An old topic and has probally been done many times but i would like to know of your opinions on it.
Nuclear power provides cheap energy but can have very dangerous consequences. Do you think its morally correct to have such plants in this day and age where there are safer alternatives and do you think the benefits out weigh the drawbacks?
your views please :D

What are the "safer" alternatives?

Oil and coal both release C02, which according to some reports is killing us.

Natural gas is cleaner, but much more expensive and still emits CO2.

Geothermal is unrealistic at best.
Water Turbine is good, but people don't want to harm local river ecosystems.
Wind? Solar? Not this decade...

Nuclear power plants are working perfectly fine every day. I don't have the exact numbers, but when they are regulated and inspected regularly, then you do not have the same massive problems that Chernobyl and 3 Mile island has. Granted, Nuclear waste is a problem, but we may find a use for all of that crap. Hell, we might even be able to just shoot it all into space, and let the universe deal with it.

Speaking of expenses, a major reason why nuclear power is so cheap as to be competitive with other forms of generation: massive subsidies with taxpayer dollars. Subsidies in all imaginable forms from insurance to inspections, from security to waste disposal, from ore mining and transportation to massive tax dollar investments to build the beasts in the first place.

In and of itself, nuclear power is not economical.

As for solar-electric, all we have to do is mass-produce solar panels to lower cost and install them on the roof of every house in the country. This would probably give us enough excess capacity (especially during daytime when everyone's out at work anyway) that we could shut down many of our nuclear plants. If we're going to subsidise something, then this is what we should be subsidising. Then all you have to do is install some relatively cheap near-term energy accumulators on the grid such as flywheels or reversible fuel cells, and you can regulate the solar energy and make its output continuously available regardless of weather conditions or time of day. Meanwhile, solar panel efficiencies are continually improving; now around 30% (with state-of-the-art approaching 40%.) There is a way; all we need is will.

I don't think you're going to get people to do that, though, Overdoze, unless you provide a serious benefit of some sort, people are not going to just allow the US to install solar panels on their roofs, and I doubt everyone could afford it if they had the option to pay money to install them.

I didn't make a claim that nuclear energy is cheap, because I just don't have the numbers in front of me to make a claim either way. I do know, though, that most power plants are working perfectly fine. Meltdowns are very very rare, leaks happen less often than oil spills (a relatively rare occurance in and of themselves) and we have plenty of Uranium to feul it at least until we finally get fusion working the way we want it to.

I dunno Rioma. Nuclear power is inherently a dangerous and volatile way of producing energy. Obviously, we need an alternative to fossil fuels...but I think a safer alternative needs to be seriously considered. I agree with Overdoze in giving solar power more attention. I also read somewhere that someone has figured out a way of harnessing the energy of ocean waves. I dunno, I need to read up on the topic but I do not think nuclear power is the answer.

But is it any more dangerous than any other energy source which we use right now? If properly maintained and supervised, nuclear power can be made significantly safer. I'm not going to deny that it's not dangerous, but with the proper effort, we can significantly reduce the risks to a level where other plants are at.

From what I have read before, nuclear power is not cheap at all. It is cheap once you get it to setup, but the setup cost is very high. The nuclear waste also cost a lot of money to process. There isn't any good ways to deal with them without harming the environment unless you send them to outer space. Danger really isn't an issue.

But is it any more dangerous than any other energy source which we use right now?
Well, when I am thinking dangerous I do not think of a meltdown scenarios. I am thinking more like truck bombs, stealing of radioactive material, radioactive waste (sending it into space could pose some problems - what the rocket explodes before it gets into space?), etc.

Maybe we can reduce the risks to current fossil fuel levels, but its a gamble. Why not invest money and time into something fundamentally safer? Do you think we do not have enough time to development other methods of energy production?

Some info on ocean power:
http://www.eren.doe.gov/RE/ocean.html

Our future source of energy should be fuel cell and solar panel. Actually nano-fabricated solar cells have effeciency close to 95%

wave power has been developed and is still in its developing stage: they are installing massive wave generators on Jura off scotland where they get alot of waves. Everyone has overlooked hydroelectric power, maybe not an alternative in every country but could be a solution to other places.

Originally posted by overdoze

In and of itself, nuclear power is not economical.


Nuclear energy averages 0.4 cents/kWh, much the same as hydro, coal is over 4.0 cents (4.1-7.3), gas ranges 1.3-2.3 cents.

In mid 2000, the approx. US $ cost to get 1 kg of UO2 reactor fuel:

U3O8 : 8 kg x $25 = $200
conversion: 7 kg U x $5.5 = $38
enrichment: 4.3 SWU x $105 =$ 452
fuel fabrication: per kg =$ 240
total, approx: US$ 930

This yields 3400 GJ thermal which gives 315,000 kWh, hence fuel cost: 0.30 cents/kWh.

If you can find any other cheaper source, I will buy 2 Gigawatt-hours and sell it to public and make tons of money.

