Skeptic Ginger
Nasty Woman
- Joined
- Feb 14, 2005
- Messages
- 96,955
The location would not have been as problematic if they had a back up cooling system in place that wasn't wiped out by the damage. There were 3 pump failures, the usual one, the back up diesel generator and the battery operated pump. And I believe how the spent fuel was stored was not ideal either.I have been thinking, and was wondering if someone more knowledgeable could answer a question for me.
On first glance, one of the critical mistakes that seems to be made with this powerplant is to stick it right on the coast in an area that is Tsunami prone (the word itself is Japanese!).
But then it occurred to me; a nuclear powerplant needs water right, as a coolant. Without it, it seems meltdown is pretty much a certainty. Do they pull water from the mains, or do they have an isolated source on site that they just recycle or something?
Seems to me, if they use mains supply, there's a real danger in the event of a large earthquake of that supply being interrupted by damaged water systems. Even if the pipes to that particular plant did not fail, damage elsewhere in the system could drop water pressure to the point that it's unusable.
(I believe loss of water pressure has proved a major problem for firefighting efforts in multiple historic disasters including the Kobe quake, the Christchurch quake, and 9/11).
Wouldn't it therefore make sense to locate a nuclear power station in close vicinity to a large natural source of water, in the event of the unthinkable? Like, I don't know, the sea? And wouldn't the threat of having zero coolant due to water mains failure be worse than having to resort to dumping sea water on the plant because a Tsunami damaged the site?
Does this seem plausible, or have I missed something?
Perhaps this has been posted somewhere:
Fukushima Nuclear Accident – a simple and accurate explanation
For the first hour, the first set of multiple emergency diesel power generators started and provided the electricity that was needed. However, when the tsunami arrived (a very rare and larger than anticipated tsunami) it flooded the diesel generators, causing them to fail.
One of the fundamental tenets of nuclear power plant design is “Defense in Depth.” This approach leads engineers to design a plant that can withstand severe catastrophes, even when several systems fail. A large tsunami that disables all the diesel generators at once is such a scenario, but the tsunami of March 11th was beyond all expectations. To mitigate such an event, engineers designed an extra line of defense by putting everything into the containment structure (see above), that is designed to contain everything inside the structure.
When the diesel generators failed after the tsunami, the reactor operators switched to emergency battery power. The batteries were designed as one of the backup systems to provide power for cooling the core for 8 hours. And they did.
After 8 hours, the batteries ran out,... [snipped a lot of details worth reading]
During this time, mobile generators were transported to the site and some power was restored. However, more water was boiling off and being vented than was being added to the reactor, thus decreasing the cooling ability of the remaining cooling systems.
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