Yes I have loads of time to tinker. No kids, no wife, and a brand new shop behind my house. My sister in law jokes that I should rent out my house since I am never in it...
Rain water... I had not thought of that, here in the Pacific NW the stuff just falls from the sky... Like, for free! Actually what I had in mind is using my column still when I get it set up again.
Thanks for the heads up on the feed pump. I will start with a larger bore pump in the first place and see which way I need to go from there. The pump I have in mind will move around 8GPM free flow so I will have to test the pressure output/flow. It has a 2 to 1 air motor on it at the moment but I have a 3 to 1 and a 5 to 1 I can try.
The pump seals I found are graphite filled PTFE rated for:
High chemical resistance
Withstand speeds up to 30 m/s (5 900 ft/min)
Wide operating temperature range, –70 to +250 °C (–95 to +480 °F)
Withstand pressures up to 3,5 MPa (500 psi)
Withstand dry running
They make a range of standard shaft size seals from .25 to 6.00 so a seal already exists for this application. If I end up going with an impeller pump I can make the housing longer to isolate the motor and seal from the impeller and heat. The isolation tube could be made with fins so that any water inside the housing near the seal is much cooler Sorta like Bart's extension tube for the steam regulator, there would be a slug of cool water against the seal. Since the systems safety valve will pop off at 250PSI at around 406degrees F and we typically run lower pressure/temp than that I figured it is a good seal to start with. If I stack a couple seals an inch apart or so I could then install a .25 copper tube between them and run the tube up next to the safety vent tube and get a heads up if the first seal blows.
To bad we don't have some metallic fluid we could easily pump through the burner and use a small coil inside a tube to make steam as needed.
Oh Wait!
Anyone know where I can get some Thorium? 
Has anyone ever built a nuclear powered Steam Launch? 
Cyruscosmo