Uranium has the advantage of being a highly concentrated source of energy which is easily and cheaply transportable. The quantities needed are very much less than for coal or oil. One kilogram of natural uranium will yield about 20,000 times as much energy as the same amount of coal. It is therefore intrinsically a very portable and tradeable commodity.

The fuel's contribution to the overall cost of the electricity produced is relatively small, so even a large fuel price escalation will have relatively little effect. For instance, a doubling of the 2002 U3O8 price would increase the fuel cost for a light water reactor by 30% and the electricity cost about 7% (whereas doubling the gas price would add 70% to the price of electricity).

Solar energy radiation in my area is 5 KWH per square meter per day that includes photonic energy and heat energy. Assuming, I can convert 100% to electricity, I need 20 square meters of area to meet my energy needs.

Random thoughts with no particular point being made:

1) Our nuclear plants are built using 1960s designs. If built today the risk of a melt-down would be non-existent.

2) The threat of terrorism makes nuclear not very attractive

3) Everybody talks about nuclear waste, but isn't all that uranium scattered around the earth more potentially dangerous than concentrating and storing it?

4) What about wind-power?

5) The figure of 20 square meters quoted above for solar power doesn't sound like very much to me -- that's 3 meters by 7 meters -- or did the writer mean 20 meters square, i.e., 20 x 20 meters.

kmguru,

If nuclear plants are so economical, then we must stop subsidising them and their waste disposal problems. Make them pay for Yacca Mountain, and all the other things.



Uranium has the advantage of being a highly concentrated source of energy which is easily and cheaply transportable. The quantities needed are very much less than for coal or oil.


As if fossil or nonrenewable fuels are our only option. Waves/tidal (these are of course only applicable along coasts), wind (good for off-shore as well as mountainous regions), solar (best in dry climates far inland), geothermal (any volcanically active region), hydroelectric (any place with rivers), temperature differential (any place with deep water). Just the viable alternatives I'm aware of. Note that for hydroelectric power we don't necessarily have to dam the rivers. We can have much greener and smaller facilities dotting the river banks and taking advantage of the river's intrinsic current. That's how water mills used to operate. Granted, the efficiency would be pretty low. But there'd be a virtually 0 environmental impact. Windmills take smaller footprint, become more efficient, and less of a hazard for birds when they are scaled up in size. 1-Megawatt peak single turbines are currently in operation.



Solar energy radiation in my area is 5 KWH per square meter per day that includes photonic energy and heat energy. Assuming, I can convert 100% to electricity, I need 20 square meters of area to meet my energy needs.


5 KWH per day?? Where do you live, North Pole? Or in a cave? Last I heard, average daylight power from the sun at 40 degree latitude is 5 KWH per hour. If your typical day consists of 6 hours of sunlight, then for each square meter you can collect 30 KWH. Assuming efficiency of, say 20% you'd be getting 6 KWH per square meter per day. Typical roof area is 10mx10m, giving 100 m². That means if your whole roof was covered with solar shingles you'd get 600 KWH each day. You'd have plenty of energy left over to sell back into the grid!

The main issue is price of solar cells, which needs to be reduced dramatically. If our government had the inclination or the balls, they might have spent an extra 50 billion a year on an accelerated solar cell R&D program than as a boost to the Pentagon budget. Arguably, energy self-sufficiency and high environmental standards are just as important to national security (if not far more so) than maintaining and even enhancing the most expensive and most powerful military machine in the world. Plus, once such technology is developed imagine the worldwide export potential under patent protections!

As for convincing people to install solar cells on their roofs, there are plenty of ways. We could change building codes to requie all future builders to configure houses with solar cells preinstalled. We could offer people sizeable tax breaks. There is also the incentive that people would be able to sell excess power back to the grid, actually generating a monthly supplemental income and paying back some of the cost of solar cells over time. Of course, first we must work intensively to develop cheap and mass-producible solar cells for the masses. If I were the President, this would be at the top of my energy agenda.

Wow... just noticed this thread.

I'm too tired now to write up an appropriate response, but I'll be in later to put in my $0.02.

I'm fairly sure I know what I'm talking about, too. ;)

Solar energy data from:

http://www.solar4power.com/solar-power-insolation-window.html

The reason nuclear power plants are so expensive here in US is due to unnecessary regulations in the areas that have nothing to do with nuclear. Such as nuclear grade pencils and toilet seats. I am not kidding.

If a 1200 MW coal fired plant costs $1.5 Billion, the same size nuclear will cost $6 Billion in US. It should not cost more than $3 billion including the waste management system. In China they do it cheaper because they strip out handouts and unnecessary regulations.

The nuclear design in US is seventies not sixties including the automated control system. They are slowly changing the control system but have a long way to go. I would prefer they hire graduate nuclear engineers as operators rather than high school rednecks.

There are newr technology such as tiny pallet based Uranium and breeder reactors that could improve safety a lot. I have designed control systems for nuclear reactors in the past.

