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suityou01
17th March 2011, 00:05
I mean perlease I can understand there are chain reactions after withdrawing the rods from the core, sure enough. And that those chain reaction take time to subside, but this type of reactor is supposed to be "safe" in that it is not Chernobyl.

Remove rods, cool core while chain reactions die down, then pop off to the pub when it is job done.

The very fact we are still talking about melt downs days later makes me think we are not being told the whole truth. Either (as the tin foil hat brigage would have us think) this is staged, or they have tried to prioritise the health of the reactors versus shutting them down and doing the best for the populous.

Perhaps someone on here can comment? Is this dragging on too long?

AtW
17th March 2011, 00:06
A couple years apparently if all is normal...

MarillionFan
17th March 2011, 00:10
A couple years apparently if all is normal...

WHS

Even spent rods have to cooled for many years to go.

Think of it like a really smelly tulip. It's terrible to start with, you have to use lots of spray in the bathroom. It's really bad in there and if you leave the door open it's going to waft into the hallway and up the stairs. Of course it stinks at a distance but doesn't make your eyes water unless you get close. After a few days and you still haven't flushed the main house is OK, but if you're close it's pretty bad. After a few months, it's only bad real close up.

Just hope the toilet never explodes!

hth

MF

TimberWolf
17th March 2011, 00:16
Even when most of the chain reactions have stopped, they take a few days for residual reactions to peter out and the fuel rods to cool down, for which the pumps have to be running, which they aren't. But even had they reached that stage they'd have needed some sort of cooling IIUC for a long time, as evidenced by the rods in the cooling tanks causing fresh alarm - and there are a lot of those - 600,000 I hear! But if the rods are a sticky mess at the bottom of the containment vessel, or beyond, who knows when they will cool. I don't think anyone does. Nuclear is so safe this kind of thing doesn't happen often enough to find out :eyes

AtW
17th March 2011, 00:16
All this makes a mockery of "safe shutdown in event of earthquake etc"... so long as plenty of water available to cool stuff, otherwise disaster even for "used" stuff! :sick

Even if it was free energy it would be too expensive risk - ban all nuclear (apart for military nukes which are still necessary and don't require that many plants on a seaside).

MarillionFan
17th March 2011, 00:21
All this makes a mockery of "safe shutdown in event of earthquake etc"... so long as plenty of water available to cool stuff, otherwise disaster even for "used" stuff! :sick

Even if it was free energy it would be too expensive risk - ban all nuclear (apart for military nukes which are still necessary and don't require that many plants on a seaside).

Seriously. Your last few days of 'devils advocat' is playing a bit thin.

At the end of the day, until someone comes up with a proper energy source(and I mean a cool Star Trek type) then Nuclear is the most cost effective. The concept of safe? Well let's define that shall we. Radiation can destroy life in high dosages. Man is invasive on every part of the planet, like a plague of insects. 7 Billion and rising.

Forget Nuclear power. It's over population of the planet that is the real issue.

TimberWolf
17th March 2011, 00:26
Seriously. Your last few days of 'devils advocat' is playing a bit thin.

At the end of the day, until someone comes up with a proper energy source(and I mean a cool Star Trek type) then Nuclear is the most cost effective. The concept of safe? Well let's define that shall we. Radiation can destroy life in high dosages. Man is invasive on every part of the planet, like a plague of insects. 7 Billion and rising.

Forget Nuclear power. It's over population of the planet that is the real issue.

You seem awfully sensible tongight, if that doesn't seem like an insult.

This might put things into perspective, assuming we don't wake up tomorrow to find Japan uninhabitable. Not so long ago we were setting of nuclear bombs in the atmosphere willy nilly for the fun of it, big ones too, and I'd image (pure guesswork) that these were dirtier than nuclear reactor meltdowns. I think we all carry radiative caesium in our bodies from those helicon days, plutonium too probably.I think Japan got hit by a couple.


http://www.youtube.com/watch?v=9U8CZAKSsNA

AtW
17th March 2011, 00:27
Nuclear is the most cost effective.

It's not - even before this disaster which would undoubtedly push up insurance rates, reduce scale of builds (and thus increase cost of building less reactors) was not much lower than gas/reasonably clean coal, I mean like 15-20% difference - **** nuclear for such a small saving especially given that you'd need to have 100% of all power made by nuclear to get 15-20% cheaper energy, I repeat it **** it.

