Or even 50,000 Kg

This is an addition to the post by ER titled “shaken, not stirred”

It is my speculation that the amount of 50 Kg of melted UO2 that is mentioned on the web, which I linked to below, is wrong.

The speculation is based on the information that, there are two reactors at Saint-Laurent-des-Eaux.  One has power level of 880 MWe, and the other one is at 915 MWe.

My speculation is based on the assumption that the UO2 melted in the core of the reactor.  If that is correct, then it would have been the whole core that melted, rather than a small portion of it.

Each bundle is roughly 20 kg, and a typical core loading is on the order of 4500-6500 bundles.

20 times the lesser quantity of 4500 = 90,000 Kg.

Some information.

The surface temperature of the sun is approximately 5505°C. (5778 K), uranium dioxide melts at 2865 °C (3140 K)

Questions.

Does 50 kg of uranium dioxide generate 880 MWe?

How much energy does it take to melt 90,000 Kg., of UO2?

More info.

The uranium dioxide powder is first pressed into cylindrical shapes and “fired” to produce fuel pellets. The pellets, about 2 cm long and 1 cm in diameter, are then trucked to a plant where they are placed in 50 cm-long zirconium alloy tubes, and fastened together into 10 cm-diameter fuel bundles.

http://en.wikipedia.org/wiki/Nuclear_fuel

French Nuclear reactors:  http://en.wikipedia.org/wiki/List_of_nuclear_reactors

Nuclear power around the world:

http://en.wikipedia.org/wiki/List_of_nuclear_reactors

Four hundred thousand million watts of power.

http://www.euronuclear.org/info/encyclopedia/n/nuclear-power-plant-world-wide.htm

It takes energy to generate power, and at least two thirds of that generated energy is wasted as heat.

Heat energy.

http://www.sciencelearn.org.nz/Contexts/Fire/Science-Ideas-and-Concepts/Heat-energy

Atomic energy.

http://en.wikipedia.org/wiki/Atomic_energy

From:

http://en.wikipedia.org/wiki/Nuclear_reaction

“The energy released in a nuclear reaction can appear mainly in one of three ways:

kinetic energy of the product particles

emission of very high energy photons, called gamma rays

some energy may remain in the nucleus, as a metastable energy level.”

” This energy is eventually released through nuclear decay.”

“ Generally, the product nucleus has a different atomic number, and thus the configuration of its electron shells is wrong. As the electrons rearrange themselves and drop to lower energy levels, internal transition X-rays (X-rays with precisely defined emission lines) may be emitted.”

 

In other words, the energy content of the nuclear fuel is greater when it is taken out of the reactor than when it was installed.

Meaning that, there is the addition of the nuclear metastable energy (radioactivity) that must also be taken into consideration when calculating the wasted energy that will be converted into heat energy during the reaction decay, according to the “half life” principle of the appropriate elements.

In conclusion:

My estimate is that there will be much more than 1,200,000 million watts of energy being wasted as heat, (from nuclear power plants alone) when the new nuclear power plants are in operation.