Construction of the Fukushima Nuclear Power Plants

 The plants at Fukushima are so called Boiling Water Reactors or BWR for short. Boiling Water Reactors are similar to a pressure cooker. The nuclear fuel heats water, the water boils and creates steam, the steam then drives turbines that create the electricity, and the steam is then cooled and condensed back to water, and the water send back to be heated by the nuclear fuel. The pressure cooker operates at about 250 °C.

The nuclear fuel is uranium oxide. Uranium oxide is a ceramic with a very high melting point of about 3000 °C. The fuel is manufactured in pellets (think little cylinders the size of Lego bricks). Those pieces are then put into a long tube made of Zircaloy with a melting point of 2200 °C, and sealed tight. The assembly is called a fuel rod. These fuel rods are then put together to form larger packages and a number of these packages are then put into the reactor. All these packages together are referred to as “the core”.

The Zircaloy casing is the first containment. It separates the radioactive fuel from the rest of the world. The core is then placed in the “pressure vessels”. That is the pressure cooker we talked about before. The pressure vessel is the second containment. This is one sturdy piece of a pot, designed to safely contain the core for temperatures several hundred °C. That covers the scenarios where cooling can be restored at some point.

The entire “hardware” of the nuclear reactor – the pressure vessel and all pipes, pumps, coolant (water) reserves, is then encased in the third containment. The third containment is a hermetically (air tight) sealed, very thick bubble of the strongest steel. The third containment is designed, built and tested for one single purpose: To contain, indefinitely, a complete core meltdown. For that purpose, a large and thick concrete basin is cast under the pressure vessel (the second containment), which is filled with graphite, all inside the third containment. This is the so-called “core catcher”. If the core melts and the pressure vessel bursts (and eventually melts), it will catch the molten fuel and everything else. It is built in such a way that the nuclear fuel will be spread out, so it can cool down.

This third containment is then surrounded by the reactor building. The reactor building is an outer shell that is supposed to keep the weather out, but nothing in. (this is the part that was damaged in the explosion, but more to that later).

About Radiation

The radiation level getting higher around TOHOKU areas after Fukushima Nuclear Plant being damaged by tsunami. However Japan Government announced that the situation is still under control and no harm to human as for now. Most cities start to monitor the radiation level. We can see latest information about radiation level from MEXT (Ministry of Education, Culture, Sports, Science and Technology)

http://eq.wide.ad.jp/index_en.html

Chart below shows about radiation levels and its effect to human body. Yonezawa City's radiation is very low at about 0.1 microseiverts. However at Fukushima Nuclear Plant it is about 1000 milisieverts (near reactor 2). 1000 milisieverts is maximum range for measurement, it means they really don’t have the real value of radiation level there…

There is massive leakage that already pollutes cooling water near the reactor. As a result of finding plutonium and finding a high density of radiated water, it’s clear that the fuel has melted. Radiation levels are soaring in seawater near the crippled Fukushima plant core. Two weeks after the nuclear power plant was hit by a massive earthquake and tsunami, tests on 25 March showed radioactive iodine had spiked 1,250 times higher than normal in the seawater just offshore the plant. Radioactive water has been found in all four of the reactors at the plant, which workers are continuing to pump out in an attempt to restore the plant’s cooling system. Nuclear safety official Hidehiko Nishiyama said that the cooling the reactors is the priority at this point. The removal of the contaminated water is the most urgent task now, and hopefully we can adjust the amount of cooling water going in,” he told the Associated Press.

What Types of Radiation Are There?

The radiation one typically encounters is one of four types: alpha radiation, beta radiation, gamma radiation, and x radiation. Neutron radiation is also encountered in nuclear power plants and high-altitude flight and emitted from some industrial radioactive sources.

1. Alpha Radiation

Alpha radiation is a heavy, very short-range particle and is actually an ejected helium nucleus. Some characteristics of alpha radiation are:

Most alpha radiation is not able to penetrate human skin. Alpha-emitting materials can be harmful to humans if the materials are inhaled, swallowed, or absorbed through open wounds. A variety of instruments has been designed to measure alpha radiation. Special training in the use of these instruments is essential for making accurate measurements. A thin-window Geiger-Mueller (GM) probe can detect the presence of alpha radiation. Instruments cannot detect alpha radiation through even a thin layer of water, dust, paper, or other material, because alpha radiation is not penetrating. Alpha radiation travels only a short distance (a few inches) in air, but is not an external hazard. Alpha radiation is not able to penetrate clothing. Examples of some alpha emitters: radium, radon, uranium, thorium.

