How big of a problem is this if nuclear is going to be an option as global temperatures rise?
Will nuclear be shut down so often in the future that we can't depend on it? Similar to the argument folks make against solar(it doesn't work at night).
Will nuclear be shut down so often in the future that we can't depend on it? Similar to the argument folks make against solar(it doesn't work at night).
Problem was these plants were designed for an amount and kind of heat sink which wasn't there for a while. If it became a frequent problem it would be fixed by building alternative heat sinks that worked in more situations.
Water cooled reactors run at about 300C, molten salt around 700C or "much higher", and some designs for gas cooled reactors go over 1000C. The weather being a few degrees hotter or even tens of degrees hotter isn't really going to matter if your cooling system is designed to handle it.
The minimum temperature gap up there is > 250 degrees, taking a few away isn't going to make anything impossible, but it might make some existing plants increasingly unreliable if there are no investments in new plants or upgrades.
It's absolutely a financial decision, but it wasn't a financial problem. Cooling towers are not free but in the grand scheme of building a nuclear plant they're not expensive either (most power stations — including non-nuclear — have cooling towers).
And "Direct cooling" is not a passive option, you're still pumping water from and to the river or body of water in order to condense steam in the secondary circuit. What you're not doing is semi-closed cycling of that water through a cooling tower, you're feeding the condenser straight from the body of water, and sending water back into it more or less directly (possibly having gone through a radiator of some sort to shed some heat).
The issue here is that the body of water is "intermediate", so it was large enough the designer felt they didn't need cooling tower as inflow would be sufficient in all but extreme case, except the extreme case is becoming the normal.