Japan Declares Fukushima STABLE!

16 December 2011 "Japan has declared that its tsunami-stricken Fukushima nuclear power plant has reached cold shutdown condition, passing a key milestone in efforts to bring under control the world's worst nuclear accident since Chernobyl 25 years ago. "The reactors have reached a state of cold shutdown condition," Yoshihiko Noda, Japan's prime minister, said at the government's nuclear emergency response meeting on Friday. "Even if unforeseeable incidents happen, the situation is such that radiation levels on the boundary of the plant can now be maintained at a low level," he said. "The government is due to set a clear road map and will do the utmost to decommission the plant," the Japanese PM said. The Fukushima Daiichi plant, 240km northeast of Tokyo, was damaged on March 11 by a devastating earthquake and a 10-metre-high tsunami, which damaged its cooling systems, triggering meltdowns and radiation leaks. Declaring a cold shutdown condition will have repercussions well beyond the plant: it is a government pre-condition before it allows about 80,000 residents evacuated from within a 20km radius of the plant to return home. A cold shutdown condition is when water used to cool nuclear fuel rods remains below its boiling point, preventing the fuel from reheating. One of the chief aims of the plant's operator, Tokyo Electric Power Company (TEPCO), had been to bring the reactors to this stage by the year-end. After months of efforts, the water temperature in all three of the affected reactors fell below boiling point by September, but TEPCO has been cautious of declaring a cold shutdown, saying it had to see if temperatures and the amount of radiation emitted from the plant remained stable. In an interview with Al Jazeera, Imad Khadduri, a nuclear scientist, said: "The Japanese PM’s plans are very formidable and very ambitious and detailed. And one measure of the success of this plan of decontamination can be juxtaposed against the efforts since March when the accident happened. "I am very hopeful that the decontamination will be done in a very meticulous and rigorous manner unlike that of the Chernobyl in Russia nearly 25 years ago," he said. Massive cleanup Khadduri said: "The nuclear power plants, in fact, are large stainless steel eggs under huge pressure, almost 72 times the atmospheric pressure. And by cold shutdown, they mean that the pressure inside the plant has been brought down to the atmospheric level. "In the past more than eight months, they have managed to reduce the temperature of fuel elements to under 95 degrees celsius, which is equal to the atmospheric pressure. "Decommission means: They can remove the top part of the stainless steel egg and take out nuclear fuel elements, store them safely and starting to dissemble the plant and tube them with concrete materials." He further added: "These [highly radioactive nuclear fuels] are stored at radio-established spent fuel storage tanks. These can be stored at nearly 54 other nuclear power stations that have large capacity for spent fuel storage." TEPCO said early in the crisis that it did not plan to entomb the damaged Daiichi reactors in concrete, the option chosen at Ukraine's Chernobyl where reactors caught fire and burned for days. Instead, it favoured the gradual removal of the nuclear fuel for storage elsewhere. The government and TEPCO will aim to begin removing the undamaged nuclear rods from Daiichi's spent fuel pools as early as next year. However, retrieval of fuel that melted down in their reactors may not begin for another decade, with the complete dismantling of the plant expected to take up to 40 years, domestic media reported on Thursday. The enormous cost of the cleanup and compensating the victims of the disaster has drained TEPCO financially. The government may inject about $13bn into the company as early as next summer in a de facto nationalisation, sources told the Reuters news agency last week. Japan also faces a massive cleanup task outside the plant if residents are to be allowed to return home. The environment ministry says about 2,400sq km of land around the plant may need to be decontaminated. The crisis shook the public's faith in nuclear energy and Japan is now reviewing its earlier plan to raise the proportion of electricity generated from nuclear power to 50 per cent by 2030 from 30 per cent in 2010. Living in fear of radiation is part of life for residents both near and far from the plant. Cases of excessive radiation in vegetables, tea, milk, seafood and water have stoked anxiety despite assurances from public officials that the levels detected are not dangerous. Chernobyl's experience shows that anxiety is likely to persist for years to come, with residents living near the former Soviet plant still regularly checking local produce for radiation before consuming them 25 years after the disaster. The announcement may not dramatically improve Noda's support ratings, eroded by his steadfast commitment to a sales tax increase to cope with a public debt burden twice the size of Japan's economy. Noda is also faced with a formidable list of other tasks, such as helping a stagnant economy deal with the yen's rise to historic highs." Taken from http://www.aljazeera.com/news/asia-pacific/2011/12/201112167758128873.html At long last we have waited this moment where Fukushima Daiichi NPP to settle down and be stable.  A joyous news for us!   PS: Okuu-chan is settling down with a cold blanket >XD

Nuclear Battery Technology

                 Many people may think about nuclear power car or plane, but do you ever think about the uclear power laptop, watch or iphone. Well, the nuclear reactor may be fitted in for large application like car(although still not possible nowdays..), how about the small device??

