First, you need to know WHY the file system gets corrupted.
I might have nothing to do with ECC. It might be a missing Capacitor (Energy storage) plus Diode on the VCC line of the flash. If the power loss is during a write/erase, you will have a lot of instable bits.
So, first check the file system with the "nand" commands of uboot.
Try to find out which type of failure it is.
regards
Wolfgang