steam drillers, page-30

I think the questions relating to the radioactivity are a perfect shareholder question. Given the number of times I have seen Adrian Williams describe the technology as 'green nuclear' I suspect they take it most seriously.

For mine, they have the perfect test bed in drilling material from the bottom of the hole, should be many cubic metres of the granite in the aquifer to conduct GCMS analysis on. I'd say it's already done on Hab1 material a long time ago.

Also for the possibility of water chemistry as onepot says, I'd imagine it's being tested in every conceivable way (esp with respect to depositation). My feeling is that the scaling issue is mitigated (but not eliminated) through the water never being exposed to air and hopefully the chemistry reaching an equilibrium (artificially if need be), but time will tell.

In general the ultimate solution to the radiation question is the provision of geiger's at the surface plumbing location, and check for what happens compared to background radiation when the taps are on. Given a non-zero background radiation level up there, any increase and they act on findings of facts to pinpoint the source and go from there. Again my gut feeling is that the statistical probability of a isotope nucleus going into the solution is small, and the subsequent one-off decay event happening anywhere that matters in the flow (i.e. at the surface) is further minute.

But the issue has to be covered. What worries me slightly after seeing our flare up on the topic here, is how it is handled as a PR exercise if someone runs with theories rather than fact in the media. Sure it can be explained and put to bed technically, but public perception is a fickle beast. Calling it 'Green Nuclear' I think is a perfect approach, as it raises the issue upfront and crosses it off... Long term employees can use some of the radioacivity badges not needed if Nuclear power is no longer required in Oz !!