'Major discovery' from MIT primed to unleash solar revolution

[[XC] riptide]

Dave, please take a look at this - pebble bed reactors

These are gas cooled and CANNOT melt down. You're thinking of the ancient designs used in current reactors where you have fuel rods and control rods and a very complex liquid cooling system that can malfunction if not maintained properly. The only issue with pebble beds is if you have a damaged pebbles - but that will cause a minor release of radiation at most. It will not and cannot cause a melt down.

Building a water cooled reactor when you could build one of these instead is just stupid. If someone wanted to build a pebble bed reactor in my area, I wouldn't object. If they tried to build a water cooled, control rod style reactor, I would be out there chaining myself to bulldozers.

Twiliyt the pebble reactors are not 100% safe. HUMAN error is the No. 1 risk to all nuclear. Just like it was with every accident. Human error.

Dave@ Chernobyle was a baby accident compared to what almost happened there. Due to the selfless sacrifice of 2 navy divers, they prevented a Thermo Vapor explosion of 1000's of gallojns of flooded water that estimates had written would poison all of europe and kill 30million. Nuclear is great.... until one of these countries goes to war... and Power stations get sabotaged by lunatics.

[Macadamia]

The only thing I saw on that link was a refereence to graphite..
Do you know what kind of reactor was at Chernobyl?
Yup, Graphite..
It has an amazing abilty to absorb heat but once" overloaded" it flashes back that heat.
I read an interesting article in National Geographic a few years back doing a timeline of what happenned at Chernobyl.
It was broken down into the millionth's of a second.
At one point they said the inside of that reactor was app 1/10th of the temp of the surface of the sun when it flashed that stored heat back.
It scares me that people would go with a potentially catastrophic technology when there are such safe ones available.
The logic just isn't there so it must be driven by the pursuit of money.
There is just no other logical answer..
Here's a simple way to look at it:
Would you rather have a Nuclear plant as your next door neighbor or a farm of solar panels?

It needs oxygen for combustion.

[Movieman]

Twiliyt the pebble reactors are not 100% safe. HUMAN error is the No. 1 risk to all nuclear. Just like it was with every accident. Human error.

Dave@ Chernobyle was a baby accident compared to what almost happened there. Due to the selfless sacrifice of 2 navy divers, they prevented a Thermo Vapor explosion of 1000's of gallojns of flooded water that estimates had written would poison all of europe and kill 30million. Nuclear is great.... until one of these countries goes to war... and Power stations get sabotaged by lunatics.

I know, I've done a lot of reading on that accident.
You read some of the stories of the Russian military guys that just kept going back in when they were told they had taken too may REM's and they went anyway.
You read what I read and it would bring tears to your eyes.
The word hero is tossed around very easily today.
\Those guys defined the word in my opinion.

[[XC] riptide]

I know, I've done a lot of reading on that accident.
You read some of the stories of the Russian military guys that just kept going back in when they were told they had taken too may REM's and they went anyway.
You read what I read and it would bring tears to your eyes.
The word hero is tossed around very easily today.
\Those guys defined the word in my opinion.

Yep. They went to the local military diving school... asked for volunteers to help. Said they needed two guys and that they were never going to make it back.

They all volunteered.

[twilyth]

Twiliyt the pebble reactors are not 100% safe. HUMAN error is the No. 1 risk to all nuclear. Just like it was with every accident. Human error.

True, but with a regular reactor, the worst that happens is that it melts down. It wouldn't go to china though, since the heat at the core of our planet is probably driven by radioactive decay of uranium. So once it gets to the center of the earth it will either kill all the dinosaurs hiding there or merge with the core. OT I know, but it seemed like a fun tangent.

With PBR's, the worst that happens is the reactor doesn't work. The pebbles will survive without any active cooling - unlike the Chernobyl design, which as I recall was considered a poorly designed reactor.

[[XC] riptide]

Well the reactor in Chernobyl was designed with an inherent flaw. When moving the control rods there comes a time when the power actually peaks before subsides. On the day of the accident a unfamiliar team of guys went on shift and were ordered to proceed with the experiment that the regular guys didn't get a chance to get done. Many mistakes compounded one after the other precipitated the disaster. Not the reactor itself... but the guys, and of course the idiot supervisor who asked for the experiment to go ahead were the cause. When they saw the power peaking they added more coolant... not realising that this would acutlaly speed up the reaction. By the zenith of the incident the reactor was producing 10 times its designed power output. These reactors are really animals of their own character. They need teams of guys ALL the time that are familiar with it... like in the good 'ol days, you had a guy manning a steam boiler who knew its 'character'. The reactors change how they behave as they consume the fuel. The many many istopes change how it works. It needs a lot different treatment when it has been producing for a while that on a fresh fuel charge.

