[P-man]

What's so dangerous about nuclear energy? People freak out when you talk about it but actually, it's not that bad. With new technology, we'll be able to secure nuclear plants to make them safer. I know there's still the problem with the radioactive waste, but hopefully soon we'll know what to do with it. I need to know how it will have long-term effects on our society and health.
Please help ASAP.
Pierre

[Donaldson Tan]

Perhaps the idea of a nuclear plant meltdown is somewhat equivalent to a nuclear fission bomb explosion. Nobody wants another Hiroshima or Nagasaki plight happen in their hometown. However, people nowadays know more myth than facts about nuclear power and they need to be educated.

A typical nuclear reactor doesnt contain fissible material at supercritical level, which is required for weapon-grade use. Moreover, the amount of fissible material put inside a reactor is such that the max pressure it can create in case of meltdown is still 10X below the critical pressure the reactor is build to endure. Modern nuclear reactors are in fact so much more safer.

The problem with nuclear plants is infact inherent of the old nuclear plants, who are slowly undergoing decommissioning. Inferior design, very prolonged radioactivity damage to strucuture, out-dated emergency protocols are among the causes to why the old nuclear plants (typically phase I) needed to phase out ASAP.

It isn't bad. People needs to be re-educated. Greenpeace anti-nuclear efforts will only hamper the progress of mankind. Does Greenpeace offer any solution to power blackouts? No. Does Greenpeace offer solution to oil crisis? No. What does Greenpeace offer?

[P-man]

I agree. People need to know that nuclear energy is the best for the environment. Nuclear reactors don't emit CO₂ into the air.

But we still need to know what to do with the waste! That's what's freaking people out. They think the waste is going to kill the entire world, and in a sense, they're right!

Pierre

P.S. What do you mean by fissible?

[jdurg]

Actually, nuclear power results in the production of a LOT of CO2 and requires a bunch of fossil fuels.  This is the thing that a good number of people tend to forget, and it's something that I had forgotten about in the beginning.  Uranium-235 doesn't just come out of the ground in a useable form.  The uranium ore has to be extracted, purified, and then isotopically separated in order to get the % of U-235 in the samples high enough for energy production.  All of this requires a lot of energy and heat which comes from the burning of fossil fuels.  As a result, the use of nuclear power really has no 'saving' on our fossil fuel consumption.  Plus, after the reactor has served its time, the fuel needs to be reprocessed and handled properly, and once again that takes energy.  

So nuclear power isn't exactly a 'free' energy source.  It can definitely be helpful in terms of our overall energy needs, but I think the best way to make efficient use of our resources is to have a wide variety of energy sources.  In perpetually sunny areas, use solar power to help generate electricity.  Use hydropower where it's effective.  Use nuclear power in areas close to the ores and separation facilities.  Use whatever is available in the area.  There is no 'one solution'.  

[Corvettaholic]

Dredging up the idea of the nuclear battery again, why not use a really big battery? Just get a lot of something with a decent half-life, and make a huge factory sized battery out of it? Don't have to worry about fuel for a good 20-40 years! Just hope nobody shoots this giant battery with a rocket launcher... that would be bad.

[Mitch]

Jdurg: Your statements are a bit misleading. You get more power from nuclear energy then you put in. The way you phrased it--made it sound like an equivalent to hydrogen cells.

[constant thinker]

No he is right about burning fossil fuels for extracting uranium from the uranium ore. I don't know much about centrifuges but a. The require alot of electricity to run. b. I think the sample is heated during the process. Look up chernobyl and you'll know why people freak. Also check out three mile island and all of the nuclear waste produced including when the facility is decommisioned some 15 or 20 years after it becomes operational.
For all its downfalls nuclear energy and all the benefits of nuclear science outway the risk. CAT scans use radiation. Radiation is used in treating cancer. Not all radiation is harmful. Radio waves are radiation. We use microwaves to cook our foods. As was previously stated it is because people are uneducated about the topic.

P.S. Mitch is right either way you get way more energy than you put it in.
Coming in the near future a mini sun on Earth hopefully.

[jdurg]

Jdurg: Your statements are a bit misleading. You get more power from nuclear energy then you put in. The way you phrased it--made it sound like an equivalent to hydrogen cells.

If that were true, then the 2nd law of thermodynamics would surely be broken.    The amount of energy you get per mass of fuel is greater with nuclear power than any other source, but it does take a great deal of energy to process that nuclear fuel and make it useable in addition to keeping it safe.  I think nuclear energy is a great source of power, but only if used properly.  Sadly, the ignorant mass known as society wants nothing to do with radiation.  

[Donaldson Tan]

Anyone here care to enlighten all of us on the mining of uranium? I have no idea what the process used in mining (other than digging into caves)..