                The answer is the nuclear battery.  Nuclear attery or atomic battery is defined as a device which use the emissions of radioactive isopote to generate electricity. While the nuclear reactor require the chain reaction to produce the energy, the nuclear battery works diffently. Conversion techniques can be grouped into two types: thermal and non-thermal. The thermal converters (whose output power is a function of a temperature differential) include thermoelectric and thermionic generators. The non-thermal converters (whose output power is not a function of a temperature difference) extract a fraction of the incident energy as it is being degraded into heat rather than using thermal energy to run electrons in a cycle.

 

Researchers create penny-sized nuclear battery.

                This technology have began in early 1913, when Henry Mosely firsr demonstrated the beta cell.  The field received considerable in-depth research attention for applications requiring long-life power sources for space needs during the 50s and 60s. Over the years many types and methods have been developed. The batery is costlly compare to other battery, thus they are mainly used as power sources for equipment that must operate unattended for long periods of time, such as spacecraft and automated scientific stations.

                The latest news about this nuclear battery are they are been used to power-up the NASA new rover thet will been send to the Mars.

            “The rover isn’t powered by a nuclear reactor but the insulated Pu-238 generates so much heat that it actually glows a dull red in the dark. This excess warmth will be put to good use, generating approximately 110 watts of electricity through thermoelectric lead tellurite –- a material that creates electricity when there is a temperature gradient. This power can keep the rover chugging along for years if needed, though MSL’s current mission is only scheduled to last 23 months.”  - http://www.wired.com/wiredscience/2011/11/nuclear-mars-rover/

 

NASA new rover

                While most people hear the word 'nuclear' and think of something very dangerous,but it already prove itself that nuclear power sources have already been safely powering a variety of devices, such as pacemakers, space satellites and underwater systems.

Happy 50 To BIG E!!

USS Enterprise is the second oldest ship still in operation in U.S. naval history and the eighth the name Enterprise. The Big E is the carrier's first nuclear powered aircraft carrier in the world and has been operating since 1961. It is the only Enterprise class carrier and use the 8 nuclear rekator! The ships of other aircraft carriers in armasa USN only use two reactors. This year it celebrated its 50 th year. Since opening its doors many historic operation was performed by the Enterprise. For example, it is a welcome return of freighter John Glenn, the first astronaut to land USA. It is also used to make a blockade against Cuba during the Cuban crisis Chavez. Want more? Vietnam War, the Gulf crisis, the Philippines coup crisis, the Balkans and the invasion of Afghanistan all involved Enterprise.Enterprise will only be retired in 2013 to make way for carrier class Gerard Ford.

Nuclear Powered Aircraft

Today, everybody have heard many nuclear powered vehicles like ships, aircraft carriers, submarines and satellites but how many of you heard of nuclear powered aircraft? Yep... an aircraft. Sounds like a very good idea, having an aircraft that can fly continuously without having to land or refuel for very long periods of time and a great military advantage. But, who want and how to put this much power...
... into an aircraft?

The idea of nuclear-powered aircraft seems crazy with the benefit of hindsight. But for the U.S. Air Force generals of the late 1940s and 1950s, it was the answer to a Cold War dilemma: How can you have a round-the-clock nuclear deterrent when the planes carrying atomic bombs have to stop for fuel every few hours? The fear was that a sneak attack from Soviet bombers could destroy the capacity of the U.S. to retaliate, thus providing an incentive for a first strike.

An atomic-powered bomber would provide the ultimate deterrent, the Air Force Generals believed. With an ability to stay aloft for an extended period, the planes could circle in Arctic airspace waiting for the orders to attack. Crews would live on the bombers much the way that submariners do in nuclear subs, which were just coming online.

US Nuclear Aircraft Project

The only US nuclear aircraft, XB-36H (developed from Convair B-36)
or better known as X-6

NEPA & ANP
In May 1946, the Nuclear Energy for the Propulsion of Aircraft (NEPA) project was started by the United States Air Force. Studies under this program were done until May, 1951 when NEPA was replaced by the Aircraft Nuclear Propulsion (ANP) program. The ANP program included provisions for studying two different types of nuclear-powered jet engines, General Electric's (an aviation company) Direct Air Cycle and Pratt & Whitney's (another aviation company) Indirect Air Cycle. ANP also contained plans for two B-36s to be modified by Convair (also an aviation company) under the MX-1589 project, one of the B-36s was to be used to study shielding requirements for an airborne reactor while the other was to be the X-6. The program was cancelled before the X-6 was completed, however.

The first operation of an aircraft engine on nuclear-power was achieved on January 31, 1956 using a modified General Electric J47 turbojet engine. The Aircraft Nuclear Propulsion program was terminated following the President's annual budget message to Congress in 1961.

General Electric's Direct Air Cycle Engine (the details are classified)

The Oak Ridge National Laboratory conducted research (Aircraft Reactor Experiment) to produce a nuclear powered aircraft. Two General Electric turbofan engines were successfully powered to nearly full thrust using two shielded reactors. The two engines complete with reactor system are currently located at the EBR-1 facility south of the Idaho National Laboratory.

