Merged nuclear power safe?

[Travis]

If nuclear power actually was safe, and nuclear waste was safe, and nuclear material was safe, nobody would be discussing it. We would just all be using safe nuclear power.

You apparently underestimate the ability of the human species to get scared of things that are not really a danger and accept things that really are a danger. See people fears of flying vs apathy towards driving.

Or, here's another example, last month Amtrak had a bad accident that resulted in several deaths. Statistically traveling by rail is one of the safest ways to travel, period. Nonetheless that one standalone accident (that wasn't even Amtrak's fault) has numerous people saying they will be driving (statistically much, much more dangerous) from now on.

Humans can be really stupid about these things.

 

[Sword_Of_Truth]

If nuclear power actually was safe, and nuclear waste was safe, and nuclear material was safe, nobody would be discussing it.

It is, and yet we are.

Helen Caldicott was making a respectable living as a pediatrician but she wasn't being treated like a rock star. So she started making @#$% up about nuclear power that wasn't supported by science (as revealed by one of her former followers) and now she gets to travel the world, rake in speaking fees, air fare and hotels all courtesy of her minions and have rooms of people fawning over her and telling her how great she is.

Nuclear power is the safest, cleanest and greenest power there is, but that doesn't stop those with the ethics of divorce lawyers and used car salesmen from telling lies to the gullible for money.

 

[uruk]

No, there aren't. Nuclear power has the lowest casualty rate per terawatt hour generated.

Coal – world average 161 (26% of world energy, 50% of electricity)
Coal – China 278
Coal – USA 15
Oil 36 (36% of world energy)
Natural Gas 4 (21% of world energy)
Biofuel/Biomass 12
Peat 12
Solar (rooftop) 0.44 (less than 0.1% of world energy)
Wind 0.15 (less than 1% of world energy)
Hydro 0.10 (europe death rate, 2.2% of world energy)
Hydro - world including Banqiao) 1.4 (about 2500 TWh/yr and 171,000 Banqiao dead)
Nuclear 0.04 (5.9% of world energy)​

Interesting. What are the nature of the casualties and how are the casualties related to the production of the power?
i.e. deaths casued by exposure to the fuel and byproducts as compared to construction of facilities.

And they never will be.

That's a bit absolutist. Do you have a crystal ball or time machine?

Europes Largest Photovoltaic Array, 70 Megawatts Peak Capacity:
[qimg]http://i30.photobucket.com/albums/c345/Kilstryke/cid_image001_jpg01CB8D49.jpg[/qimg]

BIG! Shame the solar cells aren't more efficient. Hey, you know, technoloy has a tendency to improve over the years. I wonder how costly it would be to replace solar elements with more efficient panels in that solar farm as opposed to re-purpose a nuclear reactor to run a different design?

Brookhaven Technology Groups proposed Deployable Electric Energy Reactor (two models, 50 MW + 10MW, standard output):
[qimg]http://i30.photobucket.com/albums/c345/Kilstryke/DEERcomparitivesizes.jpg[/qimg]

Even fossil fuels can't match the efficiency of nuclear.

I don't care much for fossil fuels.

 

[uruk]

You can separate out the plutonium from the waste and reintroduce it into the fuel cycle.

We can supply all our energy needs this way for tens of thousands of years.

This is where the politics screws things up. separating and concentrating plutonium makes government leaders itchy.

They see the production of weapon grade plutonium as politcal liability and a bad terrorist nightmare in the making.

This and the extra cost of building these types of reactors are what are holding back this solution.

 

[uruk]

Political problems often get solved as soon as there's sufficient incentive. Right now, the incentive is rather low. Fossil fuels remain sufficiently abundant that we can do without more nuclear, and short-term fuel storage works well enough with the quantities we have. We haven't adopted a long-term solution because we don't need a long-term solution yet. As soon as we do, we'll adopt one.

In contrast, there's no telling when the technical problems for fusion will be solved.

Yea, we tend to be more reactive than proactive.

Is it better to deal with an issue before it becomes a problem or wait untill something really bad happens then deal with it?

The latter seems to be de rigueur where money is involved.

 

[Sword_Of_Truth]

That's a bit absolutist. Do you have a crystal ball or time machine?

I neither have nor need either. I have an astronomy textbook. It just so happens that the Earth is 93 million miles from the Sun. There is a hard upper limit to how much energy that can be generated by solar, and baring any major changes to the 93 million figure, solar energy will simply never catch up to nuclear.

BIG! Shame the solar cells aren't more efficient. Hey, you know, technoloy has a tendency to improve over the years.

This is true. In fact any technology can improve. It's interesting that you appear to assume that nuclear cannot.

Why would we waste time and energy on the one that is already so far behind?

