The timeline
Nuclear power was not discovered by one person and was not realized over night, it was due to many famous minds and a long period of time dedicated to study, experiments and theory developing. The following cornerstones in time are what led to the discovery and creation of nuclear energy.
- 460-370 BC [5]- Greek philosopher named Democritus first had the theory of matter being made up of atoms [4].
- Newton along with other scientist made an atomic model [4].
- Late 1700s John Dalton proposed the same theory, it fitted perfectly with the experiments that he performed, but he still didn’t prove this, he only had a theory and a model [4].
- Bernoulli (1740s), Joule (1850s), Clausius & Maxwell (1860s), and Boltzmann (1870s) all contributed to the theory of the atom mainly using gases and how they act [4].
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1897 – [6]Rutherford and his student, C.T.R. Wilson, invented the cloud chamber, this was used for his experiment; gold foil was bombarded with Alpha radiation (helium nuclei), they found that is usually passes through but very occasionally it deflects of at a steep angle, this proved that the gold foil had something that could deflect the helium nuclei –the nucleus of an atom [4].
- October 1993 - Szilard recollects that "It occurred to me in October, 1933 that a chain reaction might be set up if an element could be found that would emit two neutrons when it swallowed one neutron." This was the first idea of fission [8].
- January to May - Many experiments on uranium fission. August 2 - Szilard, Wigner, and Teller obtain a letter from Einstein on the possibility of a uranium weapon. The President was notified [8].
- 1941 July - British 'Maud' Committee reports that a weapon could be made with 10 kg of Uranium-235; U.S. Academy of Sciences endorses bomb program [8].
- 1942 May - Heisenberg and Dopel observe the first multiplication of neutrons.
December 2 - First nuclear chain reaction at Chicago's Stagg Field by Fermi [8].
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1949 August 29 -"If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one. Now I am become Death, the destroyer of worlds." Quatation from Robert Oppenheimer, also known as the father of the a-bomb. It was detonated in a remote region of the Ustyert Desert[9].
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1954-June 27The first nuclear reactor to become operational was in Obninsk just outside of Moscow [10].
Even now we are still researching nuclear power, even though we have not seen a clear picture of an atom we still dig deeper and we discover sub atomic particles; smaller particles beyond the protons and neutrons of an atom [11]. But are we researching the right thing? Maybe we should stop researching subatomic particles and instead start looking at the big picture, its sustainability.
Advantages and disadvantages
Before advantages and disadvantages can be reviewed we must first compare them with other means of power. These will include; fossil fuels, solar, wind, tidal, wave and biomass. There are other types of energy resources but these are the ones that are most relevant, I will present the data in table format then explain it in more detail.
Nuclear energy produces the most energy by far; this is because the heat produced by fission is so fierce that only a small amount of uranium is needed to heat up the water. It does however cost a lot to build and dismantle. So here are the benefits compared to the rest: -
- Produces far more energy than the other ways of producing energy.
- The Co2 output is minute; once the building is in action it gives out almost no Co2.
- The Co output is also minute; there is more likely to be greater C02 emissions than C0.
- Reduces the use of fossil fuels.
- No need to import fuel from other countries.
- Plenty of uranium that can be used as fuel.
- Cheaper electricity prices
- Provides more jobs
And now the disadvantages: -
- The building and disassembling cost is major.
- Waste disposal plants must be built which adds to costs.
- The electricity used by the disassembly process can sometimes be more than what the plant generated in its lifetime [26].
- Can be eyesore.
- Potential health risk surrounding area.
- Mining costs for the uranium can be expensive
- Turning uranium ore into Yellowcake (uranium oxide) can also be expensive [27].
- Landfill for low-level waste must be used.
- Radiation sickness is a threat to almost all workers and can be very expensive to treat or sometimes can be invaluable and nothing can be done to treat it.
And last of all, its not sustainable.
Or is it?
The sustainability
At last we come to what everyone wants to know; is nuclear power sustainable? If you ask people on the street the chances are that they will say no, if nuclear power plants use a radioactive element then that element must run out at some point. This is a valid answer; true, one-day the world’s uranium supply will run out or it is too deep in the Earth’s crust that it will become physically impossible to reach. Well actually unbeknown to the public, nuclear power is actually sustainable; there are operations such as PUREX and Breeder reactors that can make more uranium and can also make substances that are far more abundant than uranium itself [28].
Breeder reactors
For a breeder reactor to be classified as a breeder it must produce more fissile material (material that can be a part of a chain reaction) than it does use it [29].
Breeder reactors have the amazing capability of using Thorium 232 as the fissile material in the chain reaction. This material is more abundant than Uranium 235, however it does not emit as much radiation; the breeder reactor produces less and weaker radioactive waste [29]. Uranium 238 is a non-fissionable material; it can’t start or sustain a chain reaction, however once used in a breeder reactor it changes to Plutonium 239 as shown in the diagram. Bombarding Uranium 239 makes it emit two beta decays resulting in Plutonium 239 [29].
PUREX
PUREX is an acronym standing for Plutonium and Uranium Recovery by Extraction, ther are other types of recovery opperations such as REDOX- the recovery of uranium and plutonium and THOREX- the recovery of thorium, protactinium and uraniumm 233 [30].
PUREX uses a Liquid- Liquid Extraction process. This involves dissolving mixed elements into different liquids. Due to varied properties in every element it is possible to separate them by putting those properties to use [31]. The irradiated fuel is usually immersed in nitric acid first. This dissolves the one element and levees the other element behind it will go into another solution to dissolve the other element. A mixture of tributyl phosphate (TBP) and kerosene are used to recover the uranium and plutonium. Further proceses allow sepperation of the hevier plutonium from the uranium [31].
Conclusion
Nuclear energy is a good source of energy; we can produce a lot of energy from a small piece of matter, and thanks to breeder reactors and PUREX the energy can go on. To think that what we have to day might have been sparked off as far back as 460 BC is extraordinary. Lots of famous and brilliant minds have helped us to achieve what we have today, each and everyone contributing to the atom, to the future. With CO2 levels rising nuclear energy is an agenda that seems to pop up on to MP’s lists frequently. During the life of a nuclear power plant, CO2 levels are very small, it’s the construction and decommissioning of the plant that really has an impact. We’ve solved the solution of the sustainability of nuclear power now its time look at other more pressing issues; although nuclear waste can be treated, some of it isn’t, also low level and intermediate level waste is still being put in land fill, we must tackle this situation soon before its too late.
As time goes on more and more scientists will contribute to modern science, the atom will no longer be a mystery and we can alter it to fit our needs. Man will continue to explore nature and the wonders of the universe, and in doing so will reveal more about how it all began and maybe how it will all end, for as Isaac Newton once said – “I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.” [32]
Callum O’Connor 10A