Bottomline:

Nuclear power plant is safe and can be run for many years with proper improvements

I prefer going after fusion technology...

Terrorism is not really an issue contrary to the present histeria.

For some reason, people are willing to put their life shavings to make a fast buck in the dotcom companies and losing it - yet no one wants to invest in fuel cell, continuous solar cell processing, solar cell units, timed charging systems, wind generator kits, Thermal differential heat exchangers etc....

Originally posted by Captain_Crunch
An old topic and has probally been done many times but i would like to know of your opinions on it.
Nuclear power provides cheap energy but can have very dangerous consequences. Do you think its morally correct to have such plants in this day and age where there are safer alternatives and do you think the benefits out weigh the drawbacks?
your views please :D
Virtually every scientific and technological breakthrough has been ethically ambiguous. Cant fire be misused ? Cant the wheel be misused ?
The trick is to try and minimise the chances of exploitation of the technology.

I am not sure about the safer alternatives ... do they also produce a comparable amount of energy ? I doubt it.

- Sivakami.

I am not sure about the safer alternatives ... do they also produce a comparable amount of energy ? I doubt it.

- Sivakami.

the safer alternatives are safer :D


Wow... just noticed this thread.

I'm too tired now to write up an appropriate response, but I'll be in later to put in my $0.02.

I'm fairly sure I know what I'm talking about, too.

aw naw, head for the hills! :eek: :D

Originally posted by Captain_Crunch
the safer alternatives are safer :D

Going by that logic you should never drive cars or fly in airplanes or use electricity .....

Its always a trade-off between safety and efficiency/comfort.

- S.

Going by that logic you should never drive cars or fly in airplanes or use electricity .....
i dont....:D
i'm not taking part in this conversation, i am wanting to see peoples opinions on the subject. All the examples you have gave if an accident occurs only a small number of people will be killed and there is no lasting effect on the surrounding area if i were to be killed by an electric shock for example. If a nuclear reactor goes into melt down, well, use your imagination.

Well, I understand that nuclear power plants could now be built that wouldn't melt down in hours if something went wrong. Instead the timeline would be months. So, I think that should remove that fear.

kmguru - you said terrorism isn't a threat and left it at that. WHY isn't it a threat? It seems like a big threat to me!

Doesn't anyone here know anything about the economics of wind-power? I was in Germany recently and was told their wind-mills currently produce 1% of Germany's electricity. There is easily enough room over there for 100 times as many wind-mills as there are right now. Why aren't they building them like crazy?

o.k, what the hell, i'm getting involved in the conversation even although it will just turn out that everybody will be attacking my views. lol. :D

Well, I understand that nuclear power plants could now be built that wouldn't melt down in hours if something went wrong. Instead the timeline would be months. So, I think that should remove that fear.
o.k, although, you must understand that i am sceptical. What about radiation leaks and nuclear waste? all of which are dangerous.

kmguru - you said terrorism isn't a threat and left it at that. WHY isn't it a threat? It seems like a big threat to me!

Terrorism is not really an issue contrary to the present histeria.
i think you are misunderstanding wht kmguru is saying, he is not saying it is'nt a threat, just not as big a threat than most people think or are lead to believe by the government on their crusade against terror.

Doesn't anyone here know anything about the economics of wind-power? I was in Germany recently and was told their wind-mills currently produce 1% of Germany's electricity. There is easily enough room over there for 100 times as many wind-mills as there are right now. Why aren't they building them like crazy?
Windpower is in-effecient and it takes up a hell of alot of space because of this, also, people dont like the 'looks' of a wind farm.

I know people are opposed to the looks of a wind-farm, but it isn't nearly as bad, or as space consuming, as solar panels generating the same amount of power would be.

Nuclear waste -- isn't there natural nuclear waste scattered all over now? Isn't that what uranium ore is? By mining this ore and concentrating it, then storing it after we've used it, aren't we actually cleaning up the environment? ;)

As for the terrorism issue. Someone is going to have to show me evidence that terrorist attacks on nuclear power plants aren't a significant risk.

I know people are opposed to the looks of a wind-farm, but it isn't nearly as bad, or as space consuming, as solar panels generating the same amount of power would be.
i have nothing against the looks, if it means closing a nuclear plant in favour of wind.

Nuclear waste -- isn't there natural nuclear waste scattered all over now? Isn't that what uranium ore is? By mining this ore and concentrating it, then storing it after we've used it, aren't we actually cleaning up the environment?
By mining this ore and concentrating it, then storing it after we've used it, aren't we actually cleaning up the environment?
no, it becomes more dangerous because you are concentrating it. It still adds to the background radiation reguardless if its underground or not. Isn't that what uranium ore is Uranium ore is unpure Uranium. isn't there natural nuclear waste scattered all over now? no. it is background radiation, its supposed to be there in no way is it a waste product its the balance of nature.