Price of uranium ain't cheap either, though it might be now since there will be less buyers. Frankly this whole "peaceful" nuclear tulip appeared because of desire to build nuclear weapons and having "peaceful" element was a way to shift costs to taxpayer without directly calling it military spending, clever trick that worked nicely some decades ago, but right now nuclear chickens are coming home to roost. :frown

MarillionFan
17th March 2011, 00:28
You seem awfully sensible tongight, if that doesn't seem like an insult.



Bought a home gym. Bought a cross trainer(now fixed). Worked out for an hour and a half. Had soup. Not drinking. Can't bloody sleep! :tantrum::tantrum::tantrum:

suityou01
17th March 2011, 00:32
Bought a home gym. Bought a cross trainer(now fixed). Worked out for an hour and a half. Had soup. Not drinking. Can't bloody sleep! :tantrum::tantrum::tantrum:

My mate Tim (of the Cheshire mansion fame) could not sleep after stopping drinking. He could not sleep unless he had a few beers. The outcome was that he had a mild alchohol dependancy. He had to go through many sleepless nights and sweats to overcome the addiction.

Given the stress he has been under it was always on the cards.

Perhaps you have the same thing? :confused:

No bad thing to admit it, just good to recognise it and deal with it.

MarillionFan
17th March 2011, 00:37
It's not - even before this disaster which would undoubtedly push up insurance rates, reduce scale of builds (and thus increase cost of building less reactors) was not much lower than gas/reasonably clean coal, I mean like 15-20% difference - **** nuclear for such a small saving especially given that you'd need to have 100% of all power made by nuclear to get 15-20% cheaper energy, I repeat it **** it.

Price of uranium ain't cheap either, though it might be now since there will be less buyers. Frankly this whole "peaceful" nuclear tulip appeared because of desire to build nuclear weapons and having "peaceful" element was a way to shift costs to taxpayer without directly calling it military spending, clever trick that worked nicely some decades ago, but right now nuclear chickens are coming home to roost. :frown

Right.

So the idea of using Nuclear is, that you are reducing the amount of fossil fuels(a source that is becoming more expensive and is diminishing in size) available.

Nuclear offers you a 'cleaner' form of energy. Basically meaning you're not digging up the entire planet.

What is interesting is, that the whole process is still based around turbines moved by steam. It's a sad indictment of human technology that we are still limited by that concept. Newcomen must be turning in his grave.

It is the over population of the planet that requires more and more resources to feed it. We are like a plague of locusts devouring the crops of a field are a limited by our abilities.

The question is, when will the discovery and leap in 'free energy' occur?

For now. It's Nuclear.

MarillionFan
17th March 2011, 00:38
My mate Tim (of the Cheshire mansion fame) could not sleep after stopping drinking. He could not sleep unless he had a few beers. The outcome was that he had a mild alchohol dependancy. He had to go through many sleepless nights and sweats to overcome the addiction.

Given the stress he has been under it was always on the cards.

Perhaps you have the same thing? :confused:

No bad thing to admit it, just good to recognise it and deal with it.

Grumble, grumble. Just knocked back a bottle of wine to take the edge off, so you may be right.

Churchill
17th March 2011, 07:21
Grumble, grumble. Just knocked back a bottle of wine to take the edge off, so you may be right.

Go and see a Doctor.

centurian
17th March 2011, 07:32
I mean perlease I can understand there are chain reactions after withdrawing the rods from the core

Actually "chain" reactions stop almost instantly - as soon as the control rods are inserted - a chain reaction being where a splitting uranium atom causes other atoms to split.

The problem is the "normal" radioactive decay of the isotopes produced when uranium atoms are split, typically iodine and caesium. These decay on their own without any stimulus - in fact little can be done to stop them radio-acting (i.e. decaying), so it's down to the normal rules of radioactive half-life. The half life of iodine is about 8 days

VectraMan
17th March 2011, 08:36
Actually "chain" reactions stop almost instantly - as soon as the control rods are inserted - a chain reaction being where a splitting uranium atom causes other atoms to split.

