As long as we are not talking about things like Plutonium 238, I think we are still safe.
These droplets will quickly burn as soon as they enter in the atmosphere since Na and K are highly reactive. Both the sodium and potassium will absorb CO2/H20 becoming small crystals of inoffensive carbonates. The most dangerous compound coming from this Na/K coolant might be Argon-39 (released from the radioactive Sodium-24).
Now, Argon-39 has a beta-decay mode, with around 300 years half-life. First, beta-decay is one of the least dangerous types of decay. For example, tritium is much more dangerous than Argon-39 since it has a half-life of only 10 years. But tritium is used everywhere today, in exit signs for example, or other "glow in the dark" toys. You can order this stuff on the Internet today...
There is a delicate balance between the percentage of CO2 in our atmoshpere and the percentage of O2. Both are needed for maintaining life on Earth.
Right now, we are not really in control on maintaining the CO2 under the right limits. If all these coal plants, etc. are generating a log of CO2, then how do you take it from the atomsphere? Right now there is no way to extract the surplus of CO2 and replace it with oxygen. We just have (proposed) theoretical methods until now.
I wouldn't be too much worried... we just need to provide around 10^19 kg of nitrogen (or some inert gas) and 0.3 x 10^19 kg of oxygen.
These are absolutely huge numbers. Even if we take all oxygen from all our water from the Earth this won't be enough to fill out the Mars atmosphere...
BTW, some facts about Martian Atmosphere (from http://nssdc.gsfc.nasa.gov/planetary/factsheet/mar sfact.html) Surface pressure: 6.36 mb at mean radius (variable from 4.0 to 8.7 mb depending on season)
[6.9 mb to 9 mb (Viking 1 Lander site)] Surface density: ~0.020 kg/m3 Scale height: 11.1 km Total mass of atmosphere: ~2.5 x 10^16 kg Average temperature: ~210 K (-63 C) Diurnal temperature range: 184 K to 242 K (-89 to -31 C) (Viking 1 Lander site) Wind speeds: 2-7 m/s (summer), 5-10 m/s (fall), 17-30 m/s (dust storm) (Viking Lander sites) Mean molecular weight: 43.34 g/mole Atmospheric composition (by volume):
Major : Carbon Dioxide (CO2) - 95.32% ; Nitrogen (N2) - 2.7%
Argon (Ar) - 1.6%; Oxygen (O2) - 0.13%; Carbon Monoxide (CO) - 0.08%
Minor (ppm): Water (H2O) - 210; Nitrogen Oxide (NO) - 100; Neon (Ne) - 2.5;
Hydrogen-Deuterium-Oxygen (HDO) - 0.85; Krypton (Kr) - 0.3;
Xenon (Xe) - 0.08
Until now, the mankind was unable to do any sort of "terraforming" of our planet. So I would say that currently we are doing the opposite thing - the percentage of carbon dioxide in our atmosphere is growing every year! Soon, Earth will look like Mars.
When we will proof that we can do any controlled changes at macro scale in our atmosphere, then probably terraforming would be a solution... for our planet first.
If we scroll down below from the article, we get an interesting reply from Mark Russinovich... he is one of the leading authorities in Windows kernel although he has originally had a Unix/Linux background.
Re: What Differentiates Linux from Windows? Posted by: Paul_Murphy 2004-03-11 15:52:44 In reply to: Paul Murphy I just received this email: -- From: "Mark Russinovich" To: Subject: Linux and Windows Date: Thu, 11 Mar 2004 17:30:24 -0600 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Thread-Index: AcQHwNOxdSTMYl4xToudyRPyZYimCg== Hi Rudy (aka Paul Murphy), I read your article (http://www.linuxinsider.com/perl/story/33089.html ) posted today at Linux Insider comparing Windows and Linux from a design philosophy point of view and am writing to tell you that its full of blatant innacuracies, misconceptions and ridiculous postulations on the reasons behind the way Windows is architected. Your descriptions of Windows memory management, process management, and kernel behavior demonstrate almost complete ignorance of the Windows OS. Its exactly this type of irresponsible writing that the Linux community always accuses the Windows community of using to promote FUD. If you're interested in maintaining journalistic integrity for Linux Insider (or your psuedonym of Paul Murphy), reply to this e-mail and I'll provide you point-by-point corrections for you to publish. You can also research the OS yourself by reading the official book on the internals of Windows NT/2000 that I coathored, Inside Windows 2000. -Mark Russinovich ---
"GUID" stands for "Globally Unique IDentifier" and is a technology standard specified by the Open Software Foundation (OSF) to create unique and non-repeating "ID Tags". Such "ID Tags" are generated once then stored, typically in the Windows Registry.
