutral is divided into plus pole and minus pole. Flow on ionization is detected as electricity. It’s the GM.
【An instrument measuring radioactivity】
《Survey meter》
On the other hand, scintillator has nature emitting light when radiation exposes. The nature has been made use of in the scintillator, so the radiation goes into the scintillator, and is changed into the light, and the light is changed into electricity, finally it’s detected as electricity.
GM is adopted mainly so as to detect pollution on the surface of material.
On the other hand, how much is exposed to radiation if being in the place? Scintillation detects the amount of radiation in the air.
There is difference on the way of adopting. The author said he is going to express it and the concrete way of measuring in detail from now on.
【At the atomic power disaster, measurement was done according to a manual on measurement in emergency】
Radioactive material was released owing to the accident in the nuclear power plant and its pollution becomes problematic.
Various inspections have been done and is reported almost daily. Whether or not the radioactive material is attached to or is mixed in agricultural products like vegetable or livestock products like milk, or there are people who…
【At the atomic power disaster, measurement was done according to manual on measurement in emergency】
…or there are people who live in an evacuative area went home at one time, or others who were engaged in the atomic power plant. The same inspections were done on those people.
The way of measuring pollution and procedure has been fixed as manual on measurement in emergency on the atomic power plant accident like this time.
Precise and huge measuring apparatus is indispensable originally so as to measure the amount of pollution by the radioactive material, but when being in emergency…
【At the nuclear power disaster, measurement was done according to manual on measurement in emergency】
…but when being in emergency, a portable measuring apparatus is adopted, and making sure the polluted situation, and close measurement is done on the pollution which is worried about being beyond average level.
In this case, the measuring instrument is sometimes adopted for different use which is different from the original way of using. What’s difference between the way of using the measuring apparatus?
《Using measuring way depending on a goal》
GM is abbreviation on Geiger Muller counter
【At the nuclear power disaster, measurement was done according to manual on measurement in emergency】
《Using measuring way depending on a goal》
GM is inexpensive and is highly sensitive, being able to observe low amount of radiation. It’s measured the number the radiation went into the apparatus. How many times does go into the apparatus?
We’ve heard of the unit on sievert, but measuring the pollution by the unit which considering the influence over the human body isn’t accurate. The radiation which is detected is gamma rays.
On the other hand, scintillation is expensive, but…
【At the atomic power disaster, measurement was done according to manual on measurement in emergency】
《Using measuring way depending on a goal》
…but being able to measure the amount of radiation and the scale of energy with high sensitivity. Moreover, the result on measurement is able to be converted into the unit of sievert. The apparatus calculates automatically, and the numerical value is shown with the unit on sievert. Gamma rays are detected mainly.
How much being exposed to radiation in a place? Usually adopting gamma rays of which ability of permeating power is strong so as to measure
【At the atomic power disaster, measurement was done according to manual on measurement in emergency】
《Using measuring way depends on a goal》
So scintillation which is higher sensitivity than gamma rays is adopted so much. When measuring the pollution on the surface, measuring beta rays. If measuring the gamma rays, it’s hard to distinguish the one in the air from the gamma rays, so the GM is adopted.
When there is radiation in the air, the ionization container can measure electricity, so more precise measurement on the amount of radiation becomes possible. Its detail is later.
【At the atomic power disaster, measurement was done according to manual on measurement in emergency】
《Using measuring way depending on a goal》
The ionization container isn’t appropriate for detecting low amount of radiation, but measurement on high radiation is possible. On the other hand, neither GM nor scintillation detect the high radiation.
In general, in the facility of atomic power plant or monitoring post on radiation, there are both of measuring apparatus of scintillation and ionization container. When the amount of radiation becomes high temporarily in the facility….
【At the atomic power plant disaster, measurement was done according to a manual on measurement in emergency】
《The way of measuring is uded depending on a goal》
When the amount of radiation becomes high temoprarily in the facility, the meter on apparatus on scintillation shook off, so the numerical value was measured by the ionization container then.
The one in which a semi conductor was adopted has low sensivity on the radiation, but it's so small that it has been used as personalas dosimeter 線量計. The dosimeter can measure how much a person is exposed to the radiation.
【Measurement is done according to a manual in emergency】
《Measurementis used depending on a goal》
The apparatus on the scintillation is originllay used so as to measure the amount of the radiation in the air, but the sensitivity on the gamma rays is so hight the way of measuring the radiation on food is described.
For example, as to the ionization container, measuring on pollution to food in which there is low radiation isn't suitable, moreover, as to the GM, the sensitivity to the gamma rays is so low that it isn't more suitable than the scintillation.
【Measurement is done according to a manual in emergency】
《We should chop vegetabel and put a detector in milk》
Can ordinary people who don't have any expert knowledge like us use the apparatus on measurement actually? It seems too hard, the author says like that.
The way of measuring is fixed minutely according to the manual in emergency. Leafy vegetable has to be shredded and to be stuffed in a container without any space.
When measuring milk, the tip on the apparatus has to be put into the depth by 10 centimeters, for the amount of radiaiton changes if there is different distance ...
【Measurement is done according to a manual in emergency】
《Vegetable is shredded and put the detector into the milk》
... for the amount of radiation changes if there is difference on distance from the radioactive material, so without using the same way of measuring, the result on measurement could change.
《Even if applying for the surface, we can't see its content》
Measuring the radiation on the surface of vegetable, it seems to be done on TV. Is it useless?
Roughly speaking, we can see whether or not there are a large amount of radioactivity, and is useful to judge whether or not the...
【Measurement is done according to a manual in emergency】
《Even if applying for the surface, we can't see its content》
...and is useful to judge whether or not the radioactive material is attaced to the surface, but it's limited to the pollution on the surface.
For example, if the radiation is taken into the vegetable, even if inspecting the surface, no one can how much the radiation is included, and the liquid like milk is the same.
As a result, the radioactive material was released in the disaster this time, as to the one of which surface the radioactive material is attached to, we can...
【Measuremen is done according to a manual in emergency】
《Even if applying for the surface, we can't see its content》
...we can't see an exact amount of radiation even if measuring the surface alone.
The government announced the amount of radiation on food, a precise measurement on the food in which there is fear on pollution seems to be done.
After the accurate measurement is done we can discuss whether or not there is a large amount of radioactivity against the criterion value.
We've heard the mumerical value on measuremnt, so we have to judge whether or not it's measured precisely.
【What is the atomic power?】
After the disaster in the atomic power plant in Fukushima, we've paid attention to the nuclear power generation so much. How should we face the nuclear power generation?
It is about time we discuss in the whole country, so scientific knowledge on the nuclear power generation is indispensable than any other thing.
How is the fuel for the atomic power generation made? What is the mechanism which takes energy from the atomic nucleus? What is pluthermal? Radioactive waste is called the nuclear waste. How is it disposed of?
What is the atomic power?
The author said he was going to interpret the atomic power from the foundation.
【What is the atomic power generation?】
《How is electricity is made in atomic power plant？》
Buring coal and petroleum and water is boiled. Making the power on vaporation rotate a turbine which links to the generator, so the electricity is made.
Making the turbine rotate by steam and the electricity is made in the atomic power plant, so basically, it's the same with a thermal power generation. Then what's difference between the two of the electric power plants? It's a heat source heating water.
【What is the atomic power generation?】
《How is electricity made in the nuclear power plant?》
Uranium is used in the atomic power plant as fuel. The fuel is 燃料 in Japanese, but it doesn't mean actually that uranium is burned. Making use of phenomenon of nuclear fission, and heating water and boiling it.
The nuclear fission is the phenomenon in which an atom is broken and other atom is made.Then a large amount of energy is produced.
Making the uranium cause the nuclear fission in a container called atomic reactor and the heat is caused.
As none of material is burned, carbon dioxide isn't...
【What is the atomic power generation?】
《How is electricity made in the atomic power plant?》
...carbon dioxide which causes global warming isn't made.
On the other hand,the fault on the atomic power generation is a large amount of radioactive material is made. Being careful of safety so as to prevent the radioactivity from leaking outside in the atomic power plant.
When something unusual breaks out like a great earthquake, stopping operating the atomic reactor automatically, and cooling down at once,still more, shutting up the radioactive material. Adopting multiple safeguard is done in...
【What is the atomic power generation?】
《How is electricity made in the atomic power plant?》
Adopting multiple safeguard has been done in the atomic power plant.
As to shutting up the radioactive material,five protective wall is prepared.
1 A pellet for fuel which uranium is burned and solidifying.
2 A metallic cladding tube which shuts up the pellet.
3 A steel pressure vesse of which thikcness is 16 centimeters stores the nuclear fuel.
4 A container vessel which stores the steel pressure vessel.
5 A building made of reinforced concrete of which thickness is 2 meters covering the...
【What is the atomic power generation？n？】
《How is electricity made in the atomic power plant?》
The building made of reinforced concrete of which thikcness is 2 meters covers the container vessel.
Even if an disaster happens to break out, trying to make its damage minimize as less as possible with those five protective wall, but those walls were damaged by the great earthquake in Tohoku region this time and the unprecendented nuclear disaster broke out in the atomic power plant in Fukushima prefecture.
【The whole image on the atomic power generation】
《Natural uranium which is nuclear...》
【The whole image on atomic power generation】
《Natural uranium which is nuclear fuel has been mined each country all over the world》
Uranium which has been made use of fuel in the atomic power plant is one of metallic elements. There are several uranium, and there is the one of which atomic nucleus divides. When the atomic nucleus divides, a large amount of energy is produced, and taking advantage of the large amount of energy for electricity generation is the atomic power generation.
The natural uranium exists in the rock as chemical compound with oxygen. Uranium ore including the...
【The whole image on the atomic power generation】
《Natural uranium which is a nuclear fuel is mined each nation all over the world》
Uranium ore which includes the natural uranium has been mined in uranium mine all over the world.
The amount of deposit on uranium at the uranium mine in the world is estimated some 630 ton in 2009,according to International Atomic Energy Agency. It has been thought the amount of deposit has been atopted in the world for a hundred years.
《The power generation is possible with a small amount of deposit, but there is a problem》
The uranium fuel which is used...
【The whole image on the atomic power generation】
《Power generation is possible with a small amount, but there is a problem》
The uranium fuel which is used for the atomic power generation is a small amount extremely.
Let's suppose that there was an electric power plant of which ability on generating electricity of a million watt. It's equal to a single atomic reactor. The fuel which makes the electric power plant operate for a year is some 1.5 million ton of petroleum. But if it's uranium, it's no more than 21 ton.
The prblem on the atomic power generationis the spent nuclear fuel after...
【The whole image on the atomic power generation】
The problem on the atomic power generation is the spent nuclear fuel after the power generation using the uranium fuel, for the spent nuclear fuel has lots of radioactive material which is harmful to the human body, so we have to pay cloes attention when dealing with it.
『Uranium which has spread over in wide range all over the world』
Uranium is one of metallic elements discovered in 1789. Uranus which is a planet was discovered in 1781, and Uranium was named after Uranus. Uranium exists in the rock broadly in the natural world as oxide
【The whole image on the atomic power generation】
『Uranium which speads in wide range all over the world is an element』
When ultraviolet rays shine on the uranium as oxide, it glows green. When appraising or probing, the nature of glowing green is made use of.