The problem is the "normal" radioactive decay of the isotopes produced when uranium atoms are split, typically iodine and caesium. These decay on their own without any stimulus - in fact little can be done to stop them radio-acting (i.e. decaying), so it's down to the normal rules of radioactive half-life. The half life of iodine is about 8 days

From what they were saying on the telly, this secondary process produces about 10% of the normal heat, which means with the rods inserted, the cooling system needs to get rid of 10% of the heat it deals with normally - doesn't sound too hard. And with the main reaction stopped, this process dies away rapidly (i.e. over days). So nearly a week later they ought to producing a fraction of the heat that they would be at normal operation.

I guess the irony is that if they hadn't shutdown the main reaction, the reactor probably would have continued producing power and there would be no crisis.

Dropping water from helicopters sounds like a last desperate solution and makes you wonder if Homer Simpson is in charge (I was trying to find a video of Homer saving the power plant from meltdown by going eeny-meeny-miney-moe and pressing a button at random).

rhubarb
17th March 2011, 08:44
Is this dragging on too long?

I believe they are jolly hot! Takes a while.

NotAllThere
17th March 2011, 08:56
Instead of water, they should drop liquid Xenon. That should cool things down.

doodab
17th March 2011, 09:25
From what they were saying on the telly, this secondary process produces about 10% of the normal heat, which means with the rods inserted, the cooling system needs to get rid of 10% of the heat it deals with normally - doesn't sound too hard. And with the main reaction stopped, this process dies away rapidly (i.e. over days). So nearly a week later they ought to producing a fraction of the heat that they would be at normal operation.

I guess the irony is that if they hadn't shutdown the main reaction, the reactor probably would have continued producing power and there would be no crisis.

Dropping water from helicopters sounds like a last desperate solution and makes you wonder if Homer Simpson is in charge (I was trying to find a video of Homer saving the power plant from meltdown by going eeny-meeny-miney-moe and pressing a button at random).

You're a project manager aren't you?

Fukushima I Nuclear Power Plant - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant)

Fukushima I – 1 460 MW
Fukushima I – 2 784 MW
Fukushima I – 3 784 MW
Fukushima I – 4 784 MW
Fukushima I – 5 784 MW
Fukushima I – 6 1100 MW

10% of 1GW (units 1 and 2) is 100MW. Allowing for inefficiencies in the power generation process that's probably 200MW of heat output that needs shifting.

A quick calculation based on specific heat capacity and latent heat of vaporisation of water, 1L @ 10 degrees C will require about 2650 kJ to boil, we have 200,000 kJ / s to get rid of, so we need about 80L of water a second to replenish the stuff that is turning to steam.

If you wish to avoid it turning to steam you have a much bigger problem, as most of the energy (2270 kJ) is absorbed by the vaporisation rather than the raising of temperature.

MarillionFan
17th March 2011, 09:34
You're a project manager aren't you?

Fukushima I Nuclear Power Plant - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant)

Fukushima I – 1 460 MW
Fukushima I – 2 784 MW
Fukushima I – 3 784 MW
Fukushima I – 4 784 MW
Fukushima I – 5 784 MW
Fukushima I – 6 1100 MW

10% of 1GW (units 1 and 2) is 100MW. Allowing for inefficiencies in the power generation process that's probably 200MW of heat output that needs shifting.

A quick calculation based on specific heat capacity and latent heat of vaporisation of water, 1L @ 10 degrees C will require about 2650 kJ to boil, we have 200,000 kJ / s to get rid of, so we need about 80L of water a second to replenish the stuff that is turning to steam.

If you wish to avoid it turning to steam you have a much bigger problem, as most of the energy (2270 kJ) is absorbed by the vaporisation rather than the raising of temperature.

I don't need to know the details. I want you to fix it.:tantrum:

Bloody techies. :mad:

PAH
17th March 2011, 09:45
Dropping water from helichopters does look a bit homer simpson but I guess the water cannon boats are now further inland than the reactors.

Isn't the whole area going to be somewhat polluted by dirty water now they've been pumping in seawater (that has to go somewhere) and now splashing it around?

If only they'd built a great big wall around the reactor in the first place. :rolleyes:

BigDogStudioX
17th March 2011, 09:50
Tbh it does seems like pure desperation on their part. Save face and all that doing them harm I think

EternalOptimist
17th March 2011, 09:55
why are they using seawater ?

