QUESTION: What is the efficiency of a nuclear power plant?
ANSWER : the efficiency of a nuclear power plant is of the order of 30%.
EXPLANATION: This means that 70% of the "atomic" energy produced by the fission of uranium 235 is "wasted" as heat in the cooling towers.
For a 2 GW electric power plant with 1,3 reactors, this corresponds to a thermal loss of the order of 6 GW and an atomic power of 8,6 GW.
These 6 GW are "evacuated" in the cooling towers of French power plants, there is one tower per reactor (you can therefore easily know the number of reactors in a plant by counting the number of towers).
The heating needs of a modern house are roughly (smoothed over the year) 60 W per m2. Or for a house of 100 m2, 6 kW.
The thermal energy "lost" from a single 2-reactor power station therefore corresponds to the heating of a million houses!
Assuming (which is not the case but it is for the image) that this energy was recoverable in the form of cogeneration, 14 16 to nuclear reactors would be enough to heat the whole of France without any consumption of heating or electrical or fuel oil or gas!
the number of "cooling towers" not corresponding to the number of reactors, eg the "Bugey" plant
has 4 "PWR 900 MW" reactors; two reactors (bugey 2 and 3) do not have cooling towers and two 900 mw rep reactors (bugey 4 and 5) have two cooling towers per reactor; another example: Tricastin power station, two cooling towers for
4 reactors, therefore, no relationship between the "number of cooling towers / number of reactors".
We should install a dozen small nuclear reactors in the middle of Paris. They would only be started in winter and the heat "lost" (70%) would be sent to the district heating network. As I live in the province, I do not care much about the risk of a nuclear accident in Paris.
You do not know how right you are! Some have seriously thought of the engineer Boris Pregel for example:
https://www.econologie.com/forums/energies-fossiles-nucleaire/le-nucleaire-en-ville-energie-du-futur-boris-pregel-1961-t10675.html
INA video: https://www.ina.fr/video/CAF97017672/boris-pregel-l-utilisation-civile-de-l-energie-nucleaire-video.html
you just killed me with laughter
Where do you think the SMRs will be deployed? Look carefully, it will be near the cities.
Uh there is a difference between energy (kWh) and power (kW) and in the presentation evoking the energy lost by a nuclear power plant and that which could be used by the habitat, there is a sacred mixture!
Many nuclear power plants simply dump the waste heat into a river, lake or ocean instead of having cooling towers. Many other power plants, such as coal-fired plants, also have cooling towers or these large bodies of water. This similarity exists because the process of converting heat into electricity is almost identical between nuclear power plants and coal-fired power plants. The efficiency of a nuclear power station is determined in the same way as for other heat engines, since, technically, the power station is a large heat engine. The amount of electrical energy produced for each unit of thermal energy gives the plant its thermal efficiency, and due to the second law of thermodynamics, there is an upper limit to the efficiency of these plants.
If all thermal power plants, including nuclear, are required, the steam or gas cycle must be kept at the lowest possible temperature. In the case of nuclear power plants where the output is low (30-35%), it is possible to block the steam cycle, using a second cycle using N2, for example, which works from the temperature of the condenser (isothermal or adiabatic expansion), and condensation at 100K. The 100K cycle does not generate useful work, but generates cold, the work that is reinjected into a common place where it is obvious that the thermal energy escapes, it is enough to displace the fluid (hydrogen as gas, is not consumed alone) as a passive agent, no consumption of H2, only the losses caused by the elements that make up the cryogenic system.
I regret to say that my message is not correctly formulated. No blockages and other things. What I am trying to describe is much simpler. A maximum thermal potential at 600ºK generates a cycle with thermal spillage at 320ºK and efficiency of 32%. A closed system is created where a fluid (hydrogen) is enclosed in a hypothetical cylinder of 20 m diameter and 20 m useful stroke. with hydraulic piston (Nitrogen) which, by suction of a pump, causes an isothermal expansion of the Hydrogen (60-30bar) closing the cycle with a work deficit of 40%, that is, the isothermal work is not enough to close. No heat is generated, there is only a mass displacement without compression, to return to the beginning. The work depends on the path, it is not a state property, in the end the internal energy of Hydrogen and the entropy remain constant, the important thing is that the saturated Nitrogen has been condensed at a pressure of 10 bar. This system allows performances higher than 84% in the nuclear power plant cycle