There's no way to tell if this action alone caused the prompt criticality reaction that ended up destroying the core complex
Reports that I've read indicate that the scram rods were the most likely trigger of the accident. As you pointed out, the RBMK had a positive void coefficient, initial insertion of the scram rods caused the power to increase, which then caused more water to boil, which then led to even more voids and inceases in power. Now couple that with the event occurring at the end of core life, the reactor was primarily burning 239Pu with a much lower delayed neutron fraction than 235U, so it didn't take much to exceed the prompt critical threshold.
A point about SCRAM on the RBMK - the initial insertion of the SCRAM caused an increase in reactivity - a very bad thing when the reactor had a positive void coefficient and a low delayed neutron fraction at the end of core life.
Not sure if it still around, but there was an outfit that sold EMF proof clothing, which included items such as underwear with copper mesh sewn in. A co-worker ran across the site as it was a god source for coper mesh.
The road signs cause their own special problems. When you read a planning document for a section of road, you see lines like "A 4.8km stretch of 30mph limit" and so on. Crazy.
No crazier than a say 250mm wide tire on a 15 inch rim...
Prolly the most bizzarro mixture of English/SI units is the definition of HO scale - 3.5mm per foot.
A small part of the asteroid might vaporize and likely there will be cracks and dislodged chunks. They will, however, merrily continue straight on their Earthbound route of doom.
A moderately large nuke (say 10MT) placed inside a 1 km diameter asteroid will most assuredly blow it into small pieces - just watch the film of the test of the Spartan missile warhead done in Alaska ca 1970 - or watch the film of the Sedan test (100kT). The detonation only needs to occur a few hours before impact to prevent the majority of the material from hitting earth.
Given a few months warning, all you need is a good shove - and that can be done by a close in detonation vaporizing the nearby surface.
Best method of execution would be to have them lie face down, tie their legs together, jab a canula in the base of their skull and vacuum their brains out.
Gun type on the other hand, are easy. Just slam two hemispheres of Uranium together hard enough and BOOM. With that kind of ease of use, why would any non-superpower bother with implosion devices? (For the record, gun-types were retired by the military due to safety concerns. If anything accidentally sets off the explosive trigger... BOOM! Whereas implosion devices can be designed to fizzle if accidentally detonated before arming.)
A couple of corrections on gun type weapons.
One is that the Little Boy bomb shot a cylindrical slug through a hollow cylinder of U-235 - much less weight to accelerate than half a hemisphere - also a better match for the gun barrel (and it was a gun barrel).
The second is that gun type weapons are incredibly inefficient in use of fissile material - critical mass for a spherical assembly of U-235 is 52 kg which would yield 1 MT if completely fissioned (a good implosion device may be good for fissioning 25% of the fissile inventory). The Little Boy's yield was about 12 kT, implying that maybe 1% of the U-235 fissioned.
The crime isn't that he lied. The crime was that he lied when he took the oath of office to uphold the constitution. I know a lot of people don't care about civil liberties and regard the constitution as just a piece of paper that sometimes gets in the way of their goals. I don't. Its sacred to me as much as anything could be; I know that is silly, but I don't care.
Compared to Woodrow Wilson, Bush is a piker when it comes to violating the constitution and getting involved in wars with unbelievably bad repercussions.
All I can say is that you're confused about what happened at Chernobyl. The design flaw with the scram rods was (ahem) critical to the accident - had the scram rods not had the initial boost to the reactivity, the accident would likely have never happened. The point is that the kick in reactivity caused the power to increase, which then caused increased nucleate boiling (increased voids) which caused a further increase in power (remember that most of the moderation was in the graphite). The next key point is that the reactivity increased until the reactor was critical on prompt neutrons alone - that's when all hell broke loose. Te only American prompt critical reactor accident was SL-1 in 1962.
With standard PWR's and BWR's, the coolant is the moderator and any increase in voids will reduce reactivity. This would be especially true for the AP-1000 at the beginning of core life.
As for containment, I have heard no plans to reduce containment to the levels of the RBMK-1000's - at least in the US. Containment design prior to TMI was predicated on an radio-iodine release several orders of magnitude higher than is likely to happen from a loss of coolant accident.
So if a reactor is built in the US to today's abbreviated containment standards, yes, that reactor would include a failure mode similar to what occurred at Chernobyl.
The failure mode at Chernobyl was very specific to the design of the RBMK-1000 and to it being near the end of the core life. The problems at Chernobyl were that it had a positive coolant void coefficient, the reactor was burning Plutonium (delayed neutron fraction of 0.2% versus 0.65% for 235U), the graphite moderator was not thermally coupled to the fuel or coolant, and last but not least, the scram rods increased reactivity at their initial portion of travel - the Chernobyl accident was triggered by an operator scram'ing the reactor.