VectraMan
17th March 2011, 09:58
If only they'd built a great big wall around the reactor in the first place. :rolleyes:

They keep saying you can't make things tsunami proof, but putting the reactor, or just the backup diesel pumps on a small artificial hill would have done it.:rolleyes:

MarillionFan
17th March 2011, 10:01
They keep saying you can't make things tsunami proof, but putting the reactor, or just the backup diesel pumps on a small artificial hill would have done it.:rolleyes:

Then it would have fallen down the hill into the sea.

VectraMan
17th March 2011, 10:03
I think they've run out of Evian.

You'll know they're really desperate when they start sending people down the local petrol station to buy all the supplies of bottled water and smoothies.

doodab
17th March 2011, 10:10
They keep saying you can't make things tsunami proof, but putting the reactor, or just the backup diesel pumps on a small artificial hill would have done it.:rolleyes:

I suspect they would need to be anchored to the bedrock to avoid being washed away. Building them on higher ground a bit further away from the sea might have made sense though.

Is there any footage of the tsunami hitting the plant?

TimberWolf
17th March 2011, 10:11
Not nearly as dirty as a nuclear reactor going off.

I guess this depends on whether Fukushima results in an explosion as with Chernobyl or more localised event. Chernobyl was a meltdown and a dirty bomb, which made it particularly nasty and hopefully not a model for all meltdowns.


Strontium 90 was the isotope of choice back in the 50s & 60s.

Which is produced by nuclear fission in both nuclear bombs and nuclear reactors.

doodab
17th March 2011, 10:12
I'm particularly impressed by the way the spent fuel pond has boil itself dry.

Has it though, or have they used the water from it? Or has it leaked out because the spent fuel pond is cracked or something?

OwlHoot
17th March 2011, 10:16
If only they'd built a great big wall around the reactor in the first place. :rolleyes:

If only they had built it a couple of miles underground, as I've been suggesting for years.

One of these days it won't just be earthquakes and tsunamis but bombs being used against nuclear power stations, and a fat lot of use a 20 foot wall will be then, or blow out walls, or even three foot thick containment vesssels.

And when the power station came to the end of its life, you wouldn't even need to dismantle it at vast expense, just seal off that branch of the tunnel and start a new power station in a parallel tunnel.

eek
17th March 2011, 10:28
If only they had built it a couple of miles underground, as I've been suggesting for years.



Sadly that is toshiba's plan for their small 4S reactors. Toshiba 4S - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Toshiba_4S)

TimberWolf
17th March 2011, 10:36
You're a project manager aren't you?

Fukushima I Nuclear Power Plant - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant)

Fukushima I – 1 460 MW
Fukushima I – 2 784 MW
Fukushima I – 3 784 MW
Fukushima I – 4 784 MW
Fukushima I – 5 784 MW
Fukushima I – 6 1100 MW

10% of 1GW (units 1 and 2) is 100MW. Allowing for inefficiencies in the power generation process that's probably 200MW of heat output that needs shifting.

A quick calculation based on specific heat capacity and latent heat of vaporisation of water, 1L @ 10 degrees C will require about 2650 kJ to boil, we have 200,000 kJ / s to get rid of, so we need about 80L of water a second to replenish the stuff that is turning to steam.

If you wish to avoid it turning to steam you have a much bigger problem, as most of the energy (2270 kJ) is absorbed by the vaporisation rather than the raising of temperature.

That's perhaps the cooling needed when things are operating normally, but what about when fuel rods are in an uncertain state (possibly melted), the control rods integrity questionable, plus the presence of water acting as moderator? A reactor working at 100% in a puddle on the floor?

VectraMan
17th March 2011, 10:37
:eek:


The greatest radio-iodine releases ever seen so far occurred during US nuclear weapons tests in Nevada prior to 1970: Americans suffered the iodine equivalent of three Chernobyls during that period, but because they were not told about the hazard they didn't notice it. The bulk of the health effects came from children being fed contaminated milk, children being especially prone to thyroid damage from iodine; in fact they are the main group likely to suffer major effects. Millions of children were also fed contaminated milk following Chernobyl: according to the IAEA the incidence of thyroid cancer among such children and young people rose to one case in 4,500.

:eek:

TimberWolf
17th March 2011, 10:43
If only they had built it a couple of miles underground, as I've been suggesting for years.