If you're really curious, use the Windows "RegEdit" program to look under this key name: HKEY_CLASSES_ROOT\CLSID and you'll see a billion GUID's (Don't change anything!)
In the past, the use of GUID's has aroused the wrath and concern of privacy advocates the world over, since they are like "serial numbers" which can be used to uniquely identify software users.
lol. This "Conspiracy Site of the Day" looks kinda weird... maybe they should go and learn what a GUID is:-)
You are right - I just double-checked this and the control rods were vertical at the Chernobyl reactors.
Still, other graphite-based reactors like the Hanford ones had two systems of control rods - one for normal operation (horizontal) and another one just for safety.
Reading more about this on the internet, it looks like two separate control rods systems wouldn't help them anyway. The temperatures were so high that the control rods refused to enter in the reactor at some point.
Anyway, thanks for the reference - I'll look for that book.
No. Actually a piece of pure radium metal will emit a faint glow too. This is caused by the air ionization around the metal surface, caused by the emmited alpha particles.
This fenomenon is unrelated with Cherenkov radiation, fluorescence etc.
Not only the problem was using the graphite as a moderator, but also the reactor did not have an additional system of neutron-absorbing control rods. By inserting/retracting the control rods in the main core you could suppress the generated neutrons and ultimately control the speed of the nuclear chain reactions. For example, if you fully insert these rods then the reactor is shut off. If you take them out completely, the reactor will probably overheat.
A safety system for vertical control rods is designed to work even if there are serious failures in the electromechanical part. For example if the electrical motors are not working, this system still works since the rods will just enter in the core by gravitational force.
For example, the US Hanford reactors built in 50's were also graphite-based. They had both horizontal control rods (for normal power control) and also a backup system of vertical control rods (to be used in emergency situations). Fortunately, the safety control rods were never used in an emergency. Even the first man-made nuclear reactor (made at University of Chicago) had a primitive system of vertical safety control rods.
AFAIK, the Cernobyl reactors had only one horizontal set of control rods, and no safety rods.
I give you a more challenging problem: given a language X that doesn't support GOTOs, can you write a preprocessor to create the extended language that supports GOTOs?
Most chemical elements are older than the solar system. The fusion reactions that happen in our Sun will never produce an element heavier than iron (heavier in terms of atomic mass). These heavier elements are produced only in supernova explosions.
So, next time you look at a gold ring, remember that his atoms were "baked" in a supernova, a couple of billion years ago...
>>> The big problem is that the dust is so fine, it'd be very difficult to wipe it off with anything akin to a windshield wiper. You might remove the dust, but the grit would scratch the glass, eventually causing enough opacity that the panels would eventually be rendered useless.
Probably using a vaccum would not damage the glass. Although this approach also adds more complexity...
>>> One thought I had was to gradually apply a charge to the solar panels and then suddenly apply an opposite charge, causing the dust to be repelled from the surface, to be carried away by the Martian winds.
Unfortunately this will not work since the electrical charge is not uniformy applied in only one direction on the surface glass. The small irregularities of the surface will cause a variation in the electrical distribution over time - for example a small peak in the glass might be more positively charged compared with inner of a nearly-located scratch. The same thing happens on some dust particles - due to their free movement in the air, their electrical distribution will end up non-uniform as well. So they will end up attracting as magnets - the small peak will attract particles on their negative-charged part, and the scratch will do the same on positively-charged surfaces. Now, since all these materials are good electrical insulators, the non-uniform distribution will stick on for a long time.
Probably what would help is to use a blower that would wipe off the dust with martian air. The blown air needs to be ionized to prevent more electrostatic charge to add up by just blowing. The ionized air will have a weak electrical conductivity which will tend to "shortcut" the charged areas. Now, since the martian air is mostly CO2 this pre-ionization process shouldn't require too high voltages - the energy consumption would be pretty low...