In addition, uranium is included in sea water, and the way of colecting has been studied at present.
《Nuclear fuel cycle which is used by Japan as well. What's it?》
At first, the uranium ore is dealt chemically and processed into yellow powder. It's 重ウラン酸塩.
There is uran 235 which causes the nuclear fissure easily and uran 238...
【The whole image on the atomic power generation Ⅱ】
《Nuclear fuel cycle which is used by Japan as well. What's it?》
...and uranium 238 which doesn't cause the nuclear fissure easily.
There are little uranium 235 which doesn't cause the nuclear fissure easily in the natural world, so the work of heightening the rate on uranium 235 is done. We call it concentration.
The concentrated uranium is formed into a cylindrical lump of which height is some 1 centimeter, and of which weight is 6 gram and is burned and is solified. It's the real form on the nuclear fuel and we call it the pellet of fuel
【The whole image on the aotmic power generation】
《Nuclear fuel cycle which is used by Japan as well. What's it?》
The pellet of fuel is stuffed in cladding tube of which length is 8 meters and of thickness is 0.8 millimeters. The cladding tube is a metallic tube, and the number on the fuel of pellet is some 350. We call it a fuel rod, and the from 60 to 260 of the fuel rod are bundled. It's a fuel assembly and is used in the atomic power plant.
《Processing the spent nuclear fuel again》
The nuclear fuel which is used in the atomic fuel is exchanged into a new one from three to four years.
【The whole image on the atomic power generation】
《Processing the spent nuclear fuel again》
The spent nuclear fuel which was taken from the atomic reactor is buried underground as waste in America.
On the other hand, Japan processes the spent nuclear fuel again and makes use of it as nuclear fuel again. We call it the nuclear fuel cycle. Taking uranium which we can take advantage still and plutonium which was made when the uranium burned in the atomic reactor. Processing them as the nuclear fuel again.
But the nuclear fuel cycle in Japan is experimental, so the complete cycle on the ...
...so the complete nuclear fuel cycle has never been achieved in Japan.
【Mechanism on the atomic power generation】
《What is the uranium fuel? How is it made?》
We can't use the natural uranium as nuclear fuel as it is. The natural uranium is made up with uranium 238 which doesn't cause the nuclear fission easily. The uranium 235 which causes the nuclear fission easily is included no more than 0.2%.
As a result, the natural uranium is forced to be concentrated and to be heightened the ratio on uranium 235 so as to make the nuclear fuel.
Uranium 235 is lighter than Uranium 238 slightly.
【Mechanism on the atomic power generation Ⅰ】
《What is the uranium fuel? How is it made?》
Making use of the difference on the weight between two of them for the concentration on the uranium.
Changing the uranium into gazeous body and making it rotate in an apparatus called a centrifuge 遠心分離機. Then centrifugal force works on atom in uranium.
When being in a car and turning a curve, our body is drawn to the outside, and it's the centrifugal force. The heavier the material is, the more the centrifugal force works.
In consequence, the centrifugal force works on the uranium 238 stronger....
【Mechanism on the atomic power generationⅠ】
《What is the uranium fuel? How is it made?》
...the centrifugal force works on the uranium 238 stronger than the uranium 235, for the uranium 238 is heavier than the uranium 235. In short, the heavy uranium 238 is forced to draw to the side which is near the outside, and the lots of the uranium 238 tends to gather in the part on the outside.
0n the other hand, the light uranium 235 is apt to gather inside a lot.
《Repeating the same process and heightening the concentration》
Moving the part where the uranium 235 is dense to the other centrifuge.
【Mechanism on the atomic power generation Ⅱ】
《Repeating the same process and heightening the concentration》
Then doing the same process, so the uranium 235 becomes denser. Repeating the process over and over again, and heightening the ratio on the uranium 235 little by little. Adjusting the ratio on uranium 235 so as to be from 3 to 5 % in the uranium fuel.
《What is chain reaction on the nuclear fission which causes thermal energy in the atomic reactor?》
It doesn't always mean that uranium fuel burns actually like petroleum or natural gas in the thermal energy generation. What is the...
【Mechanism on the atomic power generation Ⅱ】
《What is the chain reaction on the nuclear fission which causes thermal energy in the atomic reactor?》
What is the phenomenon on burning? It means that the fuel connects with oxygen in the air and giving off heat and light violently.
On the other hand, the fuel isn't burned violently in the atomic power generation. Making use of the phenomenon on the nuclear fission and taking out the heat.
《If absorbing neutron, the nuclear fission is caused》
Though the uranium 235 causes the nuclear fission easily, it doesn't always mean that the nuclear...
【Mechanism on the atomic power generation Ⅱ】
《When absorbing neutron,the nuclear fission is caused easily》
...it doesn't always mean that the nuclear fission is caused automatically.
The atomic nucleus on uranium 235 becomes unstable when absorbing neutron. Then the atomic nucleus frequently divides into two atomic nucleus, at the same time, a large amount of energy also gives off.
The nuclear fission in the uranium 235 makes the neutron jump out, and the neutron is absorbed in other uranium 235 and the next nuclear fission is caused, and the neutron pops out again, and the next ...
【Ｍｅｃｈａｎｉｓｍ on the atomic power generation Ⅱ】
《When absorbing neutron,the nuclear fission is caused easily》
...the next nuclear fission is caused. That chanin reaction is caused.
Whenever the nuclear fission is caused, a few of neutrons pop out in lots of cases, and if all of the neutrons trigger the next nuclear fission, the nuclear fission multipiies like rats.
On the contrary, almost all of the neutrons which are caused by the nuclear fission are absobed in the material except for the nuclear fuel,it doesn't cause the next nuclear fission. Then the chain reaction stops.
【Mechanism on the atomic power generation Ⅱ】
《Critical is caused in the atomic reactor》
Adjusting the number on the nuetron in the atomic reactor, and a single nuclear fission causes the next one. We call the chain reaction on the nuclear fission is a critical.
Putting beryllium 9,or californium which release the neutron easily among the fuel assembly. Those neutrons become the first one which cause the nuclear fission.
《Light-water reactor by boiling has been used in the atomic power plant in Fukushima》
Two types of atomic reactor have been used in Japan manily. One of them is the...
【Mechanism on the atomic power generation Ⅲ】
《Light water reactor by boiling has been used in the nuclear power plant in Fukushima as well》
One of them is the light water reactor by boiling. The one which caused the serious disaster is also the same type.
《A large amount water is boiled in the core》
There are the fuel assembly of which length is some 4.5 meters at the pressure vesselin the light water reactor by boiling. Its total number is from 400 to 760.
The pressure vessel is made of special steel of which thickness is some 16 centimeters. There is water more than 300 ton in the...
【Mechanism on the atomic power generation Ⅲ】
《A large amount water is boiled in the core》
There is the water more than 300 ton in the pressure vessel, and the water is boiled direct by the heat on the nuclar fission. The pressure vessel which is operated then is filled with steam of which temperature is some 280 degrees, so the place becomes high pressure of some 70 atmospheric pressure.
The steam made in the pressure vessel is sent to the turbine, and making the turbine linking to the generator rotate and electricity is produced.
The water is boiled by the nuclear fuel, so its steam ...
【Mechanism on the atomic power generation Ⅲ】
...so its steam also includes the radioactive material. As the steam is sent to the turbine in the building on the facility, controlling the radiation becomes necessary, but when comparing it with other type on the light water reactor, its structure is simple.
《Shutting up the radioactive material》
The pressure vessel is sealed hermetically in the containtment vessel made of steel of which thickness is some three centimeters.
When the pressure vessel is broken, the containtment vessel prevents the radioactive material from leaking, but...
【Mechanism on the atomic power generation Ⅲ】
《Shutting up the radioactive material》
...but its sealability was lost at the accident of the atomic power plant in Fukushima.
The containtment vessel is covered with concrete of which thickness is 2 meter and prevents the radioation from leaking from the inside. The containtment vessel is in the building for the atomic reactor, and the thickness on its wall is 1 meter
《The light water reactor by pressurizing which passes and receives the heat with two steps》
The one more atomic reactor which has been adopted in Japan is the one by pressurizing
【Mechanism on the atomic power generation Ⅳ】
There are 54 of the atomic reactors in Japan at present, and 24 is the one by pressurizing.
《Making the water of which pressue and temperature is high boil the water in the plumbery 配管》
The fuel assembly of which height is some ４ meter is in the pressure vessel made of steel of which thickness is about 14 centimeters in the atomic reactor by pressurizing. The number on the fuel assembly is from 120 to 190.
The pressure vessel is filled with the water of 350 ton, and the water is also heatd by the atomic fule like the one by boiling.
【Mechanism on the atomic power generation Ⅳ】
《Making the water of which pressure and temperature is high boiled in the plumbly》
But the water is put on the pressure of some 160 atmosphere, and the temperature on the water is usually no less than 320 degree, so even if the temperature on the water is so high the water doesn't boil.
The water of which pressure and of which temperature is sent to the apparatus of generating steam and passing heat to water running in the other plumbly and making the water boil.
t
The steam is made like that, and it's sent to the builiding where there is ..
【Ｍｅｃｈａｎｉｓｍ on the atomic power generation Ⅳ】
《Making the water of which temperature and of which pressure is high boiled in the other plumbly》
...and the steam is sent to the building where there is the turbine, and making the turbine rotate with the steam and generating electricity.
As a result, the water and the steam which include the radioactive material doesn't have to be sent to the turbine, so controlling radiation in the builiding where there is the turbine is unnecessary.
On the other hand, the structure on the atomic reactor becomes complicated. The pressure vessel and ...
【Mechansism on the atomic power generation Ⅳ】
《Making the water of which temperature and of which pressure is high is boiled in the other plumbly》
The pressure vessel and the apparatus on generating steam are stored in the containtment vessel, and the containtment vessel in the Pressured Water Reactor is made of steel of which thickness is a few centimeters or the other made of conctrete which there is thin steel inside it.
As to the former, its outside is covered with a building made of concrete, and as to the latter, the containtment vessel itself functions as the building.
In the worst scenario like the pressure vessel itself is damaged,it's designed to shutting up the radioactivity
【The mechanism on aotmic power generation Ⅴ】
《Inserting and removing the control rod and controlling the atomic reactor》
Adjusting the chain reaction how much it goes ahead is done so as to adjust the output on the atomic reactor. The output on the atomic reactor means the amount of heat on nuclear fuel.
The nuclear fission on uranium 235 breaks out when uranium 235 absorbs neutronl. In short, if adjusting the number on nuetron in the atomic reactor, we can advance or control...
【The mechanism on atomic power generation Ⅴ】
...and we can advance or suppress the chain reaction on the nuclear fission,
《Adjusting the number on neutron by the control rod》
The one which plays a part on adjusting the number of the neutron is the control rod. What is the control rod? It's covered with material of which nature absorbing the neutron, and the material is covered with stainless.
Inserting and removing the control rod in the atomic reactor and adjusting the amount on the neutron in the atomic reactor.
The control rod is inserted from beneath the containment in the...
【The mechanism on atomic power generation Ⅴ】
《Adjusting the number on neutron by the control rod》
The Boiling Water Reactor has a structure of inserting the control rod from beneath the containtment, making use of nitrogen of high pressure and water pressure and it is done from beneath.
