Topic: When is glass not used as glass?

[Anne]

This local to me story (Cumbria) caught my eye tonight: http://news.bbc.co.uk/1/hi/england/cumbria/7147957.stm - I had no idea that nuclear waste was turned into glass. I've been told that it's to lock the radiation in and make it safe to bury - is that really the case? It surely isn't used in commercial glassmaking.

[Paul ADK]

I believe it is called vitrification and is used because glass is so stable, taking many thousands of years to break down.  Here in the states, the eventual plan is to store the resulting material in an underground facility under construction in the southwest. 

[Frank]

I think glass was chosen as it has the reputation for stability and most people readily accept that.  The reality is a little different as glass is likely limited to a stability much shorter than the half-life of the material being stored. The hunt to find a material that will stay stable for the time needed  is towards fusing the waste with more ceramic like material and by mimicking the way that metals bind stabley to stone.