Radioactive Waste disposal methods
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Transcript of Radioactive Waste disposal methods
RADIOACTIVE WASTE DISPOSAL METHODS
MSc. Pt 1 Environmental ScienceK. J. Somaiya College of Sci and Comm.
Dhananjay PatilBruno FernandesMilind JoshiChirag Patel
Content
1. Motivation
2. Learning objective
3. Introduction
4. Methods of waste disposal
5. Conclusion
6. Facts
7. Take away message
8. References
Motivation
The current trends say that nuclear power is a huge source of energy. On the
contrary the byproducts obtained after production of energy are hazardous and
have a very great impact on the environment as well as on human health.
The well known incident of Hiroshima and Nagasaki and also the Fukushima
disaster is deeply rooted in the minds of every individual and the effects are
faced by the people till date.
Learning objective Since nuclear power being used on a large scale today our main objective is to
learn and understand the harmful after effects of these nuclear toxicants and understand the way in which their disposal takes place without causing much harm to the environment.
Advantages and disadvantages of radioactive materials.
Introduction
Composed of radionuclides.
Classification
Low, Medium, and High-level waste
High-level waste produced in nuclear reactors
Consists of
Fission products (short-half lives)
Actinides (long-half lives)
Examples
Methods of waste disposal
1. Decay in Storage (DIS)
2. Dump to Sanitary Sewer
3. Dispose as if not radioactive
4. Vitrification
5. Geological disposal
6. Reprocessing
7. Transmutation
8. Space disposal
9. Deep boreholes
Decay in Storage (DIS)
Store waste in the laboratory if the half-life is no more than 120 days.
“DIS” Isotopes must be held for decay for at least 10 half-lives.
Survey monitoring of material must read close to background.
All radioactive labeling must be defaced.
Document in log
Dump to Sanitary Sewer
Must be water soluble or readily dispersible biological material in water.
Concentration per month is limited by the regulations, check with the
Radiation Safety Officer.
May obtain permission from the Radiation Safety Office prior to dumping -
Only way to know if other people are dumping.
Dump to Sanitary Sewer Contd.
Annual Limit per Facility
H-3 - 5 curies
C-14 - 1 curie
All other radionuclides combined - 1 curie
Dispose as if not Radioactive
Scintillation medium containing no more than 0.05 microcuries per ml of H-3, or
C-14 may be discarded as if it was not radioactive. If chemical solvent is
disposed of properly the radioactivity will not pose a problem.
A record shall be kept of each such disposal for the life of the license; it may be
sent to the RSO
Vitrification
Radioactive waste to glass
Low solubility
Immobilization of waste for thousands of years.
Widely used for storage purpose.
Vitrification
Geological Disposal
Burrowing nuclear waste into the ground
to the point where it is out of human reach
Large variety of geological environments
suitable for disposal
Depth of burial is very high
Waste can be recovered
Most widely used method
Practically feasible with current
technology
Reprocessing
Long term method
Separating useful components from non useful
Fissionable material out from irradiated nuclear fuel
Transmutation
Long term disposal.
Converting a chemical into non harmful one.
Example: Cl to Ar, K to Ar
Outside stimulus like proton hitting reaction materials
Natural transmutation
Space Disposal Near infinite storage space
Completely removes waste from biosphere Technical risks and problems
High risk of space vehicle failure
Relatively limited volume per launch
High energy cost of space launch o The current cost to launch an object into orbit around
the earth is about $20,000 per kilogram.
Beamed energy technology (BEP)
Deep boreholes
Kilometers deep rather than hundreds of
meters.
Provide Further isolation from ground
water.
More potential borehole locations around
the globe.
Can be created in many cases close to
power plants.
Conclusion
Proper disposal of nuclear waste is still a challenging issue that constrains the growth of
nuclear power. The most currently-used method for nuclear waste disposal is storage,
either using steel cylinders as radioactive shield or using deep and stable geologic
formations.
References1. Bhabha Atomic Research Centre (BARC). (n.d.) Radioactive waste management
[online]. Available from: http://www.barc.gov.in/ [Accessed 10th October 2014].
2. Organisation for Economic Co-operation and Development (OECD). (1989) NEA Issue
Brief: An analysis of principal nuclear issues [online]. Available from https://www.oecd-
nea.org [Accessed 9th October 2014].
3. Th. Briggs, P. L. Kunsch and B. Mareschal. (1990) "Nuclear Waste Management: An
Application of the Multicriteria PROMETHEE Methods“ Eur. J. Oper. Res. 44, 1
4. World Nuclear Association. (2014) Radioactive Waste Management [online]. Available
from: http://www.world-nuclear.org [Accessed 9th October 2014].
5. U.S. Nuclear Regulatory Commission.(n.d.) “Radioactive waste." Available from:
http://www.nrc.gov/waste.html. [Accessed 9th October 2014].
Facts It still contains 95% of its energy. That's like taking a couple tablespoons out of a liter of
pop and throwing the rest away if we don't make use of it!
Nuclear fuel is around 20,00,000 times more energy dense than coal, oil, and biomass.
This means the quantity of nuclear waste is super tiny for the super huge amount of
energy it produces. 20,00,000 times is like the difference between the diameter of the
moon compared to the height of an adult person
It can be recycled, and actually produces energy while being recycled, instead of
requiring energy to recycle!
Even including the worst accidents in worldwide nuclear history, nuclear has the best
safety record (deaths/yr) of any type of energy source, including wind, solar, natural gas,
and coal. There have been no deaths in the history of U.S. commercial nuclear power
due to exposure to nuclear waste.
Take away message
Money and radioactivity go hand in hand, both have a large half life and both of them when used in excess harms the nature
Thank You!