After leaving you can't go back, even if you did not convince Pers. Eden to blow hp the base/himself. You can destroy the blast door outside, but it only leads to an empty tunnel. If you need to go back for the energy weapons bobble head, I would suggest re-loading the most recent save before you left RR. In the 'Broken Steel' DLC that is to be released in April you may get to go back as this is billed as the pack in which the BOS wipes out the last remnants of the Enclave in the Capital Wasteland. But that last bit is speculation on my part.