Into Eternity (how to explain the danger of a nuclear waste site to anyone around 100,000 years from now)

Into Eternity is a 1hr 15min documentary from 2010 looking at the Onkalo spent nuclear fuel repository. The plan is to safely store nuclear waste underground for 100,000 years.

In part, the documentary is a letter to the long future:

My civilisation depends on energy as no civilisation before us. Energy is the main currency for us. Is it the same for you? Does your way of life also depend on unlimited energy? 

I re-watched it recently as some of the ideas in the documentary popped back into my head.  If you want to avoid spoilers, go find it and watch it now.

https://youtu.be/lBqyb3qfHCE

The plan is to fill the site with the waste from Finland, and after 100 years seal the site.

Two ideas in particular have suck with me. The first is the point that you need the facility to run unmaintained, unmonitored for a very long time:

A very important factor for us is that the repository is self-contained. You shouldn’t have to guard it in the future. It should just be able to be left. And that’s a necessarily because conditions on the ground will change.  Conditions down in the rock will be stable, and won’t change. But on the surface you never know what will happen. There could be wars, there could be an economic recession […] it’s the most stable environment we know of.

— Berit Lundqvist, Science Editor, Nuclear Fuel and Waste Management, Sweden. 

There is a debate between leaving a “marker” (or warning) vs. trying to deliberately forget the site. Anyone finding the site might interpret it as a treasure of some kind. This would be bad for them, to follow curiosity, to open the site. 

If you did leave a marker, what would you say?

This is not an important place. It is a place of danger. Stay away from the site, and don’t disturb the site.

— Narrator 

The problem is how to communicate to 100,000 years in the future. Languages change.  I was thinking 100,000 years isn’t so long compared to the age of the planet. But you have to think in human terms. It’d be like us trying to communicate with Neanderthals.

I had to draw a diagram to put it in context. Each dot is 2,000 years. Everything since the fall of the Roman empire until today is in that first dot:

Another 100 years? Sure, I think we can do that. The first row of dot? Now I’m not so sure. And after 49 dots, I really don’t fancy the chances of anything written today being easily read.

The documentary talks about simple signs, or trying to give a sense of “this is something that is wrong, not inviting”. History tells us archeologists will ignore these warnings. (I’ve since learned there’s such as thing as nuclear semiotics.)

So maybe it’s better to forget the site, as leaving markers creates more risk of intrusion. Perhaps the site will pass into legend, as stories told to children. Keep away. This is not safe. “To remember forever, to forget.”

As I understand it, Finish law will require a description of the site (in Finish) to be recorded.  Future generations will need to decide if they want to keep porting those details into new languages and norms.