One of these days it won't just be earthquakes and tsunamis but bombs being used against nuclear power stations, and a fat lot of use a 20 foot wall will be then, or blow out walls, or even three foot thick containment vesssels.

And when the power station came to the end of its life, you wouldn't even need to dismantle it at vast expense, just seal off that branch of the tunnel and start a new power station in a parallel tunnel.

AtW mentioned this proposal a day or so ago and I asked him how you'd keep the reactor cool, with something like 2GW of heat to remove. Okay, getting water down there won't be a problem under gravity feed, but you might need to be pumping a tonne or more water a second (I did a rough calculation once but have forgotten the result) 2 miles uphill. Assuming you can't cool the water underground.

doodab
17th March 2011, 10:44
That's perhaps the cooling needed when things are operating normally, but what about when fuel rods are in an uncertain state (possibly melted), the control rods integrity questionable, plus the presence of water acting as moderator? A reactor working at 100% in a puddle on the floor?

Yeah, It's probably not even a ballpark figure. I've assumed some sort of thermal equilibrium while removing the heat generated after a normal shutdown. I also haven't allowed for any inefficiency in the cooling process, or for steam to be heated above 100 degrees once it's boiled.

I guess if the fuel rods are super hot, you need to work out how much extra cooling capacity is required to bring them back down to the target temperature.

Churchill
17th March 2011, 10:50
Build a sarcophagus around the damaged reactor.

We just need some very brave souls to go and build it.

Those chaps at Chernobyl were incredibly brave in their self sacrifice. :(

TimberWolf
17th March 2011, 10:59
Yeah, It's probably not even a ballpark figure. I've assumed some sort of thermal equilibrium while removing the heat generated after a normal shutdown. I also haven't allowed for any inefficiency in the cooling process, or for steam to be heated above 100 degrees once it's boiled.

I guess if the fuel rods are super hot, you need to work out how much extra cooling capacity is required to bring them back down to the target temperature.

You feel the fuel and control rods are still in place more or less intact?

doodab
17th March 2011, 10:59
AtW mentioned this proposal a day or so ago and I asked him how you'd keep the reactor cool, with something like 2GW of heat to remove. Okay, getting water down there won't be a problem under gravity feed, but you might need to be pumping a tonne or more water a second (I did a rough calculation once but have forgotten the result) 2 miles uphill. Assuming you can't cool the water underground.

The primary loop uses sodium I believe, and hfss no reason for coolant to travel to.and from the surface. The secondary probably allows the hot water to rise as steam, so should get back up there all by itself.

TimberWolf
17th March 2011, 11:02
The primary loop uses sodium I believe, and hfss no reason for coolant to travel to.and from the surface. The secondary probably allows the hot water to rise as steam, so should get back up there all by itself.

That's true, maybe the idea has merit. Thermodynamic efficiency might take a bit of hit though.

MarillionFan
17th March 2011, 11:03
AtW mentioned this proposal a day or so ago and I asked him how you'd keep the reactor cool, with something like 2GW of heat to remove. Okay, getting water down there won't be a problem under gravity feed, but you might need to be pumping a tonne or more water a second (I did a rough calculation once but have forgotten the result) 2 miles uphill. Assuming you can't cool the water underground.

Come on. All we need to do is find the team who've been working on making the London Underground cool in the summer.

Send them over to sort it out. Then push the useless ****ers in.

TimberWolf
17th March 2011, 11:04
So what about the spent fuel rods (there are an awful lot of them, far more than in all the reactors I hear). How much cooling do they need?

doodab
17th March 2011, 11:23
So what about the spent fuel rods (there are an awful lot of them, far more than in all the reactors I hear). How much cooling do they need?

Apparently after a year or so it generates about 10kW per tonne.

Decay heat - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Decay_heat)

TimberWolf
17th March 2011, 11:34
Apparently after a year or so it generates about 10kW per tonne.

Decay heat - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Decay_heat)

That's a rather surprisingly benign figure, 10W/kg, with only passive cooling required. I thought some had reportedly caught fire and were becoming a real menace.

TimberWolf
17th March 2011, 12:01
That's a rather surprisingly benign figure, 10W/kg, with only passive cooling required. I thought some had reportedly caught fire and were becoming a real menace.

