The Challenger Fatma Hanafy Mohammed Hanafy. Marwa Yehya Galal Gad. Naira Tarek Saleh Mohamed Abd Alla . Shaimaa Esam Abd_Elsalam. Zeinab Hanafy Mohammed Hanafy.
introduction Risks of nuclearradiation and itsaccidentsSolutions Please press on Title
The Definition:-A nuclear reactor is adevice to initiateand control asustained nuclearchain reaction.
History:- The Enrico Fermi and Leo Chilard were the first to:- 1) Built a nuclear reactor at the University of Chicago in 1942. 2) Used the first nuclear reactors in the forties of the twentieth century to generate plutonium [t] of nuclear weapons. 3) Then used the other reactors in the Navy for the conduct of submarines .
History (cont.):- In the mid-fifties of the twentieth century were in the Soviet Union and other Western countries Research on the use of nuclear reactors for non- military purposes. In 1951, electrical energy produced for the first time from the nuclear-powered generators. The first reactor generates electricity for commercial purposes was built in Russia in 1954. And began operating the first nuclear reactor to generate electricity in the United States in 1957.
The history (cont.):- Having created hundreds of reactors in many countries stop built in some countries, including the United States (in the eighties), and that was for economic reasons and then re- consider that in 2004, and will build new nuclear reactors to generate electricity because it does not cause the release of gases harmful to the environment .
Uses:- The most common use of nuclear reactors is for the generation of electric energy and for the power in some ships. Heat from nuclear fission is used to raise steam, which runs through turbines, which in turn powers either ships propulsion or electrical generators.
Uses (cont.):- Nuclear power provides the world with more than 16% of electric power;– they provide 35% of the needs of the European Union.– Japan gets 30% of its electricity from nuclear energy,– Belgium, Bulgaria, Hungary, Slovakia and South Korea, Sweden, Switzerland, Slovenia and Ukraine relies on nuclear power to provide the third of its energy.
How Nuclear Reactors Work:- When an atom undergoes fission it splits into smaller atoms, other particles and releases energy. It turns out that it is possible to harness the energy of this process on a large enough scale for it to be a viable way of producing energy.
How Nuclear Reactors Work (cont.):- The fundamental point about nuclear energy is that the energy content of 1 gram of Uranium is equivalent to approximately 3 tonnes of coal. This means that we need to consume about 3 million times less material with Nuclear Power compared to using Coal or any other Fossil Fuel.
How Nuclear Reactors Work (cont.):- This substantially reduces the volumes of fuel and waste of nuclear power compared to Fossil Fuels. Nuclear power stations that generate energy occupy small areas of land compared to power stations that rely on solar energy or wind power
The Different Types of Nuclear Reactors:-There are a number of different types of Nuclear Reactors currently in operation throughout the world. Some of the most common types are described here.
Any imbalances that might occur in a nuclear reactor could cause a human catastrophe of unforeseeable consequences, such as disaster Chernobyl which resulted in thousands of tonnes of radioactive material that leaked into the atmosphere, As the output fuel of the nuclear reactor is considered hazardous materials , its effects continuous for thousands of years and can not be disposed of it easily.
High level waste:- Includes the fuel used in the nuclear reactor called spent fuel. It is highly radioactive and very dangerous. A special disposal site is needed for this type of spent fuel
Low level waste:- can come from nuclear reactors or from hospitals or universities. Low- level waste is not as dangerous as high- level waste
Nuclear power has at least four waste streams that contaminate and degrade land:-1) they create Spent nuclear fuel at the reactor site (including plutonium waste)2) they produce tailings at uranium mines and mills3) during operation they routinely release small amounts of Radioactive isotopes4) during accidents they can release large quantities of radioactivity
Disposal of nuclear waste is done in several ways vary according to the strength of outgoing radiation, including "the weak and medium," where is placed after cooling in the earth, and surrounded by a layer of cement or rocks,
nuclear radiation at large doses of radiation caused in deformities and disabilities are difficult to treat and may be them effect reach to the extent of death for who infected with it, also nuclear radiation affects directly on the components of living cells as a result of interactions not related to the natural interactions in the cell
AND the evidence on the harmful effects on people is the risk of cancer where:- There have been several epidemiological studies that claim to demonstrate increased risk of various diseases, especially cancers, among people who live near nuclear facilities.
