FAQ about Nuclear Power

I am reproducing here an FAQ about nuclear power that I had written two years ago for Kannabiran and which was probably translated into Telugu.

Frequently Asked Questions about Nuclear Power

What is nuclear power?

[wpcol_1half id=”” class=”” style=””]Nuclear power or more precisely, nuclear energy is energy released from the nucleus of atoms.  Unlike energy from steam which is released when water boils (at the molecular level) and unlike energy from combustion of gas (at the level of a chemical reaction), nuclear energy comes from a much deeper level of material

What are the kinds of nuclear power known?

There are two major sources of nuclear power known, fission and fusion.  Fission occurs when an atom splits in two different smaller atoms, and releases some energy in the process. Only atoms of specific elements are unstable and undergo this splitting, and they are called radioactive isotopes.  Fusion, occurs when two atoms join, or fuse, and release energy in this process.  Here too, only some elements can practically be fused to produce energy.

Fission energy is in practice, extracted from Uranium which is rare in nature and it is possible to do so from Thorium too, which is more abundant.

Fusion energy has not yet been stably extracted through a controllable reaction for commercial use.  The smallest fusion reaction occurs when two Hydrogen atoms fuse to form a Helium atom.

How is nuclear energy different from conventional energy?

Nuclear energy is different from conventional energy in the manner in which heat is produced.  The excess energy when the atom splits is released as heat.  This heat is harnessed by technology to produce electricity.

How does nuclear power generation work?

When the atom splits and heat is generated, this heat is transferred to either water or gas and extracted from it.  In India, the technology uses an intermediate medium (sometimes water) to absorb the fission energy from the radioactive substance.  This intermediate medium then heats water which is then converted to steam used to run a conventional turbine driven generator that produces electricity for use in the electricity grid.

How is nuclear power different from nuclear weapons?

In nuclear weapons, either atomic splitting or atomic fusion is uncontrolled and releases vast amounts of energy in a very short time resulting in a massive explosion capable of mass destruction.  When nuclear power is used for peaceful purposes the energy release is controlled and harnessed to produce electricity.

What is the source of radioactivity?

The source of radioactivity is the isotope that provides nuclear energy through fission.  Fusion reaction does not seem to result in the release of radioactive isotopes (yet).

What are the dangers of radioactivity?

Radioactivity weakens and disrupts chemical bonds in a manner that results in the failure of the structure and function of organic materials.  Thus biological tissue is destroyed and its ability to reproduce itself is also often destroyed.  When life is exposed to radioactivity, the organism dies, relatively fast (in a matter of days) if the dose is massive, and relatively slowly (taking months) if the dose is less massive.  However, beyond a specific dosage, any radiation is fatal and the only question is how long one has to live and suffer.  Below that dosage, the problem that arises is that of genetic mutation and maiming of children for several generations, as has been demonstrated in Hiroshima and Nagasaki.

What is the safety of a nuclear power plant?

When it functions normally, a nuclear power plant is fairly safe since the radioactivity is limited within the containment chamber and is absorbed through shields to ensure that nothing escapes.  The intermediate heat transfer medium is shielded from the radioactive material adequately and the water that is ultimately heated usually does not come in contact with the radioactivity.  This safe water/steam runs a turbine that operates a generator to produce electricity.  From the turbine onwards, the power generation is conventional and well known – there are no radioactive hazards in the electricity that is produced and transmitted since the radioactive substance does not travel with the electricity.[/wpcol_1half] [wpcol_1half_end id=”” class=”” style=””]What are the dangers of a nuclear power plant?

1. The main danger of a nuclear power plant occurs when the control and moderation of the radioactive core generating the primary energy fails.  Then uncontrolled radioactive generation can cause a meltdown, resulting in the failure of containment.  This will then discharge vast amounts of radioactive energy in the atmosphere around the nuclear facility, without necessarily an explosion, but leading to death and long term maiming of all forms of life in the vicinity.  Reproductive capacity is also affected.  The radius of destruction depends on the magnitude of failure.  Three Mile Island in the USA and Chernobyl in the USSR are examples of what can happen when a reactor fails.  The latest and the most horrendous of all is the Japanese Fukushima reactor failure that has now occurred.
2. Less serious danger occurs when there is a leak of radioactive material from the containment area.  In that case the personnel and sometimes innocent bystanders face death due to undetected nuclear radiation.  Here again the extent of damage and destruction depends on the seriousness and extent of the nuclear leak.
3. A third potential danger that is unavoidable is that posed by the wastes of nuclear power generation.  Since the plant cannot work with low levels of radioactivity, it is necessary to remove and destroy spent nuclear fuel.  However this fuel still remains dangerously radioactive and its disposal given the chemical stability of radioactive materials is extremely difficult. This is a problem that is yet to be tackled with political will and is due to become critical in the decades to come, when the radioactive material in the existing plants begin to fall in their yield below sustainable limits.  This is another source of danger from the Fukushima disaster – spent rods, which generate heat spontaneously due to fission reaction, were kept cool in pools of water that also absorbed the radioactivity.  When the earthquake occurred these pools of water dried out due to leakages, and this resulted in the overheating of rods, and the release of radioactive material.
4. A fourth potential danger is the waste material that is released from the uranium mines, from the plants that convert ore to metal, and finally the factories that enrich uranium to increase its radioactive isotope, in order to make it suitable for use in power generation or bomb production.   Radioactive wastes can kill many an unwary rag-picker.

What is a fast breeder reactor?

One of the difficulties of nuclear power technologies so far in use is that the fuel comes to the end of its use cycle and has to be disposed.  Waste disposal and the production of fresh uranium to continue running the plants are two major problems.  Fast Breeder Reactors, which are in the experimental stage, generate fuel fresh fuel as part of the power generation process, thus attempting to solve the perennial problem of source material alongside the process of producing power.

What is the use of Fast Breeder Reactors?

Theoretically, I am not sure why though, if it is possible to have technologies of normal Uranium based nuclear power plants, fast breeder reactors and finally Thorium based nuclear power plants, it would be possible to eliminate nuclear wastes.  This is because spent material from the first plants would go into the fast breeders, which will then alongside power production, also produce fuel for the Thorium based plants, whose waste material in turn would go back to the normal Uranium plants, and onwards to the next cycle.

What is fusion power?

Fusion power is the generation of power by a fusion reaction: the most elementary fusion reaction occurs when two hydrogen atoms fuse to produce helium and release energy.  This energy is much more than fission energy and has no radioactive hazard except at the moment of generation. Hydrogen is also an abundantly available material and thus there are no source constraints.   However methods to control fusion reactions have not yet been devised and fusion power is not yet a practical possibility.