Why Fukushima Reactor Explode? The explosion at a nuclear reactor in Fukushima has happened three times since the quake rocked Japan with 9 strength on Friday (03/11/2011) then. The first explosion occurred in reactor number 1 last Saturday, followed by an explosion in reactor number three on Monday, and the last explosion occurred in reactor number 2, Tuesday. Many feared a large nuclear radiation as a consequence of the explosion.
However, how the explosion could actually happen? Then, did the explosion will spur a nuclear disaster as great as feared? For that, need to see some important aspects to the process of explosion of the reactor, including reactor type, how reactors work, and the factors that trigger the explosion.
Faculty of Engineering Physics Department, Gadjah Mada University who now participate in the safety assessment of nuclear technology in Sweden, Dr Alexander the Great ST, M. Sc, an interim analysis reveal the related explosion Fukushima reactor 1 at the official web site of Engineering Physics GMU.
He revealed that the Fukushima I Nuclear Power Plant Unit 1 is the type BWR (boiling water reactor). The electric power generated is 460 MW capable, with 1553 MW thermal power and thermal efficiency assumption of 30 percent. The reactor was built at the end of the 1960s and operates the early 1970s.
He said, "In a nuclear reactor, energy is produced from the fission or splitting of atomic nuclei." Fission reaction also produce energy radioaktf that will decay. The amount of energy produced from a fission reaction is the total energy of fission and radioactive decay energy.
The size of the energy produced in fission reactions depending on the extent of the fission process. Fission reaction can be controlled with control rods or control rods. If all control rods inserted, the reactor will be extinguished, known as the shut down.
Securing nuclear reactor familiar jargon 3C, namely Control, Cool and Contain. Control-related efforts to prevent a sharp increase in energy, Cool associated with efforts to cool the fuel, and Contain related to efforts to keep the radioactive material to remain in a reactor.
"Keep in mind that all three could serve as an aspect of defense," he said. If the control does not function, then there are the cooling system. Then, if the cooling system is not functioning well, then there is still a reactor containment which would prevent the escape of radioactive materail.
Well, Fukushima reactor explosion at an associated with the failure of the protection system and factors related to it. When an earthquake occurs, the actual control system is functioning successfully extinguish the reactor so that the fission reaction in the reactor does not happen again.
"However, there is the energy of radioactive decay. At the time of the reactor outage, there are still 7 percent from 1553 MW, or equal to 107 MW," he said. In these conditions, the cooling system should be working to drain the water at the beginning of the system to function.
Unfortunately, the cooling system finally crashed after an hour because the electric generator killed by the tsunami. "The situation is known as LOFA (loss of flow accident), which is cooler still exist, but does not flow," explained Alex. As a result, heat can not be transferred.
According to Alex, there are two phenomena that can occur. First, the rising temperatures trigger a boiling coolant so that the top of a closed reactor water vapor. "If this happens, the possibility of fuel melting. If the melted fuel, radioactive materials are released into the cooling system," explained Alex.
The second possibility is to increase the temperature of the fuel cartridge. Sleeve is wrapping fuel made from zirconium alloy. If the temperature rises to 900 degrees celsius, the zirconium is oxidized by water to produce hydrogen.
Alexander revealed, until now the phenomenon is unclear whether that happened. However, he suspected that the accumulated hydrogen reacts with oxygen so that hydrogen explosion. This caused the explosion in Fukushima 1 Unit 1. Force of the blast was strong enough to demolish the building around it, but not to damage the reactor protective sleeve.
In fact, the explosion occurred at these reactors after TEPCO (Tokyo Electric Power Company) drain the sea water to cool the reactor directly. Explosion also called part of the reactor cooling process which does not harm the plant.
Radiation is reported to have reached Tokyo, but do not endanger human health. Tokyo Metropolitan Government official said, "We are monitoring the radiation levels that exceeded the normal limit occurred this morning in Tokyo. However, we do not consider that it is already at the level that is harmful to human body."
