"Following up our discussion on the GDY thread, Nightspore, it...

"Following up our discussion on the GDY thread, Nightspore, it is highly unlikely that the heat exchanger GRK is targeting will produce radioactive fluid, despite the geological conditions. I don't know if anyone was wondering about this, as GRK are in an area of know uranium mineralisation. The concentrated deposits are far more likely to occur elsewhere - for example, as roll-front deposits in the overlying sediments. The granite itself does not contain the concentrations necessary for contamination of the geofluid (with the U content of granite being around 10ppm)."

Actually, I suspect Joe Public doesn't realise that the source of geothermal heat is radioactive material; I think most people vaguely think that "it's simply hot down there". I predict that as geothermal power becomes more prominent in the public eye a lot of people will start worrying (unnecessarily) about this. "What if there's an earthquake, and all the radioactive material comes to the surface", etc. It would be wildly ironic if goethermal power proves to be a goer but public prejudice against anything associated with nuclear material stops it from going ahead. And if the coal lobby decides to feed people's fear....