2. Beta Radiation

Beta radiation is a light, short-range particle and is actually an ejected electron. Some characteristics of beta radiation are:

Beta radiation may travel several feet in air and is moderately penetrating. Beta radiation can penetrate human skin to the "germinal layer," where new skin cells are produced. If high levels of beta-emitting contaminants are allowed to remain on the skin for a prolonged period of time, they may cause skin injury.

Beta-emitting contaminants may be harmful if deposited internally. Most beta emitters can be detected with a survey instrument and a thin-window GM probe (e.g., "pancake" type). Some beta emitters, however, produce very low-energy, poorly penetrating radiation that may be difficult or impossible to detect. Examples of these difficult-to-detect beta emitters are hydrogen-3 (tritium), carbon-14, and sulfur-35.

Clothing provides some protection against beta radiation. Examples of some pure beta emitters: strontium-90, carbon-14, tritium, and sulfur-35.

3. Gamma and X Radiation

Gamma radiation and x rays are highly penetrating electromagnetic radiation. Some characteristics of these radiations are:

Gamma radiation or x rays are able to travel many feet in air and many inches in human tissue. They readily penetrate most materials and are sometimes called "penetrating" radiation. X rays are like gamma rays. X rays, too, are penetrating radiation. Sealed radioactive sources and machines that emit gamma radiation and x rays respectively constitute mainly an external hazard to humans. Gamma radiation and x rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations differ only in the amount of energy they have. Gamma rays and x rays are the most energetic of these. Dense materials are needed for shielding from gamma radiation. Clothing provides little shielding from penetrating radiation, but will prevent contamination of the skin by gamma-emitting radioactive materials. Gamma radiation is easily detected by survey meters with a sodium iodide detector probe. Gamma radiation and/or characteristic x rays frequently accompany the emission of alpha and beta radiation during radioactive decay.

Examples of some gamma emitters: iodine-131, cesium-137, cobalt-60, radium-226, and technetium-99m.

[Reference: Health Physics Society]

http://www.hps.org/publicinformation/ate/faqs/radiationtypes.html

Fukushima Daiichi Nuclear Plant...

As we all know after the earthquake occurred giant scale of tsunami wiped all cities near the sea. As I mentioned before it was the worst tragedy I ever saw. It happened in just 6 minutes then it ended. However another disaster happened when Fukushima Daiichi (means No 1) Nuclear Plant that was hit by tsunami had major damages. At that time, eleven nuclear reactors at the four nearest power plants automatically shut down upon sensing ground accelerations, stopping the nuclear fission of uranium in their cores. Nuclear fuel requires continued cooling even after a plant is shut down, though, because residual fission products continue to decay and produce a huge amount of heat.

TThe Japanese plants use continually-pumped water, which absorbs a great deal of heat, to cool their nuclear reactors. The earthquake knocked out the electricity at the Fukushima Daiichi plant run by Tokyo Electric Power Company (TEPCO). Emergency diesel generators were used to pump water to cool Reactor Units 1, 2 and 3, which had been operating at the time of the quake, but an hour later, the back-up generators were knocked out by tsunami flooding.

Insufficient power means that water could not be pumped through the nuclear cores quickly enough. As the water inside the reactors heated up too high and started boiling, the water level dropped inside the cores, and the pressure rised from the steam. TEPCO declared a state of emergency. Japanese authorities ordered the evacuation of residents within a 20-kilometer radius of Fukushima Daiichi, and told people within a 20 to 30-kilometre radius to remain indoors. There had been release of radiation from the nuclear power plant.

Reactor Units 5, 6 thought to be in a cold and safe shutdown and the cooling water temperature was found to be dropping. Japanese Government and TEPCO still struggle to solve Unit 1,2,3,4 cooling problems.

Over the following days there was evidence of partial nuclear meltdowns in reactors 1, 2 and 3; hydrogen explosions destroyed the upper cladding of the building housing reactors 1 and 3; an explosion damaged reactor 2's containment; and severe fires broke out at reactor 4. The Japanese authorities rated the events at reactors 1, 2 and 3 as a level 5 (Accident With Wider Consequences) on the International Nuclear Event Scale, while the events at reactor 4 were placed at level 3 (Serious incident).

