Before beginning the rough pumping of the Vertex volume this morning I sprayed helium around to North door's periphery and filled test slots to check for any significant outer O-ring leaks.  We have been pumping the annulus volume since yesterday via a turbo mounted locally at the pump port which is backed be the leak detector.  

~1030 hrs. local -> began roughing.  

1700 hrs. local -> Isolated pumps from Vertex volume via closing the Turbo header isolation valve, Safety Valve and 10" gate valve -> We will resume pump down in the morning.