pyne/pyne — pull request #526 by scopatz (2014-09-05 10:47:08+00:00)
Title: update for spontaneous fission for branch_ratio()

This is a corollary to #523 for spontaneous fission in the branch ratio function. Again for @katyhuff or @gidden since this is for cyclus or @crbates since it is a pretty hefty refactor of one of his functions.

**Bounty** - 2