On the other hand, the contril rod on the Pressured Water Reactor has the structure of inserting and removing from above. Adjusting how much the control rod is inserted in the fuel assembly by the electirc driving gear.
《When detecting something unusual, the control rod is inserted automatically》
【Mechanism on atomic power generation Ⅴ】
《When detecting something unusual, the control rod is inserted automatically.》
When detecting something unusual in the atomic reactor like a big earthquake, all the control rods are inserted at once so as to prevent an accident from breaking down. Then the chain reaction on the nuclear fissure stops immediately. The emergency stop on the atomic reactor is called scram.
It seems that the scram succeeded in the nuclear power plant in Fukushima this time.
Boric acid ホウ酸 also has nature of absorbing neutron, so pouring water including lots of the...
【Mechanism on atomic power generation Ⅴ,Ⅵ】
...so pouring lots of water including boric acid in the pressure vessel and prventing the chain reaction on the nuclear fission from breaking down. It was done in the disaster in the atomic power plant in Fukushima actually.
《When burning the nuclear fuel, plutonium and iodine are caused》
When burnig the uranium fuel in the aotmic reactor, the uranium changes into other material by the nuclear fission. As a result various radioactive material appears from the uranim as the starting point like plutonium, cesium, iodine, and strontium.
【Mechanism on atomic power generation Ⅵ】
《When burning atomic fuel, plutonium or iodine are caused》
Radioactive material gives off radiation and changes into other one one after another. We call the phenomenon radioactive decay.
The period when the decay started is different, according to the kinds on the radioactive material.
For example, iodine 131 takes eight days when half of iodine decays and changes into xenon. Thus the number on atom of radioactive material decreases to the half by the radioactive decay, and we call its period half life. Its periods are various, for the one is a...
【ＭＥＣＨＡＮＩＳＭ on atomic power generation Ⅵ】
The one is a few seconds and other is hundreds years, so it's varied, according to the kind on the radioactive material.
《Even if the atomic reator stops, cooling down has to be done. Why?》
When the radioactive decay breaks out, the heat always occurs. We call it the decay heat.
As to the disaster in atomic power plant in Fukushima prefecture, even if the atomic reactor stops, the fuel gives off the heat continuously owning to the decay heat. It's not the nuclear fission.
The radioactive decay of which half life on the material is short advances.
【Mechanism on the atomic...Ⅶ】
《The system on pouring water in emergency》
Even if both of the atomic reactor and the chain reaction on the nuclear fission stop, the heat continues to give off owning to the decay heat accumulating various radioactive material in the atomic reactor.
As to the amounnt of decay heat immediately after the atomic reactor stops, it could have made water no less than 3 ton boil in a second. It's equal to the water in 10 bustub in ordinary house, but it's equal to no more than one seventh of the amount of heat when operating the atomic fuel.
【The mechanism on nuclear...Ⅶ】
《The system on pouring water in emergency》
If the nuclear fuel exposed from the water and being unable to cool down, the temperature on the fuel rod reaches two thousand degree in a few minutes, and the cladding tube covering the fuel rod melts and a large amount of radioactive material leaks in the pressure vessel. The melting point on the cladding tube is one thousand and nine hundred degree.
In addition, there is a possibility that the pellet of fuel itself melts. We call it core meltdown. If the core meltdown breaks out, the fuel of which temperature is...
【The mechanism on the atomic...】
《The system on pouring water in emergency》
If the core meltdown breaks out, the nuclear fuel of which temperature is high melted and there is a fear that the pressure vessel may have been damaged.
《The system which defends the core meltdown》
Without being able to circulate the water, evaporation on the water goes ahded or the plumbing is damaged and the water is deficient, Emergency Core Cooling System functions.
Pouring water into the core direct and prevents melting from breaking out, but the system couldn't be maintained in the disaster in Fukushima.
【The mechanism on the atomic..Ⅶ】
《The system preventing the melting from breaking out》
Electric power is essential so as to make the pump work which functions the system, so even if ordinary electricity is lost, receiving power transmission from the outside the power plant, or preparing for diesel generator in emergency so as to function the Emergency Cooling Core System.
But those apparatus became of no use on account of the super big earthquake and the great tidal wave.
As a result, being unable to cool down the nuclear fuel which gives off the decay heat, so core meltdown broke out...
...so core meltdown broke out partly from the first to the third atomic reactor.
【The place where the spent nuclear fuel has gone Ⅰ】
《Reprocessing of taking out plutonium from the nuclear fuel》
The spent nuclear fuel includes lots of components that it is possible to use as nuclear fuel. Taking out the component is the reprocessing.
《Shredding material and melting with nutric acid 硝酸》
The spent nuclear fuel is put into a cask and is carried away to the factory for reprocessing. The cask is exclusive container for carrying away to the factory for reprocessing. The spent nuclear fuel is...
【The place where the spent nuclear fuel has gone Ⅱ】
《Shredding material and melting with nitric acid 》
The spent nuclear fuel is taken out from the cask and is stored in the pool again until the reprocessing starts.
After taking out from the pool, the spent nuclear fuel is shredded and becomes the situation in which the pellet of the fuel is exposed.
The fuel rod which is shredded is put into the solution of the nitric acid. Then the fuel in the tube begins to solve in the solution. Separating the component on the solution and taking out plutonium and uranium as fuel which is able to use.
【The place where the spent nuclear fuel has gone Ⅱ】
It's the whole image on the reprocessing.
《The work has been done by remote control because of high radioactivity》
The spent nuclear fuel and the solution in which the spent nuclear fuel is solved have such the high radioactivity that no one can approach, so the reprocessing has done by a remote control.
The factory where the reprocessing is done needs serious management so as not to leak the radioactivity and radiation outside like the atomic power plant.
When reprocessing, radioactivity except for plutonium and uranium is taken out.
The radioactivity which is exhausted as waste has such a high radioactivity that it's disposed as high level radioactive waste.
【The place where the spent nuclear fuel has gone Ⅲ】
《What is pluthermal?》
Plutonium and uranium which are taken out by the reprocessing is used as new material for the fuel. We call the fuel MOX fuel. The word on the MOX is taken the first letter of the word on mixed oxide. The MOX is the mixture of plutonium and uranium, so we call it like that.
The word of pluthermal is a coined word 造語, so there is formal name for it.
【The place where the spent nuclear fuel has gone Ⅲ】
What is the pluthermal?》》
Generating electricity using the MOX fuel in an ordinary atomic reactor like the light water reactor is called pluthermal, in general.
Without repairing, the MOX fuel is able to be used in the present atomic reactor.
In general, when using the nuclear fuel, changing from uranium fuel to MOX fuel for the third one in the whole amount.
《The ration on the amount of generating electricity by plutonium has heightened》
In an ordinary atomic reactor in which the ordinary uranium fuel is used, plutonium is contained...
【The place where the spent nuclear fuel has gone Ⅲ】
《The ration on the amount of generating electricity by plutonium has heightened》
...and the plutonium causes the nuclear fission and the heat gives off.
There is electricity which is made by ordinary uranium fuel. It is calculated the amount of electricity in which plutonium from uranium is used accounts for 30%.
On the other hand, as to the pluthermal, its ration heightens to 50% on the whole amount.
《When using, we must be careful of the MOX fuel》
As to the MOX fuel, its melting point is lower than uranium fuel by 70 degrees,
【The place where the spent nuclear fuel has gone Ⅲ】
《When using, we must be careful of the MOX fuel》
In short, the heat doesn't transfer easily with regard to the MOX fuel. Moreover, the amount of gas is lot with the atomic fission, so the pressure becomes high easily in the fuel rod.
In consequence, we need to be careful of the MOX fuel rather than uranium fuel.
Plutonium issues radiation of alpha rays, and as it's heavy metal, it has chemical poison, and is harmful to the human body. The amount of plutonium is from 4 to 9% in the MOX fuel. The amount is so lot that when thinking of a...
【The place where the spent nuclear fuel has goneⅢ】
《When using, we must be careful of the MOX fuel》
...the amount on plutonium is so lot that when thinking of a serious disaster that the nuclear fuel melts and leaks outside, it causes concern.
There are 54 atomic reactors in Japan, and when the great earthquake broke out in Tohoku region, the pluthermal was made use of in four atomic reactors. One of them is the third atomic reactor in Fukushima prefecture.
《A fast breed nuclear reactor which causes fuel more than it uses》
Uranium 235 is used for an ordinary atomic reactor.
【The place where the spent nuclear fuel has gone Ⅳ】
《Fast breeder nuclear reactor which causes fuel more than it uses》
Uranium 235 which causes the nuclear fission easily is included no more than 0.7% in natural uranium.
As long as using the ordinary atomic reactor, we can make use of the natural uranium only below 1% for the generating electricity, but there is other atomic reacotr in which we can take advantage of 60% of the natural uranium. It's the fast breeder nuclear reactor, but there is none of the fast breeder atomic reactor which has made use of commercially at present, so...
【The place where the spent nuclear fuel has gone Ⅳ】
As a result, the fast breeder nuclear reactor has been under study and development at present.
《Mechanism which the fuel increases》
The plutonium causes the nuclear fission as fuel at the center of the core in the fast breeder atomic reactor. Neutron which is high speed is caused with a large amount of heat there.
There is an arrangement which the high speed neutron surrounds the fuel of plutonium.
To my sorrow, I can't understand the mechanism on the fast breeder atomic reactor any more, so I'm forced to omit it. I'm sorry for it.
【The place where the spent nuclear fuel has gone Ⅳ,Ⅴ】
《Mechanism on fast breeder atomic reactor》
Plutonium is consumed for the nuclear fission, but is caused more than it's used for the nuclear fission.
The fuel increases. It's a story as if it were a witchcraft.
On the other hand, the fast breeder atomic reactor has a fault that dealing with it is hard.
The author said he was going to express the difference between the ordinary atomic reactor and the fast breeder atomic reactor which is light water reactor.
《Sodium is efficient, but is hard to handle》
A big difference between...
【The place where the spent nuclear fuel has gone Ⅴ】
《Sodium is efficient, but is hard to handle》
The big difference between the ordinary atomic reactor which is the light water reactor and the fast breeder nuclear reactor is not the water but sodium which is used for cooling down the heat from the nuclear fuel.
Sodium is liquid made of metal. Though I've expressed, to tell the truth, I can't imagine it very well. When the metal is melted, it becomes the one like liquid, I'm wondering.
To my sorrow, I have little knowledge on the atomic power plant, so lots of questions occur to me.
【The place where the spent nuclear fuel has gone】
《Sodium is efficient but is hard to handle》
The melting point on the sodium is higher than water, so the heat transfers easily. As a result it's better than water as coolant, moreover it doesn't make the neutron of high speed be slow. The proper is indispensable so as to increase the fuel.
But there is a big problem on the sodium. When touching water or air which is oxygen, the sodium issues hydrogen or heat, responds violently.
The accident that the sodium of high temperature leaked in the fast breeder atomic reactor, もんじゅ, in Fukui.
【The place where the spent nuclear fuel has gone Ⅴ】
A fire caused in the accident, and hiding the accident becomes such a big problem that the fast breed atomic reactor was forced to stop almost 15 years.
