Waterlogged: they might have calculated that and made it so that in each of those tubes amount of unobtainium used never crosses critical mass. As for radiation itself, it probably can be used with some smart accessories that convert part of it to UV lighting - imagine that, you don't even have to power LEDs anymore and have rad shine in green slimy light 7*24. And are you that against gills, extra legs and hands you might have grown by using such rad? I sure do miss sometimes not having 3rd hand .