If your spouse is a non-resident alien, does not have a tax number, and you are filing MFS, then you don't have to enter a tax or SSN number for your spouse. However, you can't e-file without a tax number. So, you need to print your return and file by mail, and write "NRA" in the space for the tax number.
If turbotax won't let you print without a tax number, you can use a fake number 999-88-9999, then white it out and write "NRA" before you file.