《Radioactive waste which is the price for generating electricity》
The atomic power generation is the way of generating electricity of producing a large amount of electric power from a little fuel extremely. On the other hand, radioactive waste which is troublesome is caused as by product.
The radioactive waste is classified into high level and low level.
【The place where the spent nuclear fuel has gone Ⅵ】
《Radioactive waste which is the price for generating electricity》
It doesn't always mean that it's classified with the amount of the content on the radioactive material.
To be concrete, the low level radioactive waste is a filter which prevents the air including radioactive material from leaking from the facility on the atomic power plant, or parts on the fuel rod.
As to the low level radioactive waste, if being able to burn, it's burnt. Making the bulky on the low level radioactive material as less as possible. Finally, putting it...
【The place where the spent nuclear fuel has gone Ⅵ】
《Radioactive material which is the price for generating electricity》
Finally, putting it into a drum and hardening with cement, and burying in a shallow stratum comparatively which is several meters underground.
When reprocessing the spent nuclear fuel, the radioactive waste of high density is exhausted, and the radioactive waste of high density is hardened with glass. We call it the high level radioactive waste.
The way of thinking or of disposing on the high and low level radioactive material is adopted in Japan.
【The place where the spent nuclear fuel has gone Ⅷ】
《The way of making the high level radioactive waste》
The high level radioactive waste which is solidifying with glass. How is it done?
The radioactive waste is exhausted from the reprocessing, and is mixed with raw material of glass in the reactor. The liquid of high temperature in which the waste is mixed with the glass is pouring down in an exclusive container made of stainless and is hardened. Thus, the waste becomes solid like the glass.
Why is the waste mixed with the glass? As the glass is stable chemically, so even if burying...
【The place where the spent nuclear fuel has gone Ⅷ】
《The way of making the high level radioactive waste》
...even if burying underground, there is low possibility of melting and flowing out underground.
《Radioactivity which reaches to lethal dose in twenty second》
As the radioactive waste hardening with glass has high radioactivity extremely, without having any protection, no one can approach it. If touching it without having any protection, it's exposed to radiation of fatal dose in no more than twenty second.
If placing a wall of which thickness is 1.5 meter from the waste hardening..
【The place where the spent nuclear fuel has gone Ⅷ】
Placing wall made of concrete of which thickness is 1.5 meter from the solidified glass, it becomes the safe amount of radiation for the human being at last.
When changing the radioactive waste of high level into the glass, it has to be controlled from the remote place on account of such the high radioactivity.
《How do we dispose of the radioactive waste of high level? 》
The radioactive material decreases owing to the radioactive collapse as the time passes. In short, when the time passes, the radioactive waste becomes a waste.
【The place where the radioactive material has gone Ⅷ】
《How do we dispose of the radioactive material on high level？》
Though it takes thousands of years to change the radioactivity from the solidified glass into the original uranium fuel when making the atomic energy with regard to 600 ton.
Both of the uranium ore and solidified glass give off the radioactivity. It takes dozens of million years when two of them become the same amount of the radioactive material in relation to no more than 500 gram.
It has taken some seven million years from the birth on us the human being, but...
【The place where the spent nuclear fuel has gone Ⅷ】
It takes by far longer time to become the safe amount of the radioactive material.
《Burying underground deeply and waiting for that the time passes》
Controlling the harmful solidified glass for the long time is absolutely impossible actually, so there is the next way.
Covering the dangerous solidified glass with clay or metal thickly and burying underground deeper than 300 meter. After burying, no one deal with it basically. It's just that we are forced to wait until the radioactivity becomes weak automatically underground.
【The place where the spent nuclear fuel has gone Ⅷ】
《Burying underground deeply and waiting for the time passes》
It has been thought that disposing of it underground is the most realistic way at present, but the place where the disposing is done has never been completed in the world at all.
The place for planning of disposal has been determined in Sweden and Finland, but it has never been in Japan, though the radioactive waste continues to accumulate even at present.
《Where does the atomic power generation go from now on？》
After the nuclear disaster in Fukushima, it has never been ...
【The place where the spent nuclear fuel has gone Ⅷ】
《Where is the atomic power generation going from now on？》
...it has never been clear that the atomic power generation is going to go ahead in Japan or in the world. We have to get more scientific information on the atomic power and deep argument. It has been sought for us to do at present.
The place which is deeper than 300 meter is there is little influence by volcanoes, and thick layer made of rock is suitable for the place on disposal.
The place on disposal for 公募 has been done in Japan since 2002. but it has never been decided.
【The place where the spent nuclear fuel has gone Ⅷ】
《Covering with several barriers》
The harmful solidified glass is carried away to the underground and is placed in interval beneath the tunnel by using heavy machinery. The solidified glass is put into container made of steel of which thickness is 20 centimeter and is covered with clay which isn't soaked into the water easily and is buried.
After burying the solidified glass, the tunnel itself is buried with the soil and is shut out. Finally, the pit for going underground is buried so the whole facility underground is buried completely.
【The place where the atomic power generation is going and the problem on electric power】
It is said the atomic power generation accounts for six percent in the amount of elctricity in the world at present, and the number on the atomic reactor which is possible to generate the electricity is 432, but the nuclear disaster in Fukushima prefecture has wavered our certanity on the safe atomic power generation so much.
The atomic power plant at Hamaoka in Shizuoka prefecture has determined to stop, but it has been regard as danger even if being stopped.
Decommission on the nuclear reactor...
Decommission on the nuclear reactor has been tried though it doesn't seem go well when this expression was described.
Interpretation on the being lack of electricity is going to be done from basic material, the author said like that.
【The present situation on the atomic power generation】
《The reality that nuclear power generation makes up for 6% in the amount of electric power in the whole world 》
There have been 432 atomic reactor which are possible to generate electricity at present in the world, and those atomic reactors account for 6% in the amount of electricity which is consumed...
【The present situation on the atomic power generation】
《The reality that the nuclear power generation accounts for 6% the amount of electric power in the whole world》
There have been 432 atomic reactors which are possible to generate electricity in the world, and those atomic reactors have made 6% of electricity which is consumed in the world.
There are 54 in Japan and 19 were operated in Japan when this description was done and generating electricity was done. I'm sure it has been done at present.
Thermal power generation which makes use of petroleum has been adopted in Japan since 1980.
【The present situation on the atomic power generation】
《The reality that the nuclear power makes up for 6% on the amount of electricity in the whole world. 》
The electricity which was made by the thermal power generation used to occypy 46% and the one by the atomic power generation was 17% in 1980, but the ration on the electricity which the petroleum accounts for decreased to no more than 5% from 2005 to 2009.
On the other hand, the atomic power generation makes up for some 30% in the whole amount of generating electricity, and the amount of generating electricity by coal and natural...
【The present situation on the atomic power generation】
《The reality that the atomic power generation accounts for 6% on the amount of electricity in the whole world》
...and the amount of electricity using by coal and natural gas increased. The oil shock that the price on the crude oil soared in 1973 and in 1979 caused the change the ration in which various energy is used.
Generating electricity by using fossil fuel like the petroleum and the coal exhausted carbon dioxide leads to the global warming, so it's been regarded as problematic recently.
On the other hand, the atomic power...
【The present situation on the atomic power generation】
《The reality that the atomic power accounts for 6% the amount of electricity in the whole world》
On the other hand, the atomic power generation which doesn't exhaust the carbon dioxide used to be paid attention as measure for the global warming.
It has been thought that the demand for the electricity will increase in the future. Several atomic power plants have been planned to build so as to meet the demand for the electricity, but the nuclear disaster in Fukushima prefecture has changed the situation so much.
【Present situation on the atomic power generation】
《The reality that the atomic power makes up for 6% on the amount of electricity in the whole world》
Some nations which have the atomic power plants have reconfirmed design on the existing nuclear power plant or arranging opportunity so as to reexamine the plan for building the atomic power plant. Those movements have begun to appear.
How should we meet the demand for electric power which continues to increase? The atomic power disaster this time has made us face the common theme in the world.
【The atomic power plant in Hamaoka】
《Does...》
【The atomic power plant in Hamaoka】
《The atomic power pland in Hamaoka has been regarded as dangerous. Why？》
Will the great earthquake break out in Tokai area？ Is its measure enough？
As receiving the request from the former prime minister, Naoto Kan, Chubu Electric Power Company has decided to stop operating all the atomic reactors on Hamaoka atomic power plant for a while at Omaezaki city in Sizuoka prefecture May in 2011.
It has been pointed out the possibility on the great earthquake of which magnitude is 8 breaks out directly under the atomic power plant. It's a boundary earthquake.
【The atomic power plant in Hamaoka】
《The reason why the Hamaoka atomic power plant has been regarded as dangerous》
What kind of the one is the earthquake in Tokai area? Is there possibility that it's beyond assumption like the one in Tohoku this time?
Naoto Kan held a press conference and announced that he demanded the Chubu Electric Company to stop operating all the atomic reactors in the Hamaoka atomic power plant the sixth day May in 2011.
As receiving the announcement, the Chubu Electric Company decided to accept the demand after three days. The fourth and fifth atomic operator were...
【The atomic power plant in Hamaoka】
《Will the earthquake break out in Tokai area really? Is its measure enough?》
Both of the fourth and fifth atomic reactor were being operated but would stop by the fourteenth day, the third one which was under regular inspection was postpone its operation. The operation on the first and the second have come to an end in 2009.
Being worried about on the shortage of the electric power summertime and the influence over the direction on the policy for energy in the future caused arguments from various viewpoints.
《The earthquake in Tokai area which broke...》
【The atomic power plant in Hamaoka】
《The earthquake in Tokai area which broke out repeatedly》
What is the earthquake in Tokai area which has been problematic? Though it doesn't break out yet, it's already been named. It's strange, but there is a reason for it. The earthquake in Tokai area looks set to happen in the future. Why？
The earthquake of which magnitude was 8 used to break out in the location of the center of the earthquake in Tokai area with an interval from a hundred to a hundred and fifty years in the past. It turned out to be clear from the research on a historical archive.
【The atomic power plant in Hamaoka】
《The earthquake in Tokai area which used to break out repeatedly》
The earthquake which has been assumed is the boundary earthquake on the plate. The surface on the earth has been covered with the plate. The plate is made of dozens of rock of which shape is the plate, and those rock have moved slowly.
Roughly speaking, half of Japan is on the Eurasia plate, and Philippine plate has sunk under the Eurasia plate from south to northwest some four centimeters a year.
The earthquake breaks out on the boundary between the two plates. It's the earthquake...
【The atomic power plant in Hamaoka】
《The earthquake in Tokai area which broke out repeatedly》
It's the earthquake on the boundary of plate.
With the sinking plate, the energy on the earthquake is accumulated, and the energy is released by the earthquake. After that the energy is accumulated... the cycle has been repeated. As a result, the period between the earthquakes is so irregular that its prediction is hard.
It has presumed that the earthquake in Tokai area will break out on the boundary of the Eurasia and Philippine plate, in the area from the Suruga bay to Hamana lake.
【The atomic power plant in Hamaoka】
《The energy on the earthquake has already been accumulated》
The atomic power plant in Hamaoka is in the center of the areas where the earthquake will break out.