American light water reactors were design explicitly to have a negative coolant void and temperature coefficient.
OTOH I'm sure I've read statements by proponents of wind power stating that on a grid as large as the UK's (and the UK's not that big), drops in wind in one part of the country would almost always be compensated for by other parts of the country.
And I've seen references stating that the UK experiences a few days per year of calm over the whole territory. What's worse is that these days of calm occur during the winter.
Only problem is that the conversion efficiency for thermal energy storage really sucks - assuming that the initial energy is electricity. Does make more sense for solar thermal power plants.
Hmm, probably still better than pumped storage and less problems with siting. It would be interesting to find out where the energy is lost in the charge/discharge cycle.
Probably more effective to line the coast with RO desal plants - use the generated water to cover all of coastal Calif with high transpiration plants - resulting humidity drenches everything west of the continental divide.
In that case, it would probably be cheaper trucking the water from the nearest fresh water source than using one of these units. IIRC, the Cerro Gordo resort "up the hill" from Keeler, Calif gets their water by truck.
The theoretical limit for reverse osmosis from sea water is something like 830 watt-hours per cubic meter. Commercially available systems are close to 2,000 watt-hours per cubic meter or 2 watt-hours per liter.
The summary kind of implied that the material would be used to replace lead-tin solder - but with the ferrite it would not be something you want in the bore of an MRI machine.
Sun is getting out of low-end SPARC systems as well--the official announcement will probably be within a year.
Sun quietly stopped selling Sparc workstations a few months ago. Not too unexpected as they dropped the US-IIIi+ and the Niagara based systems have lame single thread performance. On the other hand, the latest 4 core Sparc64 in the M3000 system would make for a nice workstation processor.
Bit of a pity as dealing with OBP is a lot nicer than most of the BIOS's on PeeCee's.
Wonder if Disney thinks the community of Tarzana infringes on their trademark???
I really think the penalty for trademark abuse is loss of all IP rights.
Re:A site geared towards Linux user, to learn Open
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OpenBSD 4.4 Released
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Lucky for you, less is more and pdksh isn't a bad shell (not everyone loves bash..). In the BSD realm it's extremely easy to add a package or even compile it from scratch via ports, so even vim is within your reach! If you don't like messing with defaults, might I suggest that neither openbsd nor linux are for you?
Reminds of the saying: "Linux is for those who hate Windows, BSD's are those who love UNIX".
Solaris is also heavily criticized by the Linux crowd for not mindlessly following the GNU "standards" - OTOH Sun has done a much better job with backwards compatibility than Linux.
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There's no way to tell if this action alone caused the prompt criticality reaction that ended up destroying the core complex
Reports that I've read indicate that the scram rods were the most likely trigger of the accident. As you pointed out, the RBMK had a positive void coefficient, initial insertion of the scram rods caused the power to increase, which then caused more water to boil, which then led to even more voids and inceases in power. Now couple that with the event occurring at the end of core life, the reactor was primarily burning 239Pu with a much lower delayed neutron fraction than 235U, so it didn't take much to exceed the prompt critical threshold.
A point about SCRAM on the RBMK - the initial insertion of the SCRAM caused an increase in reactivity - a very bad thing when the reactor had a positive void coefficient and a low delayed neutron fraction at the end of core life.
Not sure if it still around, but there was an outfit that sold EMF proof clothing, which included items such as underwear with copper mesh sewn in. A co-worker ran across the site as it was a god source for coper mesh.
QDOS was a clone in pretty much the sense that Linux is a clone of UNIX - the API's were copied, but the underlying code is different.
SCOPE was a bootleg project that got started because of the delays in SIPROS ASCENT.
The road signs cause their own special problems. When you read a planning document for a section of road, you see lines like "A 4.8km stretch of 30mph limit" and so on. Crazy.
No crazier than a say 250mm wide tire on a 15 inch rim...
Prolly the most bizzarro mixture of English/SI units is the definition of HO scale - 3.5mm per foot.
A small part of the asteroid might vaporize and likely there will be cracks and dislodged chunks. They will, however, merrily continue straight on their Earthbound route of doom.
A moderately large nuke (say 10MT) placed inside a 1 km diameter asteroid will most assuredly blow it into small pieces - just watch the film of the test of the Spartan missile warhead done in Alaska ca 1970 - or watch the film of the Sedan test (100kT). The detonation only needs to occur a few hours before impact to prevent the majority of the material from hitting earth.
Given a few months warning, all you need is a good shove - and that can be done by a close in detonation vaporizing the nearby surface.
Best method of execution would be to have them lie face down, tie their legs together, jab a canula in the base of their skull and vacuum their brains out.
