TO ADD YOUR COMMENTS OR OPINION ABOUT THE NUCLEAR ENERGY OR THE TREATMENT OF NUCLEAR WASTE, PLEASE CLICK ON "COMMENTS".

IF YOU ARE NOT REGISTER TO WEBLOG, JUST CLICK ON ANONYMOUS AND SIGN YOUR MESSAGE.

Thank you.

WHAT IS NUCLEAR WASTE ?

What is nuclear energy ?

The development of nuclear industry has been a cornerstone for the world's technological revolution. Since the discovery of fission 60 years ago, nuclear power has become a major source of the world's electricity supply. By 1989, 416 nuclear power plants were in operation, thus provid about 20 percent of the world's electricity. With more than one hundred nuclear operating plants, the United States have the world's largest nuclear energy program.

In the nature exists different kind of chemical elements, certain kind contains light nucleaus as(hydrogen, nitrogen,…) and other one are considered to be heavy elements (uranium, thorium,..) and those one could be used in certain reactions to product nuclear energy.
Nuclear energy originates from the splitting of uranium atoms is a process called fission. Fission represent a splitting of an heavy atom into two or more lighter atoms upon absorption of a neutron. This process generates a large amount of energy and usually at least two neutrons. The act of fissioning is also referred to as burning. At the power plant, the fission process is used to generate heat for producing steam, which is used by a turbine to generate electricity. Because nuclear power plants do not burn fuel, they do not emit air pollutant emissions.

What is a nuclear power plant and how it works ?

A nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors.

A nuclear reactor include combustible elements which contain fissionable nucleus as uranium 235. With time, the combustible grows poorer in his contents of uranium 235 therefore the product from the fission will increase. Nevertheless, nuclear combustible do not disappear in burning as other fossilized combustibles (as gas for example), but it changes its nature step by step.
During its evolution, the product from fission absorbs neutrons consequently they are not able anymore to make the fission process anymore. Because of this incapability to process the fission, it is necessary to put them out of the irradiated combustible and to replace it by new combustible. But this irradiated combustible is very dangerous for the environment and human being, so it must be stocked in a very careful way. In a nuclear reactor, there is different kind of barriers to keep the radiation inside to protect the neighbourhood against the nuclear radiation, but when the nuclear goes out of the system, it has to be secured and in extremely strict conditions of protection.

Main problems link with the production of nuclear waste :

The product of fission is nucleus enriching in neutrons, so very unstable. To become stable, those nucleus have to transform their neutrons in protons to emit electrons. That mean, they have to do several desintegration process to become stable and not to be dangerous anymore. But those desintegrations can be very long, it depends of the elements, for example :

- Cesium 137 and Srontium 90 elements will exist in an unstable form for about 30 years and a regular nuclear reactor product till 30 kg/year which represent a huge amount of elements.

- Selenium 79 and Iode 129 will be unstable for a very long period and we can count it in million of years and a nuclear reactor will product about 65 kg/year of those elements.

In nuclear reactor, there are also isotopes of plutonium and minor actinides which are called transuranium elements, because they are heavier than uranium. Those elements are radioactive type a and they involve a big amount of energy and are more radiotoxical than nucleus beta. The production of the type of radioactive waste depends of the kind of reactor used.
In fact, the problem to stock this huge amount of nuclear waste is that we still don’t know many things about how those kind of radiations can change our ecosystem, thus many tests are done to find solutions to eliminate or to stock those dangerous waste which will exist for thousand or million of years.
So the question is, what to do with all those unstable and radiotoxical elements when they are not anymore useful to product energy.

WHY NUCLEAR WASTE IS DANGEROUS FOR HUMAN BEING AND ENVIRONEMENT ?

Nuclear waste is dangerous, because it contains radioactive elements which emit radiation for tens of thousand of years.
In brief, radiation is an energy which is travelling in the form of particles or waves, such light or heat. Certain kind of atoms, like uranium, thorium,... emit a very high-power type of energy which is called "ionizing radiation", this radiation can change the structure of atoms when it collides with. Often, it makes atoms loose their electrons, so they become ions. An atom which is able to ionized is called "radioactive".

