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Nuclear Power/Nuclear Power vs. Coal Combustion

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Question
Dear Dr. Osman Kemal Kadiroglu.

I'll be honest, I'm new to this sort of thing, specifically AllExperts.com, so please forgive me for any faux pas and the like in this inquiry.

I am currently in the process of writing a research paper on how Nuclear Power is an exponentially better alternative to power generation through coal burning/combustion. I'd like to ask you a few questions about the topic considering your clear expertise in an interview type fashion if you don't mind. (I'll be adding "if any" or similar phrases to most if not all of my questions even if I know for a fact that there are financial advantages for instance. This is just to remain as impartial as possible even while knowing the way some things are or that there are in fact advantages to using Nuclear power over coal combustion in one way or another. I'm sure this sounds odd and I apologize if it in fact does.)

1. In what ways, if any, is nuclear power more efficient than coal combustion?

2. What are the financial advantages, if there are any, of using Nuclear power in place of coal combustion?

3. Is the Nuclear power generation "process" more dangerous or more safe than coal combustion and in what ways is it safer or more dangerous?

4. Does Nuclear power generation have a greater or smaller negative impact on the environment than coal combustion and why?

5. I hear many things about most (about 96% specifically) nuclear waste or rather, the byproduct from nuclear power generation, having the ability to be recycled into fuel and other such similar things. Is this true or false and if it is true how exactly is it recycled and into what exactly. (This is a question that has been bothering me for a long time.)

6. Are the potential health risks, if there are any, of nuclear power generation more or less serious and harmful than those from generating power through coal combustion?

7. Which is overall more harmful to people, the atmosphere, and the environment in general: byproducts from Nuclear power generation or byproducts from power generation from coal combustion?

8. In your opinion overall, is Nuclear Power generation more efficient, effective, and overall better than power generation through coal combustion? Furthermore, do you believe that all "power plants" that are using coal combustion as their method of generation said power should be replaced with Nuclear power plants? Why or why not to both of these.

I know that this is a large amount of inquiries that have a degree of repetitiveness to them but I would greatly appreciate an answer. I can't thank you enough in advance for simply reading this if you do sir and look forward to a response. Lastly, please don't feel rushed and take all the time you need to respond, I can understand how a man like you could often be busy and I am do not require a response immediately. However, I would greatly appreciate a response at your earliest convenience preferably within the next eight days if it's not too much trouble.

Once again I cannot thank you enough for everything in advance and look forward to your response.

Sincerely, Matthew

Answer
Dear Matthew,

Sorry for the delay, I was away from home for few days.  You are welcome to ask anything nuclear, I hope I can help you. You have not mentioned what kind of research paper that you are preparing, so my answers may be bit underestimating or over estimating your knowledge of nuclear technology.

1. In what ways, if any, is nuclear power more efficient than coal combustion?

When you talk about efficiency we usually understand the thermodynamic efficiency. Thermodynamic efficiency is related to the maximum and minimum temperatures that the heat engine operates. The minimum temperature that a thermal machine operates is the atmospheric conditions. The higher the operating temperature of the machine the higher the efficiency. Diesel engines have the highest efficiency (~ 45%), fossil fired plants efficiency depends on the fuel they use but usually the efficiency is around 40%. The thermal efficiency of a nuclear power plants varies between 33% to 45% depending upon the type. LWR operate at around 300C  has 33% efficient and Very High Temperature Reactors (VHTR) are close to 45%. In other words there is not much difference in the thermal efficiency between coal burning and nuclear power.

2. What are the financial advantages, if there are any, of using Nuclear power in place of coal combustion?

When we calculate the cost of electricity production we consider the capital, operation and maintenance and the fuel costs. Usually a 20 year book value is considered in the cost calculations. To build a power plant one has to borrow money from a bank and pay interest for the loan. Price of land, machinery, construction and loan payment are all included in the capital cost. Gas fired plants are smaller and easier to construct so their capital cost will be lower. Coal fired plants are larger and is bit more expensive to build. Nuclear power plants are expensive investments, construction takes at least 5 years and sometimes more. The longer the construction time the more loan interest a utility has to pay. Also the loan interest rate is important. A strong economy gets lower interest rates then a shaky economy. Based on these considerations the capital cost of nuclear power is around $1000 ~ $2000 per installed kW capacity. This number is around $1000 ~ $1500 /kW installed for coal fired plants and $400 ~ $800 / kW installed for gas fired plants.

The maintenance and operations cost of various types of power plants are similar. The main difference is the cost of fuel. Gas and petroleum are expensive and coal is a problematic fuel, that needs transportation (trains miles long!) Nuclear fuel is the cheapest among all electricity generating fuels.

One considers all the money spent in building, operating and decommissioning of the power plant for 20 years and the money earned from selling electricity for 20 years one can calculate how much a kWh of electricity cost. This is the important number. When we do such calculations and also compared with real life results from operating power stations we see that nuclear power is the cheapest way of producing electricity. Please see:

( http://www.iea.org/textbase/npsum/ElecCostSUM.pdf )


3. Is the Nuclear power generation "process" more dangerous or more safe than coal combustion and in what ways is it safer or more dangerous?
4. Does Nuclear power generation have a greater or smaller negative impact on the environment than coal combustion and why?
6. Are the potential health risks, if there are any, of nuclear power generation more or less serious and harmful than those from generating power through coal combustion?
7. Which is overall more harmful to people, the atmosphere, and the environment in general: byproducts from Nuclear power generation or byproducts from power generation from coal combustion?