Gun type on the other hand, are easy. Just slam two hemispheres of Uranium together hard enough and BOOM. With that kind of ease of use, why would any non-superpower bother with implosion devices? (For the record, gun-types were retired by the military due to safety concerns. If anything accidentally sets off the explosive trigger... BOOM! Whereas implosion devices can be designed to fizzle if accidentally detonated before arming.)
A couple of corrections on gun type weapons.
One is that the Little Boy bomb shot a cylindrical slug through a hollow cylinder of U-235 - much less weight to accelerate than half a hemisphere - also a better match for the gun barrel (and it was a gun barrel).
The second is that gun type weapons are incredibly inefficient in use of fissile material - critical mass for a spherical assembly of U-235 is 52 kg which would yield 1 MT if completely fissioned (a good implosion device may be good for fissioning 25% of the fissile inventory). The Little Boy's yield was about 12 kT, implying that maybe 1% of the U-235 fissioned.
The crime isn't that he lied. The crime was that he lied when he took the oath of office to uphold the constitution. I know a lot of people don't care about civil liberties and regard the constitution as just a piece of paper that sometimes gets in the way of their goals. I don't. Its sacred to me as much as anything could be; I know that is silly, but I don't care.
Compared to Woodrow Wilson, Bush is a piker when it comes to violating the constitution and getting involved in wars with unbelievably bad repercussions.
I liked Unix Review in its early years, where each issue had a topic that was covered by several articles.
With standard PWR's and BWR's, the coolant is the moderator and any increase in voids will reduce reactivity. This would be especially true for the AP-1000 at the beginning of core life.
As for containment, I have heard no plans to reduce containment to the levels of the RBMK-1000's - at least in the US. Containment design prior to TMI was predicated on an radio-iodine release several orders of magnitude higher than is likely to happen from a loss of coolant accident.
So if a reactor is built in the US to today's abbreviated containment standards, yes, that reactor would include a failure mode similar to what occurred at Chernobyl.
The failure mode at Chernobyl was very specific to the design of the RBMK-1000 and to it being near the end of the core life. The problems at Chernobyl were that it had a positive coolant void coefficient, the reactor was burning Plutonium (delayed neutron fraction of 0.2% versus 0.65% for 235U), the graphite moderator was not thermally coupled to the fuel or coolant, and last but not least, the scram rods increased reactivity at their initial portion of travel - the Chernobyl accident was triggered by an operator scram'ing the reactor.
American light water reactors were design explicitly to have a negative coolant void and temperature coefficient.
FWIW, I do have a degree in nuclear engineering.
OTOH I'm sure I've read statements by proponents of wind power stating that on a grid as large as the UK's (and the UK's not that big), drops in wind in one part of the country would almost always be compensated for by other parts of the country.
And I've seen references stating that the UK experiences a few days per year of calm over the whole territory. What's worse is that these days of calm occur during the winter.
Only problem is that the conversion efficiency for thermal energy storage really sucks - assuming that the initial energy is electricity. Does make more sense for solar thermal power plants.
Hmm, probably still better than pumped storage and less problems with siting. It would be interesting to find out where the energy is lost in the charge/discharge cycle.
The wikipedia article on sodium sulfur batteries claims that they are about 90% efficient - which is noticeably better than pumped storage.
Probably more effective to line the coast with RO desal plants - use the generated water to cover all of coastal Calif with high transpiration plants - resulting humidity drenches everything west of the continental divide.
In that case, it would probably be cheaper trucking the water from the nearest fresh water source than using one of these units. IIRC, the Cerro Gordo resort "up the hill" from Keeler, Calif gets their water by truck.
Still pretty small compared to the amount of energy needed to get the same amount of water from dehumidification.
IOW, your comment is an understatement.
Thanks for the clarification.
Sun is getting out of low-end SPARC systems as well--the official announcement will probably be within a year.
Sun quietly stopped selling Sparc workstations a few months ago. Not too unexpected as they dropped the US-IIIi+ and the Niagara based systems have lame single thread performance. On the other hand, the latest 4 core Sparc64 in the M3000 system would make for a nice workstation processor.
Bit of a pity as dealing with OBP is a lot nicer than most of the BIOS's on PeeCee's.
I really think the penalty for trademark abuse is loss of all IP rights.
Lucky for you, less is more and pdksh isn't a bad shell (not everyone loves bash..). In the BSD realm it's extremely easy to add a package or even compile it from scratch via ports, so even vim is within your reach! If you don't like messing with defaults, might I suggest that neither openbsd nor linux are for you?
Reminds of the saying: "Linux is for those who hate Windows, BSD's are those who love UNIX".
Solaris is also heavily criticized by the Linux crowd for not mindlessly following the GNU "standards" - OTOH Sun has done a much better job with backwards compatibility than Linux.