It exists 3 types of radiation :

- alpha, which is a low energy radiation and which can be stop by paper

- beta, which is also a low energy radiation, but a bit more powered than alpha and which can be stop by aluminium.
- gamma, which is in the form of high-energy waves (e.g.: x-rays) and requires certain materials such as lead to absorb the wave.

The radiation alpha and beta could be very dangerous for the health if the body is exposed for a long period or if it exposed of a bit amount of those radiation suddenly, as in Hiroshima. But the effect of those radiation won't be obvious straight away, it often appears, after some weeks or months.
Moreover, concerning the gamma radiation, it will have immediate effects on people, as serious burning of the skin, the eyes and the breathing system, so if people are exposed to a certain amount of that type of radiation, they will not survive.

Concerning the sources of radiation, they are diversified. In fact, every human being absorbs radiation from the Earth it self, the atmosphere and the food they eat, all those sources are natural. There are also many types of anthropical radiations as smoke detectors, television sets, and nuclear power, but that amount of radiation represents yet only a few pourcents of the radiations our bodies absorb each day. By the way, this amount of radiation could increase a lot with the development of nuclear energy in the future.

What can involve radiations on human being :

The precise effects of radiation on human being is not well-known, but one thing is sure : it is extremenly harmful for the health. What happen in Hiroshima on August 1945 (http://www.monde-diplomatique.fr/2005/08/HERSEY/12425) or in Tchernobyl on April 1986 (http://www.un.org/french/ha/tchernobyl/) showed to the scientific world how bad the ionizing radiation could be for human health and environment .We know that according to the amount and the type of radiation body absorbs, it appears all kind of illness as cancers, sterility, anaemia, infections, foetus malformation. And concerning the environement, radiation can destroy the balance of a whole ecosystem, therefore certain kind of new species can appear and other died, but scientifics still don't know exactly the consequences in long term of such a ionized radiation as the one happen in Hiroshima 60 years ago or even less with the accident of Tchernobyl of 19 years ago.

How to protect from the radiation :

There are 3 important things to look for to prevent from the harmful exposure to radiation :

- controlling the distance from the radioactive source, because further body is from the source, less radiation exposure it will receive.

- the shielding, which depends of the type of radiation. It can be a kind of barriers between the body and the source which will provide a certain degree of protection.

- the time of exposure, because less time the body receive radiation, less it will be affected.

Thus, it is necessary to think about those 3 parameters to find a solution about the stocking or redisposal of nulcear waste.

SOLUTIONS OF STOCKING AND REDISPOSAL OF NUCLEAR WASTE

Using nuclear power energy has several implications. One of the most severe is that nuclear technology produces a great amount of toxic waste that remains radioactive for thousands of years. Thus, the waste must be disposed of in a safe manner to avoid the contamination of future generations. Every country has its own policy and rules for nuclear energy and its stocking and several type of stocking is existing, but none miraculous solutions yet.
In that part we will make a synthesis of the main stocking solutions we found in our research and reading :

- Dumping radioactive waste into the sea :

The global ocean represents about three-fourths of the world's surface. Until last century, it would have been difficult to imagine that humans could significantly pollute these huge amount of water, but as long as there have been human inhabitants along the coast, people have been utilizing the ocean as a dumping ground for garbage and all kind of rubbish. Even if in many minds oceans are endless and having plenty of room for the waste, that is not true at all. The ocean can not accommodate dumpings without being constantly damaged. Moreover, from the industrial revolution of the end of 19th century, all the new technology are able to damaged the ocean even more. The nuclear energy is one of those new technology which could have significiant effects on the ocean and its ecosystem if the nuclear waste are dumped into the sea.

Until the late seventies, no regulations were available to avoid the dumping of nuclear waste into the ocean from ships, so a big amount of radioactive waste were thrown into the sea and not in safe way, because nobody really knew the effects of such a dumping on our planet. At that period the ecologist associations started to do campaign against the disposal of nuclear waste on the ocean floor, but it is in october 1993 that the international community decided to ban sea dumping of radioactive waste from ships in the London Convention. Then in november 1996, a draft treaty was decided to prevent the pollution of the ocean due to the dumping of nuclear waste and the imersion of waste and the transporting of waste by ship to other country became forbidden. Unfortunaltely, the ratitification of this treaty is still not done so a lot of waste are still dumped into the sea.

