Haeji

**1. How nuclear energy is used to solve energy scarcity?**
Fossil fuels are running out and people are predicting all the fossil fuels (Oil, Gas, Coal) will run out in 2090. But nuclear energy can replace fossil fuels. Nuclear energy can produce electricity more than alternative energies like solar or wind since it doesn't have conditions. Also, nuclear energy produces more energy than fossil fuels. For example to operate a million kW power plant for an year, 1.5 million tons of oil is needed, but when we use nuclear energy, we only need 30 tons of Uranium.

Same amount of energy produced with : Uranium 1g = Coal 3 ton = Oil 9 drum

**2. How is nuclear energy produced?**

 * a) What is nuclear fission?**

When nuclear fission happens, it means that a neutron bombarded to an Uranium atom, and it divided into lighter atom. When a Uranium is divided, it releases neutrons and a lot of radioactive energy.




 * b) How is nuclear energy used to generate electricity?**

When a Uranium atom is divided, it releases neutrons and energy. The released neutrons splits other uranium atoms in the nuclear rod and it produces energy and neutrons which will split other uranium atoms and the nuclear fission does on and on. This is called the nuclear chain reaction. When nuclear chain reaction happens, it produces a lot of energy which is very hot. Because the nuclear rods are in the water, the heat from the nuclear fission turns the water into steam.The steam produced, turns the turbines and produces electricity.



3. What are the advantages and limitations of nuclear energy?

 * Advantage**
 * It produces a lot of electricity with less fuel than fossil fuels.
 * 1) To produce the same amount of electricity, we need Uranium 1g = Coal 3 ton = Oil 9 drum
 * 2) One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil.
 * 3) To operate a 1,000,000 kW power plant for an year it needs Uranium 30 t / LNG 1,100,000 t / Oil 1,500,000 t.

>
 * When nuclear energy produces energy, it doesn't release carbon dioxide.
 * 1) Coal and oil burning plants pollute the air. Well-operated nuclear power plants do not release carbon dioxide and pollute the environment.
 * 2) Amount of carbon dioxide produced - Coal 950~1250 g/kWh, Oil 700~800 g/kWh, Natural gas 360~575 g/kWh, Nuclear 2.8~24 g/kWh.
 * Large amount of Uranium is still left in the earth, when fossil fuels are running out.
 * 5,404,000t of Uranium is left (2009)
 * 1) Years of production left in the ground with the current proved reserves and flows above
 * Coal: 148 years
 * Oil: 43 years
 * Natural gas: 61 years

> The world's nuclear fleet creates about 10,000 metric tons of high-level spent nuclear fuel each year >
 * Disadvantage**
 * Nuclear waste is produced when we use nuclear energy.
 * 1)  Around 20–30 tons of high-level waste are produced per month per nuclear reactor.


 * Accidents can happen when we use nuclear power plant.
 * 1) In a meltdown accident the fission reaction goes out of control, leading to a nuclear explosion and the emission of great amounts of radiation.


 * It is expensive to build a nuclear power plant
 * 1) Construction cost - Case 1 = 1 billion, Case 2 = 1.4 billion, Case 3 = 2 billion, Case 4 = 2.5 billion, Case 5 = 5 billion


 * Limitation**
 * Uranium will eventually run out
 * 5,404,000t of Uranium is left (2009)


 * Uranium costs high
 * 1) $10.75 per pound = 2003, $45.00 per pound = 2006, $100.00 per pound = 2007

fuel than fossil fuels. || • || Nuclear waste is produced when we use nuclear energy || • || Uranium will eventually run out || it doesn't release carbon dioxide || • || Accidents can happen when we use nuclear power plant || • || Uranium costs high || the earth, when fossil fuels are running out. || • || It is expensive to build a nuclear power plant || • ||  ||
 * ||= **Advantage** ||  ||= **Disadvantage** ||   ||= **Limitation** ||
 * • || It produces a lot of electricity with less
 * • || When nuclear energy produces energy,
 * • || Large amount of Uranium is still left in

**4. How does nuclear radiation affect the environment?**
 1986 in Chernobyl in the Ukraine  Huge numbers of animals had to be slaughtered and food had to be destroyed because it had been contaminatedby radioactive material. After the disaster, four square kilometers of pine forest directly downwind of the reactor turnedreddish-brown and died, earning the name of the "Red Forest". Some animals in the worst-hit areas also died orstopped reproducing and most domestic animals were removed from the exclusion zone. Many animals borned with birthdefects. 

**5. How does nuclear radiation affect health?**
There is 3 kinds of typical radioactive rays, which is a-ray, beta ray, and gamma ray. These rays can pass through our body, and when it enters in our body through food, a-ray is causes the most damage. When radiation meets an atom, it makes the electrons go out from it's place so of the radiation goes through our body, the cell will get damaged. When exposed to radiation in large amounts, humans can develop cancer, in addition, it can also cause birth defects in humans.


 * Over 200 mSv : It can affect white blood cells
 * 1000 mSv : Vomiting, fatigue and other symptoms appear
 * 2000 mSv : People can die when systemic exposure happens
 * 3000 mSv : Hair loss can appear
 * <span style="font-family: Arial,Helvetica,sans-serif;"><span style="font-family: Arial,Helvetica,sans-serif;">4000 mSv : When systemic exposure happens about 50% dies within 30 days
 * <span style="font-family: Arial,Helvetica,sans-serif;">6000 mSv : When systemic exposure happens about 90% dies within 14 days
 * <span style="font-family: Arial,Helvetica,sans-serif;">7000 mSv : 100% dies

a-ray : It's energy is strong but heavy, so the distance is short, and we can block it by a piece of paper. beta ray : It's p<span style="background-color: #ffffff; font-family: Arial,Helvetica,sans-serif;">ermeability 500 times bigger, and we can block it by aluminum. <span style="background-color: #ffffff; font-family: Arial,Helvetica,sans-serif;">gamma ray : It has very high energy and it has the best permeability of all the 3 rays.




 * Vocabulary :**

Enrich - Higher amount of a type of Uranium isotope useful for fission <span style="font-family: Arial,Helvetica,sans-serif;">Electrons = 전자 <span style="font-family: Arial,Helvetica,sans-serif;">Proton = 양자 <span style="font-family: Arial,Helvetica,sans-serif;">Neutron = 중성자 <span style="font-family: Arial,Helvetica,sans-serif;">Isotope = 동위 원소 = Same number of Protons but different number of Neutrons <span style="font-family: Arial,Helvetica,sans-serif;"> (When the number of proton is different it won’t be the same element) <span style="font-family: Arial,Helvetica,sans-serif;">Element = 원소 <span style="font-family: Arial,Helvetica,sans-serif;">Nuclear fission = 핵분열 <span style="font-family: Arial,Helvetica,sans-serif;">Nuclear fusion = 핵융합 <span style="font-family: Arial,Helvetica,sans-serif;">Replicate = (정확히) 모사하다


 * Source :**

[] [] <span style="background-color: #ffffff; display: block; font-family: Arial,Helvetica,sans-serif; text-align: left;">[|http://en.wikipedia.org/wiki/Environmental_impact_of_nuclear_power#Power_plant_emissions] <span style="background-color: #ffffff; color: #000000; font-family: Arial,Helvetica,sans-serif;">Last modified on 23 April 2012 at 17:47. <span style="background-color: #ffffff; color: #000000; font-family: Arial,Helvetica,sans-serif;">Written by wikimedia []