Japan Hit By Tsunami

[maynard]

i was unaware that there was more then one volcano in japan.

i am aware japan lies on the ring of fire

lol....


anyway yeah, on the news they were saying that it could end up being like the next chernobyl.... not cool.

[Steamer]

I still don't understand what exactly is happening at the power plants. I have a cursory understanding on how they work, but here we have explosions and people aren't exactly freaking out... and these things have been pretty much off since what saturday? Wouldn't they have the control rods balls deep in those reactors within minutes of the quake? Why are they still hot?

The control rods stop the fission reaction. You still have the radioactive decay to cool no matter what. Once fission is stopped this reactor still roughly produces 5%? production from radioactive decay. This reactor is ancient in this day and age.

[acolyte_to_jippity]

The control rods stop the fission reaction. You still have the radioactive decay to cool no matter what. Once fission is stopped this reactor still roughly produces 5%? production from radioactive decay. This reactor is ancient in this day and age.

this

bsically, we don't get electricity from radiation. the way it works is that the fuel undergoes fission, which produces heat. lots, and LOTS of heat. this heat is high enough to cause the metal caseing of the core to spontaneously combust, BUT there are pipes of coolant flowing all through the core. this coolant absorbs the heat, and becomes super hot. the coolant pipes lead out from the core and water (plain water) is exposed to these now super hot pipes. that makes steam, which turns turbines.

the control rods only absorb radioactive particles, so they stop the fission. BUT it's still hot as fuck. a SCRAM (term used for emergency shutdown of a reactor) doesn't cool it immediately, it simply halts the production of radioactive shit. After all, to take something as hot as a reactor core and cool it down in a short time, even a whole day would cause the entire unit to explode (hot suddenly cold = shatter)

tl;dr the news media is blowing this out of proportion. they've been pumping seawater in to maintain core integrity. it's fine

[StarsMine]

FYI
http://online.wsj.com/video/not-anot...WILLIAM+TUCKER

my dad is one of the leading Nuclear scientists in our country and was the. The Director of our nuclear defense policy here for late Bush through early Obama.

and I can tell you that that guy in the video is pretty much spot on to whats going on there. Sure the situation isnt desirable, but those japs know what they are doing

[Curdy]

still more reason to invest in cold fusion

[StarsMine]

as of right now though with modern tech, fission is still safer then most forms of energy we use today.

[Steamer]

After all, to take something as hot as a reactor core and cool it down in a short time, even a whole day would cause the entire unit to explode (hot suddenly cold = shatter)

With new standards core heat & output can be reduced to 90% within ~2 seconds.

^True

[Nemesis]

hey Aco, i always thought a SCRAM would instantly stop a meltdown from happening, is it because what my knowledge is based off of is nuc subs instead of giant reactors? and also, by SCRAMing it with the raw sea water, it'll be totally destroyed, right? as in that is a last ditch effort, once you expose it to sea water you'll never be able to use it again...yes?

[acolyte_to_jippity]

hey Aco, i always thought a SCRAM would instantly stop a meltdown from happening, is it because what my knowledge is based off of is nuc subs instead of giant reactors? and also, by SCRAMing it with the raw sea water, it'll be totally destroyed, right? as in that is a last ditch effort, once you expose it to sea water you'll never be able to use it again...yes?

meltdown does not mean explosion. that's called an explosion. meltdown means just that; the radioactive fuel becomes so hot they actually melt/burn through their containment structure (literally 'melting down') SCRAMing isn't done to reduce heat (though often they'll perform those opperations in conjunction) it's designed to halt the fission taking place. it's done by lowering the control rods into the core in the fastest possible manner. depending on the method of SCRAM used, reactors could be started up easily, or with very much difficulty. the most common SCRAM involves shoving the control rods all the way into the core at one time, halting fission completely. backups for this (and possible primary systems, but i hope not) amount to basically dumping buckets of neutron-absorbing material into the core.

since water (even ion-rich sea-water) doesn't attenuate radiation very well, SCRAMing w/ seawater is not feasible. what they were probably doing, was pumping seawater into the coolant pipes to keep temperatures down while they fixe the main coolant system

[Nemesis]

ah, well thank you. and the whole sea water thing is what i know of from nuc subs. bvasically if there's no other way to stop it from melting down they just open up the reactor to sea water, it fries everything but at least it wont destroy the sub. i assumed it worked the same way here.