Natural Energy And Nuclear Energy

Natural & Renewable Energy and Nuclear Energy. 1. Natural & Renewable Energy and Nuclear Energy (1) Nuclear Energy Nuclear Energy is being used in Electricity Generation Plant. Every matter is organized by Atom. Atom is organized by Proton, Neutron which is in the Nuclear, and Electron which is orbiting the Nuclear. When Heavy Atom (such as Uranium) absorbs Neutron, Nuclear is going to break with a lot of energy and a few Neutrons. These Neutrons are going to break other Atoms. This phenomenon is called Chain Reaction of Nuclear Fission. 1gram of Uranium Nuclear Fission makes a lot of energy equal to burning 9 drum of oil or 3 ton of coal. The basic process is 1) Boil the water with Chain Reaction of Nuclear Fission and this will make the super vaporized steam. 2) The super vaporized steam will go to the turbine of electric generator.

(2) Natural & Renewable Energy Solar Energy, Wind Energy, Tidal Energy, Terrestrial heat Energy are also good power resources. These Energies have no toxic waste, and are clean and renewable. In this document we will focus specially on Solar Energy.

Solar Energy is coming from the Sun. This energy can be used by distillation and power generation. Distillation is one of the great invention technologies. It can be used to transform the seawater to the fresh water. For example, Symi island in Greece have Solar distillation facility. This facility has hemisphere shape. Seawater is going to vaporize inside of hemisphere with solar energy and vapor is going to condense inside of hemisphere surface and fall down. With This process it can supply 1 gallon of fresh water to each 4000 people of this island in one day. This facility doesn’t need a complex device to build it. Just with this, hemisphere shape can make 4000 gallon of fresh water per day. Concentrating Solar Power plant has same basic idea from conventional power station to produce electricity. Because they both are using the steam to run the turbine, but CSP plant uses solar energy to make steam. There are 4 major parts of Concentrating Solar Power generation, Concentrator, a receiver, storage and power conversion. CSPs are classified with how they can concentrate the sunlight. Until now four types of concentrators have been invented. The Parabolic Trough has parabolic surface to concentrate the sunlight to the center of trough. Central Receivers has many mirrors to reflex the sunlight to the Central Tower. Parabolic Dish has looks like reflexible antenna. it concentrates the sunlight to the one point and this point has receiver. Linear Fresnel has similar structure with Parabolic Trough but plane mirror reflexes the sunlight to the receiver. Information of four types of concentrator is given in Table 1. 

Table 1. Type of Concentrating Solar Power Generation. Parabolic Trough

Central Receivers

Parabolic Dish

Linear Fresnel

Capacity(MW)

10~200

10~200

0.1~1

10~200

Efficiency(%) Temperature (℃) Investment cost (Euro/KW) Development status

10~25 350~415

10~25 250~565

16~29 750~800

9~17 2700~500

3,000~6,500

4,000~6,000

4,000~10,000

2,500~5,500

Commercializati on completed

Commercializati on progressing

Prototype Test

Prototype

Stabilized system High efficiency

High Temperature High efficiency

Highest efficiency Module system

Hard to improve Efficiency

Commercialization not proved High operation cost

Untested Technology Impossible to Store the heat

Low Investment cost Efficiency improvement expected Low Efficiency

Type

Advantage

Disadvantage

Reference

Deutsche Bank(2009), The CSP industry An awakening giant, Greenpeace(2009), Concentrating Solar Power Global Outlook 09