 

[uruk]

Most of the waste will be U-238. Which can be turned into Plutonium-239 and then burned (this is where the "doing it over and over again for thousands of years" part comes in).

The process you speak of is called PUREX and UREX+. These processes produce nonfissible but still highly radioactive waste which contain, "long lived radioactive isotopes".

This waste still has to be safely stored and kept safe from those with "ill intent" for many many years.

http://www.nei.org/keyissues/nuclearwastedisposal/policybriefs/advancedfuelcyclepage3/

 

[uruk]

I neither have nor need either. I have an astronomy textbook. It just so happens that the Earth is 93 million miles from the Sun. There is a hard upper limit to how much energy that can be generated by solar, and baring any major changes to the 93 million figure, solar energy will simply never catch up to nuclear.

You just posted a picture showing a solar farm that produces 70MW (per what? a day? a month? a year?) and that is with solar cells that only get 24% efficiency. How much power would they produce with 50% or 80% efficiency? Granted a city like New York needs over 5 GW per year. But then how many cities are there that are the size of New York?

This is true. In fact any technology can improve. It's interesting that you appear to assume that nuclear cannot.

I never assumed or implied otherwise. The problem with nuclear power plants is the nature of the waste they produce. I am all for any future developments that will significantly reduce this waste and make them safer.

Why would we waste time and energy on the one that is already so far behind?

No accumulation of radioactive waste. No decomissioned facilities with areas that are dangerous to occupy. No byproducts that can be used as threats or weapons. No possibilities of reactor accidents that release radioactive materials into the environment.

 

[Aepervius]

The process you speak of is called PUREX and UREX+. These processes produce nonfissible but still highly radioactive waste which contain, "long lived radioactive isotopes".

This waste still has to be safely stored and kept safe from those with "ill intent" for many many years.

http://www.nei.org/keyissues/nuclearwastedisposal/policybriefs/advancedfuelcyclepage3/

Highly radioctive means very short live. Think for example Francium. So those are not a problem. Long term waste are not a problem either. They deliver so few radioactivity you could nearly manipulate them by hands, the toxicity of the heavy metal kick in maybe, but not the radioactivity.

A few decades or hundred years storage of waste is nothing. Look at our own dumps .
What is problematic MIGHT be medium term waste, like half life of thousand or ten thousand of years. And even there the problem has been inflated and exaggerated to "what if our long distant ancestor were to discover it or what if geology changed in 4000 years ?".

Basically radioactive waste are much less a problem than mining wash off of poisons or buried heavy metals and otehr nasty chemicals. Those are there *forever* whereas radioactive waste has at least the blessing of getting smaller and smaller with time.

As for your comment on efficiency and solar : there is a hard limit on quantum efficiency, and a hard limit on insolation per surface. Anything above that is science fiction.

 

[Sword_Of_Truth]

You just posted a picture showing a solar farm that produces 70MW (per what? a day? a month? a year?) and that is with solar cells that only get 24% efficiency. How much power would they produce with 50% or 80% efficiency?

Not enough to compete with nuclear. The "hard cap" on solar is hard wired into the orbit, rotation of and atmospheric conditions on Earth. A nuclear reactor never needs to worry about the weather or the time of day and is has an energy density millions of times greater than a few watts per square meter.

I never assumed or implied otherwise.

We're agreed then, that nuclear technology can improve and it's starting position is far ahead of solar.

The problem with nuclear power plants is the nature of the waste they produce. I am all for any future developments that will significantly reduce this waste and make them safer.

The waste generated by a family of four over their entire lifetimes under a nuclear economy, would be enough to fill a coffee cup, and would cease to be a hazzard after ~300 years.

And that's not taking into account proposed solutions like neutron spallation technology that could reduce the wastes lifespan to within a human lifetime.

No accumulation of radioactive waste. No decomissioned facilities with areas that are dangerous to occupy. No byproducts that can be used as threats or weapons. No possibilities of reactor accidents that release radioactive materials into the environment.

If you don't mind checking the weather report to see if you'll be able to watch TV or surf the internet. Or paving over whole forests to feed the needs of small cities for just a few hours a day.

 

[Sword_Of_Truth]

The process you speak of is called PUREX and UREX+. These processes produce nonfissible but still highly radioactive waste which contain, "long lived radioactive isotopes".

As has been pointed out to you, radioisotopes can be "highly radioactive" or "long lived", they can't be both.

This waste still has to be safely stored and kept safe from those with "ill intent" for many many years.

Same with airplane cockpits. No one seriously thinks we should stop using airplanes.