>>> Get your facts straight, will you? Plutonium-239 will not boil water.
The facts are pretty straight I think. A reasonable quantity of Pu 239 (a little bit over its critical mass which is around 250 grams) will generate enough heat to boil water... Note that Pu-239 is (or at least was) used as the main type of fuel in some types nuclear reactors like the fast-breeder ones.
Not to mention what would happen if someone goes to the supercritical mass domain and puts together, say, couple of Kg of Pu 239. Hard to guess?
Truth is that nuclear reactors are dangerous: 1) They are extremely messy. The spent fuel contains very radioactive elements - check www.hanford.gov to see why the US is spending billions of dollars in a project to get rid of just a couple of thousands of tons of radioactive material. 2) These materials are very dangerous if they reach in the wrong hands. You know what I mean by that. 3) They are very hard to build, operate, and dissasemble. 4) A single operational mistake might have disastrous consequences.
Did I mention that no new nuclear reactors were built in US after the 70's?
>>> Radium is only dangerous if you digest the stuff. And even then it's not guaranteed to kill you. It just increases your risk of cancer.
Really? Simple mental exercise: every human has a average daily intake of 2 picograms of Ra-226. That's OK, since the lethal limit is 8,000 times more than that. Now, you let me know what would happen if you would take (by breathing for example) 0.1 micrograms of Ra-226. Not grams, not miligrams but micrograms. Exercise left to the reader...
>>> The stuff that's really hot only lasts for 10 seconds to 20 years.
Not really. Some facts:
1) Plutonium - Pu 239 has a half-life of 24,000 years. A piece of plutonium feels warm since it actually generates heat by nuclear reactions. A large lump of plutonium generates enough heat to boil water.
2) Radium - a extremely radioactive element. It has a half-life of around 1600 years...
And all this stuff is lethal at extremely low quantities!
Slashdot Mirror
As long as we are not talking about things like Plutonium 238, I think we are still safe.
These droplets will quickly burn as soon as they enter in the atmosphere since Na and K are highly reactive. Both the sodium and potassium will absorb CO2/H20 becoming small crystals of inoffensive carbonates. The most dangerous compound coming from this Na/K coolant might be Argon-39 (released from the radioactive Sodium-24).
Now, Argon-39 has a beta-decay mode, with around 300 years half-life. First, beta-decay is one of the least dangerous types of decay. For example, tritium is much more dangerous than Argon-39 since it has a half-life of only 10 years. But tritium is used everywhere today, in exit signs for example, or other "glow in the dark" toys. You can order this stuff on the Internet today...
And we will all live in the Matrix by then.
This reminds me of the AT&T outages a decade ago...
m l
I presume that everybody here already read Bruce Sterling's piece:
http://www.chriswaltrip.com/sterling/crack1j.ht
That's not what I said...
There is a delicate balance between the percentage of CO2 in our atmoshpere and the percentage of O2. Both are needed for maintaining life on Earth.
Right now, we are not really in control on maintaining the CO2 under the right limits. If all these coal plants, etc. are generating a log of CO2, then how do you take it from the atomsphere? Right now there is no way to extract the surplus of CO2 and replace it with oxygen. We just have (proposed) theoretical methods until now.
I wouldn't be too much worried... we just need to provide around 10^19 kg of nitrogen (or some inert gas) and 0.3 x 10^19 kg of oxygen.
r sfact.html)
These are absolutely huge numbers. Even if we take all oxygen from all our water from the Earth this won't be enough to fill out the Mars atmosphere...
