Posted on
Thursday, 8 December 2011
•Some spontaneous fission (SF).
•Specific activity of U low due to long half-lives …. but …
•Decay through chain of daughter products, ultimately leading to lead or bismuth.
•At secular equilibrium:
–All decay rates are same throughout the chain.
–Daughter product concentration in proportion to half-life.
–~ 95% of specific activity (Bq/kg) is due to daughter products.
•Radon gas most significant.
FABRICATION
FUEL PROPERTIES
1.Nuclear reactivity and control
2.Adequate thermal-hydraulic and heat transfer characteristics (i.e. coolant flow rate, surface area etc.)
3.Containment of radioactive materials under normal and transient conditions (i.e. fission product containment)
4.Minimisation of neutron absorbing impurities
5.Cost competitiveness
a)Long fuel residency (high-burnup)
b)Standardisation of product for economic manufacture
c)Reliability
d)Realistic specifications with good quality control within the acceptable tollerance
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NUCLEAR PROPERTIES OF URANIUM
•U isotopes all alpha emitters.•Some spontaneous fission (SF).
•Specific activity of U low due to long half-lives …. but …
•Decay through chain of daughter products, ultimately leading to lead or bismuth.
•At secular equilibrium:
–All decay rates are same throughout the chain.
–Daughter product concentration in proportion to half-life.
–~ 95% of specific activity (Bq/kg) is due to daughter products.
•Radon gas most significant.
•HEX is converted into UO2
•UO2 is manufactured into pellets and loaded into pins (or rods)
•The rods are combined into assemblies
1.Nuclear reactivity and control
2.Adequate thermal-hydraulic and heat transfer characteristics (i.e. coolant flow rate, surface area etc.)
3.Containment of radioactive materials under normal and transient conditions (i.e. fission product containment)
4.Minimisation of neutron absorbing impurities
5.Cost competitiveness
a)Long fuel residency (high-burnup)
b)Standardisation of product for economic manufacture
c)Reliability
d)Realistic specifications with good quality control within the acceptable tollerance
Posted on
Wednesday, 7 December 2011
The nuclear fuel cycle is the series of industrial processes which involve the production of electricity from uranium in nuclear power reactors.
Uranium is a relatively common element that is found throughout the world. It is mined in a number of countries and must be processed before it can be used as fuel for a nuclear reactor.
Fuel removed from a reactor, after it has reached the end of its useful life, can be reprocessed to produce new fuel.
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Posted on
Tuesday, 6 December 2011
WASTE CANNISTERS
The waste are securely confined in the cannisters and stored in disposal facilities inaccessible to intruders.
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As we near the end of the century, the disposal of nuclear waste is becoming a concern. Many nuclear power plants around the world are nearing the end of their operating lives.
The disposal of radioactive waste from nuclear power plants and nuclear missiles is as politically intense an issue as the plants and missiles themselves. Yet the three issues have remained curiously separate in spite of their close physical ties. Few debates on nuclear power or nuclear weapons discuss the problems of waste disposal should the power plant or missile be decommissioned.
Nuclear waste can be generally classified a either "low level" radioactive waste or "high level" radioactive waste. Low level nuclear waste usually includes material used to handle the highly radioactive parts of nuclear reactors (i.e. cooling water pipes and radiation suits) and waste from medical procedures involving radioactive treatments or x-rays. Low level waste is comparatively easy to dispose of. The level of radioactivity and the half life of the radioactive isotopes in low level waste is relatively small. Storing the waste for a period of 10 to 50 years will allow most of the radioactive isotopes in low level waste to decay, at which point the waste can be disposed of as normal refuse.
High level radioactive waste is generally material from the core of the nuclear reactor or nuclear weapon. This waste includes uranium, plutonium, and other highly radioactive elements made during fission. Most of the radioactive isotopes in high level waste emit large amounts of radiation and have extremely long half-lives (some longer than 100,000 years) creating long time periods before the waste will settle to safe levels of radioactivity. This area will describe some of the methods being under consideration, for dealing with this, high level, waste. These include short term storage , long term storage, and transmutation.
WASTE CANNISTERS
The waste are securely confined in the cannisters and stored in disposal facilities inaccessible to intruders.
Posted on
Fast neutrons produced in the fission reaction are slowed when they bounce off light atoms such as hydrogen or carbon and contains a large amount of such moderating material to slow down the fission neutrons. This takes advantage of the fact that the probability of a neutron being absorbed into another 235U nucleus is much higher at low neutron energy.
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Thermal and fast nuclear reactors
A nuclear reactor converts the fissile components, such as 235U, of nuclear fuel into energy, and fertile components, such as 238U, into fissile components and then into energy. A fissile atom is one that is very likely to be fissioned (split) when a neutron is absorbed, thereby enabling a nuclear chain reaction. A fertile atom is one that can be converted to a fissile atom by absorbing one neutron.In the fission process, which is an exothermic reaction, about 0.09% of the total mass of a uranium atom is converted to energy. Most of this energy is manifested as increased temperature inside the reactor fuel. Liquid heat-transfer material is circulated through the reactor to control the temperature. It also extracts heat for useful purposes, such as to produce steam to drive a turbine connected to an electric generator.
A nuclear reactor converts the fissile components, such as 235U, of nuclear fuel into energy, and fertile components, such as 238U, into fissile components and then into energy. A fissile atom is one that is very likely to be fissioned (split) when a neutron is absorbed, thereby enabling a nuclear chain reaction. A fertile atom is one that can be converted to a fissile atom by absorbing one neutron.In the fission process, which is an exothermic reaction, about 0.09% of the total mass of a uranium atom is converted to energy. Most of this energy is manifested as increased temperature inside the reactor fuel. Liquid heat-transfer material is circulated through the reactor to control the temperature. It also extracts heat for useful purposes, such as to produce steam to drive a turbine connected to an electric generator.