The problem that scares me is about Nuclear Radiation leakage. I personally think the accidents are different from Chernobyl nuclear plant because the type of reactor used is very different. The Chernobyl plant used graphite as a neutron moderator to produce nuclear fission of the fuel rods. The reactor had no core containment vessel. After the explosion, the graphite, which is made of carbon, burned along with the fuel rods in an exposed state. The possibility is low that a large fire will break out at the Fukushima plant.

On the other hand, the six reactors at the Fukushima plant have a much higher combined power output, and the volume of radioactive materials contained in the reactors are several times greater than at Chernobyl. The outputs of the reactors at the Fukushima No. 1 plant range from 460,000 kilowatts at the No. 1 reactor to 784,000 kilowatts for the No. 2, No. 3 and No. 4 reactors. The combined power output is about three times than 1 million-kilowatt output at Chernobyl. There is a high possibility of large amounts of toxic radioactive materials in the fuel rods, but the levels depend on how long the fuel rods have been used.

[For Detail Information]

1. http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant
2. Timeline of Events at Japan's Fukushima Nuclear Reactors By Natalie Wolchover, Life's Little Mysteries Staff Writer]

WHAT HAPPEN...

When the earthquake occurred, I was at my office explaining about method to analysis data. Suddenly my office started shaking slowly for few seconds and turn bigger. I only waited for 4 seconds and I started walking out from the building. I have learned a lot about earthquake when I experienced Niigata Chuetsu earthquake, therefore eventhough it was a scary moment but I still can control myself to stay calm. The whole building started to shake strongly and it was a very noisy sound all around. Maybe for people who had never experience earthquake, they will think that the building is going to collapse.

Yonezawa city is located in the center between the Pacific Ocean and Sea of Japan. Earthquake is rare phenomenon here, therefore most of people here are not well prepared. Most of the workers were panic, we all assembled in the large ground behind the factory. The most scary thing when big earthquake like this occurred is all live line such as electric powers, water, phone lines will be out of order. We were lucky most of live line work as normal. Only all phone lines cannot be used. I tried to call my wife but the phone not even ringing.

I was really worried about my wife because it was her first time experiencing earthquake, she will be shocked and panic. I waited until the shake stopped, it took about 5-6 minutes. Then I immediately took my car and rushed to my house which is about 15 minutes from my office. As I imagined, my wife freaked out and crying scared. I never see her like that before, it makes me felt really sad. I was speechless and no single word came out from my mouth for her, I could only hold her tight in my arms. After a big earthquake like this, there will be a series of aftershock, therefore we decided to not stay in the house for a while. I took my car and went to the petrol station to refill petrol in my car, then we went to buy some instant food in case of emergency. At that moment no one were rushing to buy things yet because most of the people still don’t know what to do. Then we went to my company to report and I took my notebook pc home. At that evening when I watched TV, I was really shocked with the scale of the tsunami. The real panic happened the next day when everybody started filling petrol and buying everything in the shop. In a day all petrol, foods, daily supplies are gone!

Earthquake and tsunami destroyed most of logistic network in TOHOKU. Most of supplies are stopped and it started to turn to negative spiral when all oil and petrol are not enough for transportations. All petrol stations are closed they only have petrol for emergency usage such as ambulance, police patrol car and etc. During weekend we just stayed at home gathering information. Now at these moment supplies started to come but still have a lot of limitations. I waited for almost 2 hours or more 6:50am~9:00am just to fill about 20 litres of petrol which is less than ½ tank. Foods also very limited. The main reason is most of people are hoarding so there is not enough oil and supplies for affected area. It is getting better now, I was really sad and ironic without been noticed the people in safer place slowdown the supplies for needed ones. Nobody doing it purposely but it is how the economy works. We are all connected in economic world. Another reason why supplies is slow is due to the earthquake, oil factories and logistic companies have to check their facilities first to ensure the safety. I hope by next week most of logistic problems can be solved because most of disaster area needed supplies as soon as possible.

I started work on 14^th March as usual. My wife was still scared because the Fukushima Nuclear Power Plan still in critical situation. However as Top Manager I have to show my commitment towards the company, two of our factories had been destroyed by tsunami and another one in Sendai city had major damage because of earthquake. I really felt grateful, although my wife was still in shock, however she really understand my situation and let me go to work. I felt complicated but I really love her so much, she is a great wife!