As for the terrorism issue. Someone is going to have to show me evidence that terrorist attacks on nuclear power plants aren't a significant risk.
i'm not going to argue someone elses point, please forgive me.

captain crunch.

Originally posted by postoak
Doesn't anyone here know anything about the economics of wind-power? I was in Germany recently and was told their wind-mills currently produce 1% of Germany's electricity. There is easily enough room over there for 100 times as many wind-mills as there are right now. Why aren't they building them like crazy?

Wind farms only make sense in places where there are strong, consistent winds.

Smaller turbines cost more (for the same amount of power), cover a larger land area, and are less efficient than larger turbines. So the evolution of wind turbines has seen their sizes grow steadily. Larger turbines are safe, environmentally friendly, and if desined well can even look good. Imagine a 200-story high snow-white spike of gossamer metal soaring over a mountain range, above water far off-shore, or high above the greenery of a forest. The sweeping yet shapely blades arcing leisurely in graceful silence, gleaming in sunlight... :)

The technology and cost-effectiveness keeps improving. Already wind power is competitive with coal/gas and nuclear, and those are already state of the art while wind power is just getting started.

Originally posted by postoak
Nuclear waste -- isn't there natural nuclear waste scattered all over now? Isn't that what uranium ore is? By mining this ore and concentrating it, then storing it after we've used it, aren't we actually cleaning up the environment? ;)


Natural uranium is not intensely radioactive and is very dilute. Concentrating it makes it hazardous. Burning it in nuclear reactors produces transuranic and other radioactive waste which is much more lethal and far nastier than uranium, and takes many thousands of years to decay into something benign.

I don't want to seriously argue that we shouldn't be concerned about the storage of nuclear waste -- although I think terrorist attacks are a more serious concern.

BUT, let's get the facts straight. Naturally occuring radiation is NOT benign. X number of people die each year from radon gas. I'll bet X number of people die each year from the radiation given off by granite buildings.

And it isn't always so dilute. They've found the remains of a naturally occuring nuclear reactor in the rift valley in Africa. This thing was active for 250,000 years, because the uranium deposits there were so concentrated.

But, I'm not a proponent of nuclear power.

I don't think wind-farms are visually appealing, but given the choices, I would opt for them, IF they were economically viable. I'm dubious that they are, in quantities large enough to replace all our energy needs. It would be great if they were, though. We could use the energy to produce hydrogen which could run our cars and would produce no pollutants other than heat and water.

BUT, let's get the facts straight. Naturally occuring radiation is NOT benign. X number of people die each year from radon gas. I'll bet X number of people die each year from the radiation given off by granite buildings.
I'll bet X number of people die each year from the radiation given off by granite buildings - This is'nt a fact, this is your opinion. Granite buildings will have a larger background radiation but is certainly not fatal. :rolleyes:

If you use solar power then you have to dispose of the batteries used in the storage that is collected during the day. Almost all wet cell batteries contain hazardous materials to dispose of. Being as solar cell output is dc you must also use an inverter of some sort to change that to ac. The majority of solar collectors do not give that great of a total output in electricity. Certainly not enough to power what you are used to in everyday life. At best you can augment the amount of power used.

To give you an idea of what we are talking of, let us say you can buy power off the grid for around 84˘ per kWh (to pull a number out of the air). That might be a bit high but it will stand for an example.

Most houses run in the neighborhood of needing 1400 kWh/per day. This can be lowered if you buy everything with power consumption in mind. It is possible to lower that to around 200 kWh/day by things like purchasing a laptop instead of a desktop, buying the most efficient refrigerator, washer, and eliminating those huge power consumers like air conditioning and heating, or those items that use heating elements, and items like microwave ovens. Changing all lighting to fluorescent from incandescent and eliminating that which is not essential.

To get the 200 kWh/day will require a solar panel of around 17' square. That will cost you around $16,000. Batteries, inverter, and necessary equipment for maintaince will nearly double the cost. It is a lot cheaper to just buy the power unless your location will not allow it. If it won't allow it get ready to have a standby generator or to do without electricity if you have several days without sunshine. (These figures are rough estimates and averages that came from the site of How Things Work.)

One method I have not seen mentioned is ocean current turbines. Ocean current, similar to the Gulf Stream Current provide enough force to power such turbines and unless I remember wrong, the Japanese have made a test bed to verify the idea.

Wave power, which has been mentioned, is another method of power generation however the total output is not great in that either.

Wind power is limited and too expensive for practical purposes.

We have a ways to go to make the next step beyond nuclear power. Nuclear power as has been mentioned suffers from the drawbacks of waste security, waste handling, and safety. I am sure that Emfuser will correct me if I am wrong, but I also believe that I have read that the radiation will eventually lead to metal fatigue resulting in piping failures.

The high sulfur content of coal in the US makes generating power from that source unlikely as the cost to reduce the sulfur from the coal increases an already expensive process.

Captain Crunch - I'm not suggesting that people who work in granite buildings fall over dead from radiation like the workers at Chernobyl. But I thought that if enough people are exposed to low levels of ionizing radition a certain number of them will get cancer, which can prove fatal.

