Use of the privilege is not based on the type of proceeding (ie, it applies to more than just criminal cases), but upon the nature of the statement or admission and the exposure that would invite. Precedent has shown self-incrimination is enforceable in non-disciplinary public school "proceedings".
If the students were "coerced" or "compelled" to take a survey that may self-incriminate them, then it could probably be shown the privilege did apply.