[gabrielblack]

Having a counter, I think it's easy to found some source around, for example in surplus stores, etc. For example, old naval compass and clock are treated with tritium. You could find also rocks near the rivers with some interesting material.

[sixothree]

My goal is to ensure I _don't_ have an interesting material near my dwelling. Considering I know of at least one case where some was discovered near a home and was probably there for 40 years.