Posted on
Saturday, 3 December 2011
Enrico Fermi nearly discovers nuclear fission while bombarding uranium with neutrons. The sample was wrapped in aluminium foil, preventing him from detecting the splitting of the atom
Soviet Union (USSR) tests its first atomic bomb
The first nuclear reactor to provide electricity to a national grid opens in Calder Hall, England
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 |
| Albert Einstein |
1905
E = mc2, Albert Einstein establishes equivalence of mass and energy
1911
Ernest Rutherford probes the structure of the atom
1932
James Chadwick discovers neutrons
1934
 |
| Enrico Fermi |
1941
Manhattan Project begins at Los Alamos National Laboratory in New Mexico, US
1942
Manhattan Project achieves first controlled nuclear fission reaction in a basement in Chicago, US
1945
16 July - first atomic bomb is tested in Los Alamos
6 August - US drops atomic bomb on Hiroshima, Japan
9 August - US drops another atomic bomb on Nagasaki, Japan
1949
 |
| Atomic Bomb |
1952
The world's first hydrogen bomb is tested by the US on a remote Pacific Ocean atoll. The nuclear fusion device is 500 times more powerful than the atomic bombs dropped on Hiroshima or Nagasaki
The United Kingdom detonates its first atomic bomb
1954
US launches first nuclear-powered submarine
1956
 |
| First Nuclear Reactor |
1957
United Nations establishes the International Atomic Energy Agency, its nuclear watchdog
1959
US operationally deploys first intercontinental ballistic missile
1960
France tests its first nuclear bomb
1964
China tests its first nuclear bomb
1968
Nuclear Non-Proliferation Treaty (NPT) is signed
1974
India detonates a "non-weapon" nuclear explosion underground
1979
Israel and South Africa suspected of jointly testing a nuclear bomb
A cooling problem causes the meltdown of the Three Mile Island nuclear reactor in Pennsylvania, US
1980
Last known atmospheric nuclear test is conducted by China
1986
The reactor meltdown and explosion at the Chernobyl nuclear power plant in the USSR (now Ukraine) becomes the worst nuclear accident in history
1991
The Cold War, which started after World War Two, ends with the collapse of the USSR. Disarmament accords follow during the 1990s, ending the US-Soviet nuclear arms race
1998
India conducts five nuclear weapons tests and Pakistan conducts six
1999
US Senate rejects Comprehensive Nuclear Test Ban Treaty
70 people are exposed to radiation in the Tokaimura nuclear facility in Japan
2002
North Korea claims it has a nuclear weapons programme
2003
North Korea withdraws from Nuclear Non-Proliferation Treaty
Libya ends its nuclear weapons programme
2004
Pakistani nuclear scientist Abdul Qadeer Khan is exposed as supplying a global black-market in nuclear technology
2005
Nuclear Non-Proliferation Treaty review meeting in May ends with no agreement
By Tui
Posted on
Friday, 2 December 2011
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What is Greenhouse Gas?
Greenhouse gas is a gas in atmosphere that absorbs and emits radiation. 3 priority Greenhouse gases in Malaysia is carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).
How to control the Greenhouse Gas?
First we have measure the emission of the greenhouse gases. Now in year 2011 we have World Carbon Dioxide emission data so that we can compare which country raise up their carbon emission and which are gone down their CO2 production.
To estimate C02 emission in Malaysia it were measured from the major source of the following sector :
1. Energy - Fuel Combstion
2. Industrial Processes
3. Waste - Industrial waste water treatment
4. Land use change and Forest y - Forest and grassland conversion
For Malaysia : United Nations data shows Malaysia's carbon emissions in 2006 stood at 187 million tonnes or 7.2 tonnes from each Malaysian.
By Amir
Greenhouse gas is a gas in atmosphere that absorbs and emits radiation. 3 priority Greenhouse gases in Malaysia is carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).
How to control the Greenhouse Gas?
First we have measure the emission of the greenhouse gases. Now in year 2011 we have World Carbon Dioxide emission data so that we can compare which country raise up their carbon emission and which are gone down their CO2 production.
To estimate C02 emission in Malaysia it were measured from the major source of the following sector :
1. Energy - Fuel Combstion
2. Industrial Processes
3. Waste - Industrial waste water treatment
4. Land use change and Forest y - Forest and grassland conversion
For Malaysia : United Nations data shows Malaysia's carbon emissions in 2006 stood at 187 million tonnes or 7.2 tonnes from each Malaysian.
A traffic jam during morning rush hour in east west highway connection towards capital city Kuala Lumpur, Malaysia, Monday, March 29, 2010.
Lets reduce the Greenhouse gases together for a brighter future for human kind.
By Amir
Posted on
Thursday, 1 December 2011
The Klang Valley Mass Rapid Transit is a proposed 3-line 150 km Mass Rapid Transit ‘”(MRT)”’ system in the Klang Valley/Greater KLconurbation which envisages a “Wheel and Spoke” concept comprising two northeast-southwest radial lines and one circle line looping around Kuala Lumpur city. Klang Valley MRT will not only significantly increase the current inadequate rail network but will also serve to integrate the existing rail networks and expectantly alleviate the severe traffic congestion in the Greater KL metropolitan area. The proposal was announced in June 2010 and was approved by the government of Malaysia in December 2010. Construction of the first line is targeted to commence in July 2011. The project also represents one of the economic entry point project identified for the Greater Kuala Lumpur/Klang Valley National Key Economic Area under the Economic Transformation Programme.
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