[madcho]

oh yeah... the only problem photovoltaic has right now is price, if it gest cheaper, lets say 2-3€ per m² and has a efficency of 2-3% hell yeah i take that any day over nuclear energy. With that price efficency doesn't matter. I just plaster my roof with that.

Nuclear energy is only a short term solution, we already consume more uran than it is mined and it doesn't get better, there are 93 plants planed worldwide with 24 in china alone.

http://www.world-nuclear.org/info/info.html

19 here in France

from wiki.fr

I don't know how is power in other country, but there it's never power loss !!!

How is power in us ?

[Movieman]

True, but with a regular reactor, the worst that happens is that it melts down. It wouldn't go to china though, since the heat at the core of our planet is probably driven by radioactive decay of uranium. So once it gets to the center of the earth it will either kill all the dinosaurs hiding there or merge with the core. OT I know, but it seemed like a fun tangent.

With PBR's, the worst that happens is the reactor doesn't work. The pebbles will survive without any active cooling - unlike the Chernobyl design, which as I recall was considered a poorly designed reactor.

I think you have this wrong. The China Syndrome is a misnomer as what happens is it does "meltdown" till it hits groundwater then the sudden huge amount of steam generated causes an explosion and the radioactive parts are tossed into the atmosphere upto and including the troposphere..From there it is into the wind currents and depending on the weight of the particles drops to earth or is carried in the winds till rain drops the particles..
The basic point to me is that since ONE error can be so catastrophic, why would any sane person choose this technology over solar,wind,hydro or geothermal?
Now I may not be the smartest person alive but I'm no dunce either.
I just can't see the logic.

[twilyth]

I think you have this wrong. The China Syndrome is a misnomer as what happens is it does "meltdown" till it hits groundwater then the sudden huge amount of steam generated causes an explosion and the radioactive parts are tossed into the atmosphere upto and including the troposphere..From there it is into the wind currents and depending on the weight of the particles drops to earth or is carried in the winds till rain drops the particles..
The basic point to me is that since ONE error can be so catastrophic, why would any sane person choose this technology over solar,wind,hydro or geothermal?
Now I may not be the smartest person alive but I'm no dunce either.
I just can't see the logic.

OK, you REALLY couldn't tell I was joking? Anyway, I keep saying that current designs are bad so on that score we agree. You need to look at the PBR's I linked to above. These are designed precisely to deal with the issues you're raising.

[Shintai]

Just thinking on a commercial here in TV from the goverment. Its about old lightblubs vs those little more expensive power saving onces.

Its not the cheapest one No, but it will be.

Same thing with solar cells and such.

And the guarantie from the factories are 20-25years on solar cells. That doesnt mean they stop working after that time like some seem to think. Your tray CPU from newegg didnt stop working either after 90 days, did it?

[Movieman]

OK, you REALLY couldn't tell I was joking? Anyway, I keep saying that current designs are bad so on that score we agree. You need to look at the PBR's I linked to above. These are designed precisely to deal with the issues you're raising.

ok, sorry, I tend in this kind of thread to shut off my sense of humor.
BUT back to my question dear sir:
Which would you rather have as your neighbor?
A solar farm or a nuclear power plant?

[twilyth]

ok, sorry, I tend in this kind of thread to shut off my sense of humor.
BUT back to my question dear sir:
Which would you rather have as your neighbor?
A solar farm or a nuclear power plant?

I've already said that if they decided to build a PBR near me I wouldn't object. But it depends on how much land we're talking about. How big would the solar farm have to be to equal the output of a nuclear reactor? Around here, land is very expensive. You can pay $250k for just a building lot. So the fact of the matter is that it's unlikely anyone would want to build either.

But to answer your question, yes, I definitely prefer wind and solar over nuclear. My only point is that nuclear isn't your father's Oldsmobile. Things have changed a lot in 30 years and PBR's while not absolutely idiot proof are pretty damn close. If we can generate enough power with wind and solar in an accelerated time frame, I'm all for it. But we shouldn't exclude nuclear based on disasters associated with antiquated technology.

[[XC] gomeler]

Very interesting, could prove to be a rather useful technology. Just add to this a few thorium breeder reactors and let's start over-generating electricity. Next step, cutting back on consumption.

[[XC] riptide]

More about pebble reactors... http://www.tmia.com/industry/pebbles.html

[twilyth]

Hmmm an organization called three mile island alert huh? Will have to see how objective they are. In the meantime here are some other opinions.

Basic physics guarantees that PBR's cannot melt down.

In the pebble bed reactor high temperature U238 atoms absorb neutrons to prevent run away overheating. At normal operating temperatures the U238 atoms have a low probability of absorbing a neutron, because the relative velocities of the neutron and U238 must be within a narrow range. The process is said to have a low cross section for absorbtion of the neutron by U238. As the reactor heats the U238 atoms vibrate more rapidly, increasing the chance the neutron and U238 nucleus will have the right relative velocity to absorb a neutron. This is called Doppler broadening, much like the Doppler effect that raises the pitch of oncoming train whistles. The captured neutrons can not further the U235 chain reaction, so as the reactor heats up the chain reaction is checked and the temperature approaches a steady state.