Permbangkit nuclear power plant is located 250 kilometers northeast of Tokyo. Kyodo News Agency also reported that radiation levels in the city of Maebashi, 100 kilometers north of Tokyo, rose 10-fold above normal limits.
However, how the explosion could actually happen? Then, did the explosion will spur a nuclear disaster as great as feared? For that, need to see some important aspects to the process of explosion of the reactor, including reactor type, how reactors work, and the factors that trigger the explosion.
Faculty of Engineering Physics Department, Gadjah Mada University who now participate in the safety assessment of nuclear technology in Sweden, Dr Alexander the Great ST, M. Sc, an interim analysis reveal the related explosion Fukushima reactor 1 at the official web site of Engineering Physics GMU.
He revealed that the Fukushima I Nuclear Power Plant Unit 1 is the type BWR (boiling water reactor). The electric power generated is 460 MW capable, with 1553 MW thermal power and thermal efficiency assumption of 30 percent. The reactor was built at the end of the 1960s and operates the early 1970s.
He said, "In a nuclear reactor, energy is produced from the fission or splitting of atomic nuclei." Fission reaction also produce energy radioaktf that will decay. The amount of energy produced from a fission reaction is the total energy of fission and radioactive decay energy.
The size of the energy produced in fission reactions depending on the extent of the fission process. Fission reaction can be controlled with control rods or control rods. If all control rods inserted, the reactor will be extinguished, known as the shut down.
Securing nuclear reactor familiar jargon 3C, namely Control, Cool and Contain. Control-related efforts to prevent a sharp increase in energy, Cool associated with efforts to cool the fuel, and Contain related to efforts to keep the radioactive material to remain in a reactor.
"Keep in mind that all three could serve as an aspect of defense," he said. If the control does not function, then there are the cooling system. Then, if the cooling system is not functioning well, then there is still a reactor containment which would prevent the escape of radioactive materail.
Well, Fukushima reactor explosion at an associated with the failure of the protection system and factors related to it. When an earthquake occurs, the actual control system is functioning successfully extinguish the reactor so that the fission reaction in the reactor does not happen again.
"However, there is the energy of radioactive decay. At the time of the reactor outage, there are still 7 percent from 1553 MW, or equal to 107 MW," he said. In these conditions, the cooling system should be working to drain the water at the beginning of the system to function.
Unfortunately, the cooling system finally crashed after an hour because the electric generator killed by the tsunami. "The situation is known as LOFA (loss of flow accident), which is cooler still exist, but does not flow," explained Alex. As a result, heat can not be transferred.
According to Alex, there are two phenomena that can occur. First, the rising temperatures trigger a boiling coolant so that the top of a closed reactor water vapor. "If this happens, the possibility of fuel melting. If the melted fuel, radioactive materials are released into the cooling system," explained Alex.
The second possibility is to increase the temperature of the fuel cartridge. Sleeve is wrapping fuel made from zirconium alloy. If the temperature rises to 900 degrees celsius, the zirconium is oxidized by water to produce hydrogen.
Alexander revealed, until now the phenomenon is unclear whether that happened. However, he suspected that the accumulated hydrogen reacts with oxygen so that hydrogen explosion. This caused the explosion in Fukushima 1 Unit 1. Force of the blast was strong enough to demolish the building around it, but not to damage the reactor protective sleeve.
In fact, the explosion occurred at these reactors after TEPCO (Tokyo Electric Power Company) drain the sea water to cool the reactor directly. Explosion also called part of the reactor cooling process which does not harm the plant.
Radiation is reported to have reached Tokyo, but do not endanger human health. Tokyo Metropolitan Government official said, "We are monitoring the radiation levels that exceeded the normal limit occurred this morning in Tokyo. However, we do not consider that it is already at the level that is harmful to human body."
Permbangkit nuclear power plant is located 250 kilometers northeast of Tokyo. Kyodo News Agency also reported that radiation levels in the city of Maebashi, 100 kilometers north of Tokyo, rose 10-fold above normal limits.
