Cleared some errors concerning the use of Popen
Cleared some errors concerning the use of Popen

mbmcgarry/cyclus,rwcarlsen/cyclus,gidden/cyclus,gidden/cyclus,hodger/cyclus,mbmcgarry/cyclus,mbmcgarry/cyclus,hodger/cyclus,Baaaaam/cyclus,gidden/cyclus,mbmcgarry/cyclus,hodger/cyclus,gidden/cyclus,hodger/cyclus,rwcarlsen/cyclus,rwcarlsen/cyclus,Baaaaam/cyclus,rwcarlsen/cyclus,Baaaaam/cyclus,hodger/cyclus