I did this a few times, with a 100 min program. I exported QT Ref or Same As Source, with 709 levels, then used Sorensen Squeeze to encode for BluRay. Make sure that, in the Advanced video settings, you select the option that the source footage is already 16-235. Also make sure that the total file size will end up being under 23GB. I then used Avid DVD to create a Disk Volume, then used Avid DVD to burn this Disk volume.
All in all, this is a pretty time consuming operation, and you will need to spend some time getting it right, I’m afraid.
You could also use Avid DVD straight from the QT Ref and let Avid DVD do the transcoding, but then you need to export at RGB levels, as Avid DVD gives you no control over these levels, and assumes all inputs are 0-255.