How much safe is Nuclear Power Plant?

Increase in the number of reactors will increase the the possibility of exposure to radiation hazards.

by

Dr. Nitish Priyadarshi

Japan has raised its assessment of the accident at the crippled Fukushima Daiichi nuclear power plant to the worst rating on an international scale, putting the disaster on par with the 1986 Chernobyl explosion.

The decision to raise the alert level to 7 from 5 on the scale amounts to an admission that the accident at the nuclear facility, is likely to have substantial and long lasting consequences for health and for the environment.

Living with radiation can in fact be frightening. Plants making nuclear-weapons materials also pollute our environment. Three Mile Island and Chernobyl, as well as other nuclear power plant accidents, have alarmed us. Nuclear waste is piling up.

What is radiation anyway? Although the term is broad enough to include sunlight and heat, radio waves and microwaves, it is most often used to mean ionizing radiation. Every radioactive substance contains unstable atoms, or radionuclides. They want to become something else- something stable- so they change or decay. With each change energy is released. A radionuclide may transform itself many times before becoming stable. An atom of radioactive uranium 238 goes through 14 changes before stabilizing as lead 206. These sequences are known as decay chains.

If body tissues and cells become ionized, abnormalities in DNA can result. Cancer and birth defects can also result from exposure to ionizing radiation.

Even more than Three Mile Island, the explosion at the Chernobyl power plant in soviet Ukraine confirmed the worst nuclear fears. Poor design magnified operator negligence to cause disaster. The explosion sent the graphite slabs of the reactor core through the roof, setting it afire and spewing radioactive materials around the world. Twenty percent of the plant’s radioactive iodine escaped, along with 10 to 20 percent of its radioactive cesium. Thirty persons died; 237 suffered severe radioactive injury. Chernobyl affected the health of many people throughout Russia. Around 600,000 were classified as being ‘significantly exposed’ and will have their health monitored their whole lives.

The main economic cost of the Chernobyl explosion was from the effect the fallout had on the agriculture. Enormous amount of milk in Poland, Hungary, Austria and Sweden were made unusable by the contamination from radioiodine and radioiodine and radiocesium. Also many countries across Europe had numerous amounts of vegetation burned because of contamination. A ban on many agricultural goods was placed in Eastern Europe. The longest effect the radiation had was on the reindeer and sheep in Sweden.

The Three Mile Island accident was a core meltdown in Unit 2 (a pressurized water reactor ) 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. It was the most significant accident in the history of the USA commercial nuclear power generating industry, resulting in the release of up to 481 P Bq (13 million curies) of radioactive gases, and less than 740 GBq (20 curies) of iodine-131.

On December 12, 1952 a partial meltdown of a reactor's uranium core at the Chalk River plant near Ottawa, Canada, resulted after the accidental removal of four control rods. Although millions of gallons of radioactive water poured into the reactor, there were no injuries.

On October 1957 fire destroyed the core of a plutonium-producing reactor at Britain's Windscale nuclear complex - since renamed Sellafield - sending clouds of radioactivity into the atmosphere. An official report said the leaked radiation could have caused dozens of cancer deaths in the vicinity of Liverpool.

Other accident took place on Winter 1957-'58 when a serious accident occurred during the winter of 1957-58 near the town of Kyshtym in the Urals. A Russian scientist who first reported the disaster estimated that hundreds died from radiation sickness.

On January 1,1992 four tons of heavy water spilt at Rajasthan nuclear power plant (India).

Lots more are there to be listed.

Fears of radiation hazards from nuclear energy arise on the following counts:

1. release of radioactivity into the atmosphere.
2. doubts on safety of operating nuclear reactors and associated health risks.
3. management and safe disposal of radioactive waste.
4. possibilities of nuclear plant accidents including sabotage.
5. risk of proliferation of nuclear weapons.

Nuclear power plants are subject to a number of hazards that may originate from outside. Among natural hazards are earthquakes, flooding of the site, ground settlement, etc. Other hazards could be accidents in near by industries, fire, aircraft crash, or sabotage such as bombing and missile attacks during war and terrorist activities.

Accidents in nuclear power plants in the past have been attributed mainly to operation errors, design deficiencies and a series of equipments failures. But the accident in Japan is the first case due to earthquake.

Controversies regarding actual number of deaths, the quantity of radioactivity released and delayed effects still persist.

The demand for energy in several countries is being substantially met through nuclear reactors. It is feared that the phenomenal increase in the number of reactors during the last 40 years or so has increased the possibility of exposure to radiation hazards and accidents.

Can animals predict earthquakes?

Most animals show increased restlessness before an earthquake.