A Wiki (http://en.wikipedia.org/wiki/Boiling_water_reactor_safety_systems) has already been updated to say that a spent fuel pond did catch fire:


But if the pool were to be drained of water, the discharged fuel from the previous two refuelings would still be "fresh" enough to melt under decay heat. However, the zircaloy cladding of this fuel could be ignited during the heatup. The resulting fire would probably spread to most or all of the fuel in the pool. The heat of combustion, in combination with decay heat, would probably drive "borderline aged" fuel into a molten condition. Moreover, if the fire becomes oxygen-starved (quite probable for a fire located in the bottom of a pit such as this), the hot zirconium would rob oxygen from the uranium dioxide fuel, forming a liquid mixture of metallic uranium, zirconium, oxidized zirconium, and dissolved uranium dioxide. This would cause a release of fission products from the fuel matrix quite comparable to that of molten fuel. In addition, although confined, BWR spent fuel pools are almost always located outside of the primary containment. Generation of hydrogen during the process would probably result in an explosion damaging the secondary containment building. Thus, release to the atmosphere is more likely than for comparable accidents involving the reactor core. [4] (http://en.wikipedia.org/wiki/Boiling_water_reactor_safety_systems#cite_note-3) A spent fuel pool accident releasing radioactive material to atmosphere happened in a Mk-1 type BWR reactor in Fukushima, Japan, on March 14, 2011.

TimberWolf
17th March 2011, 12:03
http://www.spiegel.de/images/image-191816-galleryV9-nhjp.gif

PAH
17th March 2011, 12:30
Build a sarcophagus around the damaged reactor.

We just need some very brave souls to go and build it.

Those chaps at Chernobyl were incredibly brave in their self sacrifice. :(


If only the japs had been more advanced with that humanoid robot stuff we had a thread on in the last week or so. Send in the robots to build it and have them seal themselves in if they get too contaminated.

They could use prisoners on day release. Send our life-sentenced scum over as part of a multinational effort. Everyone's a winner, who deserves to be.

AtW
17th March 2011, 12:39
AtW mentioned this proposal a day or so ago and I asked him how you'd keep the reactor cool, with something like 2GW of heat to remove. Okay, getting water down there won't be a problem under gravity feed, but you might need to be pumping a tonne or more water a second (I did a rough calculation once but have forgotten the result) 2 miles uphill. Assuming you can't cool the water underground.

Build it under ocean floor....

MarillionFan
17th March 2011, 13:15
Build it under ocean floor....

You are Patrick Duffy, but you can keep your £5, you need it more.:smokin

suityou01
17th March 2011, 13:21
Has anyone called Red Adaire? :rolleyes:

OwlHoot
17th March 2011, 13:26
Build it under ocean floor....

Sorry, but that's a ridiculous idea.

There'd be too much sediment in most places. Having to shore up several thousand feet of mud would be hideously expensive and probably technically impossible.

Also, if a meltdown occurred it would seep back up through the mud and contaminate the ocean.

Far cheaper and simpler to drill into watertight basement rock (basalt or granite or something) on dry land.

OwlHoot
17th March 2011, 13:27
Has anyone called Red Adaire? :rolleyes:

or failing him, Red Robbo?

AtW
17th March 2011, 13:30
Sorry, but that's a ridiculous idea.

I did not say "ocean floor" on this planet :smokin

OwlHoot
17th March 2011, 13:43
I did not say "ocean floor" on this planet :smokin

That's an idea - Stick a load of nuclear power stations under Mare Imbrium (http://en.wikipedia.org/wiki/Mare_Imbrium) on the Moon, and beam the energy back to Earth via microwaves.

You'd probably be better off at the lunar poles though, as you could easily arrange a constant supply of "cold" (shielded from the Sun) for cooling. Anywhere else is periodically on the Sun side ("daylight"), and during that time baking hot (http://www.asi.org/adb/m/03/05/average-temperatures.html) at least at the surface.

AtW
17th March 2011, 13:55
That's an idea - Stick a load of nuclear power stations under Mare Imbrium (http://en.wikipedia.org/wiki/Mare_Imbrium) on the Moon, and beam the energy back to Earth via microwaves.

You got it ...

doodab
17th March 2011, 13:59
That's a rather surprisingly benign figure, 10W/kg, with only passive cooling required. I thought some had reportedly caught fire and were becoming a real menace.

I guess when you have several hundred tonnes of it, it's somewhat less benign.