Originally posted by postoak
kmguru - you said terrorism isn't a threat and left it at that. WHY isn't it a threat? It seems like a big threat to me!


1. The biggest terrorism stuff is happening in Israel for many many years (at maximum level). I have not heard their nuclear power plants or regular power plants or chemical plants blowing up. Have you?

2. US got caught off guard, like pearl harbor. Consider that as an accident. It wont happen again. There will be some minor stuff like columbine shooting etc for sure, but no more major stuff and unless there is a real major war, or plain stupidity of people, our power plants are safe.

Aaauuuugghhh... why do I have to be caught up in moving right now!!! I have so much to say but no time to write it.

Maybe after the Brickyard tomorrow (errr... later today)... :D

Originally posted by Captain_Crunch

i dont....:D
i'm not taking part in this conversation, i am wanting to see peoples opinions on the subject. All the examples you have gave if an accident occurs only a small number of people will be killed and there is no lasting effect on the surrounding area if i were to be killed by an electric shock for example. If a nuclear reactor goes into melt down, well, use your imagination.

And why should you think that our tools will be less powerful as we advance ?! Then where's the advance ?! ;)

My point was that the trick is not to make technology less powerful, but to use it more carefully.

- S.

Alright... I'll try a response (even though I can't come up with one that addresses everything).

Of course I think nuclear power is a great idea.

The "alternatives" to fossil fuel or nuclear power such as wind, solar, tidal, hydro, etc all suffer from a common set of problems:

1.) RELIABILITY
ONLY ONE of them has something that is absolutely crucial to a power generating station and that's reliability. Weather can screw with solar and wind on a day to day basis and affect non-oceanic hydro as well over a longer period of time. Only tidal energy has anything close, but I'm still not sold on that.

2.) AVAILABLE LOCATION
We figured out awhile ago that you could damn up every fresh water flow on the planet and still not come anywhere close to meeting current or future energy needs. Wind power requires vast locations with predictable winds at certain minimum speeds to work at all (good luck finding lots of those). Solar stations need vast areas with LOTS of sunlight all year long (again, good luck). Tidal energy requires coastline, not all countries have that. Not all countries have much coastline suitable for tidal power.

3.) TECHNOLOGY
Solar panels are good for ~33% at best, are complex, vulnerable to environment, and wear out. Whoever mentioned 95% efficiencies is thinking WAY into the future. The complex array of photons in sunlight is NOT easy to efficiently harness. Windmills have pathetic efficiencies. The turbines and flow systems for tidal have had some corrosion problems (yay salt water) but have fared well with fresh-water hydro.

Good stuff about nuclear:
1.) IT'S CHEAP
Even with all the incredibly stupid and restrictive rules in place, nuclear can still be brought to market and operated for profit. If someday the idiots making policy in this country will allow a scaling back of the rules from "ridiculous" to "really safe", it'd be even cheaper.

2.) NO EMISSIONS
Aside from the rare release of some short lived, gaseous isotopes, the only things coming from a nuclear power plant are heat and electricity.

3.) FUEL POWER DENSITY
Go by a coal powered power plant some day and note the MILES of cars full of coal required to power the plant EVERY SINGLE DAY. Go by a nuclear power plant and note the single flatbed truck HALF loaded with fuel that'll power the plant for 18-36 months. Any questions?

4.) SAFETY
The safety systems designed today are among the most ingenious technological innovations conceived by mankind. Three mile island proved that the safety systems designed in the 60s and 70s WILL WORK even in the face of glaring human error and a seemingly minor design flaw that causes you to melt the top 30 feet of your core into slag. Add to this the extremely robust construction of the reactor pressure vessels and the the containment buildings. Most of the US and other non-soviet containment buildings are built to withstand a total meltdown on the inside and still maintain their integrity. A nifty side effect of this is that MOST of the containment buildings can withstand a direct impact from a fully loaded 747.

Bad stuff about nuclear:
1.) WASTE
Nuclear waste is nasty stuff. Fortunately, most of the really dangerous high level waste (HLW) is solid and easily stored/transported.

I've seen the testing videos of the nuclear waste transport and containment vessels and I can tell you that I'm impressed. They dropped these things on unyielding surfaces, dropped them on spikes, burned them in jet fuel for several hours and immediately submerge them to some depth for several more. NO LEAKS!!! The British even went so far as to hit one with a train. It was spectacular! The train was totally destroyed but the transport cask sustained only surface damage, was still perfectly intact, and sealed. The fools that protest nuclear waste moving through their locality are nothing but scared and ignorant. There's no danger to them. Even a terrorist attack would be fruitless because the containment casks are to well built.

A lot of the lower level wastes can be concentrated out of their current states and their volumes' greatly reduced. Unfortunately, nobody thinks this is a good idea because the driving forces behind nuclear waste policy are still fear and ignorance.