Although the international community decided to protect our planet, they do not found real solutions about what to do with the big amount of nuclea waste. Consequently, a lot of research started to discover a solution to stock the nuclear waste and not to damaged then environement, but the idea of ocean dumping is still a potential solution, but in very secured and regulated way.

The purpose it to put nuclear waste as far as possible from where the human being are living, so redisposal on the deep ocean floor could be a solution. All kind of research are done to discover what could be the best way and the best place to put the nuclear waste on the ocean floor or into the subduction falt, so very deep into the Earth and many reasearchers think it could be the best solution. This option could be viable because deep within the ocean floor, the radiation from the waste would not harm people or the environment.

The principle of redisposal nuclear waste on the ocean floor consist in treating the radioactif elements into the power plant and put them into concrete barrels. Then the projects is to burry them under the ocean floor for years until they are not harmful anymore. The main problem with that method would be the difficulty of recovering the waste, if necessary, once it is emplaced into the ocean floor. It would be also necessary to establish an effective international structure to develop, regulate, and monitor that repository.

The other idea is to put the nuclear waste into subduction falts, so very deep into the ocean, so in that way all the radioactive elements could be reabsorb by the Earth with time. But even if many research were done on that subject, nobody really knows how to do in a practical way without damaged the ecosystem. Anyway it is still difficult to imagine what can be the global effect of such a redeposit of big amount of radioactive elements into these deep falts. Plus, many research are made about the ecosystem, organisms and chemical process into those falts to discover the beginning of life on the Earth, so the redeposit of nuclear waste there could bother those important research programs.

- The concept of repository on the continent :

The repository of nuclear waste on the continent can follow 2 main alternatives : the dispersion or the burying into the ground. Most of the waste (noxious gases and many toxic pollutants) is dispersed directly into the atmosphere while some solid waste containing toxic pollutants is buried in shallow ground, so what is the best alternative to protect the environement. The waste is dispersed or buried at concentrations considered not harmful. For nuclear waste it seems more difficult, because it needs all kind of political agreements to allow such a dispersion or redeposit, because it is important to know very well the amount of radioactive waste which can be dispersed and not be dangerous for human and the cumulative waste over many years of a large number of waste producing activities could damaged the natural environment.
The concept of dispersion of nuclear waste seems to be based on calculus and hypothesis and in fact the effects on long term is still difficult to predict so that alternative is not completely safe.
Burrying seems preferable to dispersion, but is economically feasible only when waste volumes are small and arise under easily controlled conditions. A nuclear plant produces annually about 350-450 tonnes of short lived low and intermediate level waste, but that type of waste is only able to contaminated clothing, machine parts and industrial resins. Consequently, those waste can be put into containers and then buried into the ground. Those waste does not require shielding during handling or transportation, and are by the was less radioactive than the equivalent weight of coal plant fly ash or even coffee beans and fertilizer which contain natural radioactive material. In fact, the main purpose to use the geological repository is to keep waste away from people and the environement for 10,000 years or so.

Many geological study are done to find safe place and soil to place nuclear waste, because the nature of the soil is important to determinate before burying dangerous waste in it. The nuclear waste would have been vitrified and under a solid form before be put into the ground, and as long it stay under that form and remains deep underground, it will not be harmful because layers of rock and dirt will shield its radiation. If the waste were not vitrified, the water circulating into the ground could break down the block of waste in tiny radioactive particles and then carry them into the environment, so the strategy of vitrification is to keep the waste as dry and isolated for tens of thousands of years, so till they are not harmful anymore. About one thousand feet of solid rock will be above the repository to restrict the amount of water that could reach buried radioactive waste.
Every country has its own license and geological studies to decide where to burry the nuclear waste, and they start to consider deep underground geological formations which have not been disturbed for many millions of years to put waste in and that seems to be the best solution yet.

- Transmutation of nuclear waste :

The principle of transmutation is to use a chemical process to separate out plutonium and fissionable uranium to reduce the volume of waste material. Transmutation refers to a technology that involves reprocessing spent nuclear fuel then changing the radioactive elements into generally shorter-lived substances. If developed, this technology could reduce the amount of time that some of the elements in spent fuel would remain radioactive. The US Department of Energy conducts many research projects about transmutation and development, but it will not be able to be used after at least several decades, because it still need to be improved and tested. Plus, the transmutation would still produce waste, but wich will remain only for short period of time. So, the main advantage of transmutation would be to minimize the amount of waste and to make their harmful radiation being shorter.