[Mitch]

If that were true, then the 2nd law of thermodynamics would surely be broken.      

No it wouldn't.

I would defend my position, but I'm too lazy.

[jdurg]

I still have to defend my argument there Mitch.  You simply do not get more energy out of a nuclear reactor than you have to spend to get it all running effectively.  In my argument, the energy input is the combination of the energy required to mine the fuel, process the fuel, form the fuel into a useable shape, store the fuel, transport the fuel, remove the spent fuel, reprocess the spent fuel, etc. etc.  It's not like a coal plant where you dig the coal out of the ground, shove it in a furnace and watch it burn away.  There's no real processing done and the amount of security and safety guards is far less than with nuclear power.  (Remember, it costs money and energy to have the proper safety and security levels).

[Donaldson Tan]

i attached a picture to illustrate the nulcear fuel cycle.

p-man: fissible material refers to material that are susceptible to nuclear fission, eg. plutonium-239.

constant-thinker: arguing that nuclear power is beneficial or not is irrelevant to its secondary uses, such as CAT scan. You can't actually transport radiation from a nuclear reactor directly for CAT scans. Neither are the radioisotopes used in generating X-rays for CAT scans are obtained from nuclear reactors. Reprocessing the spent nuclear fuel (SNF) is a very expensive and thus ineconomic process to obtain radioisotopes for CAT scans. microwaves are generated using electronic devices, not through a nuclear source.

nuclear power refers to generation of electricity using atomic energy. typically, there are few types of nuclear reactors available in the market: LWR (light water reactor, normally american), HWR (heavy water reactor, normally canadian), MAGNOX (uses CO2 as the heat transport agent, british), and the french type (that employs liquid metal, normally Na or Li, as the heat transport agent)

Jdsurg is right to point out we should examine the entire fuel cycle to determine the "green-ness" that nuclear power offers. on one hand, uranium mining generates alot of CO2 (according to Jdsurg); on the hand, nuclear reactors can operate for many years without refueling. Comparing the CO2 generated by uranium mining per MW of electrical energy generated in nuclear plants, the nuclear plant still beats conventional fossil fuel power plants. In fact, the amount of CO2 generated by fossil fuel plants during the same operation span of the nuclear plant exceeds the amount of CO2 generated in mining sufficient uranium to run the nuclear plant for that particular operational span.

Moreover, modern nuclear reactors are much more efficient than fossil fuel power plants, espeically the french and british type of nuclear reactors. Gas and liquid metal exhibit higher heat transfer coefficient, and they can operate at much higher temperature (unlike the pressurised water reactors). This means more energetic neutrons from fission are allowed to heat up the the heat transport agent, instead of being absorbed (and thus wasted) by the control rods.

it all points out that nuclear plants are not only more green, but also more efficient. however, from an engineering point of view, the operational cost must be taken in account to evaluate the economic value of the nuclear plant, unless fossil fuel is fast becoming scarce, then nuclear plants are the next power generators we can turn to, to meet mankind's demand for energy. harnessing nuclear power is inevitable.

The rising oil price in view of much-talk-about petroleum shortage will make fossil fuel plants less and less economic to run as time goes by. increased operational cost is inevitable, and this is where nuclear plants prove their capability over fossil fuel plants.

SNF reprocessing is an area that still needs alot of research breakthrough in order to convince the cynics of their short-sightedness. The current procedure for handing SNF is to let it stand for few weeks, so that all the short-life radioactive nuclei will decay, leaving the less radioactive elements present in the SNF. (if electromagnetic radiation energy can be captured and stored as a standing wave, we could extract so much more energy from the fresh SNF)

[Mitch]

I still have to defend my argument there Mitch.  You simply do not get more energy out of a nuclear reactor than you have to spend to get it all running effectively.  In my argument, the energy input is the combination of the energy required to mine the fuel, process the fuel, form the fuel into a useable shape, store the fuel, transport the fuel, remove the spent fuel, reprocess the spent fuel, etc. etc.  It's not like a coal plant where you dig the coal out of the ground, shove it in a furnace and watch it burn away.  There's no real processing done and the amount of security and safety guards is far less than with nuclear power.  (Remember, it costs money and energy to have the proper safety and security levels).

Okay, I'll rephrase. The amount of energy you get from nuclear power is cheaper then the amount of energy that is used to isolate/enrich/prepare the uranium for use.  

[Donaldson Tan]

You simply do not get more energy out of a nuclear reactor than you have to spend to get it all running effectively

are u suggesting that energy input by mining, centrifuging, making UO₂ pellets exceed by what is offered by E = mc²? It sounds incredible. I cant see how energy input from physical & chemical processes will exceed the energy output by a nuclear reaction.

[Mitch]

Yeah, I still agree with Geodome.