1. The Future of Nuclear Waste Management, Storage, and Disposal
Thanassi Lefas
26 November 2008
ChE 359 Energy Technology and Policy
Hi, my name is Thanassi Lefas. I’m a senior in Chemical Engineering at the University of Texas and today I’m going to talk to you about the future of nuclear waste management, storage, and disposal

2. Road Map Identify importance of nuclear waste management
Define nuclear waste
Identify health risks
Discuss initial treatments of waste options
Vitrification
Ion Exchange
Discuss permanent disposal of waste options
Geological Repositories
Deep Boreholes
Separation and Transmutation
Space Disposal
Conclusions/Recommendations

3. Importance of Nuclear Waste Management
Nuclear power carbon free energy source
Currently limited by economics, safety, and technology
Clear limiting factor, lack of permanent disposal
Growth of nuclear capacity will require development of permanent disposal options
Critical considerations
Safety
Security

4. Nuclear Waste Composed of radionuclides
Low, Medium, and High-level waste
High-level waste produced in nuclear reactors
Consists of
Fission products (short-half lives)
Actinides (long-half lives)
Of note: 99Tc, 129I, 239Pu, 240Pu, 235U, 238U

5. Health Risks Somatic Effects Genetic Effects Teratogenic Effects
Cancer
Genetic Effects
Hereditary Genetic Damage
Teratogenic Effects
Birth defects
Prenatal death

6. Vitrification/Ion Exchange
Purpose
Prevent reaction or degradation of waste for extended period of time
Vitrification
Combine waste with molten glass, harden to form new solid
Ion Exchange
Combine with chemical to concentrate waste and encase in cement

7. Geological Repositories
Isolate High-level nuclear waste
Waste Package
Engineered Seals
Natural Bedrock
Sites w/ appropriate Hydrological and Geochemical environments
Low solubility and mobility of radionuclides
In United States, Yucca Mountain north of Las Vegas

8. Deep Boreholes Similar concept to basic geological repositories
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
Not subject to tectonic, volcanic, and seismic interference

9. Separation & Transmutation
Long-lived isotopes extracted from nuclear waste and destroyed
Removal of long-lived isotopes
opens up more repository options
reduces thermal load on repositories, thereby increasing their capacity
destroys plutonium, ensuring that it can’t be recovered and used for nuclear weapons

10. Space Disposal Removes the waste from the biosphere entirely
High risk of space vehicle failure
High energy cost of space launch
Relatively limited volume per launch
High cost

11. Conclusions/Recommendations
Optimization of ion exchange
Results in compact form of waste that will not interact with biosphere
Research and Pursuit of Deep Boreholes
Further development of deep boreholes that are more reliable are an ideal option
Reasonable Cost
Global availability
Human Safety

12. Thanks