We are gladly to introduce the knowledge about NUCLEAR POLLUTION to everyone who is going to view this blog page.

Saturday, October 29, 2011

NUCLEAR POLLUTION

 NUCLEAR POLLUTION
“We can’t see it. We can’t smell it. We can’t touch it. The effects may not show up now, in this decade, this generation even in this century. Nevertheless, these senseless nuclear impacts on us are far beyond imagination…”

Since the discovery of nuclear fission occurred in 1938, following nearly five decades of work on the science of radioactivity and the elaboration of new nuclear physics, nuclear technology are served for civilian uses such as power plant and medical, industrial, commercial, food processing and agriculture applications. Unfortunately, nightmares occur : 6 August 1945, "Little Boy"(uranium gun-type device) was detonated over the Japanese city of Hiroshima; three days later, "Fat Man"(plutonium implosion-type device) was exploded over Nagasaki, Japan; March 1979, Three Mile Island accident; April 1986, Chernobyl disaster; September 1999, Tokaimura nuclear accident; March, 2010, Fukushima Daiichi nuclear disaster…… (1)

Causes of Nuclear Pollution
Nuclear waste comes from a number of sources:
  • Operations conducted by nuclear power stations produce radioactive waste. Nuclear waste may generate low to medium radiation over long period of times. The radioactivity may contaminate and propagate through air, water, and soil as well. The main issue is the fact that nuclear waste cannot be degraded or treated chemically or biologically. Nuclear-fuel reprocessing plants in northern Europe are the biggest sources of man-made nuclear waste in the surrounding ocean. Radioactive traces from these plants have been found as far away as Greenland. (2)
  • Mining and refining of uranium and thorium. Mining of radioactive ores (such as uranium and phosphate ores) involve the crushing and processing of radioactive ores and generate radioactive by-products. (2) 
  • Nuclear fuel cycle (used in many industrial, medical and scientific processes). (2)

The sources of radiation pollution involve any process that emanates radiation in the environment. The most common ones that can pose moderate to serious health risks include:
  • Nuclear weapons – probably the highest amounts of human-induced radiation pollution have been generated in the mid twenty century through various experimental or combat nuclear detonations (that ended the Second World War). Nuclear fuel cycle (used in many industrial, medical and scientific processes). (2)
  • Defense weapon production – may also release radioactivity from the handled radioactive materials (usually of high health risks). However, unless accident occurs, the current standards will not allow the release of any significant amount of radiation. (2)
  • Nuclear accidents – an already classic example of such accident is the nuclear explosion, 1986 at a former Soviet nuclear power plant from Chernobyl and explosion, 1979 at Three Mile Island nuclear-power generating plant near Harrisburg, PA. The effects are still seen today. Even accidents from handling medical nuclear materials or wastes could have radiation health effects on workers. (2)


Negative impact on health and environment
Dose of 25 rems (unit of radiation needed to damage cells) causes changes in blood, above 100 rems cause nausea, vomiting, headache and loss of leucocytes whereas 300 rems and above cause internal harm including damage to nerve cells. The immediate effects occur within few days such as hair loss, subcutaneous bleeding, change in metabolism and proportion of cells. The delayed effects occur in few months or years which included genetic mutations and tumors formation. The free radicals slowly and steadily destroy proteins, membranes, and nucleic acids in human body. The most sensitive regions exposed to radiation are actively dividing cells such as skin, gonads, intestine, and bone marrow. (3)

Nuclear accidents may produce fallout which can pollute water supplies for years after the incident. The organism lives in water show sensitivity to the radiations. The 1986 explosion of a nuclear generator in Chernobyl (Ukraine) created a large radioactive cloud which polluted existing water supplies and produced contaminated rain in nearby countries. The radiations which are harmful influence nature and occur in the coastal areas. The fishes and water polluted by the radiation. Nuclear radiation can contaminate soil, leading to plants which contain radiation and pose a health threat to individuals. Researchers explored the Marshall Islands, an area widely known for nuclear bomb testing by the U.S. military in the 1950s and 1960s. They found that current soil samples and local foods, including coconut meat, contained radiation levels significant enough to pose a health risk to individuals. Radiation also damages chromosomes. It increases the frequency of chromosomal aberrations and causes genetic mutations. Such genetic changes may adversely affect plant metabolism or change their characteristics in subsequent generations. (3)

Ways to handle nuclear pollution

Vitrification is a proven technique in the disposal and long-term storage of nuclear waste or other hazardous wastes. Waste is mixed with glass-forming chemicals in a melter to form molten glass that then solidifies in canisters, immobilizing the waste. The final waste form resembles obsidian and is a non-leaching, durable material that effectively traps the waste inside. The waste can be stored for relatively long periods in this form without concern for air or groundwater contamination. Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing nuclear weapons. With the commercialization of nuclear power, the reprocessed plutonium was recycled back into MOX nuclear fuel for thermal reactors. The reprocessed uranium, which constitutes the bulk of the spent fuel material, can in principle also be re-used as fuel, but that is only economic when uranium prices are high. Finally, the breeder reactor can employ not only the recycled plutonium and uranium in spent fuel, but all the actinides, closing the nuclear fuel cycle and potentially multiplying the energy extracted from natural uranium by more than 60 times. (4)


Conclusion
Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity. Through the conscious of tragedy that comes after nuclear technology, many countries opposed to nuclear power. The Fukushima Daiichi nuclear disaster is exacerbating many of the problems that nuclear energy is facing. According to World Nuclear Industry Status Report 2010-2011, for the first time in history total installed nuclear power capacity in the world (375 gigawatts) fell behind aggregate installed capacity (381 GW) of three specific renewable — wind turbines (193 GW), biomass and waste-to-energy plants (65 GW), and solar power (43 GW). It is everyone’s dream to find others alternative power generator that can take the place of nuclear reactor. (5) 



4 comments:

  1. haha LOL.. i like the background XD

    ReplyDelete
  2. nuclear power is very dangerous for human life,So it can only be used for helpful processes

    ReplyDelete