Among recent studies, a widely cited 2007 meta-analysis of 17 research papers was published in the European Journal of Cancer Care. It offered evidence of elevated leukemia rates among children living near 136 nuclear facilities in:- the United Kingdom, Canada, France, United States, Germany, Japan, and Spain.
Also these radiations affect on aquatic where there is another type of the pollution is the thermal pollution which is produced by using the water of oceans. or seas or rivers in large quantities for cooling the reactor andwhich are thrown in the source after that ,so them temperature is increased resulted
imbalance in the environmental system (Eco- system) and damage all the aquatic which are living in the water whereit decreases the rate of dissolved oxygen in the water and required for the life of marine organisms.
And to overcome this problem, some states put laws committed these stations by cooling hot water before throwing them in the sea orlakes, and some stations established artificial lakes for them to use them in cooling purposes
The amount of radioactive waste resulting from the nuclear fission in the stations of producting electricity by nuclear reactors is limited compared to the amount of waste in thermal stations powered by fossil such as oil or coal , the nuclear waste reach to (3 mg/kwh) compared to about (700 gm /kwh) of carbon dioxide in normal thermal stations
A nuclear power plant may be safer than a coal power plant, but it still hurts the surrounding environment.
butthis tiny quantity of nuclear radiation may be fatal or may cause deformities and distortions there isnt a treat for them. Forthis, all countries that use nuclear energy for electricity production are working to disposal from radioactive waste by buring them in deep geological layers beneath the surface of the earth away from the people,
and may the effectiveness of radiation continues for centuries but for thousands of years, until the radiation dies down or reach to a level equivalent to natural radiation So scientists are trying currently to generate nuclear energy through nuclear fusion instead of nuclear fission
In March 2011 an earthquake and tsunami caused damage that led to explosions and partial meltdownsat the Fukushima I Nuclear Power Plant in Japan.
Radiation levels at the stricken Fukushima I power plant have varied up to 1,000 mSv/h (millisievert per hour), which is a level that can cause radiation sickness to occur at a later time following a one hour exposure. The level of radiation within the 20 km exclusion zone surrounding the power plant is such that people have been advised to evacuate,
and people within the 20-30km zone are being advised to stay indoors. Explosions and a fire have resulted in dangerous levels of radiation, sparking a stock market collapse later, the UK, France and some other countries told their nationals to consider leaving Tokyo, in response to fears of spreading nuclear contamination.
New Scientist has reported that emissions of radioactive iodine andcesium from the crippled Fukushima I nuclear plant have approached levels evident after the Chernobyl disaster in 1986.
As of April 2011, water is still being poured into the damaged reactors to cool melting fuel rods. John Price, a former member of the Safety Policy Unit at the UKs National Nuclear Corporation, has said that it "might be 100 years before melting fuel rods can be safely removed from Japans Fukushima nuclear plant".
During the 2011 Fukushima nuclear emergency in Japan, three nuclear reactors were damaged by explosions.
Mapshowing Caesium-137 contamination in Belarus, Russia, an d Ukraine as of 1996.
The 1986 Chernobyl disaster in the Ukraine was the worlds worst nuclear power plant accident, resulting in an estimated 4,056 deaths. Large amounts of radioactive contamination were spread across Europe, and cesium and strontium contaminated many agricultural products, livestock and soil. The accident necessitated the evacuation of 300,000 people from Kiev
Chernobyl disasterThe nuclear reactor after the disaster. Reactor 4 (center). Turbine building (lower left). Reactor 3 (center right).
Nuclear power plant accidents with more than US$300 million in property damage, to 2009:- Date Location Description Cost (in millions 2006 $)December 7, Greifswald, Electricians error causes US$443 1975 East Germany fire in the main trough that destroys control lines and five main coolant pumps
Date Location Description Cost (in millions 2006 $) Jaslovské Severe corrosion of reactor US$1,700 Bohunice, and release of radioactivityFebruary 22, 1977 Czechoslovakia into the plant area, necessitating total decommission March 28, Middletown, Loss of coolant and partial US$2,400 1979 Pennsylvania, core meltdown, see Three US Mile Island accident and Three Mile Island accident health effects March 9, Athens, Instrumentation systems US$1,830 1985 Alabama, US malfunction during startup, which led to suspension of operations at all three Browns Ferry Units - operations restarted in 1991 for unit 2, in 1995 for unit 3, and (after a $1.8 billion recommissioning operation) in 2007 for unit 3
Date Locatio Description Cost n (in millions 2006 $) Plymouth, Recurring equipment problems Massachuset force emergency shutdown ofApril 11, 1986 ts, US Boston Edisons Pilgrim Nuclear US$1,001 Power Plant April 26, Chernobyl, Steam explosion and meltdown 1986 near the with 4,057 deaths (see Chernobyl town of disaster) necessitating the Pripyat, evacuation of 300,000 people Ukraine from the most severely contaminated areas of Belarus, US$6,700 Russia, and Ukraine, and dispersing radioactive material across Europe (see Chernobyl disaster effects)
Solutions 1-Procedures for nuclearsafeguards . 2- team Ideas .
