dr_mabeuse
seduce the mind
- Joined
- Oct 10, 2002
- Posts
- 11,528
I recently learned a new word: agnotology. Agnotology is false science promulgated or presented in such a way as to discredit hard science. The word comes from studies on the climate "debate" (there is no debate. The earth is getting warmer, make of it what you will), and now we have this fine piece of nuclear engineering agnotology from this doofus.
I hardly need to point out how full of shit this guy is, because events as of Tuesday morning at 10:00 CST have already proven him wrong and misinformed. I worked on reactor safety and design at Argonne National Laboratory as a lowly technician early in my career, and while there've been significant improvements in reactor design since then (we're talking 35 years ago), these reactors are 40 years old, so I'm pretty familiar with them.
The main thing is, a total core meltdown is not the most likely disaster scenario. What this guy fails to mention is that in the Fukushima reactors, spent fuel is stored above the reactor core, and it contains all sorts of really nasty radionuclides other than Cesium and Iodine, and it's cooled by the same system as the core. The explosions we're seeing over there are either hydrogen or steam explosions, and while the containment vessels are designed to provide defense in depth (not, "defense of depth" as he calls it, which just means redundant safety systems), they're not designed to withstand multiple and repeated insults and overpressures. The exterior containment building, in fact, is built with a concrete "cap' that just sits on top of it and is designed to pop off in an explosion so as to direct the force of the blast upwards rather than down or laterally. It's a pop-top good for one use only.
Steam explosions are physical. They're what you get when water turns from a liquid to a gas in a closed vessel due to intense heat. The power of steam is impressive.
Hydrogen explosions are chemical, the result of igniting a mixture of hydrogen and oxygen to create water. They're happening because at a certain temperature, zirconium catalyzes the splitting of water into hydrogen and oxygen. This hydrogen/oxygen mixture that collects in the primary cooling loop of a reactor is extremely explosive and unstable, and has to be vented to the atmosphere (it's not radioactive at all). If it's allowed to build up in one of the containment vessels and there's some ignition source (a spark, some hot steel), then the vessel becomes, in effect, a bomb. (NOT a hydrogen bomb, btw. That's something totally different.) Remember the Hindenburg?
Also, the uranium oxide used as fuel is technically a ceramic, but it's in the form of a fine powder compressed into pellets, so its melting point is hardly relevant. If the tubes rupture either through heat or explosion, you'll get a fine mist of UO2 particles floating down, radioactive as hell.
On top of that, they're pouring sea water on the cores now to try and cool them off. The ultra-purified water they normally use in the primary cooling loop can't become radioactive by exposure to radiation, but sea water contains all sorts of dissolved minerals that can. The sea water's probably pretty much turning into steam as soon as it hits the cores, and boiling off with all these irradiated minerals in it. It's just not good.
This guy's not only an uninformed asshole, he's a dangerous uninformed asshole. An agnotologist. If the only things crippled reactors produced is "short lived" Cesium and iodine then how does he account for what happened at Chernobyl and their estimated 10,000 cancers?
I've always been a proponent of nuclear power. I thought it was safe enough and that most of the problems had been ironed out. How the ultra-cautious Japanese could design these reactor to only withstand a 5.0 quake is hard to understand. And how they could fail to prepare for the tsunamis that invariably follow seaquakes is just incomprehensible. This is a major disaster and probably the end of nuclear as a viable energy source for a long, long time.
I hardly need to point out how full of shit this guy is, because events as of Tuesday morning at 10:00 CST have already proven him wrong and misinformed. I worked on reactor safety and design at Argonne National Laboratory as a lowly technician early in my career, and while there've been significant improvements in reactor design since then (we're talking 35 years ago), these reactors are 40 years old, so I'm pretty familiar with them.
The main thing is, a total core meltdown is not the most likely disaster scenario. What this guy fails to mention is that in the Fukushima reactors, spent fuel is stored above the reactor core, and it contains all sorts of really nasty radionuclides other than Cesium and Iodine, and it's cooled by the same system as the core. The explosions we're seeing over there are either hydrogen or steam explosions, and while the containment vessels are designed to provide defense in depth (not, "defense of depth" as he calls it, which just means redundant safety systems), they're not designed to withstand multiple and repeated insults and overpressures. The exterior containment building, in fact, is built with a concrete "cap' that just sits on top of it and is designed to pop off in an explosion so as to direct the force of the blast upwards rather than down or laterally. It's a pop-top good for one use only.
Steam explosions are physical. They're what you get when water turns from a liquid to a gas in a closed vessel due to intense heat. The power of steam is impressive.
Hydrogen explosions are chemical, the result of igniting a mixture of hydrogen and oxygen to create water. They're happening because at a certain temperature, zirconium catalyzes the splitting of water into hydrogen and oxygen. This hydrogen/oxygen mixture that collects in the primary cooling loop of a reactor is extremely explosive and unstable, and has to be vented to the atmosphere (it's not radioactive at all). If it's allowed to build up in one of the containment vessels and there's some ignition source (a spark, some hot steel), then the vessel becomes, in effect, a bomb. (NOT a hydrogen bomb, btw. That's something totally different.) Remember the Hindenburg?
Also, the uranium oxide used as fuel is technically a ceramic, but it's in the form of a fine powder compressed into pellets, so its melting point is hardly relevant. If the tubes rupture either through heat or explosion, you'll get a fine mist of UO2 particles floating down, radioactive as hell.
On top of that, they're pouring sea water on the cores now to try and cool them off. The ultra-purified water they normally use in the primary cooling loop can't become radioactive by exposure to radiation, but sea water contains all sorts of dissolved minerals that can. The sea water's probably pretty much turning into steam as soon as it hits the cores, and boiling off with all these irradiated minerals in it. It's just not good.
This guy's not only an uninformed asshole, he's a dangerous uninformed asshole. An agnotologist. If the only things crippled reactors produced is "short lived" Cesium and iodine then how does he account for what happened at Chernobyl and their estimated 10,000 cancers?
I've always been a proponent of nuclear power. I thought it was safe enough and that most of the problems had been ironed out. How the ultra-cautious Japanese could design these reactor to only withstand a 5.0 quake is hard to understand. And how they could fail to prepare for the tsunamis that invariably follow seaquakes is just incomprehensible. This is a major disaster and probably the end of nuclear as a viable energy source for a long, long time.
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