Some interesting reading here. The Future of Nuclear Power: In-Depth Reports (http://www.scientificamerican.com/report.cfm?id=nuclear-future)

Board Game Geek
17th March 2011, 14:03
Has the cost of loading it up in to space-capable dumpsters and blasting them in to the Sun been assessed ?

People will usually say "Ohh, that's going to be expensive", but considering the cost of cleanup operations, and the environmental cost for generations to come, I would have thought that if there was a "Nuclear Waste Disposal Club", funded by all the nations using nuclear power, then surely it would still be more cost-effective to blast it in to the Sun.

With the decreasing costs of space travel, and the economies of scale contributions from all parties to central programme, surely it should be worth a consideration ?

I don't know how many fuel rods are globally used each year, and how much tonnage we are looking at, (10 ? 20 ? 50 ?), but chucking it at the Sun isn't going to bother it much.

suityou01
17th March 2011, 14:08
I guess when you have several hundred tonnes of it, it's somewhat less benign.

Some interesting reading here. The Future of Nuclear Power: In-Depth Reports (http://www.scientificamerican.com/report.cfm?id=nuclear-future)

Surprisingliy patient and diplomatic of you. Are you demob happy or something? :wink

suityou01
17th March 2011, 14:09
Has the cost of loading it up in to space-capable dumpsters and blasting them in to the Sun been assessed ?

People will usually say "Ohh, that's going to be expensive", but considering the cost of cleanup operations, and the environmental cost for generations to come, I would have thought that if there was a "Nuclear Waste Disposal Club", funded by all the nations using nuclear power, then surely it would still be more cost-effective to blast it in to the Sun.

With the decreasing costs of space travel, and the economies of scale contributions from all parties to central programme, surely it should be worth a consideration ?

I don't know how many fuel rods are globally used each year, and how much tonnage we are looking at, (10 ? 20 ? 50 ?), but chucking it at the Sun isn't going to bother it much.

:eek:

What happens if we accidentally litter someone elses patch? We'd have a bunch of angry aliens demanding we pick up our litter. Then where would we be. :rolleyes:

Go to the back of the class. :spank:

:D

AtW
17th March 2011, 14:09
Has the cost of loading it up in to space-capable dumpsters and blasting them in to the Sun been assessed ?

The expensive part there is getting 3rd party insurance until the moment it leaves Earth and sets course to the Sun. I guess it will remain so until Tesco gets into that business.

HTH

doodab
17th March 2011, 14:25
Has the cost of loading it up in to space-capable dumpsters and blasting them in to the Sun been assessed ?

People will usually say "Ohh, that's going to be expensive", but considering the cost of cleanup operations, and the environmental cost for generations to come, I would have thought that if there was a "Nuclear Waste Disposal Club", funded by all the nations using nuclear power, then surely it would still be more cost-effective to blast it in to the Sun.

With the decreasing costs of space travel, and the economies of scale contributions from all parties to central programme, surely it should be worth a consideration ?

I don't know how many fuel rods are globally used each year, and how much tonnage we are looking at, (10 ? 20 ? 50 ?), but chucking it at the Sun isn't going to bother it much.

I think unreliability of launch vehicles is as much of a factor as cost.

You will need to blast thousands of tonnes (and it is thousands, apparently the US alone has over 60,000 tonnes of used fuel rods, and you would need to launch their containers as well) of payload into space, and space launchers just aren't that reliable. The US Delta IV Heavy rocket will lift about 9 tonnes on an escape trajectory, so that's at least 7000 launches, which I doubt is going to happen without a few failures, and those failures will involve tonnes of nuclear waste falling out of the sky in an uncontrolled manner.

The most viable long term solution is to bury the stuff deep deep underground.

Board Game Geek
17th March 2011, 14:37
:eek:

What happens if we accidentally litter someone elses patch? We'd have a bunch of angry aliens demanding we pick up our litter. Then where would we be. :rolleyes:

Go to the back of the class. :spank:

:D

LOL !

Well, I'd like to hope that we can pretty much guarantee to hit the Sun, which is in our solar system and therefore ours.

As for littering someone else's patch, the nearest star is about 4.2ly away, and would take approx 40,000 years at current tech to reach, and there are no planets there.

Going further afield, the nearest extrasolar planet from earth is Epsilon Eridani B and it is about 10.5 light years from Earth. 100,000 years at current tech level to get there is a top end guess.