The assumed center of the earthquake on Tokai area has released energy on the scale of magnitude 8 with the interval from a hundred and a hundred and fifty years.
It means that the area has an ability of accumulating the energy in the period from a hundred to a hundred and fifty years.
It was in 1854 when the last earthquake broke out in the Tokai area. 157 years have passed from the last...
【The atomic power plant in Hamaoka】
《The energy on the earthquake has already been accumulated》
157 years have passed from the last earthquake in Tokai area. It means that the assumed center of the earthquake in Tokai area has accumulated energy which makes the earthquake of which magnitude is 8 at present. It's the ground that the earthquake on Tokai areas is impending.
When looking over the Japan Archipelago there is hardly other place like Tokai area where the outbreak on the earthquake is set to happen concretely and its scale is over magnitude 8.
Needless to say, there is the risk...
【The atomic power plant in Hamaoka】
Needless to say, there is the risk on the earthquake in the other atomic power plants, but its risk on the one in Hamaoka is by far bigger than any other ones.
《When will it break out? 》
When will the big earthquake occur in Tokai area concretely? Is it today or after thirty years? No one can foresee it. What makes the earthquake happen? it remains unclear, and how is the plate on the boundary underground? No one knows it.
The one which makes the situation be complicated is there has been none of the cases in which the single big earthquake broke out...
【The atomic power plant in Hamaoka】
《When will it break out? 》
The single big one has never broken out in Tokai area as long as the author knows, he said like that. When the big one happens, it worked with other plates together.
The boundary continues on the west of the assumed center of the earthquake, and the earthquake of which location of the center of the earthquake is offing in Mie prefecture and is the offing from Wakayama prefecture to Shikoku area broke out repeatedly in the past.
For example, the one in 1707 was two areas worked together and in 1854, two of them worked ...
【Atomic power plant in Hamaoka】
《When will it break out？》
...in 1854 two of them worked together, to make matters worse, the third one broke out after thirty-two hours.
In 1946, 南海地震 of which location of the center of the earthquake is from Wakayama prefecture to Shikoku area broke out, but then in the location of the center of the earthquake on 東海地震, none of the earthquake broke out then.
There is none of the case in which the big single earthquake didn't broke out in the past in Tokai area, and other two of the big earthquakes worked together, so there have been some seismologists ...
【Atomic power plant in Hamaoka】
《When will it break out？》
...so there are some seismologists who have insisted that the big earthquake in Tokai area will work with other two together.
If the big earthquake in Tokai area breaks out with other two together, we know the time when the two of the earthquakes breaks out, we can foresee the time when the big earthquake in Tokai area break out as well logically.
But except for the big earthquake in Tokai area, it has never been clear the time when two of the other big earthquakes occur.
It seems that it occurred with the interval from a...
【Atomic power plant in Hamaoka】
《When will it break out? 》
We know it seemed it broke out with the interval from a hundred to a hundred and fifty-years, according to the historical archive. Considering the last outbreak in 1944 and 1946, the time has been given until the next outbreak, but we can't deny the possibility it will occur with shorter interval than before.
In addition, we can't deny other possibility that the big single earthquake which has accumulated enough energy in Tokai area will break out in the future.
The earthquake offing in the Pacific Ocean on Tohoku area has...
【Atomic power plant in Hamaoka】
《When will it break out？ 》
The earthquake offing in the Pacific Ocean at Tohoku area has made us informed painfully the assumption being based on limited knowledge by the humankind was overturned easily by the nature this time.
Mr.Kan incited the probability on the earthquake in Tokai area in the future is 87%. It was led by the committee on the research for earthquake established by the educational Ministry statically.
When will the big earthquake break out? if being asked like that, we are forced to answer we don't know after all, but it's the fact that...
【Atomic power plant in Hamaoka】
...but it's fact that the location on the center of the earthquake in Tokai area has accumulated enough energy to break out the earthquake of which magnitude is 8.
《Having been worried about the outbreak on the tidal wave which is beyond the present assumption》
Those things have already been clear before the earthquake offing in the Pacific Ocean at Tohoku area broke out. Even if the big earthquake breaks out in Tokai area, we assume that the atomic power plant in Hamaoka would be operated safely until the big earthquake broke out this time in Tohoku area.
【Atomic power plant in Hamaoka】
《Having been worried about the outbreak on the tidal wave which is beyond assumption at present》
So the operation on the atomic power plant in Hamaoka could have been continued, but the prime minister demanded to stop operating the atomic reactor, for he would think of danger which is bigger tidal wave beyond assumption attacks the atomic power plant in Hamaoka.
It seems that he judged that there is the possibility that the same thing in the atomic power plant in Fukushima will break out in Hamaoka as well.
The big earthquake broke out in 1854. Then two ...
【Atomic power plant in Hamaoka】
《Having been worried about the outbreak on the tidal wave which is beyond assumption》
Then two of the earthquakes worked together and the height on the tidal wave which was the highest was 6 meters, judging from the trace on the tidal wave, according to data in Chubu Electric Company, so estimating the tidal wave of which highest wave was 8 meters so as to keep the safety.
There are dunes of which height is from 10 to 15 meters on the site of the atomic reactor in Hamaoka along the coast. The dune will play a part as natura embankment.
But having...l
【Atomic power plant in Hamaoka】
《Having worried about the outbreak on the tidal wave which is beyond assumption》
But as having responded with the nuclear disaster in Tohoku area, Chubu Electric company has taken a new measure of setting new generators in emergency on the roof of the building for the atomic power generation.
Even if stopping supplying electricity from the outside, going on cooling down on the atomic reactor and the spent nuclear fuel becomes possible. Or setting other two generators at the high place on the site of the atomic power plant, furthermore, building embankment....
【Atomic power plant in Hamaoka】
《Having been worried about the outbreak on the tidal wave beyond assumption》
...moreover, building the embankment wall of which height is at least more than 12 meters inside the dune. Taking a few years to complete it has been decided.
If a bigger tidal wave beyond assumption until then breaks out before those construction is over, the safety can't be maintained, Mr. Kan judged like that, so he demanded to stop operating the atomic reactor this time.
Is there possibility that bigger tidal wave occurs beyond assumption in the big earthquake in Tokai area ?
【Atomic power plant in Hamaoka】
《Having been worried about the outbreak on the tidal wave beyond assumption》
I'm not sure of it at present situation, the author said like that.
If being able to solve out the mechanism which caused the big earthquake this time offing in the Pacific Ocean at the Tohoku area, we may have got something suggestive.
If assuming the possibility that the first earthquake breaks out and after dozens of minutes other earthquake occurs, the tidal wave on both of the earthquake are overwrapped and the height on the tidal wave becomes higher.
In the worst case...
【Atomic power plant in Hamaoka】
In the worst case, calculation on the height of the tidal wave is over 10 meter near Omaezaki where there is the atomic power plant in Hamaoka was reported.
《Is there enough measure against shaking? We have to consider it》
Generally, it has been considered that the pump for cooling down broke down and the generators in emergency was out of order owing to the tidal wave in Fukushima.
Isn't there any fault owing to the shaking at all? It's very important.
Putting into the control rod was done safely so as to stop the reaction on nuclear fission.
【Atomic power plant in Hamaoka】
《Is there enough measure against shaking? We have to consider it》
Putting the control rod into the nuclear reactor was done safely in emergency, but whether or not the function on the whole facility like plumbing was safe against the shaking should be solved out thoroughly in the future.
Inspection against the seismic standard is also indispensable in the atomic power plant.
In the disaster by the earthquake this time, the shaking which excessed the seismic standard so much is observed this time in other atomic power plant. The shaking beyond the...
【Atomic power plant in Hamaoka】
The shaking beyond measure so much was observed sometimes at some of atomic power plants so far.
《Having influence over the policy on energy in the future》
The number on the atomic reactor in the whole Japan is 54 and the ration in which the atomic power plant accounts for in the whole amount of the electric power reached around 25%.
The atomic disaster in the nuclear power plant in Fukushima and stopping operation on the atomic reactor in Omaezaki will have influence a lot over the policy on energy in the future.
【The route to decommissioning】
【The route to steep decommissioning】
《How do we take out the melting nuclear fuel? What is the lots of themes standing in front of us? 》
The atomic power plant in Fukushima prefecture which has caused the nuclear power disaster. Various works continued so as to come to an end the disaster completely June in 2011 when this description was done.
The atomic reactor which caused the disaster has determined to decommission finally, it has been clear that meltdown was done and it turned out that the route to decommissioning is steep.
How is the decommission going to be done? and what's kind ...
【The steep route to decommissioning】
《How do we take out the melted nuclear fuel? What are the lots of themes stand in front of us? 》
...and what kinds of theme is there? The atomic power disaster broke out at the Three Mile Island in America some forty years ago.
The author said he was going to express the decommissioning in detail, using the disaster in Three Mile Island as reference.
After four months from the disaster in the atomic power plant in Fukushima, it didn't come to an end then.
It proved that the meltdown that the nuclear fuel melted by heat broke out in the atomic reactor.
【The steep route to decommissioning】
《How do we take out the melted nuclear fuel? What are the lots of themes standing in front of us? 》
Meltdown that nuclear fuel melted by the heat broke down from the first to the third atomic reactor, according to the announcement by the Tokyo Electric Power Company May in 2011.
In addition, the melted nuclear spent fuel destroyed the pressure vessel which contained the nuclear fuel and was pointed out that the possibility that the part of the nuclear fuel flowed out beneath the pressure vessel.
Lots of the people were engaged in the work in...
【The steep route to decommissioning】
《How do we take out the melted nuclear fuel? What are the lots of themes standing in front of us? 》
Lots of people were engaged in the work so as to come to and end the unprecedented disaster as early as possible. The work was going to be done, being based on the schedule by the Tokyo electric power company updated May in 2011. Five items are being set up and is showed to work on them in order to come to an end the disaster perfectly.
One of the big themes is cooling down the atomic reactor. Even if being stopped, inside the atomic reactor has to be...
【The steep route to decommissioning】
《How do we take out the melted nuclear fuel? What are the lots of themes standing in front of us? 》
Even if being stopped, inside the atomic reactor has to be remained cool, but after the big tidal wave attacked, the existing system for cooling down couldn't function owing to the influence by the tidal wave. As a result, being unable to cool down the atomic reactor, so the serious disaster broke out this time.
The nuclear fuel continued to give off the heat in the atomic reactor even if after four months passed from the disaster, so pouring water of 1...
【The steep route to decommissioning】
《How do we take out the melted nuclear fuel? What are the lots of the themes standing in front of us? 》
...so, pouring 1 ton of water an hour continued, but part of the pouring water leaked underground on the building of the atomic reactor.
A new system purifying the polluted water which was accumulated in the atomic reactor and circling the purifying water and continues to cool down has been developed.
If the system functions enough, the temperature on the water which cools down the nuclear fuel can keep low. It's the goal for the time being.
【The steep route to decommissioning】
《How we take out the melted nuclear fuel? What are the lots of themes standing in front of us? 》
It's the goal for the time being.
Other item being on improvement on the circumstance like restraining the pollution by the radioactive material which leaked from the atomic reactor, decontamination, its monitoring, the measure after the shock has established.
