RICHMOND, Va. (AP) _ Gov. Bob McDonnell is asking the General Assembly to keep Virginia’s 30-year ban on uranium mining in place while a new multi-agency working group conducts a comprehensive study on the issue.      The governor said Thursday the study group will look further into the specific issues surrounding mining, including on-site issues.      Many expected the ban to be debated in the 2012 session because of an intense lobbying effort by Virginia Uranium Inc., which is seeking to mine a 119-million pound deposit in Pittsylvania County.