Nuclear Power : A Prudent Answer

Internet is filled with people in either volley trying to persuade the common-er about merits and demerits of nuclear energy at large. Most of these discussion are mainly very ideological and filled with fervour and passion. I will, in this blog try to give you a balanced view in this regard.

Well, if you ask me to answer in one line, for or against. My answer would be for it, but there's more to it. For those who have the patience and time read on...

Nuclear energy in its present form is mainly fission based i.e. a single atomic nucleus is smashed by a neutron into two smaller nuclei. The bombardment of this nucleus with neutron makes it unstable which eventually results in its splitting into fragments also called as fission fragment. Since this process makes the atom split into two, nuclear scientist call it fission reaction. There's another kind of nuclear reaction wherein atomic nucleus are fused together and quite appropriately it's called fusion reaction. Anyway, that's another topic. But most importantly, how does splitting or joining of nucleus generate energy? For answering this answer, you need to go to the celebrity equation prophesied by the celebrity scientist, Dr. A. Einstein.

The equation also known among physicists as "mass energy equivalence", equates the inertial mass and the energy associated with it. Anyway, when atoms are split, there is a mass deficit in the resultant daughter nuclei. It is as if you throw a 100 gram pebble on a 100 kilogram boulder and it got break into 2 pieces. But to your surprise the combined mass of the pieces only amount to 99.1 kilogram (99 kilogram from the bigger boulder and 100 gram from the pebble you threw). What happened to the remaining mass? Yes, it was this mass deficit which get converted to energy.

Oh...I did that again!!!! I am digressing from the orignal topic and wandering off to something else.. Okay so, let's cut short this basics. This mass-defect as nuclear scientist call it, is what causes the enormous energy burst in a nuclear explosion, which if tamed properly powers an entire city for generations.

Okay now let's get to our business. What are the merits of using nuclear energy -

1. The sheer amount of energy generated per unit fuel : Let's do a simple maths, let's say we have a kilogram of natural Uranium, ya the fuel to be used in reactor. But then natural Uranium is mainly U-238, the useless cousin of U-235 which can be used to produce energy. The percentage of U-235 in natural Uranium is 0.7 %. This gives us, 70 grams of U-235. So far so good. Now, a bit of high school chemistry will tell you that there's something called Avagadro's Number which relates the microscopic number of atoms in a sample and macroscopic weight of the sample. In short, 70 grams of U-235 contains, 1.7E23 atom. But wait, we get 200 MeV from a single nuclear fission, so 1.7E23 fissions will give you 5.7 E12 joules of energy! Now, that's quite a quantity that too from a single kilogram of natural uranium. Just for a comparison, this energy is equivalent to a whole train of coal dumped into a coal fired power plant.
2. Volume of waste generated : This argument follows directly from the above point. In a coal fired power plant, one of the main contributor of waste is the fly ash. For producing an equivalent amount of electricity from coal, the volume of fly-ash produced is substantially large, which equates to a larger number of people getting affected due to it. Nuclear power plant works in a much subtle manner. The waste are concentrated and stored in underground silos, away from human settlement.
3. Deaths from producing unit power in a particular power plant: There's one infographics which shows the comparison of human death resulting from generating unit power. The source of this infographic can be found here, these are from WHO studies. The important fact here is that opponents of  nuclear energy doesn't take into consideration the enormous amount of 'other' pollutants which say for instance a coal powered power plant generate like soot and CO₂. Tens of thousands of people die every year because of asthma and other respiratory ailments.
   
   
4.  Reliance on other renewable sources of energy : This has been the trump card for opponents of nuclear power plant. But, if one takes into account the real facts and figures about the efficiency, stability and the throughput of these alternative energy sources, it becomes quite clear that they can't be relied upon especially in such a situation where a large portion of the world population lives in developing regions. Let's discuss alternative energy sources separately.

Alternative Energy Sources (Wind, Geothermal, Solar) 

The main issues with alternative energy is cost, scalability and storage among the rest.

Cost

As I mentioned earlier, a large portion of our population lives in a underprivileged society, many of whom still struggles to get a daily meal. In such a scenario, how can the hefty installation and maintenance charges of a windmill or say a solar panel be justified, when it produces just a few thousands of watts?

Scalability

We are living in an era of Energy consumption, where the development index is measured in terms of megawatts you have consumed. Every year total energy consumption is going upwards. The International Energy Agency expects the increase in demand for new electrical generation to be 450 terawatt-hours per year, which was the average annual increase every year from 1985 to 2011 (1 terawatt = 1 million megawatts). How much solar energy would be needed to meet that demand? Bryce notes,

 "Germany has more installed solar-energy capacity that any other country, with some 25,000 megawatts of installed photovoltaic panels. In 2011, those panels produced 18 terawatt-hours of electricity. Just to keep pace with the growth in global electricity demand, the world would have to install about 25 times as much photovoltaic capacity as Germany’s total installed base, and it would have to do so every year."

Where are we going to put all those panels?
For wind, the problem is even greater. For instance, Bryce notes that by the end of 2011, the U.S. had 47,000 megawatts of installed wind-energy capacity which produced about 120 terawatt-hours of electricity.

"Thus, just to keep pace with the growth in global electricity demand by using wind energy, we would have to install about 3.75 times the current installed wind capacity in the U.S. every year."

Should we carved out that much of land from natural habitat every year? Fossil fuel and nuclear plant generation have a much smaller footprint. Moreover, windmills are known to reduce birds population, thus affecting the fauna and which in effect has an overall effect on biosphere.

Storage

 How does energy produced from say a hydel power plant reach your home? This is does through an elaborate network of transmission cables interconnected with each other to form a transmission grid. This is a key infrastructure in a countries development. When a power plant is connected to a national grid, the power plant has to be synchronized with the grid, which is an elaborate process in itself. Now, in case of a solar or wind power station, which themselves are not a reliable source of energy, be connected to a grid. Even storing this power is not possible when the scales are increased from a few watts to a few mega watts.There's talk organized by TED, which illustrated the problem with alternative energy sources and their storage.



I will conclude this blog by the next video again by TED which is a debate between two learned men, one in favour of nuclear energy and the other against it. This strikingly contrast what happens in my country, where the person opposing nuclear energy almost always knows nothing about it!!  Hope you will enjoy the debate...