All human endeavors are dangerous! Nuclear processes are definitely one of the most dangerous undertaking, that is why nuclear industry and national regulatory bodies are so keen on safety. Generating electricity by nuclear power is the safest way. To judge the safety of various forms of electricity generation one needs to look at the numbers of death, wounded, sick generated per kWh electricity generated. Please see following documents for further and better analysis of health and environmental effects.

(http://www-pub.iaea.org/mtcd/publications/pdf/trs394_scr.pdf ,
http://www.world-nuclear.org/info/Energy-and-Environment/Environment-and-Health- ,
http://www.ewp.rpi.edu/hartford/~odells2/EP/Other/references/Nuclear%20power%20a )


5. I hear many things about most (about 96% specifically) nuclear waste or rather, the byproduct from nuclear power generation, having the ability to be recycled into fuel and other such similar things. Is this true or false and if it is true how exactly is it recycled and into what exactly. (This is a question that has been bothering me for a long time.)

Let me explain this by telling you how nuclear fuel is made. UO2, that is the rust of uranium, is in powder form. Cylinders of 1cm in diameter and 1cm in height
are pressed and baked at high temperatures to make ceramic fuel pellets. Then this pellets are put into zircaloy (an alloy of zirconium) or stainless steel tubes of 3.5 m long. The ends are sealed after some helium gas under small pressure is injected into the tubes, which are called fuel rods. Many fuels rods are tied together in a square pitch of 12x12 rods and this is called a fuel element. (Shape and dimensions of fuel elements differ from one type of nuclear reactor to another.) Fuel elements are the elements of nuclear fuel. They are not dangerous, one can handle them without any harm to humans. They are put into the nuclear reactors side by side and when the reactor starts they generate heat. Each fuel element stays in the core of the nuclear reactor for almost 4 years. When they are taken out they are extremely radioactive and dangerous. That is why refueling is done under water with at least 6m of water between the worker and the fuel element. If one inspects the used fuel element, other than being extremely radioactive, one can not differ it from an unused fuel element. The reason for taking some fuel elements out of the reactor is that their fissile fuel is not sufficient to operate the reactor.

After many years in spent fuel pools, which are deep pools filled with cooled water, some fuel elements are discharged from the spent fuel pools. They are put into a shipping cask, which can withstand train collition, fire, etc., underwater and shipped to repossessing plant. There the fuel elements are dissolved in acid and U and Pu elements are extracted as well as medical and industrial isotopes. What nuclear industry calls waste is the waste that comes out of the reprocessing plant. The amount of waste is very small. Please see the following web pages for further information.

(http://www.nrc.gov/waste.html ,
http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Nuclear-Wastes/Waste-Manage ,
http://www.whatisnuclear.com/articles/waste.html )


8. In your opinion overall, is Nuclear Power generation more efficient, effective, and overall better than power generation through coal combustion? Furthermore, do you believe that all "power plants" that are using coal combustion as their method of generation said power should be replaced with Nuclear power plants? Why or why not to both of these.

Yes, in my opinion nuclear is the best form of electricity generation. (I am a nuclear engineer! :) ) Nevertheless, present days nuclear power plants need a lot of improvement. They are dangerous (much less than the other power plants) because they have metal cladding of fuel in pressurized hot water. If for some remote reason pressure is lost then in few minutes the fuel can melt. ( Three Mile Island, Chernobyl, Fukushima ) ( Bear in mind nothing harmful came out of TMI, only 31 deaths in Chernobyl and not much from Fukushima) There are other types of nuclear power plants that do not use water as coolant and metal cladding for fuel rods. Fast Reactor or VHTR technologies must phase out LWR technologies if the world wants improvement in power generation. Also such reactors can be used for process heat generation to make synthetic fuel and hydrogen. Burning fossil fuel not only pollutes the world but also wastes very important chemical raw materials for pharmaceuticals. US with heavy investment in nuclear navy and LWR is not too keen on changing the nuclear industry. I do not think that all coal fired plants will be replaced by nuclear power plants. There is not enough money in the world for such an ambitious project. On the other side when China and India starting a coal fired plant per week would help to slow down the climate change. Meanwhile all available forms of electricity production, like alternative sources such as solar, wind, etc. should be used if they are economical.

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Osman Kemal Kadiroglu

Expertise

Nuclear Engineering, Nuclear Engineering Education, Nuclear Reactors, Pebble Bed Modular Reactors, Engineering Education

Experience

Has been teaching Nuclear Engineering for more than 20 years and been in this field for more than 30 years

Organizations belong to
American Nuclear Society
Society of Nucelar Engineers of Turkey
Emeritus Prof. Nuclear Engineering Department, Hacettepe University Ankara Turkey

Extra-ordinary Prof. Nuclear Engineering Department, North-West Uni. Potchefstroom South Africa

Education/Credentials
(Mak. Y. Müh.) MS in Mech. Eng. Istanbul Technical University '68
MS in Nuclear Eng. MIT'72
Sc.D. in Nuclear Eng. MIT'76

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