First day of work is a disaster. We cannot use phones and faxes so we cannot contact our clients or makers. We checked the damages then tried to continue gathering information. I ordered our IT department to printout all orders balance and checkout the materials that we are able to produce. We were lucky mobile internet can be used so we can contact many clients and makers using emails. Second day most phone lines can be used so we started to contact our client to ask their conditions. We set 3 stages for labeling our clients' conditions, RED as destroyed or cannot be reached, Yellow as can be reached but cannot operated for few days (weeks) and BLUE for fully operating. Production priority is focused on Blue level while setting up the supply chain. Even we had aftershock threat and power problem, we use whatever we have to support our clients. Most of clients and makers are now able to start working however some of them were destroyed in tsunami and will be taking long time to fully recover.

Some people asked me, why I went work at this kind of time, I simply said a lot people in trouble needed us. There is a lot of method to help. If I can help my clients through my work it is honorable things to do. However I had decided I will leave Japan when Malaysian Government or Japanese Government ask me to go back. I work as professional so I cannot just run from responsibility, I need some reason to return home. If Malaysian Government Authority read this blog please sponsor us in Yonezawa to go back to Malaysia so I have reason to apply for holiday to my company (laughing). I’m really in a complicated situation.

At this moment nothing happens yet, I will continue to monitor the situation. To be frankly the Fukushima Nuclear Power Station situation not showing any good results, I believe Japanese Government and Tokyo Power Corp with solve this problem. Yonezawa city is just 97km from Fukushima Nuclear Power Plant The radiation level is rising up however it is still in a safe zone. I hope they can solve this problem before it became worst. I am also worried about how radiation will affect the soil, water and air for future. I will write about Fukushima Nuclear Power Plant in my next post.  

TOHOKU EARTHQUAKE AND TSUNAMI (東北地方太平洋沖地震)

14:46 JST (05:46 UTC) on Friday 11 March 2011 is one moment that I will never forget in my whole life. 9.0-magnitude mega thrust earthquake occurred in "Tōhoku region Pacific Ocean offshore. The epicenter was 130 kilometers (81 mi) off the east coast of the Oshika Peninsula of Tōhoku near Sendai, with the hypocenter at a depth of 32 km (19.9 mi). The earthquake triggered extremely destructive tsunami waves of up to 10 meters that destroy almost all cities near ocean offshore.

I live in Yamagata Prefecture Yonezawa City. My area also have been hit by more than 5 almost 6.0 magnitude earthquake. It was not my first experience, I had experienced a 7.0-magnitude earthquake when Niigata Chuetsu earthquake occurred on 23 October 2004. During that time I slept in my car for 5 days and it take months to recover from all the damages. I was really scared and focus to survive. After 7 years I was shocked again with giant earthquake. This time I even felt more than 5.0 magnitude, the scale of this earthquake are far bigger than I or anyone could imagine. It was the biggest disaster I ever can imagine. The duration of the earthquake is only 6 minutes but during this 6 minutes, it was the scariest moment in Japan. In these 6 minutes almost 8,450 people were killed, including missing people is about 21,000 people and the numbers increasing from time to time. 19,000 buildings have been destroyed by the tsunami. I was very near to the area at that moment, the most sad moment in Japan, seeing most of the cities were destroyed by the tsunami.

Now almost 340,000 people living in evacuation shelters. Some of them still searching for their families and relatives. Can you imagine how they feel searching for their families in the worst environment, no one wanted to go to visit the mortuary because they still cannot accept losing their loving family members. I cannot stand watching people suffering for their lost, it makes my tears drop again and again. Although this is the worst disaster in the history, we will try to rise back with whole strength and spirit to keep living. My sincere condolences to everyone who are affected with earthquake and tsunami. I pray to God for the safety and well-being of the people in Japan.

We in Japan now working hard to fix the situation to be back to normal. However the situation does not allow premature conclusions because Fukushima Nuclear Power Plant still in critical situation. I will explain in future post regarding this matter. I also will explain the detail situation in my future post.

I call upon people who wanted to support and help the victims of this disaster, please donate because they need a lot of support and also prayers. My area Yonezawa city is situated near Fukushima and Sendai. I also send some money and foods for some people. If anyone of you wanted to help the victims of this disaster in Japan you can donate from google site http://www.google.co.jp/intl/en/crisisresponse/japanquake2011.html 
or other organizations which are collecting donation for the earthquake and tsunami victims in Japan. Please be very careful about nominal donation scam for earthquake victims.