Blog - Does nuclear energy contribute to warming? 

Page / - last modified by Jan Rhebergen on 2020/12/27 11:26 

Does nuclear energy contribute to warming? 
last modified by Jan Rhebergen
on 2020/12/27 11:26

Table of Contents

SPOILER: Yes it does,...(like almost any other activity, remember thermodynamics?) but infinitesimally especially compared to other sources. It is rediculously little!
Redundant thermal energy released by nuclear power plants vs. the thermal energy as provided by the sun
This notebook is a first stab at an approximate calculation to get an idea of the magnitude of the redundant thermal energy that is released by nuclear power plants as compared to that which is supplied by the sun through irridiating Earth.
Calculate the incident infra-red solar energy at the surface of Earth.
import math
Earth radius in meters is:
equatorial_radius = 6378e03  
polar_radius = 6357e03
Approximate Earth surface exposed to solar irradiance can be calculated from  $\pi\cdot r^2$. This can be though of as a disc (plane) facing the sun (i.e. perpendicular to the rays) that is illuminated by sunlight.
earth_disc_surface = math.pi * equatorial_radius**2  
print('irradated surface area: ', earth_disc_surface,'m^2')
irradated surface area:  127796483130631.38 m^2
Sunlight's composition at ground level, per square meter, with the sun at the zenith, is about 527 watts of infrared radiation, 445 watts of visible light, and 32 watts of ultraviolet radiation.
https://ag.tennessee.edu/solar/Pages/What%20Is%20Solar%20Energy/Sunlight.aspx
infrared_sol_power = 527
Total solar infrared power available at the surface is thus:
earth_sol_power = earth_disc_surface * infrared_sol_power  
print('Total power: ',earth_sol_power / 1e12, 'Tera Watt' )  
print('Total power: ',earth_sol_power / 1e15, 'Peta Watt')
Total power:  67348.74660984274 Tera Watt  
Total power:  67.34874660984273 Peta Watt
Total energy delivered over a year is thus:
earth_sol_energy = earth_sol_power * 24 * 365  
print('Total energy: ', earth_sol_power * 24 * 365 / 1e18, 'Exa Watt hour' )
Total energy:  589.9750203022223 Exa Watt hour
Calculate the total thermal energy released by all nuclear power plants on Earth
Nuclear energy now provides about 10% of the world's electricity from about 440 power reactors. In 2018 nuclear plants supplied 2563 TWh of electricity.
https://www.world-nuclear.org/information-library/current-and-future-generation/nuclear-power-in-the-world-today.aspx
Nuclear power plants usually have efficiency about 33%. In modern nuclear power plants the overall thermodynamic efficiency is about one-third (33%), so 3000 MWth of thermal power from the fission reaction is needed to generate 1000 MWe of electrical power.
electric_energy = 2563e12  
efficiency = 0.33  
thermal_energy = electric_energy / efficiency  
print('Initial thermal: ', thermal_energy / 1e12, 'Tera Watt hour')
Initial thermal:  7766.666666666666 Tera Watt hour
released_energy = thermal_energy - electric_energy  
print('Released thermal: ', released_energy / 1e12, 'Tera Watt hour')
Released thermal:  5203.666666666666 Tera Watt hour
Ratio of solar infrared energy and heat released by nuclear power plants
ratio = released_energy/earth_sol_energy
The ratio of thermal energy released by all nuclear power plants in the world over the period of a year, to the total delivered thermal energy by the sun over the period of a year is given below.
print(ratio)
8.82014744285448e-06
Jupyter notebook can be found here: https://gitlab.com/JayBeRayBearGun/energy/-/tree/master#
Posted by Jan Rhebergen · Categories: Antinuclearism - debunking · Permalink