since this chance is checked before your city comes technically comes out of disorder.
hmm, interesting.... But we are talking about a 3% chance, and even then, a good player will only have disorders happen if an other civ causes unhappiness on his turn (by causing WW, or by breaking a trade for a lux resource, and even the WW can be controlled by a good player, so that only leaves breaking the trade route)
but again, by the time you can build a nuke plant, this will rarely happen.
Also, the damage might be a annoying, but its still almost nothing. You should have enough workers at hand by then, and everything railed, to fix it in 3 turns turn. (1 turn to move on the them on the unroaded tiles, 1 turn to road/rr/iri/mine, and 1 turn to clean.
If you really fear a meltdown, and you enough cash, you could indeed opt to sell the plant when a disorder happens, then rush-buy a new one the next turn. All you lose is a bit of production for one turn, and you have to restart the unit you where building.
But if you where building a wonder, restarting it might not be a good idea, you may be be better of then, to do the cleaning process described above.