- Launch nuclear waste into space :

The NASA and other national department of Energy and sustainable development are doing research to find several methods of disposal in space. The main idea is to put nuclear waste into shielding or containers and to send them into obit arount the sun. That alternative will offer the possibility to get an permanent slit between the waste and the human environment, but the real effect of such a lauch is completely hazardous. Moreover, the risk of an accident during lauch will make yet this solution unsafe, because if the lauch was unsuccessful and the containers explosed, the whole environment could be damaged and contaminated for a long time. However, the big amount of waste which is produce by each nuclear waste will require several launches per year and that will make that space disposal option difficult to impliment, also because it will need to build international conventions which could be very difficult to establish.

- Ice sheet disposal in polar region :

Some finish and american scientists consider the option to dispose nuclear waste in the ice of Greenland or Antarctica. The principal of that solution is to dispose containers of radioactive waste on the ice surface and let them go down into the ice in melting it slowly with their own heat. The containers could be attached with a cable to an anchor to limit its descent depth and to allow retrieval when the waste won’t be harmful anymore.
The main advantage of that option is that those polar region are far from any population and also the stability and the thickness of the polar ice could make that solution pretty safe.
Nevertheless, it would be very difficult to transport the waste to those region and the effects of the future climate changes on the stability and size of the polar ice mass could be a big problem. Moreover, if the radioactive waste were released into the sea water, because of the increased of polar ice melting, for example, they could be transport by the global ocean circulation and contaminate the environment.
Finally, that disposal is yet not possible because of the Antarctic Treaty of 1959 which prohibits disposing of radioactive waste on the Antarctica continent.

- Burying nuclear waste under isolated islands :

The alternative to burry radioactive waste beneath unpopulated isolated islands is considered by certain scientist, especially from Finland. In the world, there are a countless number of remote island very far from all kind of resources and human being, so those islands could be potential location to place nuclear waste without taking risk to damaged human being environment. The idea is to put containers of nuclear waste, vitrified or not in ships to go to those isolated islands to burry them there. That option seems to be avalaible, but the main risk in choosing it is the unstability of the islands which are usually vulcanic and also the fact that the waste could be assiocated with the ocean water and to be transported and consequently contaminate the global ocean.

NUCLEAR ENERGY AND MANAGEMENT IN FRANCE

In France, the principle service which is taking care of the management of radioactive waste is ANDRA (The French National Agency for Radioactive Waste Management). This agency is a public industrial and commercial organisation created in 1991 to control the treatment of nuclear waste in operating independently of waste producers. Andra operates independently of waste producers. It comes under the supervision of the French Ministries for Industry, Research and the Environment, and is responsible for the long-term management of radioactive waste produced in France.Today in France, 75% of the electricity is produced by nuclear energy versus 15 % at the USA. There are 23 power plants all over the countries, next to villages and populated area.

Map showing the location of the 23 power plants in France

The most famous nuclear center and nuclear plant is located in La Hague, in the north part of the country and that center is the only one which does reprocessing of high level waste in France. Many country, as Switzerland, Germany, UK,...transport their high level energy nuclear waste to La Hague by ship, train or for short trip by trunk.
In France, the main principle to treat the important amount of high level nuclear waste produced by the plants is the high level reprocessed waste is vitrified and stored at La Hague for several decades, where it awaits final geologic disposal.

Power plant of La Hague

And another important nuclear center is located at the Aube and it contains all the low- and intermediate-level radioactive waste produced in France which need to be disposed.

ANDRA is doing yet many research about the geological disposal and in the 2005 report they are exposing the 2 main projects. In fact, the purpose is to place vitrified nuclear waste in granit geological formation or in clay :

- Research about the stocking of nuclear waste in clays :

A undergroud lab in the Meuse-Haute Marne is studying the option of disposed nuclear waste in stable clay geological formation dated of 150 millions of years and located about 500 m undergroud. The purpose of this research is to study the parameters and the stability (erosion and earthquake) of the foramtion. The quality of this rock seems to be interesting and really stable on ling term, moreover, that site is located very deep into the ground so will be protected by the surface perturbation.

