So you guys are sending students solo without briefing them on where they are to go in the event of the runway becoming blocked/airfield closed?
My Deputy CFI once had a student on second solo have to divert because the runway was closed. Three times this year I have seen the runway at my airfield closed for over an hour due to various incidents.
All our students are to briefed on a suitable diversion in the event of the above happening. They are to carry a copy of the airfield plate for the diversion airfield from either the VFR flight guide/Pooley's and the Instructor is to make sure the VOR that is located "on aerodrome" at the diversion airfield we use is tuned and the OBS set to the radial inbound the links the two airfields.
My airfield handles everything from 150's to 757's. Occasionally one has to orbit or extend downwind. It makes sense to ensure students are familiar with doing so and what to do if they feel unhappy about doing it.
I will apologise to my students who have reached the solo stage and who are familiar with what to do if they have to divert and have an engine failure. It was unnecessary for me to have taught them what to do.