However... Epsilon Eridani B has not been verified 100% and remains unconfirmed due to the heavy magnetic field associated with that star system (which interferes with radial velocity measurements). If Epsilon Eridani B is not our nearest planetary neighbor, then that honour falls to the 3 planet system detected at Gilese 876 about 15 light years from our planet.

Still, that's assuming we cannot point and fire a rocket in to the biggest thing in the sky.

Board Game Geek
17th March 2011, 14:39
I think unreliability of launch vehicles is as much of a factor as cost.

You will need to blast thousands of tonnes (and it is thousands, apparently the US alone has over 60,000 tonnes of used fuel rods, and you would need to launch their containers as well) of payload into space, and space launchers just aren't that reliable. The US Delta IV Heavy rocket will lift about 9 tonnes on an escape trajectory, so that's at least 7000 launches, which I doubt is going to happen without a few failures, and those failures will involve tonnes of nuclear waste falling out of the sky in an uncontrolled manner.

The most viable long term solution is to bury the stuff deep deep underground.

Cheers for the facts, always good to know !

doodab
17th March 2011, 14:40
Cheers for the facts, always good to know !

That sciam link I posted earlier has a good, but very US centric, article about the "what to do with it" side of things.

suityou01
17th March 2011, 14:41
LOL !

Well, I'd like to hope that we can pretty much guarantee to hit the Sun, which is in our solar system and therefore ours.

As for littering someone else's patch, the nearest star is about 4.2ly away, and would take approx 40,000 years at current tech to reach, and there are no planets there.

Going further afield, the nearest extrasolar planet from earth is Epsilon Eridani B and it is about 10.5 light years from Earth. 100,000 years at current tech level to get there is a top end guess.

However... Epsilon Eridani B has not been verified 100% and remains unconfirmed due to the heavy magnetic field associated with that star system (which interferes with radial velocity measurements). If Epsilon Eridani B is not our nearest planetary neighbor, then that honor falls to the 3 planet system detected at Gilese 876 about 15 light years from our planet.

Still, that's assuming we cannot point and fire a rocket in to the biggest thing in the sky.

I wonder just how much we know of our current tech. I reckon some boffin somewhere has developed some kind of flux capacitor antimatter wormhole hyper drive we know nothing about.
As AtW said if we were exploring other worlds the first thing to go up would be a Tesco Metro though.

TimberWolf
17th March 2011, 14:44
I guess when you have several hundred tonnes of it, it's somewhat less benign.

Some interesting reading here. The Future of Nuclear Power: In-Depth Reports (http://www.scientificamerican.com/report.cfm?id=nuclear-future)

Ah, but check out Thorium as a nuclear fuel (http://en.wikipedia.org/wiki/Thorium#Thorium_as_a_nuclear_fuel) which if memory serves correctly could consume spent fuel rods too. Japan has one or two small Thorium reactors and had proposals for more but I think India lead the way.

EternalOptimist
17th March 2011, 14:45
LOL !

Well, I'd like to hope that we can pretty much guarantee to hit the Sun, which is in our solar system and therefore ours.



You are ignoring the fact that there is a 50/50 chance that the stuff will land at night. So it wont be destroyed and it could be a danger to future manned expeditions



:rolleyes:

suityou01
17th March 2011, 14:47
You are ignoring the fact that there is a 50/50 chance that the stuff will land at night. So it wont be destroyed and it could be a danger to future manned expeditions



:rolleyes:

:laugh

Coffee / keyboard moment of the day (C.K.M.O.T.D.)

TimberWolf
17th March 2011, 15:22
LOL !

Well, I'd like to hope that we can pretty much guarantee to hit the Sun...



Not really. Imagine swinging a ball around on the end of a piece of string and trying to fire something off that ball in order to hit the centre of rotation (you). Or flicking a peanut from the edge of a turning record LP and trying to hit the spindle. Almost guaranteed miss. You've got upwards of 30 km/s of speed to scrub off to fly into the Sun, whereas Solar system escape speed from Earth's orbit is only about 17 km/s.

Check out how long NASA have taken to get a probe to orbit Mercury (the nearest planet to the Sun) with the Messanger (http://en.wikipedia.org/wiki/MESSENGER) probe. Hitting the sun isn't easy.