Why choosing clay : clay possess excellent proprieties and is an homogen, hard and not much permeable rock. The water circulate very slowly into clays, so than can avoid the damaging of the radioactive waste which could be disposed there.

The 10 years research which has be done in the Meuse-Haute Marne lab seems to be positive and show that such a stocking could be implement in a safe way, but it still need some time to improve especially the quality of the containers and the maneer to dispose the waste underground. Moreover the long term effects seems still difficult to predict.

- Research about stocking of nuclear waste in french granit :

Granit present interesting proprieties to stock high level waste, because it is hard, resistant, not much porous and very few permeable. Moreover, its heating conduction could allowed to burryed waste even if they are still degaged heating.

In France, most of the granit formation are very deep into the ground so that offer a important flexibility for conception of stocking. The two principal place were that type of stocking could be possible are in the "Massif Armoricain" and in the "Massif Centrale", because they are the biggest location where granit formations are existing.

The disadvantage of such a stocking is that granit present many fault which can make it unstable, so it should be very important to know all the fault and their operation to make a safe stocking in the granit. That study could be very long, because rocks are evoluating all the time.

France research about the treatment of nuclear waste is in advance compared to many countries and the french global opinion seems to agree (according to national statistics) with the politic of improving nuclear energy and decrease the gas emission. Nevertheless, nobody can be sure that it is a good way to act and we need more time to see the effects of such a politic on the environment.

CONCLUSION AND BIBLIOGRAPHY

CONCLUSION

After a long research and a lot of reading, we could really understand better all the problems linked with the treatment of nuclear waste, but also questions and debates concerning the sustainable development and energy. However, our purpose was to do a neutral and attainable synthesis about the theme of the treatment of nuclear waste to understand why it is not a miraculous energy which can completely replace energy producing by gas without damaged the planet.

After all, it seems difficult anyway to know which enery is better to use, because there is advantage and harmful effects for each kind of production of energy.

Therefore, the solution to protect our planet could also be to change the way of using the energy in doing efforts in that sense. So a big change of mind of the general and of governments improve a lot the actual situation too.

Now, our purpose is to get comments on that site and opinion of people to make our opinion enriching. So please feel free to give us your way of thinking.

BIBLIOGRAPHY

IN FRENCH :

- « L’énergie nucléaire », Paul Rauss, Editions Que sais-je, Puf.

- « Mettre en pratique le développement durable, quels processus pour l’entreprise responsable ? », Olivier Dubigeon, Editions Village Mondial.


- « La radioactivité est-elle réellement dangereuse ? », Jean-Marc Cavedon, Editions Les petites pommes du savoir.

- « Le risque nucléaire », Henri de Chondens, Edition Tec&Doc.


- « Le puisatier des abîmes », romans, Bernard Tirtiaux, Editions Folio.

- « Que doit-on craindre d’un accident nucléaire ? », Rolland Max, Editions Les petites pommes du savoir.

- “Gestion du plutonium civil”, Sicard B., Zaetta A., Edité par le CEA.

- « Livret CEA : Les centrales nucléaires dans le monde », direction du CEA, Editions 2000.

- « Les recherches de l’Andra sur le stockage géologique des déchets radioactifs à haute activité et à vie longue », dossier 2005 de l’ANDRA, Collection les Rapports.


IN ENGLISH :

- “Storage of IUW : what problem ? where? Discussion-from nuclear fuel”, Tallec M., Capdevila J.-M., Dercourt J., Brezin E., compte rendu Physique 2003, Sciences direct.

- “Confinement and migration of radionuclides in a nuclear waste and repository : From nuclear waste to fuel”, Toulhoat P., De Marsily G., Gras J.-M., Brezin E., compte rendu Physique 2002, Science direct.

- “Advanced concept for using plutonium in pressurized water reactor”, Pull A., Bergeron J., Nuclear Technology n°119,1997.

- “Long lived waste transmutation in reactors”, Tommasi J. et al.,Nuclear Technology n°111, 1995.

- “Recycling of waste from nuclear facilities”, Damoy F., Joly J.-M., Revue générale nucléaire, 2003.

- “Very low level and conventional waste from nuclear facilities”, Chapalain E., Revue générale nucléaire, 2003