Those things have to be done steadily so as to come to an end on the disaster.
《Decommissioning which takes a long time and needs labor》
At least from the first to the fourth atomic reactors have...
【The steep route to decommissioning】
《Decommissioning which takes long time and needs effort》
From the first to the fourth atomic reactor which caused the accident have to be decommission finally. Decommission means dismantling the atomic reactor and disposing of it. In Japan, decommission is done in Ibaragi and Fukui prefecture.
JPDR which is an abbreviation of Power Demonstration Reactor. It's a small atomic reactor for study which succeeded in generating electricity by atomic power in Japan for the first time. Its decommission was done from 1981 to 1996. Various expertise needs on the...
【The steep route to decommissioning】
《Decommissioning which takes long time and needs efforts》
Decommissions needs various expertise like handling radioactive material, and technical skill on dismantling atomic reactor.
Decommissioning on the JPDR was done developing the technical skill on dismantling, one of specialists said like that.
Whether or not the accident happened, the most tiresome when going ahead the work is the existence on the radioactive material.
When dismantling the atomic reactor, we need to the radioactive material prevents from scattering around. We have to prevent...
【The steep route to decommissioning】
《Decommissioning which takes long tie and needs efforts》
We have to restrain being exposed to radiation on workers in decommissioning to the bottom line. Considering it, ordinary decommission is done with the procedure like the next.
After stopping operating the atomic reactor, making the cooling water circulate, and dropping the temperature on the nuclear fuel. After waiting for the temperature drops enough, taking out the nuclear fuel and sending the nuclear fuel to the facility where the nuclear fuel is treated.
In the next, decontamination is...
【The steep route to decommissioning】
《Decommissioning which takes long time and needs efforts》
In the next, decontamination is done.
The radioactive material is attached to the pressure vessel and to the plumbing where the cooling water passes through. Decontamination is washing, getting rid of the radioactive material by medicine.
Impurity included in the cooling water received strong radiation which means strong neutron beam from the core, so the pressure vessel and plumbing were exposed to radiation, and the radioactive material was caused.
The pressure vessel and the surface...
【The steep route to decommissioning】
《Decommissioning which takes long time and needs efforts》
The pressure vessel and its surface covering with concrete learn to have the radioactivity, for the material on the pressure vessel and the concrete include chemical elements like cobalt and chromium.
When burning. a large amount of neutron is caused, and the neutron bumps against the cobalt and chromium, they change into radioactive material.
The one which isn't the radioactive material originally changes into the radioactive material is called radiation, but this kind of radiation happens...
【The steep route to decommissioning】
《Decommissioning which takes long time and needs efforts》
...but this kind of radiation happens in the atomic reactor in which the neutron beam is caused alone. The radioactive ray which issues from other radioactive material like radioactive iodine or radioactive cesium doesn't give off the neutron ray, so radiation doesn't happen.
After decontamination is over, the plumbing and pump which are used in emergency have low radiation, so dismantling them at once is possible .
As to the ones which have strong radiation, we sometimes wait for the...
【The steep route to decommissioning】
《Decommissioning which takes long time and needs efforts》
As to the ones which have strong radioactivity, we sometimes wait for the amount of radiation to drop for several years, automatically.
The pressure vessel is shut up tightly in container vessel which covers the outside, and the container vessel is in the building made up with concrete for the atomic reactor.
What should we decommission the atomic reactor which stops its operation in without any flaw?
At first dismantling the pressure vessel in the container vessel and doing the container vessel
【The steep route to decommissioning】
《Decommissioning which takes long time and needs efforts》
After the container vessel is dismantled, the building is done finally, giving great attention to avoid leaking the radioactive material, the dismantling is done, but the decommissioning on the atomic power plant in Fukushima is different from the ordinary work so much, for melting down made the container in the atomic reactor destroy, so ordinary washing technical skill isn't able to be used, taking out the nuclear fuel doesn't go ahead as planned.
Keeping the cooling water which cools down...
【The steep route to decommissioning】
《Decommissioning which takes long time and needs efforts》
The way to keep cooling water which cools down the nuclear fuel low is described in the schedule announced by the Tokyo electric company, but a concrete way of decommissioning isn't indicated.
Companies which are engaged in the atomic power plant in Japan proposed they decommission in cooperate with other companies in foreign countries for a few decades.
The specialist who has studied the atomic reactor and its security said the way of treating the nuclear disaster at the Three Mile Island in...
【The steep route to decommissioning】
...the way of treating nuclear disaster at the Three Mile Island is good as reference. What is the nuclear disaster at the Three Mile Island?
《The atomic power plant in the Three Mile Island which caused melting down》
Some of disorder in facility and mistakes by workers overlapped, and it led to the big disaster like the melting down.
As being unable to cool down the cooling water at the container vessel , so the temperature in the water went up at the second atomic reactor in the Three Mile Island May in 1979.
As a result, the steam in the ...
【The steep route to decommissioning】
《The atomic power plant in the Three Mile Island which broke out meltdown》
As a result, the steam made the pressure in the pressure vessel went up. As being ready for the situation, a valve which makes steam escape from the apparatus on 加圧器 which controls the pressure on the atomic reactor to the pressure vessel.
The atomic reactor stopped in emergency, at the same time, the valve opened automatically and the pressure in the atomic reactor began to drop, but a problem happened then.
After the pressure went down, the valve which should shut
【The steep route to decommissioning】
《The atomic power plant in the Three Mile Island which broke out meltdown》
...the valve which should shut automatically was out of order and remained open.
To make matters worse, the facility indicated the valve was shut, so workers couldn't be aware that the valve was open.
The cooling water changed into steam and continued to escape to the container vessel. As a result, water level in the pressure vessel went down.
As detecting the unusual situation, ECCS, Emergency cooling core system functioned. ECCS is the apparatus which cools down nuclear fuel.
【The steep route to decommissioning】
《The atomic power plant in Three Mile Island which broke out meltdown》
Pouring water started so as to go up the water level by the ECCS, but unfortunately, a new mistake was made then.
A worker who wasn't aware that the valve escaping the pressure was open judged that the pressure vessel was filled with the water and stopping operating the ECCS by manual operation.
As the valve escaping pressure was open, the water level went down lower and lower in the pressure vessel.
Two hours and twenty minutes passed from the accident, the worker found out...
【The steep route to decommissioning】
《The atomic power plant in the Three Mile Island where the meltdown broke out》
...the worker found out the situation finally, so the main valve which was beneath the valve escaping pressure was shut then, but the cooling water in the pressure vessel decreased so much that two thirds of the whole nuclear fuel was exposed from the surface on the water. Then the nuclear fuel melted by its own heat and melting down broke out.
When the nuclear fuel exposed from the water there is possibility that hydrogen appears. Metallic tube enveloping the nuclear fuel...
【The steep route to decommissioning】
《The atomic power plant in the Three Mile Island where melting down broke out》
Metallic tube enveloping the nuclear fuel reacts with steam and hydrogen is caused, so the hydrogen was accumulated in the pressure vessel.
The large amount of steam and the pressure by the hydrogen in the pressure vessel prevented from pouring water, so releasing the steam and hydrogen into the container vessel and the work was proceeded, and as a result, the container vessel was filled with hydrogen.
After some ten hours from the disaster, the hydrogen caught fire and...
【The steep route to decommissioning】
《The atomic power plant in Three Mile Island where meltdown broke out》
Hydrogen caught in fire and explosion by the hydrogen broke out then, but the containment vessel didn't break down by the explosion, but the similar phenomenon also occurred in the nuclear power plant in Fukushima.
The hydrogen leaked from the containment vessel to the building for the atomic reactor and caught in the fire. As a result, the explosion by the hydrogen blew up the building, and then a large amount of radioactive material was released around the place.
【The steep route to decommissioning】
《The atomic power plant in the Three Mile Island where the meltdown broke out》
There is possibility of hydrogen is left in the atomic reactor in the nuclear power plant in Fukushima where the work for handling the disaster at present. Pouring nitrogen and setting up apparatus which return the hydrogen to water and be careful not to cause the explosion by the hydrogen is indispensable, one of experts said like that.
After some 16 hours, enough cooling down became possible at the nuclear power disaster in the Three Mile Island, the disaster was going...
【The steep route to decommissioning】
《The atomic power reactor in the Three Mile Island where meltdown broke out》
...so the disaster was going to come to an end. It turned out that some 50% of the nuclear fuel melted finally in the disaster.
On the other hand, the gigantic tidal wave destroyed the way of cooling down like the ECCS, emergency core cooling system, even if three months passed from the disaster, the disaster didn't come to an end then.
To make matters worse, accidents broke out in other some of atomic power plants, and it becomes an obstacle for coming to an end earlier.
【The steep route to decommissioning】
《The atomic power plant in the Three Mile Island where meltdown broke out》
INES is an abbreviation on International Nuclear Event Scale. How serious it is, is expressed with the number on the INES. According to the INES, the atomic power plant disaster in the Three Mile Island is level 5.
On the other hand, the one in Fukushima is level 7 tentatively. It's the most serious. The difference between the two of the atomic power disaster is the scale on the influence which given outside the atomic power plant.
《Getting rid of the radioactive material...》
【The steep route to decommissioning】
《Getting rid of the radioactive material at the atomic reactor in the building》
As the nuclear fuel melted at the nuclear power disaster in the Three Mile Island, a large amount of radioactive material included in the nuclear fuel leaked into the pressure vessel. Then as the steam and hydrogen were released from the pressure vessel, the radioactive material was attached everywhere in the atomic power plant.
As a result, the amount of radiation inside the containment vessel was high immediately after the disaster.
The radioactive material leaked from...
【The steep route to decommissioning】
《Getting rid of the radioactive material in the building》
The radioactive material leaked from the nuclear fuel is a large amount, and removing the radioactive material is indispensable so as to handling matters after the disaster. Then restraining to be exposed on the radiation to workers and preventing the radioactive material from scattering neighborhood would be done.
But decontamination on the atomic reactor after the accident has never been done until then, so examining the way of getting rid of the radioactive material was done, and....
【The steep route to decommissioning】
《Getting rid of the radioactive material in the building》
Decontamination was done actually and making sure its efficiencies actually. It's like a large scale of experiment on decontamination. It was done in 1982.
The most efficient is spraying water on the floor, wall, or the surface on the apparatus with high pressure, and scraping off all of the surface.
Scraping off the floor by 1.6 millimeters with the way and getting rid of the radioactive material. The amount of the radiation became one tenth from the one in 1980.
The radioactive material...
【The steep route to decommissioning】
《Getting rid of radioactive material in the building》
Radioactive material could have attached everywhere at the atomic reactor in the atomic power plant of Fukushima where the disaster broke out, for the high amount of radiation has been measured inside the building by robot controlled from remote place. A measure of obstructing radioactive material is done and the work on decontamination has to be proceed, referring to the experience on the atomic power plant disaster in the Three Mile Island.
《Taking out the nuclear fuel is the hardest》
【The steep route to decommissioning】
《Taking out the nuclear fuel is the hardest》
If the work becomes easier by decontamination the work of taking out the nuclear fuel will start in the next, but taking out the nuclear fuel is the most difficult when dealing with the atomic reactor which caused meltdown, the specialist said like that.
