Japanese Nuclear Boy Explains Disaster - LOL!

Fukushima's Cold Shutdown

Recent News on Fukushima status:

Fukushima plant declared stable; Japanese PM says reactors are in 'cold shutdown,' setting the stage for return of some evacuees

Err... Cold Shutdown? What does that means?

I've found an interesting article (Q&A session to be more precise) to provide us with better understanding with the terms "Cold Shutdown"

Q: What does it mean when a nuclear reactor has achieved a "cold shutdown?"

Answer: It means the reactors have been stabilized and shut down. Under normal circumstances this means control rods have been inserted into the gaps between the fuel rods in the reactor, and the temperature of the water in the reactor pressure containers is below 100 degrees Celsius. In this scenario, fuel rods are contained within the pressure container, with no radiation leaking out.

Q: Is this the definition being used for the Fukushima No. 1 Nuclear Power Plant?

A: No, a slightly different definition is being used. Meltdowns have occurred at the Fukushima plant and the reactors are damaged, so when the government formulated "Step 2" of its nuclear disaster management plan, the phrase took on a slightly different meaning. The government has defined a cold shutdown for the Fukushima plant as a situation in which the temperature at the bottom of the reactor pressure containers is less than 100 degrees Celsius, and the radiation levels at the edge of the plant premises are below one millisievert per year.

Q: Why does the water in the reactors have to be cooled below 100 degrees Celsius?

A: Because otherwise the nuclear fuel could break down. In a normal nuclear plant, radioactive uranium-235 contained in the fuel absorbs neutrons and breaks down into other materials. This is called nuclear fission, and it produces a huge amount of thermal energy. Nuclear plants use this heat to generate electricity. While a nuclear plant is running, the temperature of the water in the reactor, which is under pressure, rises as high as 300 degrees Celsius. Vaporized water is condensed in equipment outside the reactor and then sent back in again.

If the water is over 100 degrees Celsius when a plant is shut down it will vaporize without being condensed again, leaving the fuel rods it normally covers exposed, and the rods will melt from their own heat.

Q: Does nuclear fuel still create heat even after a plant has been shut down?

A: Yes. The fission products that come from uranium-235 break down on their own, releasing heat and radiation. This is called "decay heat." Right after a plant is shut down, the fission products will continue to release around six percent of the energy they released compared with when the plant was running. This falls quickly to around 1.5 percent a week later, but even a month later they will release around 0.2 percent, and a year later they will still release around 0.02 percent. The meltdowns at the Fukushima plant happened because this decay heat was not dissipated.

Q: So even after the government declaration of the completion of "Step 2," we can't let down our guard, right?

A: That's right. Under normal circumstances, after shutting down a plant, heat-removing equipment would let the decay heat escape to the ocean, stabilizing the water in the reactors at 50 to 60 degrees Celsius. However, at the Fukushima plant, the loss of electricity and other problems after the March earthquake prevented the nuclear fuel cooling equipment from running and the reactors melted down, opening holes in the bottoms of the pressure containers and complicating efforts to cool the fuel. The amount of decay heat is less now than it was right after the March disasters, but the fight to keep down fuel's temperature down is expected to continue for a long time. (Answers by Toshiyasu Kawachi, Science & Environment News Department)

Three Mile Island 30 Yr. Later

The Three Mile Island accident was a core meltdown in Unit 2 (a pressurized water reactor manufactured by Babcock & Wilcox) of the Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania near Harrisburg, United States in 1979.
The power plant was owned and operated by General Public Utilities and Metropolitan Edison (Met Ed). It resulted in the release of approximately 2.5 million curies of radioactive gases, and approximately 15 curies of iodine-131.
The accident began at 4 a.m. on Wednesday, March 28, 1979, with failures in the non-nuclear secondary system, followed by a stuck-openpilot-operated relief valve (PORV) in the primary system, which allowed large amounts of nuclear reactor coolant to escape. The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss-of-coolant accident due to inadequate training and human factors, such as human-computer interaction design oversights relating to ambiguous control room indicators in the power plant's user interface. In particular, a hidden indicator light led to an operator manually overriding the automatic emergency cooling system of the reactor because the operator mistakenly believed that there was too much coolant water present in the reactor and causing the steam pressure release. The scope and complexity of the accident became clear over the course of five days, as employees of Met Ed, Pennsylvania state officials, and members of the U.S. Nuclear Regulatory Commission (NRC) tried to understand the problem, communicate the situation to the press and local community, decide whether the accident required an emergency evacuation, and ultimately end the crisis. The NRC's authorization of the release of 40,000 gallons of radioactive waste water directly in the Susquehanna River led to a loss of credibility with the press and community.
This video show hows there mile island 30 years after the incident. A survey has been conduct to see how the confident of the local people towards nuclear after 30 years of the incident

Survey Analysis

Hello World

For everyone that did their survey on this page, i would like to say a million thanks for your supports and time. Here is the final results. We manage to collect 100,000 data bank for this survey (cerita gebang).

