If this is affecting nukes, then it is also affecting coal and gas fired steam plants, the power production cycle in steam plants are a the same, just minor differences to account for differences in steam temperature and pressure. All of them use condensers to cool the LP turbine exhaust steam back to water so it can be pumped forward through the feedwater heaters and then into the boiler or reactor/steam generator.
Back when we started up Comanche Peak Unit 2 in 1993, the first summer we operated at full power with both units, Squaw Creek Lake heated up to 101F at the condenser inlet. The original AE firm designed the lake about 40% too small. Output fell from the nominal 1165 MWe at 95F to 1140 MWe and we were almost at the point of having to derate the units in order to keep condensate temperatures below 140F. The condensate cleanup resins would start to break down at that temperature. Chemistry dept had to keep a close eye on condensate chemistry to ensure that did not happen as some water could be higher than the bulk temperature due to flow streaming. Management was starting to get nervous before the rains came in late August and early September.
When I left Comanche Peak in 1997 and went to work at the Dresden plant in Illinois, I found out Dresden had to derate as much as 200 MWe for days on end in late summer to avoid sending cooling water out to the Illinois river at temperatures over 93F. We eventually put helper cooing towers in that sucked out water from the hot canal, cooled it and dumped it back in the cool canal coming from the cooing lake. Those kept the derates to almost zero until the plant did a 20% power uprate 3 years later.