When taking out the melted nuclear fuel, being unable to use an ordinary instrument for taking out the nuclear fuel which isn't melted. Moreover, the melted nuclear fuel gives off strong radioactivity, so taking out is very hard.
How was the melted...
【The steep route to decommissioning】
《Taking out the nuclear fuel is the hardest》
How was the melted nuclear fuel in the pressure vessel? It was examined by ultrasonic at first in the Three Mile Island.
One third on the core became a big hollow in the upper part, and melted nuclear fuel changed into minute particles and accumulated in the lower part of the core.
The melted nuclear fuel solidified and changed into the shape of huge egg in the center on the lower part.
The nuclear fuel was in the special situation, so the special instrument was developed so as to take out the nuclear fuel.
【The steep route to decommissioning】
《Taking out the nuclear fuel is the hardest》
If taking out of the nuclear fuel, opening the lid on the pressure vessel on the upper part, and the work is done usually.
But as strong radiation gave off, two of plates made of stainless of which thickness was 3.5 centimeters were put on the upper place of the pressure vessel and blocking off the radiation. There was a space on the plate and a crane was lowered down from there, and the work was done.
The nuclear fuel in the pressure vessel was varied like minute particles, and a big mass. Flakes and...
【The steep route to decommissioning】
《Taking out the nuclear fuel is the hardest》
Flakes and wreckage which covered the nuclear fuel was also accumulated.
The tip on crane of which shape was varied was prepared so as to dig out and to break.
As to the container which gathering the nuclear fuel, we can't use a made up article as it is.
By the way, I'm tired a little and I can't continue any more today. I'm sorry for it. Please have a nice evening, the readers who read my expression. I'm grateful for you to read my response every time.
【The steep route to decommissioning】
《Taking out the spent nuclear fuel is the hardest》
The container collecting ordinary nuclear fuel is the one which is designed to put into fixed shape, so a special container so as to put into the melted nuclear fuel was prepared.
It was October in 1985 after ten years from the accident when taking out the nuclear fuel started in the Three Mile Island at last.
As to the atomic power plant in Fukushima, the special apparatus has to be developed and to take out the nuclear fuel.
How is it in the atomic reactor? We have to understand it accurately so…
【Steep route to decommissioning】
《Taking out the nuclear fuel is the hardest》
We need to understand the situation in the atomic reactor precisely before taking out the nuclear fuel, the specialist said like that.
Furthermore, taking out the nuclear fuel is by far harder in the atomic power plant in Fukushima than the one in the Three Mile Island, for there is possibility that the melted nuclear fuel made a hole at the bottom of the pressure vessel and there was the melted nuclear fuel below the pressure vessel.
Collecting the nuclear fuel which dropped in the container vessel isn’t easy.
【Steep route to decommissioning】
《Taking out the nuclear fuel is the hardest》
Developing the machine for working which we can control from the remote place and collecting would be done, the specialist said like that.
As to the atomic power plant in Three Mile Island, the work on taking out the nuclear fuel took some four years and finished January in 1990 after 11 years from the nuclear disaster.
It has been worried about that the atomic power plant in Fukushima would take longer time.
After taking out the nuclear fuel is over and decontamination finished, dismantling atomic reactor…
【Steep route to decommissioning】
…dismantling the atomic reactor would start then. As long at when reaching the situation, dismantling itself would be done as the ordinary atomic reactor.
《Unknown material existing in the pressure vessel》
To tell the truth, there is one more thing in the atomic power plant in Fukushima which is different from the one in the Three Mile Island. It’s the large amount of salt remains in the pressure vessel.
As function of pouring water into the atomic reactor was lost at the atomic power plant in Fukushima, the seawater was poured so as to cool down.
【Steep route to decommissioning】
《Unknown material existing in the pressure vessel》
It has been thought more than 100 ton of salt was poured into each of pressure vessel in the atomic reactor, and the specialist pointed out that there is the possibility that the salt becomes a new problem.
There is the possibility that the salt reacts with uranium which is component on the nuclear fuel and makes up chemical compound. The problem is we have little information on the chemical compound with the salt.
After taking out the nuclear fuel and safekeeping has to be in the container.
【Steep route to decommissioning】
《Unknown material existing in the pressure vessel》
Then there is a fear that the container decays owing to the chemical pound on uranium with the salt.
After taking out the nuclear fuel, it has to do safekeeping for dozens of years. Then the container would damage on account of the decay and the radioactive material may have leaked.
We have to think out something then. For example, put the nuclear fuel into the container made of ceramic in the first place so as to prevent the container from decaying.
What kind of nature does the chemical compound have?
【Steep route to decommissioning】
We have to study the chemical compound on uranium with the salt so as to taking out the nuclear fuel, the specialist said like that.
《Final disposal on the nuclear waste is also the big theme》
Even if having achieved the decontamination and taken out the nuclear fuel, and being able to dismantle the atomic reactor, there is also the problem. When decommissioning, radioactive waste including radioactive material gives off. How should we dispose of it?
At first, even if the nuclear disaster doesn’t break out, disposing of the nuclear waste which is given…
【Steep route to decommissioning】
《Final disposal on the nuclear waste is also the big theme》
…disposing of the radioactive waste giving off from the atomic power plant is tiresome.
In Japan, the radioactive waste is classified into low level and high level. The low level is a filter which prevents the radioactive material from leaking outside the atomic power plant, and protective clothing, gloves when working at the atomic power plant.
As to the one in low level, burning down and compressing so as to reduce its cubic content, and putting it into an exclusive drum, solidified with cement.
【Steep route to decommissioning】
《Final disposal on the radioactive waste is the big theme as well》
The radioactive waste of low level in the drum is buried on the ground below several meters and is disposed of finally.
On the other hand, the high level radioactive waste is solidification with glass which high dense radioactive material is included. It means the spent nuclear fuel itself in some other countries.
The solidification with the glass is made when reprocessing the spent nuclear fuel. The reprocessing means taking out uranium and plutonium from remained in the nuclear fuel with…
【Steep route to decommissioning】
《Final disposal on the radioactive waste is the big theme as well》
Reprocessing is taking out uranium and plutonium from remained nuclear waste with chemical disposal, and in the process, the waste liquid is made. It’s solidified with glass. It’s the solidification with glass.
The solidification with glass has high radioactivity extremely. If touching it direct, it means being exposed to radiation of fatal dose in no more than twenty second.
Therefore after putting into can made of stainless and putting into metallic container of which thickness is 20 cm.
【Steep route to decommissioning】
《Final disposal on the radioactive waste is also the big theme》
The problem on the final disposal of the radioactive waste of high level has been the big theme all over the world. Burying underground deeply, deeper than three hundred meter underground and disposing of it. It has been thought realistic.
But as to the landfill on the radioactive waste of high level from the commercial atomic reactor concretely has never been completed in the world, though its plan has gone ahead in Finland and Denmark.
There is an institution which stores the radioactive…
【Steep route to decommissioning】
《Final disposal on the radioactive material is also the big theme》
There is an institution storing the radioactive waste of high level for from three to five decade at Rokkasyo village in Aomori prefecture, but it isn’t the final landfill. Where should we dispose of the radioactive waste of high level? It has never been determined yet at present.
The radioactive waste made by the nuclear disaster is beyond assumption on the way of disposing, so we have to considerate how to dispose of it.
As to the atomic power plant in the Three Mile Island…
【Steep route to decommissioning】
《Final disposal on the radioactive waste is the big theme as well》
…the radioactive waste on low level was buried on the ground and was disposed in the landfill. The collecting nuclear fuel will be supposed to be put into the for container which is prepared and to be stored in the pool for three decade.
Meltdown broke out in Chernobyl in 1986, but collecting the melted nuclear fuel wasn’t done. Instead covering the whole atomic reactor with building made of concrete, and the nuclear fuel remains as it was at present. It’s called sarcophagus 石棺.
【Steep route to decommissioning】
《Final disposal on the nuclear fuel is also the big problem》
A large amount of radioactive waste would be made at the atomic power plant in Fukushima as well, but the way of disposing wasn’t determined when this description was done.
As to the atomic power plant in Fukushima, it’s different from the one in the Three Mile Island and a large amount of polluted water included radioactive material was made, and the work for purifying the polluted water goes ahead.
Purifying the polluted water doesn’t always mean that the radioactive material disappears.
【Steep disposal to decommissioning】
《Final disposal on the radioactive waste is also the big problem》
When disposing of the polluted water, filters and radioactive absorbent are used. It’s just that the radioactive material in the polluted water moves to the filter and the radioactive absorbent.
The polluted water contains lots of radioactive material melting from the nuclear fuel, and when the disposal was over, the radioactive material accumulates on the filter and the radioactive absorbent.
How should we dispose of the radioactive waste which has high radioactivity? It’s also the…
【Steep route to decommissioning】
《Final disposal on the radioactive waste is also the big problem》
It’s also the problem.
The nuclear disaster in Fukushima was so big that decommissioning on the atomic reactor faces lots of difficult problems. Getting over those problems and the decommissioning has to be done steadily, the author said like that.
There is polluted water includes radioactive material exhausted from the atomic power plant in Fukushima. It’s more than 100 ton and was used so as to cool down the nuclear fuel. It’s determined to release into the off the coast of Fukushima.
【Steep route to decommissioning】
The polluted water will be released to off the coast of Fukushima prefecture in the Pacific Ocean. As to the level on the radioactivity of the polluted water, it’ll be made as the same as drinking water and be released into the sea, according to the announcement in the government.
Even if it’s radioactive level is same as drinking water, I’m sure none of is ready to drink. Far from it, It’s so dangerous that it will be released into the sea. The release starts from this year. It takes dozens of years until it’s completed.
Not only local fishers’ but…
【Steep route to decommissioning】
Not only local fishers’ association but China and South Korean have been opposed to the plan.
As to the radioactive material, if the polluted water is the same as the drinking water, it doesn’t to be thrown away into the sea, but It’s so dangerous that it has to be thrown away into the sea, I’m sure.
I’m afraid the sea and creatures in the sea will be polluted by the radioactive material, and we’ll eat the polluted creature in the sea without knowing it, but what should we do? No one hate the dangerous thing is thrown away near.
【Thinking of electricity shortage from the foundation】
《When does the black out happen? What should we do in order to avoid the blackout in summertime?》
We have been worried about the electricity shortage each place in the whole nation since the disaster in the eastern Japan in 2011. If the demand for electricity exceeds the ability on supplying electricity from the power plant, it is said that there is possibility that the blackout happens suddenly.
When the demand on electricity is over the supply the electricity a little, the electricity isn’t sent to us. Why?
【Thinking of the electricity shortage from the foundation】
《When does the blackout happen? What should we do so as to avoid the electricity shortage in summertime?》
Let’s thinking of generating electricity, and sending electricity from the foundation to the mechanism which causes blackout because of the electricity shortage, the author said like that.
The big earthquake broke out on the 11th day March in 2011, and it made not only the atomic power plant in Fukushima but some other atomic power plants and thermal electric power plants stop operating.
Power plants usually generate…
【Thinking of the electricity shortage from the foundation】
Power plants usually generate necessary electricity and supply the electricity, according to the demand. If the power plants can’t supply the electricity for the demand, it is said there is a fear that the blackout occurs if the worst happens. The author said he was going to express its mechanism and measure.
