EU probe into British Drax Biomass Subsidies

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For some reason Americans tend to Associate parabolic cooling towers with nuke plants. Not sure why.

It goes back to the “cooling tower” Wikipedia answer copied elsewhere on this page. Forgive the details here, but each “detail” matters towards the final answer to your question.
Water on the surface of a hot steel surface (a tube) transfers heat energy by several DIFFERENT boiling conditions: nucleate boiling, film boiling, water-to-water vapor directly, water-to-saturated steam, water-to-superheated steam, etc. Each depends on water flow rate, heat transfer rate, cleanliness of the water and steam, percent of steam present, flow rate of the steam, etc, etc, etc. A coal-fired or gas turbine heat recovery steam generator “doesn’t care” about the heat exchange “method”, it is designed to transfer as much as heat possible as soon as possible at the gas temperatures and water temperatures present at each square cm of the tubes and tubesheets. The penalty for “failure” of a tubesheet or tube is “lost water”, less efficiency, a shutdown to fix the leak, but no catastrophic dangers. No long-term problems. “Only” lost production time, the cost of the repair, and the lost revenue. Not trivial at any time, but recoverable.
The gas turbine heat recovery steam generator or the coal-fired boiler is expensive, but they are direct heat transfer units: a very hot gas on one side of the tube, and the water being heated on the other side of the tube. Just about as simple as you can get in the complicated world of thermodynamics and fluid flow. Boilers, pressure vessels, pipe design, valve design, and weld designs we won’t go into.
A nuke is different. It starts with fuel pellets (ceramic cylinders) sliding (not a perfectly solid fit!) inside a tube that is inside a high-pressure water system. So, the pellet heats up, transfers heat through the ceramic to the gap to the inside wall of the tube, through the tube,, through that boiling heat transfer film to the water outside the tube. See the losses? MUCH HIGHER in a nuke than in a fossil plant. So the high pressure nuclear-grade water starts out at a lower temperature than the high pressure pressure water/steam in a fossil plant. Lower temperature = less efficient!
But! The nuke IS a critical system, and we don’t want nucleate boiling or film boiling at the outside of the fuel tubes because it “might” get too hot at the hottest rod of the hottest fuel bundle of the most poorly toleranced fuel pellet in the entire reactor at the worst point of the entire fuel cycle loading and fuel history.
SO, we prevent ANY nucleate boiling or film boiling at the hottest part of the reactor … which prevent ANY efficient nucleate or film boiling at ANY point of the reactor – even those that are “cooler” at any given time than the hottest part of the hottest fuel rod. Result is the entire reactor on average is running MUCH less efficient (much cooler) than is theoretically possible for the rest of the reactor all of the time.
Again, lower temperatures mean less efficient heat transfer.
So, because of their lower heat transfer efficiency, nuke plants must reject (send to the cooling water and cooling air) MORE heat energy than fossil plants for the SAME output electrical power sent to the power lines.
But it gets even worse than that!
About 2/3 of today’s nuke plants are boiling water reactors (GE designs) and about 1/3 are Westinghouse Pressurized water reactor designs. In the BWR, the “boiled water” is turned into saturated steam and goes to the turbine. BUT! Saturated steam designs are LESS EFFICIENT than the superheated steam designs common (and relatively easy to build) into fossil fueled power plants.
But it is even worse than that!
The other 1/3 of US nuke plants are pressurized water designs by Westinghouse. Those plants have to transfer all of THEIR heat through the reactors tubes to the primary water, transfer that hot primary water out of the reactor to the steam generator, then transfer that heat through the steam generator tubes to the final outside secondary steam water, then to the turbine. Every transfer loses heat heat energy – though every effort possible is made to reduce such losses – so the final Westinghouse “steam” is less efficiently produced than the GE steam. Cleaner, less radioactive, easier and cheaper to maintain, etc, etc. But still less efficiently produced than a comparable fossil-fueled gigawatt of electricity.
Because of their regulations, a nuke plant requires MUCH MORE “support and staff” per plant than a fossil powered plant does FOR THE SAME AMOUNT OF POWER OUT! (More engineers, more QA techs and radcon techs and enviro techs, and more secretaries and copiers and security staff and more tooling technicians and more test engineers, more procedure writers and trainers and evaluators, etc, etc. SO, to get as much out of THAT staff as possible, it makes sense to make the nukes as large as possible, and run them as long as possible (because once built and fueled up, a nuke has very, very low RUNNING costs!) and to combine 2 or 3 nuke plants INSIDE one physical site so they all can share the same fence and security and engineers and secretaries and legal staff and enviro staff.
But!
If you do that “sensible” design and arrangement, you end up with 2 or 3 LARGE nukes inside the same fence, EACH rejecting MORE heat energy to the environment than a comparable fossil-fired plant, because EACH nuke plant is less efficient than its equal-sized fossil plant.
Running a 1 or 2 unit nuke plant in the winter rejects a lot of heat energy to the local water supply (a lake, bay, or river).
Running the same 1 or 2 nuke plants in the summer rejects MORE heat energy into that same local body of water (lake, bay, or river.)
For many years, the local enviro groups INSISTED than nuke plants be limited in how much heat energy could be rejected, citing “environment” concerns almost all of the time. So, to reduce the heat energy sent into the “water” of the local bay or river, the nuke plant designers began rejecting the excess heat energy released into the air (because there were almost no regulations for “heating up air” compared to “heating up the fishies’ water!” that could be measured.
The best, least costly, way to heat up the air is through the hyperbolic cooling towers. So, American nuke plants became associated with hyperbolical cooling towers BECAUSE OF their thermodymanics and envirodynamics.