> So far we don't have /any/ experience with long
> term storage of anything.

But, to agree with you, in case it's not evident :-), 
examination of things that are very old shows how very very 
very hard the battle is.

> Heck, we already /know/ that most things we
> create don't last longer than a few years. How many here 
> have seriously
> (professionally) designed something to last a century? I 
> don't see any
> hands.

Nor I.
BUT I have looked at what it takes, and also looked at aged 
things with the specific aim of seeing what we are up 
against.
Gravestones make interesting indicators of what weather can 
do.
Many newer ones are 'gone" in under 50 years or even much 
under.
At 100 years the best are getting tired.
At 200 years the best are marginal.
At 300-400 years you are stuggling to find anything 
readable.
On 700+ year old buildings inscriptions may not be totally 
gone but are largely so.
On some 2000 year old buildings you can see the inscriptions 
passingly well. That usually tells you something about the 
people in between - not the original designers.

Lest you think that we with our so vastly better technology 
can do oh so vastly better, work out how much larger 
oh-so-vast needs to be to do things well enough.


> ... plenty of precedence that we /won't/ be able to avoid 
> many of the tempting
> shortcuts that may make the difference between stuff going 
> haywire after
> we're dead and going haywire a few generations later.

You set the goalposts far too high.
When people fake welding inspection certificates for valves 
in nuclear power plant cooling systems. And when the systems 
in place, or not in place make it possible to do so, then 
the odds of the barrels all even getting to the repository 
intact are only so so.

> I'm not saying that I know whether one or the other is 
> more dangerous. But
> you say you do, and that what you say is based on facts. I 
> just don't see
> the facts WRT long term.

Long ago people vitirifed nuclear waste in "barrels".
Routine measurements subsequently showed that radiation 
levels at the surface were far higher than they were 
expected to be.
Investigation showed that there were 'bugs' (microbes 
whatever) living in the waste and happily mining it and 
bringing whatever to the surface. And they probably had 
really interesting children to boot!

Murphy spits on your best precautions.
What can go wrong will go wrong.
What can't go wrong will go wrong anyway.

Certainty that we have done enough or can do enough is 
always fatal, for almost all values of always, given enough 
time. And time is something we have more than an average 
amount of in this case.

This is not to say that we may as well all give up trying 
and huddle in the corner inspecting the pattern onm the 
wallpaper. But it should always be kept open as an 
attractive fallback option :-).

An engineer needs to KNOW that for large and complex 
projects it is almost impossible to design the overall 
project and not have it go through a vast number of 
revisions throughout its construction and operating life. 
The trouble here is that for most of the operating life "we" 
won't be around to provide corrective feedback. "But what" 
you may ask "can go wrong with a passive store in a 
geologically sound location far below the ground?". The 
answer is "I don't know and you don't know BUT the answer is 
'we don't know' and not 'nothing'".
Sound alarmist and excessively cautious?
Why not?
It is.

But it also may be right.
And may not in any given case.
Which case is this one :-) ?



        Russell

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