Russia is trying to move northwards to Zaporizhzhia city. Leaving Ukrainian troops roaming freely in the Energodar town would have left their supply lines / fla

Russia is trying to move northwards to Zaporizhzhia city. Leaving Ukrainian troops roaming freely in the Energodar town would have left their supply lines / flanks exposed, so they needed to drive in and clear troops out of the town (which mostly consists of a nuclear power plant). I'm guessing the Ukrainian troops fell back to the nuclear power plant hoping they wouldn't get attacked there.