My idea for disposal is still shooting it into space... but I want to use a rail gun so rocket failure will be out of the question. ;)

2.) PEOPLE ARE STUPID
Yep. Anyone reading this is visiting sciforums.com and probably knows this already. The public's fear of {cue scary music} RADIATION {/music} and all things nuclear is a huge hindrance. People don't realize that radiation is everywhere and we evolved in it's presence. More recent studies on the effects of radiation are indicating that radiation up to certain doses is GOOD FOR US and completely natural. I love the rare opportunities I get to show people just what around them is radioactive (including themselves). Such observance in person makes people a little more calm about something that is a natural occurance to begin with

Other:
Somebody mentioned fusion as the next step in nuclear and they're quite right. My study focus for my degree was fusion. The technology and resource requirements for developing fusion power as a viable energy resource for humanity are incredible. Unfortunately, this world isn't paying enough attention to it yet and the result is that there's not enough money going to programs researching fusion devices. Fusion is fucking cool as hell, but this world isn't there yet.

Ok... now I have to bug people to get back into this. :rolleyes: ;)

Originally posted by Emfuser
3.) TECHNOLOGY
Solar panels are good for ~33% at best, are complex, vulnerable to environment, and wear out. Whoever mentioned 95% efficiencies is thinking WAY into the future. The complex array of photons in sunlight is NOT easy to efficiently harness. Windmills have pathetic efficiencies. The turbines and flow systems for tidal have had some corrosion problems (yay salt water) but have fared well with fresh-water hydro.


One of my college classmates who does research in nanotechnology said 95%, but I think he exaggerated. I have read 70-80%. That is using a totally different technology to make really small solar panel.

Traditional solar panel is using Fresnel lense to focus light on into solar cells, which are essetially some sort of solid state photo diodes.

The newer technology is using nanatechnologies to make tiny micro antennas. Light are electromagnetic waves. They can be picked up like microwave. If the antennas is not the small enough, you get losses from impedence mismatch. Nanotechnology makes this possible. You need antennas tuned to different wavelength and really close together. One of the paper I read last year said they got effeciency above 70%.

Those solar cells are small and cannot be mass produced yet.

The turbines and flow systems for tidal have had some corrosion problems (yay salt water) but have fared well with fresh-water hydro

The problems with salt water corrosion on fixed structures is easy to eliminate. Through the use of anodes and rectifiers the corrosion can be all but eliminated. These systems do require maintaince to be effective. I.e. anodes must be changed once a year and rectifiers require both critical insulators during constuction/erection phase and observation/maintaince for the rectifiers. Futher, coatings such as cement and epoxy can eliminate surface corrosion on metals that are immersed within salt water.

Originally posted by Joeman

The newer technology is using nanatechnologies to make tiny micro antennas. Light are electromagnetic waves. They can be picked up like microwave.

That is an excellent idea. Not only light but we should be able to pick up other frequencies as well. But it is probably 10 to 15 years away - since we cant even produce a decent cheap power cell.

I still think fusion is the future. Perhaps high Tesla magnetic fields may play a role along with super conductors and carbon nanotubes...

If we can produce anti-matter with less energy than using it to produce energy....that may be an area to look at...

Thanks for the well-informed post Emfuser.

A quick question:

Fortunately, most of the really dangerous high level waste (HLW) is solid and easily stored/transported.
Is it safe to dump a ton of HLW into a mountain? Why have there been so many well publized issues with nuclear storage in the US? Since the half-life is so great, wouldn't it keep building up? Eventually you would have to shoot it into space, can we be sure it wouldn't eventually get pulled back to Earth via gravity?

Sorry lots of questions there but I am still skeptical on the safety and reliability of nuclear waste storage...

Originally posted by fadingCaptain
Thanks for the well-informed post Emfuser.

A quick question:

Is it safe to dump a ton of HLW into a mountain? Why have there been so many well publized issues with nuclear storage in the US? Since the half-life is so great, wouldn't it keep building up? Eventually you would have to shoot it into space, can we be sure it wouldn't eventually get pulled back to Earth via gravity?

Sorry lots of questions there but I am still skeptical on the safety and reliability of nuclear waste storage...

I did a research paper on Yucca Mountain for an environmental engineering class I took during my last semester in school. What has people hot and bothered is that the scientists and engineers can't give the paranoid, uninformed, or just plain ignorant what they want: a 100% guarantee that it'll work forever. IMO, the science applied and research done in the past 15 years has been excellent and the results have allowed us to say, with very high certainty, that everything will be fine for time scales of 10,000 - 100,000+ years.

When I propose shooting the waste off into space, I mean clear of earth's orbit. Shooting it into the sun would work fine.

I STILL say that humans are dying from all the natural uranium ore and other sources of radioactivity that are scattered all over the place (don't believe me? -- do a web search) and which have long half-lives -- and no one seems to care because that's "natural" radiation. If it's natural, it must be good doncha know! Nuclear waste from reactors is COMPACT and poses a relatively small threat.