China has a working PBR and they have been used before in the US

There are many things about pebble bed reactors that fascinate me, but one of them is the fact that they can be configured to be able to withstand a complete loss of cooling without causing any core damage. As long as each reactor unit produces less than 400 MW of thermal energy, operators can turn off the cooling circulators and walk away knowing that the plant will heat up a bit, shut itself down, and never exceed a temperature at which any fuel damage will occur. Now that is a hot idea whose time has come!

[thor_1987]

One word people.

OVERPOPULATION!

[Shintai]

One word people.

OVERPOPULATION!

That too. But we have to hear about humanity crap then. Atleast China is doing something actively.

[Pyroe_Inc]

A Thorium "reactor" actually sounds pretty interesting. And the best part is that its not selfsustaining.

I thought this might be relevant to the OP: http://www.physorg.com/news136737643.html

[iboomalot]

best overall source for clean fuel ALGEA

Solar and wind and hydro for homes Algea products for auto and heating oil.


too bad it won't ever happen even when its cost effective

some reading material for everyone

http://www.algenolbiofuels.com/advan...efficient.html

[STaRGaZeR]

best overall source for clean fuel ALGEA

Solar and wind and hydro for homes Algea products for auto and heating oil.


too bad it won't ever happen even when its cost effective

some reading material for everyone

http://www.algenolbiofuels.com/advan...efficient.html

Using food as fuel isn't a good idea...

[kamongear]

Using food as fuel isn't a good idea...

Reading the page before commenting on it is a good idea.

If the algenol thing is true then it looks awesome.

[Aberration]

There are nuclear options that dont involve radioactivity.

And the algae option seems great.

In the last 6mo I have flown from San Fransisco to Albuquerque many times. There are VAST stretches of land in which you see not a single house.

There are options. It is just obvious that we are not at the point in which we must research and implement them.

Solar IMO is not the option though. It has been known for along time that it takes more energy to produce the panels than they get out over their lifetime. But that is just the current technology. That doesnt mean that energy from solar is not plausible, just not in its current form.

[kemist]

alternatives will come on line when they are economical compared to oil. Realistically oil is pretty damn cheap when you think about it, ~ the same as a gallon of milk.

Its just now becoming economical for alternative energy to be brought on line. Once alternatives begin being implemented and research starts going towards those alternatives they will further fall in price. Its just a matter of time; theres no grand conspiracy to keep alternatives from being developed.

[STaRGaZeR]

Reading the page before commenting on it is a good idea.

If the algenol thing is true then it looks awesome.

My comment is not related to algenol directly, as algae is not food. It was targeted at that biofuel crap. Changing oil for something even worse availavility wise is stupid. Also it is not clean by any means. Just an intermediate step to the real revolution. This intermediate steps are our worst enemy IMO.

[Bo_Fox]

Did any of you guys get my message that 90-95% of the total energy used in the world comes from gasoline (oil, petroleum) that we use out there for transportation (the energy that we use in home is nothing compared to the energy we use to get from point A to point B, or the energy used for shipping goods)?

Like in the US, an average piece of food that you eat travels 1500 miles, and for an average Canadian, the food has travelled 5000 miles? Think about what we use to mine for Uranium in the first place? A huge amount of diesel!

Think about it, an average Joe's majority of energy usage comes from driving that 2-ton SUV to work everyday. The energy required for hauling that SUV for a couple hours is probably equal to the energy required to cool or heat your house for 1 week in the summer or winter.

I think that we should just ban everybody from driving SUV's unless they are actually going camping or moving some furniture. Otherwise, the prices will eventually ban us from doing so, as the gas prices continue to rise thanks to our foolish indulgence. Like driving while talking on cell phones are banned in California, right? In big cities, it is not allowed to drive on "car-pool" lanes if you do not have anybody else riding with you. I think we should just start enforcing some kind of a law, since it drives me nuts how people drive huge 6-liter V8 pickup trucks to work everyday for no apparent reason despite paying so much for the gas.

When I was visiting Canada, I saw some people driving those mini cars on the freeway. I mean, those cars were like European mini cars, half the size of Mini Coopers. There should be a law requiring that if a person buys a V-6 automobile for over $25000, that person should already possess a mini-car for everyday driving for 1-2 people. Of course, it could be kinda difficult to enforce such a law, but it should at least do wonders in encouraging the ignorant average American from being so indulgent for no reason.

I mean, there are already so many ridiculous laws around here. This new law would probably benefit the world 1000000 times more than some other silly law already in effect.