The U.S. designed these engines to be used in a new specially designed nuclear bomber, the WS-125, which was eventually terminated by Eisenhower who cut NEPA and told Congress that there was no urgency for the program. Eisenhower did back a small scale program developing high temperature materials and high performance reactors. That program was terminated early in the Kennedy administration.

Project Pluto
In 1957, the Air Force and the U.S. Atomic Energy Commission contracted with the Lawrence Radiation Laboratory to study the feasibility of applying heat from nuclear reactors to ramjet engines. This research became known as Project Pluto. The engines being developed under this program were intended to power an unmanned cruise missile, called SLAM, for Supersonic Low Altitude Missile. The program succeeded in producing two test engines which were operated on the ground. On May 14, 1961, the world's first nuclear ramjet engine, "Tory-IIA," mounted on a railroad car, roared to life for just a few seconds. On July 1, 1964, seven years and six months after it was born, "Project Pluto" was cancelled.

Soviet Nuclear Aircraft Project
As the Allies main rival during the Cold War, the Soviets have their own nuclear aircraft program too. The Soviet program of developing nuclear aircraft resulted in the experimental Tupolev Tu-119, also known as the Tu-95LAL (LAL-in Russian mean- Flying Nuclear Laboratory). It was based on a Tupolev Tu-95 bomber. It had 4 conventional turboprop engines and an onboard nuclear reactor. The Tu-119 completed 34 research flights. Most of these were made with the reactor shut down.

The Soviet Nuclear Aircraft, Tu-95LAL (classified picture)

The main purpose of the flight phase was examining the effectiveness of the radiation shielding which was one of the main concerns for the engineers. Massive amounts of protection used resulted in radiation levels low enough to consider continuing development. But, as in the US, development never continued past this point. The obvious potential of the ICBM made the expensive program superfluous, and around the mid 1960s it was cancelled. Several other projects reached only design phase.

The Nuclear Reactor On-board Tu-95LAL (again, classified)

Nuclear aircraft is good idea actually... but we have to remember that everything (especially nuclear reactor) are not immune to accidents. Even nuclear power plant with the latest state of the art safety systems is not entirely perfect, let alone a flying "nuclear bomb" under your seat or on top of your head. We already seen many aircraft crashes in the news and sometime a nuclear submarine accidents somewhere in the deep ocean in the last decade, so its possible to assume a nuclear aircraft will suffer the same fate & greater disaster. Thankfully, the nuclear aircraft programs was cancelled since the advent of ICBM (Inter-Continental Ballistic Missile) in the 60s, kinda ironic... is it?

Again, if a nuclear aircraft crashes near your home... O_O!!!

Renewable Energy - Wind (Part 2)

Wind energy basically involves converting airflow into electricity by using wind turbines. A wind turbine is a device that converts kinetic energy from the wind into mechanical energy and the mechanical energy is used to produce electricity. There are two types of wind turbines, based on their rotation axis; wind turbines can rotate about either a horizontal or a vertical axis. Interestingly, wind power always been integrated with solar power in hybrid renewable energy system due to the both system simplicity and operation independent.

1) Horizontal Axis

Horizontal-axis wind turbines (HAWT) have the main rotor shaft and electrical generator at the top of a tower, and must be pointed into the wind. Small turbines are pointed by a simple wind vane, while large turbines generally use a wind sensor coupled with a servo motor. Most have a gearbox, which turns the slow rotation of the blades into a quicker rotation that is more suitable to drive an electrical generator.

Since a tower produces turbulence behind it, the turbine is usually positioned upwind of its supporting tower. Turbine blades are made stiff to prevent the blades from being pushed into the tower by high winds. Additionally, the blades are placed in a distance in front of the tower and are sometimes tilted forward into the wind a little. Most HAWTs are of upwind design and most commonly used between the two types.

2) Vertical Axis

Vertical-axis wind turbines (VAWT) have the main rotor shaft arranged vertically. Key advantages of this arrangement are that the turbine does not need to be pointed into the wind to be effective. This is an advantage on sites where the wind direction is highly variable. The key disadvantages of VAWT include the low rotational speed, the inherently lower power coefficient, the pulsating torque generated and the difficulty of modelling the wind flow accurately.

In VAWT configuration, the generator and gearbox can be placed near the ground, using a direct drive from the rotor assembly to the ground-based gearbox, hence improving accessibility for maintenance. When this turbine is mounted on a rooftop, the building generally redirects wind over the roof and these can double the wind speed at the turbine. This type of wind turbine is suitable in urban areas because wind speeds within the built environment are generally much lower than at exposed rural sites.

Other than wind, maybe we can directly harness the electricity from the skies, lightning...

... maybe not, but still, it's a good possibility... (if we can find a way to harness 1.21 gigawatts from a lightning bolt that is 5 times hotter than the surface of the sun!)