But, terrorism is still a major issue. The only "proof" I've seen posted that it isn't was by someone who said they read newspapers a lot and didn't "think" terrorism was such a great threat. Well, I read the news a lot too, and I say it is.

Originally posted by postoak
I STILL say that humans are dying from all the natural uranium ore and other sources of radioactivity that are scattered all over the place (don't believe me? -- do a web search) and which have long half-lives -- and no one seems to care because that's "natural" radiation. If it's natural, it must be good doncha know! Nuclear waste from reactors is COMPACT and poses a relatively small threat.

But, terrorism is still a major issue. The only "proof" I've seen posted that it isn't was by someone who said they read newspapers a lot and didn't "think" terrorism was such a great threat. Well, I read the news a lot too, and I say it is.

Are you aware that YOU are radioactive? Radiation is natural and we have a natural tolerance to it.

As far as terrorism goes, I'm not worried. Smash a plane into the plant? Fine, no worries from this nuclear engineer about a catastrophic meltdown. Take over the plant and manually melt it down? YEAH RIGHT!!!!! You'd need a small army of crack professional EXPERIENCED nuclear engineers to even have a chance and it'd only take one employee hitting the SCRAM button to ruin it for them.

Quit freaking out about it so much... :rolleyes:

Well, it's good to know we have the SCRAM button, since it won't take much to get past half-a-dozen minimum wage security guards!

Originally posted by postoak
Well, it's good to know we have the SCRAM button, since it won't take much to get past half-a-dozen minimum wage security guards!

:rolleyes:

The average adult human has about 66 grams of Uranium in their skeleton.

So now terrorists will get uranium by killing people and taking it out of their bodies!!!:D :bugeye: :eek:

Nuclear power is certainly preferable to other fossil fuels, but its proponents routinely downplay the prospects of alternatives. I'm still in favor of a distributed power generation approach using solar cell-covered roofs, wind turbines, wave/tide and hydroelectric, temperature differential, solar concentrator, geothermal, biomass, and whatever else people come up with. There's greater redundancy and self-sufficiency, fewer problems with security, virtually no waste of any kind. Certain facilities (for example, crucial military installations) might want nuclear power plants for high and secure power density and self-sufficiency. But generally speaking, objections thrown out against green energy are bogus.

For intermittent power sources such as wind turbines, wave generators and solar cells/concentrators, the best power storage technology is not batteries but flywheels. With magnetic bearings and high-efficiency motor/generator assemblies, flywheels lose very little energy, can easily handle large spikes of demand, have no polluting components, and are very compact given their power density, when compared to batteries.

The objections as to cost are spurious. Mass production will lower cost dramatically. Massive industry involvement (as would happen with massive government subsidies) would result in fast R&D cycles. All we need is a national commitment to clean energy. As I've said before, shunting an extra 50 billion a year into something like that rather than the bloated Pentagon budget would go a long way toward boosting national security and vastly stimulating US industry and exports at the same time.

Originally posted by Adam
The average adult human has about 66 grams of Uranium in their skeleton.

Try again...it should be 60 to 90 micrograms


On average, approximately 90 µg (micrograms) of uranium exist in the human body from normal intakes of water, food and air. About 66% is found in the skeleton, 16% in the liver, 8% in the kidneys and 10% in other tissues.

I did not check, if this has been posted:

Gas-Cooled, “Passive,“ Small: Pebble-Bed Modular Reactor

Designer. The Pebble-Bed Modular Reactor (PBMR) was developed by Eskom of South Africa during the 1990s. The PBMR is based on High-Temperature Reactor (HTR) designs developed and built in Germany in the 1980s. More detailed information can be found on the PBMR Web site.

Compact, versatile, and flexible. PBMRs produce 110 megawatts each. Up to ten PBMRs can share a common control center and occupy an area of no more than three football fields. PBMRs can be used either for baseload or peaking power generation.

Self-contained fuel pebbles rather than fuel rods. Unlike conventional reactors that use fuel rods, the PBMR uses fuel spheres, or "pebbles," about the size of a tennis ball coated in graphite. Inside each pebble are 15,000 uranium particles, each coated with a silicon carbon barrier so dense that no gaseous or metallic radioactive products can escape. The uranium is enriched to 8 percent and, unlike conventional reactors, so much of its fissionable material is used up that very little is left. The reactor is loaded with 440,000 pebbles, three quarters of which are fuel and one quarter graphite as an additional nuclear moderator, graphite slowing down neutrons to the speed required for a nuclear reaction to take place.

Inert helium gas rather than water or steam to transfer heat. Conventional reactors use water and steam to absorb and transfer the heat produced by the nuclear reaction to turn the turbine and drive the generator producing electricity. By contrast, in the PBMR helium gas passes through the reactor over the fuel pebbles, is heated, and then flows through the turbine. Because it does not react chemically with other elements, helium cannot burn or become radioactive.