Govindpur in Jharkhand animals were nervous before earthquake.

by

Dr. Nitish Priyadarshi

Picture credit: animalsandearthquakes.com/etho-g5.gif
In order to reduce the risk of an earthquake and reduce and mitigate its effects, it is necessary to predict where and when a future, large earthquake may occur. For example, it would be important to know when such an earthquake will hit, where it will strike, and what the level of its destructiveness may be. Earthquake prediction at the present time is not an exact science, and forecasts of earthquake occurrences have not been very accurate. Presently predictions are given in statistical terms. For example, when a prediction is made that :here is a 90% chance that an earthquake will occur in the next 50 years", it does not mean that this earthquake cannot happen tomorrow or it may not be delayed by 50 years. Thus, present predictions are not within a reasonable time frame that can be of usefulness to planners, policy makers, and those in government that deal with public safety.

Unusual behaviour of animals prior to earthquakes received wide publicity after the Haichang earthquake of February 4, 1975 was successfully predicted in China. The official report was presented by the Chinese delegation at the Inter-governmental meeting convened at UNESCO, Paris in February 1976 which stimulated considerable scientific interest. Prior to this, however, several instances of abnormal animal behaviour were noticed before occurrence of some of the damaging earthquakes in different parts of the world, but they were considered more as historical legend. In Japan, innumerable rats were seen every day in a restaurant in Nagoya city, which suddenly disappeared on the evening prior to the Nobi earthquake of 1891.
Since the beginning of recorded history, observations of unusual animal behavior before earthquakes have been recorded by people from almost all civilizations. The animal behavior reports are often ambiguous and not consistently observed. In folklore, some animals have had more reports of being able to predict earthquakes than others, especially dogs, cats, chickens, horses, and other smaller animals. There have been reports with elephants, as well. Goats, cows, and most larger animals are generally reported as being less able to predict earthquakes.

In 1920, the largest earthquake to hit China with a magnitude of 8.5 occurred in Haiyuan County, Ninghxia Province. According to reports of eyewitnesses, prior to this earthquake, wolves were seen running around in packs, dogs were barking unusually, and sparrows were flying around wildly. It is reported that prior to the 6.8 magnitude earthquake in 1966 in Hsingtai County, Hopei Province, in Northern China, all the dogs at a village near the epicenter had deserted their kennels and thus survived the disaster.

The earliest reference we have to unusual animal behavior prior to a significant earthquake is from Greece in 373 BC.

As early as 1886, a seismologist named Milne had mentioned that dogs escaped from the city of Talcahuano in Chile before an earthquake (1835). Flocks of birds flew inland before the Chilean earthquakes of 1822 and 1835. Monkeys were reported to have become restless a few hours before the Managua earthquake (1972) in Nicaragua. In the Tientsin region of China, chickens refused to enter their dens, tigers became restless, yaks declined to eat and horses and sheep started running restlessly a few hours before the earthquakes of July 18, 1969. Hens and cocks were reported restless about an hour prior to the 1896 Ryukyu earthquake in Japan. In Yugoslavia, birds in zoo started crying before the 1963 earthquake. Deer gathered and cats disappeared from villages in northern Italy two or three hours before a damaging earthquake occurred in 1976. Such observations have also been noticed among animals who live underground, like snakes, insects and worms, and those living in water (fishes).

In Japan, fishes were reported to have disappeared before the Kanto earthquakes of 1923. Just before the 1855 Edo earthquake on November 11, many grass snakes were reported to have come out of the ground near the epicentral area, despite severe cold. Other instances involving fishes have been reported in Japan near north-western coast before the 1896 earthquake and the Tango earthquake of 1927 when abundant fishes were caught near the coast.

An interesting instance of unusual behaviour of dogs (but not of other animals) was reported before the destructive earthquake on November 24, 1976 in Turkey (Toksoz,1979).

Although several destructive earthquakes have occurred in the Himalayan region and elsewhere only one authentic observation of unusual animal behaviour was reported in India. In Govindpur in Jharkhand state of India, on February 19, 1892, animals were noticed to sniff the ground and exhibit nervousness such as dog shows in the presence of an unaccustomed object, while the air had distinctly sulphurous smell an hour before the shock.

During the recent damaging earthquakes in India of Uttarkashi (1991), Latur (1993), Jabalpur (1997), Chamoli (1999) and Bhuj (2001), there were reports of isolated cases of unusual behaviour of pet dogs, but the phenomenon was not observed on a large scale. According to the Chief conservator of forests for the Indian state of Tamil Nadu, a few minutes before the killer tsunami waves generated by an underwater earthquake hit the Indian coastline in December 2004, a herd of 500 blackbucks rushed away from the coastal areas to the safety of a nearby hilltop.

