You can override the permissions. The standard Survey activity has three capabilities,
Download responses mod/survey:download,
Respond to survey mod/survey:participate, and
View responses mod/survey:readresponses
I suggest you override the teacher role for specific papers (or side-wide if necessary) to 'Prevent' or 'Prohibit'. If you set them to 'Prevent' at site level they can be changed at course level, if you set them to 'Prohibit' at site level you cannot.
I hope this helps