Continuous operation without refueling outages. Conventional light-water reactors designed in the United States shut down every 18 to 24 months to refuel. PBMRs, like Canadian heavy-water reactors, refuel while in operation. New or reusable fuel pebbles are continually being added to the reactor core from the top and removed from the bottom to measure how much fissile material is left. Each cycle takes about three months, with each fuel pebble passing through the reactor about 10 times. A fuel sphere will last about three years and a graphite sphere about 13 years. A PBMR will use about 10 to 15 total fuel loads in its lifetime.

Reduced major maintenance requirements. Because gas turbines are more efficient than steam turbines, and because, with magnetic bearings, there is less friction, the PBMR requires major maintenance only once every six years.

Passive safety design makes the use of conventional, active safety systems unnecessary. The PBMR is inherently safe because of the natural physics involved in its design, materials, and fuel configuration. Because helium is chemically and radiologically inert—cannot combine with other chemicals—it is non-combustible, and cannot become radioactive. If the reaction is not stopped by the graphite spheres or cooled by the helium, it will cool down naturally on its own in a very short time because the increase in temperature will make the chain reaction less efficient until it ceases to generate power. The peak temperature that can be reached in the reactor core is far below what would damage the fuel, because the ceramic materials coating the fuel—graphite and silicone carbide—are tougher than diamonds. Because of its shape—a high surface to volume ratio—the reactor will lose heat faster than the heat generated by the fuel in the core, so that the plant can never get hot enough for a meltdown of the fuel to occur.

Self-contained waste safe until nonradioactive. The design of PBMR fuel makes it easy to store after it is used in the reactor, because the silicon carbide coating around the fuel spheres will keep the radioactive particles isolated.

PBMR construction timetable. South Africa plans to begin operating a PBMR in 2007 and intends to construct up to 10 more in the future. In July 2002, two Japanese firms joined the construction project. Nuclear Fuel Industries Ltd. announced that it will construct a factory to fabricate the PBMR fuel pebbles, and Mitsubishi Heavy Industries Ltd. announced that it will develop the helium-powered turbine generators.

Oops, you're quite right Kmguru. Just read through the WHO's report on depleted uranium ammunition again:



Uranium is a naturally occurring, ubiquitous, heavy metal found in various chemical forms in all soils, rocks, seas and oceans. It is also present in drinking water and food. On average, approximately 90 µg (micrograms) of uranium exist in the human body from normal intakes of water, food and air; approximately 66% is found in the skeleton, 16% in the liver, 8% in the kidneys and 10% in other tissues.


Just got my numbers mixed up. :)

http://www.nci.org/nci-nt.htm


Current NRC security regulations do not address the magnitude of threat demonstrated by the September 11 attacks. NRC standards require that nuclear plant operators protect against a much smaller number of attackers than involved in these attacks. Yet, even under the current weak standards, the armed guards at nearly half of the nuclear plants tested in NRC-supervised security exercises have failed to repel mock terrorist attacks or prevent simulated destruction of redundant safety systems that in real attacks could cause severe core damage, meltdown, and catastrophic radioactive releases.


Despite nuclear industry claims to the contrary, it is highly unlikely that nuclear-power reactor containment domes are robust enough to withstand a direct hit from a jumbo jetliner. Dr. Edwin Lyman, NCI’s scientific director, has calculated that a direct, high-speed hit by a large commercial passenger jet "would in fact have a high likelihood a penetrating a containment building" that houses a power reactor. "Following such an assault," Dr. Lyman said, "the possibility of an unmitigated loss-of-coolant accident and significant release of radiation into the environment is a very real one." Such a release, whether caused by an air strike, or by a ground or water assault, or by insider sabotage could result in tens of thousands of cancer deaths.

Ewwwww... NCI.

Those guys are professional anti-nuclear proponents. Of course anything they have to say is going to be negative. Futhermore, their technical staff seems to be pretty weak and certainly not credible enough for one guy to discredit that what the industry engineers thinks is right. Breaching those containment structures is seriously difficult... they were made to withstand the energy deposited to it by a full core meltdown and that's a LOT of energy.

Find some more legitimate sources and then we'll talk. An anti-nuclear institute with one phsyicist that likes to talk out of his ass won't cut it.

The knowledge that power could be gathered from solar rays was first understood over a century and a half ago, in 1839. You'd think by now the world's main source of recoverable energy would be from the sun. The problem with it is not that it's not economically feasable, which it is, it's that solar power works best in individual systems geared for specific applications. That means that each homeowner would be an independant energy producer. After the homeowner's solar equipment was installed, then all there would be to worry about would be the monthly payment for it, which would surely be less than a car payment. And the cost of the fuel to run the system, of course.

But then, what would happen to all of the parasitic utility companies? Some of them are amongst the largest corporations in the world and, lately, what with their global warming by-product, they don't seem able to meet the demand all the time anyway. Maybe they should be given a couple of trillion dollar golden handshakes and let them wander away somewhere.