"Robert Green" wrote:

"dpb" wrote in message
...
On 3/15/2011 11:21 PM, Molly Brown wrote:

This is all about money. Reactors *could* be built to withstand tsunamis
AND earthquakes but no one would be able to afford them. It's only after
disasters that business and governments are willing to spend money on
additional protections against theoretically rare events.

I think the real problem here was believing the tsunami barriers would work.
It turns out they had multiple modes of failure. We do learn an awful lot
with each near meltdown. From what I've been reading, designs subsequent to
the GE MK1 have incorporated a lot of improvements, much of it learned from
failures at TMI and Chernobyl. This accident will probably cause regulators
to up the requirements for cooling system survivability, armoring them up
perhaps as much as the reactor containment vessels. In all the designs I've
seen posted on the net, the cooling systems seem to be a pretty serious
Achilles' heel.

Just a little clarification needed: I thought the best way to protect
any structure from earthquake damage was to "float" it. That is the
ground may move significantly side-to-side and up-and-down but as long
as the components of the building remained in the same relative
position there would be no catastrophic damage. The same principle
protects against other disasters such as hurricanes. Of course I'm
basing this on building code requirements for residential housing and
things may be more complex for very heavy and large structures such as
nuclear plants. Although enormous office buildings don't seem to come
crumbling down.

For tsunami's I presume the protection was some sort of physical
barrier between it and the sea although none of the reports I've seen
seem to talk about this. Why do reactors have to be built right next
to the ocean or river? Presumably they don't actually pump out
potentially contaminated water into the ocean/river but instead use it
as a giant heat sink. It would doubtless cost more if the reactor were
built on a bluff or even an artificial mountain/hill to elevate it 100
meters or so above sea level but in many parts of the country there
are plenty of areas where this could be done. Doubtless the pumping
would be more expensive but I'm unconvinced it would be prohibitive.

Same goes with the people. Based on the videos all the areas where the
tsunami wreaked havoc were on a large near-sea-level plain where
people would have had to run or drive miles to any sort of safety.
Just a requirement to dot hills around the place would seem to be life
saving for many.

Just a thought...