Well, if you put it that way, we don't want to demand perfection in defiance of reality. But let's start by figuring out what "reality" is.
Remember, we're talking about a situation that TEPCO claims doesn't exist -- leaking of contaminated waters. But one of the constant features of this story has been unpleasant surprises. That's bound to happen in most disasters, after all a disaster pretty much by definition is a situation you hadn't planned adequately for. But the Fukushima Daiichi catastrophe stands in a class by itself for unpleasant surprises; from day one we have heard one optimistic assessment after another brought low by horrible news. It smacks of management by wishful thinking, starting with the failure of TEPCO to adjust its preparations in response to a revised tsunami risk. During the crisis TEPCO's management was still thinking in terms of salvaging the plant. Fortunately for them they were defined by their own chief engineer onsite, Masao Yoshida, who on his own authority took drastic and irreversible action to cool the reactors.
So if it turns out this problem *does* exist, as researchers from Woods Hole seem to think it does, that shows us that TEPCO's management has still failed to grow enough spine to face unpleasant news. I'm open in this scenario to the possibility that discharging the contaminated water might be the best course of action, but not on TEPCO management's word, because if the problem exists that means their word is no good.
If I were PM, on confirmation this problem exists I'd take the solution out of TEPCO's hands. I'd charter a non-profit authority to direct the securing and cleanup of the plant, funded with TEPCO money.