 

[uruk]

Highly radioctive means very short live. Think for example Francium. So those are not a problem. Long term waste are not a problem either. They deliver so few radioactivity you could nearly manipulate them by hands, the toxicity of the heavy metal kick in maybe, but not the radioactivity.

You forget that nuclear waste is continuously accumulating and this radioactive decay happens over a period of time, not instantaneously. Sure the older material losses it's status as high level radioactive waste over time but new high level material is being accumulated at an increasing rate as more reactors come on line.

BTW, Plutonium is extremely poisonous.

At present most of this waste is being stored on site, not in a location specifically designed for safe, long term storage. That is still being held up by our fearless leaders.

A few decades or hundred years storage of waste is nothing. Look at our own dumps .
What is problematic MIGHT be medium term waste, like half life of thousand or ten thousand of years. And even there the problem has been inflated and exaggerated to "what if our long distant ancestor were to discover it or what if geology changed in 4000 years ?".

Long lived radioactive waste is problematic because we don't know what will happen down the road as large amounts of this type of waste is concentrated in small areas. (Remember, this stuff is constantly accumulating as nuclear plants operate. the more they operate, the more it accumulates, that is unless new technology comes around that deals with it better than what is being done now) You could say that's a problem for future generations to deal with, but then so is Global Climate Change.

Basically radioactive waste are much less a problem than mining wash off of poisons or buried heavy metals and otehr nasty chemicals. Those are there *forever* whereas radioactive waste has at least the blessing of getting smaller and smaller with time.

Not if new waste is continuously accumulated over time. The only way the nuclear waste gets smaller over time is that no new nuclear plants come on line and they no longer produce waste. Both of which have a low probability of happening in the near future.
BTW uranium and plutonium are heavy metals as are some of the by products of mining and processing uranium in to fuel grade purities.

As for your comment on efficiency and solar : there is a hard limit on quantum efficiency, and a hard limit on insolation per surface. Anything above that is science fiction.

All you need is enough power to run a a city or supplement other renewable sources. Good enough is good enough.
Recent developments in solar cell research is beginning to reach 80% conversion efficiencies already.

 

[PGH]

I've always had an insane idea to increase our nuclear power and simply shoot the nuclear waste into space. I know it sounds crazy and dangerous. I'm sure many of you can point out things I haven't considered.

But once you get over the initial craziness of the idea don't you think there's some merit to it? Space is empty! It is vast and lifeless. Why not pollute space as opposed to our own planet? Sure it would be real nice if we didn't have to pollute either, but things don't work that way.

Yes there's some risk. Nobody likes the sound of a shuttle exploding in our atmosphere carrying tons of nuclear waste. But that's a relatively minor risk.

Anyway have at it. Savage the idea to show me the problems I may not be considering. Because in my head even though it sounds like a terrible idea at first I really think it could help...

 

[Hellbound]

I've always had an insane idea to increase our nuclear power and simply shoot the nuclear waste into space. I know it sounds crazy and dangerous. I'm sure many of you can point out things I haven't considered.

But once you get over the initial craziness of the idea don't you think there's some merit to it? Space is empty! It is vast and lifeless. Why not pollute space as opposed to our own planet? Sure it would be real nice if we didn't have to pollute either, but things don't work that way.

Yes there's some risk. Nobody likes the sound of a shuttle exploding in our atmosphere carrying tons of nuclear waste. But that's a relatively minor risk.

Anyway have at it. Savage the idea to show me the problems I may not be considering. Because in my head even though it sounds like a terrible idea at first I really think it could help...

Because the current cost in resources to get something into orbit is roughly equivalent ot buying the weight of that object in gold.

It costs a heck of a lot.

Now if we ever get a cheap, efficient way to get something out of our gravity well that might be worth looking at, but right now....not so much.

 

[uruk]

Not enough to compete with nuclear. The "hard cap" on solar is hard wired into the orbit, rotation of and atmospheric conditions on Earth. A nuclear reactor never needs to worry about the weather or the time of day and is has an energy density millions of times greater than a few watts per square meter.

Solar is only meant to supplement other renewable sources such as wind, geothermal, and hydroelectric.

We're agreed then, that nuclear technology can improve and it's starting position is far ahead of solar.

So what? Is that reason to abandon solar power research? Solar power has applications in other areas other than mass power generation.

The waste generated by a family of four over their entire lifetimes under a nuclear economy, would be enough to fill a coffee cup, and would cease to be a hazzard after ~300 years.

And that's not taking into account proposed solutions like neutron spallation technology that could reduce the wastes lifespan to within a human lifetime.

Again really great if the number of nuclear plants in operation don't increase and the waste output stops. As the old stuff goes spent it is replaced by new stuff. they only way the waste goes away if the amount of waste being processed is greater than the output of the plants.

