About 1,665 killed people, 3,000 injured, 2,000,000 homeless and 550 million dollars damage are the frightening digits from the largest eartqueake ever happened. It occured in Valdivia, Chile and there´s never been any eartquake as powerful as this, so far.
Severe damage from shaking occurred in the Valdivia-Puerto Montt area. Most of the casualties and much of the damage was because of large tsunamis which caused damage along the coast of Chile from Lebu to Puerto Aisen and in many areas of the Pacific Ocean. Puerto Saavedra was completely destroyed by waves which reached heights of 11.5 m (38 ft) and carried remains of houses inland as much as 3 km (2 mi). Wave heights of 8 m (26 ft) caused much damage at Corral. Despite the destructive description about this earthquake. it´s not the most deadly earthqueake.
We promise we´ll write staff about the most deadly earthquakes ever happened.
We promise we´ll write staff about the most deadly earthquakes ever happened.
Terrible fire in Bangladesh
A fire broke out on Sunday in the remains of the textile factory that collapsed in Bangladesh last week, and smoke pouring from shattered concrete piles as flames forced to stop some rescue efforts.
The fire comes four days after the collapse, at a time when the rescuers trying to free a woman trapped in the rubble found. The fire started due to sparks generated as rescuers tried to cut a steel rod to reach the woman, said Syed Al-Amin lifeguard Roman.
Rescuers pulled out of the part of the remains which were the flames, but still trying to reach survivors in other parts of the eight-story building destroyed.
Firefighters tried to extinguish the fire.
"Hopefully we can control it," said Brigadier General Mohammed Alam Siddiqul Shikder, who oversees rescue operations.
The fire came hours after authorities announced that they had captured the fugitive owner of the building at a border crossing with India.
Mohammed Sohel Rana was arrested by an elite force near the border in Benapole, in western Bangladesh, when he tried to flee to the West Bengal state of India, said Jahangir Kabir Nanak, vice minister of local government. Rana now faces charges of negligence.
Rana capture by the Rapid Action Battalion was announced through a loudspeaker between jubilation and applause of the people at the site of collapsed building in Savar, Dhaka suburb.
It confirmed the deaths of at least 377 people after the partial collapse occurred on Wednesday. Three of the eight levels of the building were built illegally.
It is expected that the death toll increases in what constitutes the tragedy that has claimed the highest number of lives in the garment industry in Bangladesh, which reached $ 20,000 million a year and is the mainstay of the country's economy .
The collapse in the building and factories previous disasters in the sector have drawn attention to the poor working conditions of workers in the garment industry, who earn $ 38 a month producing clothes for major international brands.
Bengali textile industry was the third largest in the world in 2011, after Italy and China, and has expanded fastly in the last decade.
Chernobyl accident 27th anniversary
- The Chernobyl accident in 1986 was the result of a flawed reactor design that was operated with inadequately trained personnel.
- The resulting steam explosion and fires released at least 5% of the radioactive reactor core into the atmosphere and downwind.
- Two Chernobyl plant workers died on the night of the accident, and a further 28 people died within a few weeks as a result of acute radiation poisoning.
- UNSCEAR says that apart from increased thyroid cancers, "there is no evidence of a major public health impact attributable to radiation exposure 20 years after the accident."
- Resettlement of areas from which people were relocated is ongoing.
The April 1986 disaster at the Chernobyla nuclear power plant in Ukraine was the product of a flawed Soviet reactor design coupled with serious mistakes made by the plant operatorsb. It was a direct consequence of Cold War isolation and the resulting lack of any safety culture.
The accident destroyed the Chernobyl 4 reactor, killing 30 operators and firemen within three months and several further deaths later. One person was killed immediately and a second died in hospital soon after as a result of injuries received. Another person is reported to have died at the time from a coronary thrombosisc. Acute radiation syndrome (ARS) was originally diagnosed in 237 people on-site and involved with the clean-up and it was later confirmed in 134 cases. Of these, 28 people died as a result of ARS within a few weeks of the accident. Nineteen more subsequently died between 1987 and 2004 but their deaths cannot necessarily be attributed to radiation exposured. Nobody off-site suffered from acute radiation effects although a large proportion of childhood thyroid cancers diagnosed since the accident is likely to be due to intake of radioactive iodine falloutd. Furthermore, large areas of Belarus, Ukraine, Russia and beyond were contaminated in varying degrees. See also sections below and Chernobyl Accident Appendix 2: Health Impacts. The Chernobyl disaster was a unique event and the only accident in the history of commercial nuclear power where radiation-related fatalities occurrede. However, the design of the reactor is unique and the accident is thus of little relevance to the rest of the nuclear industry outside the then Eastern Bloc.
The Chernobyl site and plant
The Chernobyl Power Complex, lying about 130 km north of Kiev, Ukraine, and about 20 km south of the border with Belarus, consisted of four nuclear reactors of the RBMK-1000 design (see information page on RBMK Reactors), units 1 and 2 being constructed between 1970 and 1977, while units 3 and 4 of the same design were completed in 1983. Two more RBMK reactors were under construction at the site at the time of the accident. To the southeast of the plant, an artificial lake of some 22 square kilometres, situated beside the river Pripyat, a tributary of the Dniepr, was constructed to provide cooling water for the reactors.
