Trouble With Printable Geometry From Piped Curves

Hello,

I'd like to be able to print this model of the piped voronoi cells, and I'm having trouble creating geometry that is print-ready in terms of creating a clean, trimmed and closed volume. I've tried performing booleans with spheres at the pipe joints to fill the gaps, but that doesn't seem to work very well if at all. I'm also getting duplicate surfaces that I can't figure out how to cull from the data set. 

Thanks!