BTW, some facts about Martian Atmosphere (from http://nssdc.gsfc.nasa.gov/planetary/factsheet/ma
Surface pressure: 6.36 mb at mean radius (variable from 4.0 to 8.7 mb depending on season)
[6.9 mb to 9 mb (Viking 1 Lander site)]
Surface density: ~0.020 kg/m3
Scale height: 11.1 km
Total mass of atmosphere: ~2.5 x 10^16 kg
Average temperature: ~210 K (-63 C)
Diurnal temperature range: 184 K to 242 K (-89 to -31 C) (Viking 1 Lander site)
Wind speeds: 2-7 m/s (summer), 5-10 m/s (fall), 17-30 m/s (dust storm) (Viking Lander sites)
Mean molecular weight: 43.34 g/mole
Atmospheric composition (by volume):
Major : Carbon Dioxide (CO2) - 95.32% ; Nitrogen (N2) - 2.7%
Argon (Ar) - 1.6%; Oxygen (O2) - 0.13%; Carbon Monoxide (CO) - 0.08%
Minor (ppm): Water (H2O) - 210; Nitrogen Oxide (NO) - 100; Neon (Ne) - 2.5;
Hydrogen-Deuterium-Oxygen (HDO) - 0.85; Krypton (Kr) - 0.3;
Xenon (Xe) - 0.08
Until now, the mankind was unable to do any sort of "terraforming" of our planet. So I would say that currently we are doing the opposite thing - the percentage of carbon dioxide in our atmosphere is growing every year! Soon, Earth will look like Mars.
When we will proof that we can do any controlled changes at macro scale in our atmosphere, then probably terraforming would be a solution... for our planet first.
If we scroll down below from the article, we get an interesting reply from Mark Russinovich... he is one of the leading authorities in Windows kernel although he has originally had a Unix/Linux background.
l )
Re: What Differentiates Linux from Windows?
Posted by: Paul_Murphy 2004-03-11 15:52:44 In reply to: Paul Murphy
I just received this email:
--
From: "Mark Russinovich"
To:
Subject: Linux and Windows
Date: Thu, 11 Mar 2004 17:30:24 -0600
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165
Thread-Index: AcQHwNOxdSTMYl4xToudyRPyZYimCg==
Hi Rudy (aka Paul Murphy),
I read your article (http://www.linuxinsider.com/perl/story/33089.htm
posted today at Linux Insider comparing Windows and Linux from a design
philosophy point of view and am writing to tell you that its full of blatant
innacuracies, misconceptions and ridiculous postulations on the reasons
behind the way Windows is architected. Your descriptions of Windows memory
management, process management, and kernel behavior demonstrate almost
complete ignorance of the Windows OS.
Its exactly this type of irresponsible writing that the Linux community
always accuses the Windows community of using to promote FUD. If you're
interested in maintaining journalistic integrity for Linux Insider (or your
psuedonym of Paul Murphy), reply to this e-mail and I'll provide you
point-by-point corrections for you to publish. You can also research the OS
yourself by reading the official book on the internals of Windows NT/2000
that I coathored, Inside Windows 2000.
-Mark Russinovich
---
http://www.grc.com/downloaders.htm
:-)
"GUID" stands for "Globally Unique IDentifier" and is a technology standard specified by the Open Software Foundation (OSF) to create unique and non-repeating "ID Tags". Such "ID Tags" are generated once then stored, typically in the Windows Registry.
If you're really curious, use the Windows "RegEdit" program to look under this key name: HKEY_CLASSES_ROOT\CLSID and you'll see a billion GUID's (Don't change anything!)
In the past, the use of GUID's has aroused the wrath and concern of privacy advocates the world over, since they are like "serial numbers" which can be used to uniquely identify software users.
lol. This "Conspiracy Site of the Day" looks kinda weird... maybe they should go and learn what a GUID is
You are right - I just double-checked this and the control rods were vertical at the Chernobyl reactors. Still, other graphite-based reactors like the Hanford ones had two systems of control rods - one for normal operation (horizontal) and another one just for safety. Reading more about this on the internet, it looks like two separate control rods systems wouldn't help them anyway. The temperatures were so high that the control rods refused to enter in the reactor at some point. Anyway, thanks for the reference - I'll look for that book.
No. Actually a piece of pure radium metal will emit a faint glow too. This is caused by the air ionization around the metal surface, caused by the emmited alpha particles.
This fenomenon is unrelated with Cherenkov radiation, fluorescence etc.
Not only the problem was using the graphite as a moderator, but also the reactor did not have an additional system of neutron-absorbing control rods. By inserting/retracting the control rods in the main core you could suppress the generated neutrons and ultimately control the speed of the nuclear chain reactions. For example, if you fully insert these rods then the reactor is shut off. If you take them out completely, the reactor will probably overheat.
A safety system for vertical control rods is designed to work even if there are serious failures in the electromechanical part. For example if the electrical motors are not working, this system still works since the rods will just enter in the core by gravitational force.