2. Comparing about energy. (1) Nuclear Nuclear energy is more useful than Solar energy. Nuclear energy can generate electricity 24 hours a day. Also it doesn’t require the large land to install the plant. But nuclear power plant uses the uranium as fuel. Uranium is used in the nuclear power plant as fuel. Natural uranium consists of 0.7% of uranium 235 and 99.3% of uranium 238. Natural uranium that is going through the refining process and enrich process, will change Natural uranium concentrate to the 2~5% of uranium 235 and then it’s used by fuel in the nuclear power plant. Nuclear power process uses 3% of fuel and it remains 1% of plutonium and 95~96% of uranium. If this waste going through the separation process it can be divided with plutonium and uranium. Plutonium is a material of nuclear bomb of Nagasaki in Oct 9th 1945. There is some rumor that U.S.A threw the nuclear bomb twice because they wanted to have experiment about 2 kind of nuclear bomb which made of plutonium and uranium. This Nuclear waste has high radiation intensity and produces a lot of heat. Also, nuclear waste has toxic radioactivity. If human is exposed to radiation, it causes illnesses such as, headache, vomiting, infection, internal hemorrhage, destruction of marrow and cancer or even death. Furthermore, nuclear waste disposal technology does not exist. So, it cannot be exposed in the air. Normally it is kept in temporary tank inside of nuclear power plant with the cooling water. If it has to move, it goes into the 120~150 ton of cask and goes to the nuclear waste site. Even U.S.A, Japan and any other countries which have Nuclear Power Plant are spending a lot of money and land to keep the nuclear waste and do the experiment about nuclear waste technologies. (2) Natural Energy Solar Energy is one of the good renewable energy sources. but it has many issues. Firstly, it needs a lot of space to install the plant. Sun radiate 2cal/min of energy in 1cm2 to outer space of the earth. This is Solar coefficient and considering about latitude, weather condition, shape of the earth, normally Sun convey 1/8 of energy to the surface. According to the International Nuclear Safety School, Nuclear power plant require 1~2km2 for generate 1,000MWe but solar power plant require 20~50km2. Because of this problem, the efficiency of solar power generation is very low. This is only one issue of solar energy. Beside of this issue it has a lot of advantage. Table 2. Comparing Cost of Renewable & Nuclear power plant Renewable Power Plant Nuclear Power Plant (Gori 2nd) Unit 1015 1 Capacity(MW) 620 650 Total Capacity(MWH) 3,654,647 5,232,779 Hours of operation 5,889 8,050 Building cost(\) 1,780 billion 1,500 billion Fuel cost(\) 0 720 billion Demolition cost of 0 325.1 ~ 1,000 billion plant(\) Medium-Low active 0 400.9 billion waste(\) High active waste(\) 0 430 ~ 932.7 billion Local area support 4.7 billion 30 billion Transmission tower 0 250 billion Total 1,784.7 billion 3,656 ~ 4,838.6 billion 

Reference Environmental Movement in Korea, According to table, a nuclear power plant is 2~3 times more expensive than renewable energy. This table shows that nuclear power plant is just convenience energy source. 3. Conclusion With these facts, we can think about 3 options. First, keep using the nuclear energy which has expensive cost and risk for radiation exposure. Second, we can develop the renewable energy. Finally find another energy sources. Nuclear energy is more useful than Renewable energy on one side. This is true at some point. Nuclear energy is more powerful, useful and has a higher capacity than Renewable energy. But it is expensive because high active waste needs to be kept in safe way and keeping time will be centuries. Furthermore, the high active waste disposal technology does not exist. It’s like keeping the bomb inside of our body. Also since no one didn’t dispose the nuclear waste (Just Keep in nuclear waste site), no one knows the nuclear waste disposal cost. Renewable energy has a lot of problems but also it has a lot of possibility. It’s well known fact that clean and unlimited. Fossil fuel and nuclear fuel are has limit. Eventually, these energies are going to exhausted. But as long as the Sun exists, renewable energies are not going to exhaust. If we concentrate on renewable energies, we can develop the technologies of renewable energies. And our next generation can live with clean environment. 4. Reference Concentrating Solar Power Global Outlook 09’ (Greenpeace International, ESTELA, SolarPACES) Environment Movement in Korea. http://blog.cbs.co.kr/jwkim2.blog$1/656390 by Reporter Jewon Kim. LG Business insight 2009 9 16 p29~35. By Researcher Nakhwan Seong http://www.e2news.com/pdf/check.php?fd=115&dnfile=01.PDF by Reporter Sangbok Lee International Nuclear Safety School