International organizations which interested inmatters of protection and nuclear safetyrecommended by the establishment ofnational committees set the rules andregulations that govern all practices involvingionizing radiation or radioactive sources inorder to take advantage of the benefits ofnuclear energy and its positive aspects invarious fields with the reduction of risksposed by it to the acceptable limit .
1 - Spreading awareness of the risks and the dissemination of nuclear safety culture among employees radiation or radioactive materials at all levels.2 - Provide all equipment and technical equipment necessary for the protection and safety.3 - Providing human expertise with knowledge of procedures for the protection and safety.4- Implementation of all nuclear measurementsthat aim to ensure the protection measuresrequired..
5 - Set standards and requirements for allpractices, which include exposure toradiation and to identify the official.6 - The existence of effective planning in theevent of an emergency are known in advancefor employees and that perceptions of thedevelopment potential of the variousincidents based on the experience Available.
7 - And there must be an effectiveadministrative organization inside thebuilding used to identify sources ofradioactive radiation intensity to be alwaysin the permitted levels of radioactive sourcesand be stored in safe places and kept in theprotective armor in the case of non-use. Preferably at the creation of a new reactor to be of the type of reactor CAESAR
Claudio able Vilpon nuclear scientist and director of the Center of advanced energy at the University of Maryland American innovation and design of advanced reactor CAESAR" for the production of electricity without causing any radioactive contamination, or the spread of nuclear radiation. Unlike traditional nuclear reactors operated arms and fuel uranium-238 supplied by about 4% of uranium 235.
When the collision of neutron seed uranium 235 splits off to the nuclei and the amount of energy in the form of heat and more of the neutrinos that hit other atoms. And controls «mediator» between the fuel rods entered to slow down some of the neutrinos are moving slowly enough so that they splitting nucleus of atoms. But after two or three years of operation of the reactor, it becomes uranium-235 atoms remaining is insufficient appears to need a new fuel rods.
But Caeser reactor depends on the uranium-238 atoms fission within the fuel rods by neutrons moving at an appropriate speed as a result of the presence of steam as a mediator in the reactor, to control the density accurately, to delay the passage of neutrinos to obtain the required fission of uranium-238 atom. And the occurrence of nuclear reaction accompanied by the launching of the energy and the launch of more neutrinos, which in turn hit other uranium seed and so on. Caeser and the reactor can run for decades without the need to re-fuel it.
Because water used to cool the reactors are loaded with radiation . And to overcome this problem, some states put laws committed these stations by cooling hot water before throwing them in the sea or lakes, and some stations established artificial lakes for them to use them in cooling purposes .
1- Because the concepts of rolling stock for radiologicalhazards may sometimes have negative effects as whatpeople may be followed by action in the case ofradiation accidents and because of exaggerated fearsmay lead to negative effects on its own. One of thechallenges we face to make sure that the generalpublic have accurate information and concepts in thecase of radiation accidents until there is no reactionexaggerated.- And so it can work on the establishment of scientificmaterial received conferences or taught in schoolsaimed at educating students the dangers of reactorsand nuclear radiation and raise awareness of they needto do in the event of a nuclear disaster (anemergency).
2- Establishment the Assembly on the idea at an international level like the idea of the insurance company where the participation of nations with nuclear reactors and the amount of money can be joined with scientists.- In the event of any disruption or disaster Assembly intervene to resolve the imbalance and reduce the risks and be physical and scientific assistance.
3- Support scientific research to developprocedures for nuclear safeguards .4- Manufacture of electric-powered chillers to cool the water used in cooling nuclear reactors. Using a fraction of the electricity produced by the reactor and to minimize the risk of radiation that exists. in order to reduce ocean water used in the reactor cooling circuits .
5- For injured people: establishment a specialized health organizations to treat these people. These solutions not only contribute to the protection of the environment and the health of living organisms, but also contribute to the promotion and protection of the economy at the international level and global