Will do. Sorry if I seemed flippant and thanks for your very knowledgeable comments.
Power plants are not refineries that can be changed out as you suggest.
As I'm learning, especially any involved in a partial meltdown or otherwise.
I've actually gotten off track in pursuit of an answer to the question, "is a meltdown with containment breach possible in this particular design". From what I've heard so far, while highly unlikely, it is possible.
“I’ve actually gotten off track in pursuit of an answer to the question, “is a meltdown with containment breach possible in this particular design”. From what I’ve heard so far, while highly unlikely, it is possible.”
Helping to get back on track here....
I’ve been reading about the “core catcher” that is built into the bottom of these plants. It’s pretty rudimentary compared to what is being designed today, but the intent is the same.
In short, directly underneath the reactor is an enormously thick, dense concrete “catch basin” if you will, with some sort of graphite absorbent material in and/or on it, that is still sealed withing the thick metal containment shell. It’s intended to catch all of the molten products from a core melt down, and spread them out so that any nuclear reaction has a chance to subside and over time allow the flattened out mass to cool. The idea is to prevent the melt down products from staying in one big hot mass and spread it out.
There are modern “core catchers” that are being designed for pressurized water reactors that will fit inside the pressure shell, protect it from melting and allow emergency cooling of the mass as it spreads out; essentially preventing the traditional “China Syndrome” where the core supposedly keeps on going to China. These newer catchers are made of very sophisticated ceramic coatings that are designed to survive high heat an severe radiation and several designs are being tested.
In short, what I have learned is that these BWR series reactors were designed with multiple layers of safety in mind, and they recognized very early that a complete loss of water and resultant meltdown could occur in an extreme emergency, just by the nature of the Boiling Water Reactor design. They built the foundations accordingly and planned for the most extreme emergency they could think of by providing multiple layers of protection and many different ways of managing the waste heat.
But it takes days to remove enough heat under these kinds of emergency conditions, and the conditions they are operating under are as extreme as you get. Has anyone heard if relief crews have been able to get to work, or if they were even still alive?? I wonder how long some of the nuclear operators have been onsite without relief.
And remember, the nuclear reaction was halted withing seconds of the beginning of the earthquake. They have been managing the removal of waste heat all along, and the emergencies that have been declared are statutorily required under Japanese Law. If this occurs, you do that immediately, and we evacuate out so far.
They have a process in place, it is being used as far as I can tell, and although the situation is very serious it still appears to be under control. I think the biggest problem with this is poor Japanese emergency communications and a completely hysterical American media in the depths of yet another 24/7 crisis....