But I do have some questions on that subject.
How much energy does it take to evaporate water at the rate of 25,000 gpm?

FIRST off the value you want is POWER not energy- the energy to turn 25,000 gallons of water into steam is the same if you do it in one minute or a million years- the difference between power and energy has been explained to you countless times yet you refuse to learn that simple basic concept- and you wonder why we react with hostility to your nonsense posts.

I will do the math for you: 1 gallon is 3.785 Litres, this is 3.785 kg of water. 25,000 gallons of water is then the mass of the water: Mwater=9.464*104 kg of water. To calculate the energy needed to boil this amount of water into vapor you need the heat capacity of liquid water

(CWater=4.18*103J/(Kg*Kelvin),

and the latent heat of vaporization to turn water at 100 degrees celcius into steam

(LV=2.26*106 J/kg)

Lets say the water starts out at a temperature of 20 degrees Celcius, the energy to heat it to 100 degrees (a temperature difference of 80 degrees) Celcius will be:

Q1=DeltaT*CWater*Mwater=80*4.18*103 *9.464*104 Joules= 3.16*1010 Joules.

The energy to then turn the water to steam is

Q2=LV*M=(2.26*106) * (9.464*104) Joules= 2.14*1011 J.

Thus the Energy to turn 25,000 gallons of water into steam is:

Etotal=Q1 * Q2= 2.46*1011 Joules..

If this energy is to be delivered in one minute then the Power must be

P=Etotal / 60 seconds= 4.1*109 Watts= 4,100 MegaWatts

You then wrote:

Now suppose that it is correct that one 2436 MWt reactor will raise the temperature of the lake Ontario’s surface by 3 degrees.

You can suppose whatever nonsense you want, it doesnt make it remotely true- The sun gives lake ontario roughly PSun=1.5*103 Watts per square meter during the day- the surface of lake Ontario is roughly 1.85*1010 square meters, this means the sunlight hitting lake Ontario is about 2.8*1013 Watts - roughly 10 thousand times greater than the 2436 MW you assume. But that 2436 MW are NOT dumped into lake ontario, its spread out into the vastly larger sink of the entire Earth!!!!

Lets take the 4,100 MW value that I calculated above, lets say ALL of that 4,100 MW goes into heating lake Ontario, lets assume lake ontario is a closed system and that all the energy put into it at a rate of 4,100 Joules per second stays in the water and is not re-radiated, or dispersed into the oceans, or the atmosphere or the earth itself (VERY unrealistic). Lets do that for a year- how much will the temperature of lake Ontario be raised?

The volume of lake ontario is:

VOntario=1.64*103km3=1.64*1018cm3 -

since one cubic centimeter of water has a mass of 1 gram, this means that the mass of water in lake ontario is:

MOntario= 1.64*1015 kg

So if energy is delivered at a rate of 4100 Joules per second into this mass of water, how much will the temperature be raised after an entire year?

Well, 4100 MW delivered over a year is

EOntario=4.1*109(Joules/sec)*3.15*107 sec= 1.29*1017 Joules.

EOntario=DeltaTOntario*CWater*MOntario

Plug in the numbers and solve for DeltaTOntario and you get a temperature rise of .019 degrees....

But in reality that steam is dumped into the atmosphere of the Earth, the mass of the atmosphere is roughly

MAtmosphere=5*1018 kg. The heat capacity of dry air is roughly

CAir= 1*103 J/(kg.K)

So, If the energy EOntario is deposited in the atmosphere how much does the temperature of the atmosphere increase?

EOntario=DeltaTAtmosphere*CAir*MAtmosphere

Solve for DeltaTAtmosphere and you get a temperature increase of .000026 degrees...

BUT ITS EVEN LESS THAN THAT! In reality the energy is deposited in the atmosphere AND oceans of the earth and some is re-radiated into space....

IF you consider that energy spread out into the oceans of the world (neglecting the radiated losses).... The mass of the worlds oceans is roughly 1.4*1021kg, that 4100 MegaWatts pumped into the worlds oceans for a year gives us:

EOntario=DeltaTOceans*CWater*MOceans

solve for DeltaTOceans and you get an increase of about .000000022 degrees...

BUT ITS EVEN MUCH LESS THAN THAT! In reality the energy is deposited in the atmosphere AND oceans of the earth AND the earth itself and some is re-radiated into space....

There are the numbers for you- THIS is why we say you are wrong, this is why we say you have no sense of scale, this is why we call your claims garbage, this is why we are so damn tired of you spouting this nonsense over and over!

Spew it somewhere else!