In PyNE, and other projects which have this phenomenon, we have taken a 0) "fix it up as we go" approach.  Anytime someone touches something that is 'bad,'  they update it, and the fix comes along for the ride.  The other reasonable alternatives are 1) stop everything else and fix all instance of the problem now (like what we did for the style guide), and 2) just admit to ourselves and the world that this will never be fixed and will remain bad.  Most other strategies eventually become one of these three.  

In the specific instance of nuclide bounds, I advocate for just admitting this is bad.  Hopefully, one day I'll write a CEP that brings PyNE-like nuclide naming and handling code into cyclus.  I feel that broad issue is best avoided in this PR.