How does the internal assessement of BTEC units workWatch
This is basically just a check to see if the right grades are being given out fairly and consistently. They will look at a sample of students from your course and compare their predicted grades with the grades they previously got. If one student who got Ps previously was all of a sudden predicted Ds, that would indicate a problem. Same applies if a student who achieved D's previously all of a sudden got predicted Ps.
If a problem in grading is detected, they will either adjust the sample students predictions so they are correct or they will ask the college for everyone's grade and fix all of them. So theoretically, if there is cause to do so then your grade could be changed.
Tbh I wouldn't even worry as this most likey won't happen. Enjoy summer while it lasts!!!