The Group of Earthquakes Research of the Institute of Biophysics, China (1979) carried extensive survey of the animal behaviour before damaging earthquakes occur. Its results are summarized below.
1. Most animals show increased restlessness before an earthquake.
2. The precursor time varies from a few minutes to several days, with increased restlessness at 11 hours which becomes still more marked about 2 to 3 hours before the earthquake. In general, the precursor times of various animals are mostly within 24 hours before the earthquake.
3. These observations have been noticed predominantly in the high intensity or epicentral regions close to active faults.
4. Changes in animal behaviour are observed during earth- quakes of magnitude 5 or more.
5. More intense responses can be noticed with the increase of intensity of earthquakes.

We can easily explain the cause of unusual animal behavior seconds before humans feel an earthquake. Very few humans notice the smaller P wave that travels the fastest from the earthquake source and arrives before the larger S wave. But many animals with more keen senses are able to feel the P wave seconds before the S wave arrives. As for sensing an impending earthquake days or weeks before it occurs, that's a different story.
There is little evidence for animals being able to sense earthquakes before they happen, although it is likely they can sense the initial, weaker P-wave or ultrasonic wave generated by a big underground explosion or the rupture of an earthquake, even if the waves are too small for humans' senses. These waves travel faster than the S-wave and Rayleigh earthquake waves that most strongly shake the ground and causes the most damage. It is speculated that when this happens, animals can detect the incoming earthquake wave, and start behaving agitatedly or nervously.

Others postulate that the animal behavior is simply their response to an increase in low-frequency electromagnetic signals. The University of Colorado has demonstrated that electromagnetic activity can be generated by the fracturing of crystalline rock. Such activity occurs in fault lines before earthquakes. According to one study, electromagnetic sensors yield statistically valid results in predicting earthquakes.

Accounts of similar animal anticipation of earthquakes have surfaced across the centuries since. Catfish moving violently, chickens that stop laying eggs and bees leaving their hive in a panic have been reported. Countless pet owners claimed to have witnessed their cats and dogs acting strangely before the ground shook—barking or whining for no apparent reason, or showing signs of nervousness and restlessness.

But precisely what animals sense, if they feel anything at all, is a mystery. One theory is that wild and domestic creatures feel the Earth vibrate before humans. Other ideas suggest they detect electrical changes in the air or gas released from the Earth.

Geologists, however, dismiss these kinds of reports, saying it's "the psychological focusing effect," where people remember strange behaviors only after an earthquake or other catastrophe has taken place. If nothing had happened, they contend, people would not have remembered the strange behavior.

Reference:

Srivastava, H.N., 1983.Earthquakes. National Book Trust, India.

Toksoz, M.N. 1979. Field investigations of the 24 November 1976 earthquakes in Turkey and its precursors. Int. Symp. Eathq. Pred. (UNESCO, Paris), Abstracts.

http://www.drgeorgepc.com/EarthquakePredictionChina.html
http://earthquake.usgs.gov/learn/topics/animal_eqs.php
http://news.nationalgeographic.com/news/2003/11/1111_031111_earthquakeanimals.html

NASA, Japan Release Most Complete Topographic Map of Earth.

WASHINGTON -- NASA and Japan released a new digital topographic map of Earth Monday that covers more of our planet than ever before. The map was produced with detailed measurements from NASA's Terra spacecraft. The new global digital elevation model of Earth was created from nearly 1.3 million individual stereo-pair images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, instrument aboard Terra. NASA and Japan's Ministry of Economy, Trade and Industry, known as METI, developed the data set. It is available online to users everywhere at no cost. "This is the most complete, consistent global digital elevation data yet made available to the world," said Woody Turner, ASTER program scientist at NASA Headquarters in Washington. "This unique global set of data will serve users and researchers from a wide array of disciplines that need elevation and terrain information." According to Mike Abrams, ASTER science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif., the new topographic information will be of value throughout the Earth sciences and has many practical applications. "ASTER's accurate topographic data will be used for engineering, energy exploration, conserving natural resources, environmental management, public works design, firefighting, recreation, geology and city planning, to name just a few areas," Abrams said. Previously, the most complete topographic set of data publicly available was from NASA's Shuttle Radar Topography Mission. That mission mapped 80 percent of Earth's landmass, between 60 degrees north latitude and 57 degrees south. The new ASTER data expands coverage to 99 percent, from 83 degrees north latitude and 83 degrees south. Each elevation measurement point in the new data is 98 feet apart. The ASTER data fill in many of the voids in the shuttle mission's data, such as in very steep terrains and in some deserts," said Michael Kobrick, Shuttle Radar Topography Mission project scientist at the Jet Propulsion Laboratory. "NASA is working to combine the ASTER data with that of the Shuttle Radar Topography Mission and other sources to produce an even better global topographic map." NASA and METI are jointly contributing the ASTER topographic data to the Group on Earth Observations, an international partnership headquartered at the World Meteorological Organization in Geneva, Switzerland, for use in its Global Earth Observation System of Systems. This "system of systems" is a collaborative, international effort to share and integrate Earth observation data from many different instruments and systems to help monitor and forecast global environmental changes. NASA, METI and the U.S. Geological Survey validated the data, with support from the U.S. National Geospatial-Intelligence Agency and other collaborators. The data will be distributed by NASA's Land Processes Distributed Active Archive Center at the U.S. Geological Survey's Earth Resources Observation and Science Data Center in Sioux Falls, S.D., and by METI's Earth Remote Sensing Data Analysis Center in Tokyo. ASTER is one of five Earth-observing instruments launched on Terra in December 1999. ASTER acquires images from the visible to the thermal infrared wavelength region, with spatial resolutions ranging from about 50 to 300 feet. A joint science team from the U.S. and Japan validates and calibrates the instrument and data products. The U.S. science team is located at NASA's Jet Propulsion Laboratory.

