High Level waste

• Radioactive Waste Management and Disposal

• NUCP 2311

U.S. Waste Classifications

2NCRP Report No. 139, 2002NCRP Report No. 139, Risk-Based Classification of Radioactive and Hazardous Chemical Wastes (2002)

High Level Waste

1. Spent Fuel: irradiated commercial reactor fuel

2. Reprocessing Waste: liquid waste from solvent extraction cycles in reprocessing. Also the solids into which liquid wastes may have been converted. NOTE: The Department of Energy defines HLW as reprocessing waste only, while the Nuclear Regulatory Commission defines HLW as spent fuel and reprocessing waste.

3Definitions quoted from the Institute for Energy and Environmental ResearchWebsite: http://www.ieer.org/clssroom/r-waste.html

Nuclear Fuel Cycle Diagram

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* Figure from The Nuclear Fuel of Pressurized Water Reactors and Fast Reactors, ed. H. Bailly, D. Menessier, and C. Prunnier, (Lasovier Publishing, 1999) p. 14.

Current US Strategy

5James J. Laidler (Argonne National Laboratory)

Fission Products

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* Figure from The Nuclear Fuel of Pressurized Water Reactors and Fast Reactors, ed. H. Bailly, D. Menessier, and C. Prunnier, (Lasovier Publishing, 1999) p. 37.

Summary of Nuclear Characteristics for LWR Fuel

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The Decrease with Time of the Radioactivity and Thermal Power from PWR Spent Fuel

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The Decrease with Time of the Radioactivity and Thermal Power from BWR Spent Fuel

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Radioactivity from Principal Fission Products in Irradiated Fuel

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Radioactivity from Principal Actinides in Irradiated Fuel

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12James J. Laidler (Argonne National Laboratory)

Two Approaches for Commercial SNF• Store and dispose

– Spent fuel pool management– Monitored retrievable storage– Geologic repository

• Reprocess– Research on methods is quite active– Advanced reprocessing under AFCI (becoming GNEP)– HLW glass fabrication (vitrification)

• West Valley Plant and others (commercial HLW)• Savannah River Plant and others (defense HLW)

Note: reprocessing already used for “defense” separations

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14James J. Laidler (Argonne National Laboratory)

15James J. Laidler (Argonne National Laboratory)

16Robert N. Hill (Argonne National Laboratory)

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18Robert N. Hill (Argonne National Laboratory)

19Robert N. Hill (Argonne National Laboratory)

20Robert N. Hill (Argonne National Laboratory)

Yucca Mountain Description

• Location– In Nye County, NV (1.5 persons/mi2).– Between the Mojave and the Great Basin Desert.

• Closest Residence: 14 miles away.• Land Owned By US Air Force, DOE, and US Bureau of

Land Management.• Yucca Mt. crest 1400 to 1500 m above sea level.

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Nuclear Waste Disposal(Yucca Mt., Nevada)

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24James J. Laidler (Argonne National Laboratory)

YM Water Flow Model

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• Water travels through tuff to emplacement drift.

• Capillary forces cause water to flow around emplacement drift.

• Local seepage/drips may occur.

Preliminary Repository Design

• Location– Within Topopah Spring Welded Layer– 200-500 m below the Yucca Mountain Peak– 300 m above the water table

• Waste Package Materials– Waste Package: Steel Alloy 22 (MP: 1,375 ºC)– Drip Shield: Titanium 7 (MP: ~1,660 ºC)

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Yucca Mountain Geology

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35 MILES OF TUNNELS The repository rests 1,000 feet below the surface and midway between the mountain's peak and the water table. Some 70,000 metric tons of waste will be placed in 35 miles of tunnels and actively monitored for as long as 300 years. Some five miles of tunnels, shown in red, have been bored for experimental purposes so far.

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Yucca Mountain Geologic Setting

• Fractured Volcanic Tuff• Unsaturated Zone Hydrogeologic Layers– Tiva Canyon Welded (TCw)– Paintbrush Nonwelded (PTn)– Topopah Spring Welded (TSw)– Calico Hills Nonwelded (CHn)– Crater Flat Undifferentiated Units (CFu)

• Local Faulting

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Tunnel Boring Device

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Emplacement Drift Schematic

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QUESTIONS