If you don't mind checking the weather report to see if you'll be able to watch TV or surf the internet. Or paving over whole forests to feed the needs of small cities for just a few hours a day.

Who said you had to pave over forests to build solar power facilities? Texas has huge expanses of flat lands. Build the panels high enough and you could build subdivisions below them. You can build wind turbines on farmlands (like they do in Texas). Wind turbines have very small footprints.

 

[Ziggurat]

You just posted a picture showing a solar farm that produces 70MW (per what? a day? a month? a year?)

Power is already energy per unit time. There's no additional "per" involved. There's some ambiguity about whether that's a peak power output or an average power output (I'd guess the former), but that's it.

and that is with solar cells that only get 24% efficiency. How much power would they produce with 50% or 80% efficiency?

We don't have the technology to do that.

 

[Ziggurat]

So what? Is that reason to abandon solar power research? Solar power has applications in other areas other than mass power generation.

Nobody is suggesting abandoning research into solar power. Yes, it has applications other than mass power generation, but if it cannot fulfill mass power generation (and right now, it can't), then it cannot replace nuclear. The only thing that really can right now is fossil fuels, but that's a step backwards, not forwards.

Who said you had to pave over forests to build solar power facilities? Texas has huge expanses of flat lands. Build the panels high enough and you could build subdivisions below them.

Yeah... no. Solar is expensive enough without putting it on giant stilts, and nobody would want to live under them.

 

[PGH]

Because the current cost in resources to get something into orbit is roughly equivalent ot buying the weight of that object in gold.

It costs a heck of a lot.

Now if we ever get a cheap, efficient way to get something out of our gravity well that might be worth looking at, but right now....not so much.

Excellent point. I knew launches were expensive, I just didn't know how expensive. Thanks.

 

[shadron]

You just posted a picture showing a solar farm that produces 70MW (per what? a day? a month? a year?) and that is with solar cells that only get 24% efficiency. How much power would they produce with 50% or 80% efficiency? Granted a city like New York needs over 5 GW per year. But then how many cities are there that are the size of New York?

Uruk, MW is a unit of work continuously accomplished. It puts out 70MW (probably a peak measure) whenever the sun is up. It's like a 100 w light bulb; it uses 100 w whenever it is on. If it's on for an hour, it used 100w-hrs (a unit of energy). Are you planning on 50-80% efficiency? On what grounds? Someone asked above what the cost of retrofitting it with more efficient cells; I think the cost would be greater than the original build (if the cells were of comparable cost per square foot, not counting the sunk land cost).[/quote]

 

[shadron]

You forget that nuclear waste is continuously accumulating and this radioactive decay happens over a period of time, not instantaneously. Sure the older material losses it's status as high level radioactive waste over time but new high level material is being accumulated at an increasing rate as more reactors come on line.

Every method of energy creation you choose has the problem of accumulation. Coal has it in spades; all fossil fuels create CO2 as fast as they are burned. Hydro disallows fish spawning for as long as it is used; that could be considered an accumulation problem, not to speak about the dams themselves. You talked about replacing all those solar cells with higher efficiency ones; what are you going to do with the old ones, and their toxic metal content?

BTW, Plutonium is extremely poisonous.

Ah. no more so than the equivalent amount of arsenic or cadmium (talking here only of it's metallic, elemental poisonousness, not its radioactivity. For that you have to get more specific.)

At present most of this waste is being stored on site, not in a location specifically designed for safe, long term storage. That is still being held up by our fearless leaders.

As was stated earlier, a political problem, not a scientific/engineering one.

Long lived radioactive waste is problematic because we don't know what will happen down the road as large amounts of this type of waste is concentrated in small areas. (Remember, this stuff is constantly accumulating as nuclear plants operate. the more they operate, the more it accumulates, that is unless new technology comes around that deals with it better than what is being done now) You could say that's a problem for future generations to deal with, but then so is Global Climate Change.

Better small areas than large ones (like the typical landfill).

Not if new waste is continuously accumulated over time. The only way the nuclear waste gets smaller over time is that no new nuclear plants come on line and they no longer produce waste. Both of which have a low probability of happening in the near future.
BTW uranium and plutonium are heavy metals as are some of the by products of mining and processing uranium in to fuel grade purities.

All you need is enough power to run a a city or supplement other renewable sources. Good enough is good enough.
Recent developments in solar cell research is beginning to reach 80% conversion efficiencies already.

1) The accumulation problem is endemic to all forms of energy. You'll not get away from it, and most energy forms are much worse in this regard than nuclear.

2) Cite some evidence of that efficiency figure. Also see Solar Cell Efficiency^WP and in particular this graph:

http://en.wikipedia.org/wiki/File:PVeff(rev110408U).jpg