Death Valley

Death Valley, Calif., has the lowest point in North America, Badwater at 85.5 meters (282 feet) below sea level. It is also the driest and hottest location in North America. Located in eastern California and western Nevada, Death Valley forms part of Death Valley National Park. The region is characterized by deep valleys and high mountain ranges, located in the large Basin and Range province of the western United States. This view looking towards the northwest was created by draping an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) simulated natural color image over digital topography from the ASTER Global Digital Elevation Model (GDEM) data set. Furnace Creek ranch in the right foreground is the only place on the valley floor where vegetation grows year-round due to water channeled through Furnace Creek. The ASTER scene was acquired September 24, 2003, and is located near 36.4 degrees north latitude, 116.9 degrees west longitude.

Himalayan glaciers in Bhutan

In the Bhutan Himalayas, Advanced Spaceborne Thermal Emission and Reflection Radiometer data have revealed significant spatial variability in glacier flow, such that the glacier velocities in the end zones on the south side exhibit significantly lower velocities (9 to 18 meters, or 30 to 60 feet per year), versus much higher flow velocities on the north side (18 to 183 meters, or 60 to 600 feet per year). The higher velocity for the northern glaciers suggests that the southern glaciers have substantially stagnated ice. This view looking towards the northwest was created by draping an ASTER simulated natural color image over digital topography from the ASTER Global Digital Elevation Model (GDEM) data set. The ASTER scene was acquired November 20, 2001, and is centered near 28.3 degrees north latitude, 90.1 degrees east longitude.

Source of the article and photographs:

http://www.nasa.gov/topics/earth/features/20090629.html

Striking view of Sarychev volcano (Russia’s Kuril Islands, northeast of Japan).

A fortuitous orbit of the International Space Station allowed the astronauts this striking view of Sarychev volcano (Russia’s Kuril Islands, northeast of Japan) in an early stage of eruption on June 12, 2009. Sarychev Peak is one of the most active volcanoes in the Kuril Island chain and is located on the northwestern end of Matua Island. Prior to June 12, the last explosive eruption had occurred in 1989 with eruptions in 1986, 1976, 1954 and 1946 also producing lava flows. Commercial airline flights were diverted from the region to minimize the danger of engine failures from ash intake. This detailed photograph is exciting to volcanologists because it captures several phenomena that occur during the earliest stages of an explosive volcanic eruption. The main column is one of a series of plumes that rose above Matua Island (48.1 degrees north latitude and 153.2 degrees east longitude) on June 12. The plume appears to be a combination of brown ash and white steam. The vigorously rising plume gives the steam a bubble-like appearance; the surrounding atmosphere has been shoved up by the shock wave of the eruption. The smooth white cloud on top may be water condensation that resulted from rapid rising and cooling of the air mass above the ash column, and is probably a transient feature (the eruption plume is starting to punch through). The structure also indicates that little to no shearing winds were present at the time to disrupt the plume. By contrast, a cloud of denser, gray ash -- most probably a pyroclastic flow -- appears to be hugging the ground, descending from the volcano summit. The rising eruption plume casts a shadow to the northwest of the island (bottom center). Brown ash at a lower altitude of the atmosphere spreads out above the ground at upper right. Low-level stratus clouds approach Matua Island from the east, wrapping around the lower slopes of the volcano. Only about 1.5 kilometers of the coastline of Matua Island (upper center) can be seen beneath the clouds and ash.

Image Credit: NASA