For example, the US Hanford reactors built in 50's were also graphite-based. They had both horizontal control rods (for normal power control) and also a backup system of vertical control rods (to be used in emergency situations). Fortunately, the safety control rods were never used in an emergency. Even the first man-made nuclear reactor (made at University of Chicago) had a primitive system of vertical safety control rods.
AFAIK, the Cernobyl reactors had only one horizontal set of control rods, and no safety rods.
One other place with high levels of radiation is Uranium City
m l
http://www.interlog.com/~grlaird/uraniumcity.ht
Sure :-)
I give you a more challenging problem: given a language X that doesn't support GOTOs, can you write a preprocessor to create the extended language that supports GOTOs?
Most chemical elements are older than the solar system. The fusion reactions that happen in our Sun will never produce an element heavier than iron (heavier in terms of atomic mass). These heavier elements are produced only in supernova explosions.
So, next time you look at a gold ring, remember that his atoms were "baked" in a supernova, a couple of billion years ago...
>>> The big problem is that the dust is so fine, it'd be very difficult to wipe it off with anything akin to a windshield wiper. You might remove the dust, but the grit would scratch the glass, eventually causing enough opacity that the panels would eventually be rendered useless.
Probably using a vaccum would not damage the glass. Although this approach also adds more complexity...
>>> One thought I had was to gradually apply a charge to the solar panels and then suddenly apply an opposite charge, causing the dust to be repelled from the surface, to be carried away by the Martian winds.
Unfortunately this will not work since the electrical charge is not uniformy applied in only one direction on the surface glass. The small irregularities of the surface will cause a variation in the electrical distribution over time - for example a small peak in the glass might be more positively charged compared with inner of a nearly-located scratch. The same thing happens on some dust particles - due to their free movement in the air, their electrical distribution will end up non-uniform as well. So they will end up attracting as magnets - the small peak will attract particles on their negative-charged part, and the scratch will do the same on positively-charged surfaces. Now, since all these materials are good electrical insulators, the non-uniform distribution will stick on for a long time.
Probably what would help is to use a blower that would wipe off the dust with martian air. The blown air needs to be ionized to prevent more electrostatic charge to add up by just blowing. The ionized air will have a weak electrical conductivity which will tend to "shortcut" the charged areas. Now, since the martian air is mostly CO2 this pre-ionization process shouldn't require too high voltages - the energy consumption would be pretty low...
>>> Get your facts straight, will you? Plutonium-239 will not boil water.
The facts are pretty straight I think. A reasonable quantity of Pu 239 (a little bit over its critical mass which is around 250 grams) will generate enough heat to boil water... Note that Pu-239 is (or at least was) used as the main type of fuel in some types nuclear reactors like the fast-breeder ones.
Not to mention what would happen if someone goes to the supercritical mass domain and puts together, say, couple of Kg of Pu 239. Hard to guess?
Truth is that nuclear reactors are dangerous:
1) They are extremely messy. The spent fuel contains very radioactive elements - check www.hanford.gov to see why the US is spending billions of dollars in a project to get rid of just a couple of thousands of tons of radioactive material.
2) These materials are very dangerous if they reach in the wrong hands. You know what I mean by that.
3) They are very hard to build, operate, and dissasemble.
4) A single operational mistake might have disastrous consequences.
Did I mention that no new nuclear reactors were built in US after the 70's?
>>> Radium is only dangerous if you digest the stuff. And even then it's not guaranteed to kill you. It just increases your risk of cancer.
Really? Simple mental exercise: every human has a average daily intake of 2 picograms of Ra-226. That's OK, since the lethal limit is 8,000 times more than that. Now, you let me know what would happen if you would take (by breathing for example) 0.1 micrograms of Ra-226. Not grams, not miligrams but micrograms. Exercise left to the reader...
>>> The stuff that's really hot only lasts for 10 seconds to 20 years. Not really. Some facts: 1) Plutonium - Pu 239 has a half-life of 24,000 years. A piece of plutonium feels warm since it actually generates heat by nuclear reactions. A large lump of plutonium generates enough heat to boil water. 2) Radium - a extremely radioactive element. It has a half-life of around 1600 years... And all this stuff is lethal at extremely low quantities!