Final Remaks


From this simple survey, we can safely conclude that most of Malaysian citizens didn't have a sufficient information on nuclear technologies. Most of them are curious on how nuclear technology works but then it seem that the nuclear awareness in this country is on the minimal level. If Malaysia are serious with nuclear technologies, the government should have taken more effective ways to spread the nuclear awareness so that the people of this country would welcomed this technologies with open arms.

A nuclear power aircraft!!!

A nuclear aircraft is an aircraft powered by nuclear energy. Research into them was pursued during the Cold War by the United States and the Soviet Union as they would presumably allow a country to keep nuclear bombers in the air for extremely long periods of time, a useful tactic for nuclear deterrence. Neither country created any nuclear aircraft in production numbers. One design problem, never adequately solved, was the need for heavy shielding to protect the crew from radiation sickness. Since the advent of ICBMs in the 60s the tactical advantage of such aircraft was greatly diminished and respective projects were cancelled. Because the technology was inherently dangerous it was not considered in non-military contexts.
Unmanned missiles have been designed to use nuclear thermal rockets, but such designs were considered too dangerous for crews to fly.

Reactor Safety

Reactor Safety Systems and Why Is A Reactor Safe?

Okay..lets talk about safety.
The most important aspect of a Nuclear Reactor.

What is Nuclear Reactor?
Nuclear Reactor is an engineering device, in which nuclear fuel and structural material are arranged such that a self-sustained fission chain reaction can occur in a controlled manner.

New and advanced reactors are designed with safety in mind, including the development and application of Passive Safety Systems as far as possible.
It requires no operator intervention in the event of major malfunction.
Passive Safety Systems depends only on physical phenomena such as pressure differentials, convection, gravity or the natural response of materials to high temperatures to slow or shut down the reaction, not on the functioning of electrical or mechanical operation on command systems.

Other safety provisions includes a series of physical barriers between the radioactive reactor core and the environment, the provisions of multiple safety systems, each with backup and designed to accommodate human error.

The barriers in a typical plant are:

Fuel container within the reactor, generally thousands of sealed metal tubes, rods, or plates, fabricated to the highest quality standards.
Closed loop of water which transport the fission energy away from the reactor. Water is converted to steam by fission.  The steam passes through a turbine-generator, is condensed and the water eventually returned to the reactor to be reheated.  Note that while this loop serves to generate steam, it also serves to cool the reactor, keeping it in thermal equilibrium.  Should one or more fuel elements fail, mechanically or due to overheating, the fission fragments would be contained in the closed cooling water loop.
Most reactors (except the Chernobyl type) have a third barrier, called a containment building.  It is a large steel lined, concrete structure completely enclosing the reactor and it’s cooling loops.  It is designed to completely contain all of the coolant should a major failure leak occur in the cooling loops, and all of the water flashed to steam.  So even if fission fragments were released into the cooling loop and the loop leaked, fission fragments would be held in the containment building.
So, Is a Reactor safe?
The answer is simply Yes!

P/s:- It should be emphasize that a commercial type Nuclear Reactor simply cannot under any circumstances explode like a Nuclear Bomb. :)

Question tor For Tan Sri Leo Moggie

Q: Is Malaysia really ready for nuclear power? The citizenry are concerned over the prospect of having a nuclear plant in their backyard and much of it has to do with trust, or lack of it. Amirul, Klang.

A: It would need a full article to give a satisfactory answer to this question.

Suffice to say there are compelling reasons to include nuclear power in our energy mix in the future. Gas and coal will be increasingly expensive. Coal will also face objections from environmentalists. Hydro power has its own challenges. Renewable energy attracts a lot of excitement but it can at best only complement conventional sources. Nuclear is clean. It is comparatively cheaper in the long run.

It is important to address public concerns openly, with reliable information. Many of these concerns are associated with the spectre of the Chernobyl accident in April 1986. Chernobyl should be put in perspective. The accident was the result of a flawed reactor design. The technology of reactor design has advanced since then and there has not been any incident of that nature since Chernobyl.

Because of concerns with climate change and global warming, there is now renewed worldwide interest in nuclear power. A total of 440 nuclear power plant reactors are now operating in 30 countries, which provides about 15% of the world's electricity. About 53 nuclear plants are under construction and will be commissioned in the next five years. There is expertise worldwide in plant design and safety, in managing spent fuel and in handling radioactive waste. Even some countries in the Middle East are looking at nuclear. The United Arab Emirates is now building one. Countries in our region are also looking at building nuclear power plants.

The International Atomic Energy Agency (IAEA) is always ready to offer advice to countries starting a nuclear power programme for the first time and I know our relevant government agencies are in touch with IAEA. There is in fact already some experience on nuclear technology in this country.

At TNB, a lot of preparatory work has been done in anticipation of developing a nuclear power plant. We have completed a desk study identifying potential sites. A preliminary feasibility study, in association with Korean Power Company was completed in June 2010. We have a Nuclear Energy Unit and are building up our staffing capacity.

While there is still much work to be done, to achieve the commissioning of the first unit in 2021, Malaysia is managing the process of deploying the use of nuclear power in a considered way, including getting public acceptance from an early stage.

Source: The Star