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!