This area of Ukraine is described as Belarussian-type woodland with a low population density. About 3 km away from the reactor, in the new city, Pripyat, there were 49,000 inhabitants. The old town of Chornobyl, which had a population of 12,500, is about 15 km to the southeast of the complex. Within a 30 km radius of the power plant, the total population was between 115,000 and 135,000.
The RBMK-1000 is a Soviet-designed and built graphite moderated pressure tube type reactor, using slightly enriched (2% U-235) uranium dioxide fuel. It is a boiling light water reactor, with two loops feeding steam directly to the turbines, without an intervening heat exchanger. Water pumped to the bottom of the fuel channels boils as it progresses up the pressure tubes, producing steam which feeds two 500 MWe turbines. The water acts as a coolant and also provides the steam used to drive the turbines. The vertical pressure tubes contain the zirconium alloy clad uranium dioxide fuel around which the cooling water flows. The extensions of the fuel channels penetrate the lower plate and the cover plate of the core and are welded to each. A specially designed refuelling machine allows fuel bundles to be changed without shutting down the reactor.
The moderator, whose function is to slow down neutrons to make them more efficient in producing fission in the fuel, is graphite, surrounding the pressure tubes. A mixture of nitrogen and helium is circulated between the graphite blocks to prevent oxidation of the graphite and to improve the transmission of the heat produced by neutron interactions in the graphite to the fuel channel. The core itself is about 7 m high and about 12 m in diameter. In each of the two loops, there are four main coolant circulating pumps, one of which is always on standby. The reactivity or power of the reactor is controlled by raising or lowering 211 control rods, which, when lowered into the moderator, absorb neutrons and reduce the fission rate. The power output of this reactor is 3200 MW thermal, or 1000 MWe. Various safety systems, such as an emergency core cooling system, were incorporated into the reactor design.
One of the most important characteristics of the RBMK reactor is that it it can possess a 'positive void coefficient', where an increase in steam bubbles ('voids') is accompanied by an increase in core reactivity (see information page on RBMK Reactors). As steam production in the fuel channels increases, the neutrons that would have been absorbed by the denser water now produce increased fission in the fuel. There are other components that contribute to the overall power coefficient of reactivity, but the void coefficient is the dominant one in RBMK reactors. The void coefficient depends on the composition of the core – a new RBMK core will have a negative void coefficient. However, at the time of the accident at Chernobyl 4, the reactor's fuel burn-up, control rod configuration and power level led to a positive void coefficient large enough to overwhelm all other influences on the power coefficient.
Accident Chronology
On 25 April, prior to a routine shutdown, the reactor crew at Chernobyl 4 began preparing for a test to determine how long turbines would spin and supply power to the main circulating pumps following a loss of main electrical power supply. This test had been carried out at Chernobyl the previous year, but the power from the turbine ran down too rapidly, so new voltage regulator designs were to be tested.
A series of operator actions, including the disabling of automatic shutdown mechanisms, preceded the attempted test early on 26 April. By the time that the operator moved to shut down the reactor, the reactor was in an extremely unstable condition. A peculiarity of the design of the control rods caused a dramatic power surge as they were inserted into the reactor.
The interaction of very hot fuel with the cooling water led to fuel fragmentation along with rapid steam production and an increase in pressure. The design characteristics of the reactor were such that substantial damage to even three or four fuel assemblies can – and did – result in the destruction of the reactor. The overpressure caused the 1000 t cover plate of the reactor to become partially detached, rupturing the fuel channels and jamming all the control rods, which by that time were only halfway down. Intense steam generation then spread throughout the whole core (fed by water dumped into the core due to the rupture of the emergency cooling circuit) causing a steam explosion and releasing fission products to the atmosphere. About two to three seconds later, a second explosion threw out fragments from the fuel channels and hot graphite. There is some dispute among experts about the character of this second explosion, but it is likely to have been caused by the production of hydrogen from zirconium-steam reactions.
Two workers died as a result of these explosions. The graphite (about a quarter of the 1200 tonnes of it was estimated to have been ejected) and fuel became incandescent and started a number of firesf, causing the main release of radioactivity into the environment.
About 200-300 tonnes of water per hour was injected into the intact half of the reactor using the auxiliary feedwater pumps but this was stopped after half a day owing to the danger of it flowing into and flooding units 1 and 2. From the second to tenth day after the accident, some 5000 tonnes of boron, dolomite, sand, clay and lead were dropped on to the burning core by helicopter in an effort to extinguish the blaze and limit the release of radioactive particles.
The Lituya Bay megatsunami took place on July 9, 1958, when a large, 8.3 magnitude earthquake on the Fairweather Fault triggered a landslide that caused 30 million cubic metres of rock and ice to fall into the narrow inlet of Lituya Bay, Alaska. The displacement of water resulted in a wave of 516 metres (1,720 feet) in height, the tallest wave ever. Lituya Bay is a fjord located in Glaciers Bay on Alaska pacific coast, USA. It´s 9 miles long and can reach 2 miles on its widest point. Its average depth is 721 feet (220 meters). This amazing natural disaster took unfortunately away two fishermans life and triggered several damages.
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