《A large amount of electricity is consumed every summer》
How was the electricity used from 2008 to 2010? The author said he was going to express at first. A large amount of electricity is used in both June, August.
【Thinking of electricity shortage from the foundation】
《A large amount of electricity is consumed every summer》
Air conditionings are turned on all at once during daytime in summertime when the temperature becomes high, and necessary electricity increases then.
Tokyo electric power company repaired an old thermal power plants and making them operate, and the electricity was sent from other power company in other district so as to prepare for the electricity in summertime in 2011. It also called large scale companies to save electricity.
The electricity shortage isn’t the problem in the…
【Thinking of electricity shortage from the foundation】
《A large amount of electricity is consumed every summer》
The electricity shortage isn’t the problem in Kanto area alone, for some of the atomic power plants are under periodic inspection, so it wasn’t clear when they started to operate, so each place is worried about the electricity shortage.
There are electric power companies which doesn’t have enough ability for supplying electricity, and sending electricity to those companies from other ones was done. As a result, it seems enough ability to send electricity is lost.
【Thinking of electricity shortage from the foundation】
《A large amount of electricity is consumed every summer》
If enough ability to send electricity becomes small, there is a fear that the demand on the electricity exceeds supplying for the electricity. It is said then blackout happens unexpectedly. The demand on electricity exceeds the supply for electricity a little, the blackout happens. Why?
How is the electricity sent to every home? The author said he was going to express it so as to know why the blackout happens.
《How is the electricity sent to households?》
Power plants make…
【Thinking of electricity shortage from the foundation】
《How is the electricity sent to households?》
Power plants make electric generator revolve and generating electricity on alternating current 交流 at first. Its source of energy is hydraulic power of flow on the water accumulating in dam in high place, thermal power on burning petroleum, or atomic power made by nuclear fission from nuclear fuel. It’s various.
In the next, the electricity which was made raised its electric voltage before sending. In fact, when the energy of electricity is sent through the transmission line, the part of…
【Thinking of electricity shortage from the foundation】
《How is the electricity sent to households?》
…the part of energy on the electricity becomes heat and is lost.
When sending electric power to some extent, the electricity on high voltage has little heat to lose if comparing it with the electricity on low voltage, so after generating electricity, It’s raised to the high voltage at once. The electricity which is lost when sending is some 5% on generating electricity.
Thus the electricity with high voltage is sent for the long distance. After that the electric voltage is dropped in an…
【Thinking of electricity shortage from the foundation】
《How is the electricity sent to households?》
After that the electricity is dropped in an electric booster station near the house on contractor and electricity is delivered.
The electricity of high voltage comparatively is sent to big customer elephant like railway companies and big companies, after that the voltage was dropped in the electric booster station and the electricity is sent to companies, factories, and households through the power grid.
In this way, making the electricity which is lost when sending is as small as possible.
【Thinking of electricity shortage from the foundation】
《How is electricity sent to households?》
In addition, power plants stop generators at night when there are few people who use the electricity and make the generators operate during the daytime when using the amount of electricity increases, and generating electricity whenever the electricity needs.
In consequence, power companies make a plan of generating and change the amount of generation on electricity according to the demand, referring the change on the amount of consuming electricity, and prediction on the change of temperature,
【Thinking of electricity shortage from the foundation】
Besides, the amount of supplying for electricity must not be over the demand. It is said it has to be arranged to match the changing demand as same as possible.
《How does the black out happens?》
Why do we need to match the demand to supply?
If there is a big difference between the demand and supply, unusual sending electricity which is different from frequency and from electric voltage is done. In the worst case scenario, the transforming equipment broke down or the apparatus which received the electricity ends up malfunctioning.
【Thinking of electricity shortage from the foundation】
《How does the blackout happen?》
If there is difference between the demand and supply, it is detected before the equipment is damaged and sending electricity is stopped partly. It’s the blackout. The blackout plays a role as safety device.
But if the blackout happens suddenly, it will have big influence over the society, so the unexpected blackout must not use easily. It’s the last resort.
There are three factors which cause the blackout. The one is changing on frequency, and the other is the voltage becomes low unusually and the…
【Thinking of electricity shortage from the foundation】
《How does the blackout happen?》
…and the last one is the whole power grid becomes unstable.
The change on frequency is demand and supply on the electricity collapses so much that the frequency gets out of the fixed area and it leads to the blackout. Immediately after the earthquake on the 11th day March in 2011, it was reported that the blackout may have happened because of the change on the frequency.
What is the dropping the electric voltage unusually?
Demand on electricity surpasses the ability on sending electricity in the…
【Thinking of electricity shortage from the foundation】
《How does the blackout happen?》
The demand on the electricity surpasses the ability on sending electricity in the power grid and the electric voltage drops lower than the fixed value so much, and the blackout happens.
What is the whole power grid is unstable?
The rotation on lots of generators connecting with the power grid is disturbed over influence by an accident like thunderbolt, and the blackout happens easily. We call the situation the whole power grid is unstable.
For example, blackout happens in an area owing to the…
【Thinking of electricity shortage from the foundation】
《How does the blackout happen?》
For example, the blackout happens in an area on account of the thunderbolt, and generators connecting with power grid around is burdened, then generators stop one after another. The blackout spreads in this way and develops into the large scale of blackout sometimes.
A large demand against the electricity which is near the limit on the ability of sending electricity in the power grid causes the large scale of blackout easily.
The large scale of blackout unexpectedly causes various problems. Being …
【Thinking of electricity shortage from the foundation】
《How does the blackout happen?》
There is possibilities that being trapped in elevator, or medical equipment which is used at home stops. Means of transport is paralyzed and flow on things and the people stops and the function on the society stops.
An instance in recent years, the large scale of blackout broke out in North America in 2003, in Europe in 2006.
Does the large scale of blackout happen in Japan as well? As to Japan, the connection between electric companies is weaker, if comparing it with Europe and America, so the large…
【Thinking of electricity shortage from the foundation】
《How does the blackout happen?》
…so the large scale of blackout on the whole of the electric companies doesn’t happen easily, but there is the possibility on the large scale of blackout.
Connection among each of electric company is weak. It means that when an local area falls into electricity shortage, the electric company in the area has to secure the electricity for itself.
It will takes a long time for recovery on generating facilities and enough ability of supplying electricity isn’t secured continues for a long time.
【Thinking of electricity shortage from foundation】
《How does the blackout happen? 》
The situation in being lack of reserved energy power continues, so we can't cancel the fear of falling into the black out. Except for the Tokyo Electric Power Company, other ones have been worried about the same problem.
The atomic power plant was under periodical inspection, so it's not clear when it started again, on the other hand, other nuclear power plants which operate will be under periodical inspection soon, so the outlook on supplying electricity is hard to foresee.
《Pumping up water at night...》
【Thinking of electricity shortage from the foundation】
《Pumping up water at night and preparing for the peat during the daytime》
We need reserved from 8 to 10% electric power against the demand on electricity so as to avoid the black out, so it planned to make use of pumped storage power generation actively as one of ways in order to increase the supply for the electricity.
The amount of consuming electricity is little at night, so generating electricity more than the amount of consumption at night and pumping up the water to highland with the electricity then.
When the electricity...
【Thinking of electricity shortage from the foundation】
《Pumping up water at night and preparing for the peak during the daytime》
When the electricity needs in the daytime, flowing the stored water and generating electricity then.
We can't save the electricity as it is, but if changing it into other energy, we can. Generating electricity at night and saving it at the form of potential energy at 位置エネルギー the high place.
But whenever changing into other one, the energy decreases. As to the generating electricity by pumping up the water, the fuel on the petroleum, the electricity at night...
【Thinking of electricity shortage from the foundation】
《Pumping up the water at night and preparing for the peak during the daytime》
Fuel on the petroleum and so on, the electricity at night, water and the electricity in the daytime, as it's repeated, so its efficiency is worse than the hydroelectric power of flowing water automatically. It's the fault on the generating electricity by pumping up the water.
Generating electricity at night and saving the electricity in battery, it's all right, some people may have said like that, but the battery is expensive and inefficient so as to save...
【Thinking of electricity shortage from the foundation】
《Pumping up the water at night and preparing for the peak in the daytime》
…but the battery is expensive and insufficient so as to save the large amount of electricity. It’s not realistic.
There are thermal power plants which have been stoped, so making them operate again and building new thermal power plants are done.
《Half on the consumption of electricity in household is air conditioning for cooling during the daytime in summertime》
Decreasing the demand on the electricity leads to increase reserved electric power.
【Thinking of electricity shortage from the foundation】
《Half of the consumption on the electricity in household is air conditioning during the daytime in summertime》
The temperature is high at weekend in summertime, and the air conditioning is off and on and the setting temperature on the air conditioning is dropped, so the consumption on the electricity is the highest in the whole year then.
The amount of consumption on the electricity makes up for some one third in the household at that time. Be careful not to suffer from heatstroke, we need not to drop the setting temperature too much.
【Thinking of electricity shortage from the foundation】
《Half of the consumption on electricity in household is air conditioning for cooling during the daytime in summertime》
Dropping the setting temperature on the air conditioning not too much is efficient for saving electricity. The measure of raising the setting temperature on refrigerator has been thought.
Plugging home appliance in alone consumes standby power 待機電力, so pulling the plug from home appliance which isn’t used leads to save electricity.
Not decreasing the amount of consumption on the electricity but shifting the time when…
【Thinking of electricity shortage from the foundation】
《Half of the consumption on electricity in household is air conditioning for cooling during the daytime in summertime》
…but shifting time when the electricity is used is effective. We call it peak shift.
Immediately before the peak from twelve to thirteen o’clock when the consumption on the electricity increases, the amount of consumption on the electricity decreases owing to noon recess.
After the disaster on the earthquake in Tohoku area, part of companies have taken step of shifting the lunch recess. Moreover Sunday and national…
【Thinking of electricity shortage from the foundation】
As lots of companies are day off on Sunday, so the demand on the electricity drops on that day, so some companies make their factory operate on Sunday, and day off is one of weekday. That kind of attempt has been done.
《Is it possible the power grid in which black out doesn’t happen?》
The supply for electricity has been controlled according to the demand on electricity which changes from moment to moment. If being able to control the electricity not only supplying but the demand, we can prevent the blackout from happening definitely.
【Thinking of electricity shortage from the foundation】
《Is it possible the power grid in which the blackout doesn’t happen?》
For example, let’s suppose when the reserved electricity became small, setting upper limit on the amount of consumption at the meter in a household automatically was done.
When dropping the setting temperature on the air conditioning by 1 degree, if it exceeds the setting temperature, we can control in order not to drop the temperature, and can prevent the demand from rising.
We call the meter which has the function like that smart meter. Empirical research trying …
【Thinking of electricity shortage from the foundation】
《Is it possible the power grid in which blackout doesn’t happen?》
Empirical research trying to introduce the smart meter has been progressed. If it comes true, without planned power outage, everyone learns to be able to use the electricity at will, though it’s in limited range.
In addition, instead of everyone trying to save electricity consciously, making the home appliance and the meter save the electricity automatically. It may be possible in future, but it seems to take a long time, though we’ve hoped it, the author said like that.
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