It is due to the re-surfacing of 27L/09R, but nothing to do with FOD.
On departure Concorde doesn't like the ramps that are left between the old and the new surface during the ongoing works and so whilst the work is in progress will always use the northern runway (09L/27R) for departure.
If I remember correctly it can land on the south runway if necessary but would prefer not to if possible.
There's another thread about this somewhere around here....
WF.