IAEA 1
Sources of Radiation
Fuel Cycle - Reprocessing
Day 4 – Lecture 8 (2)
IAEA 2
Reprocessing
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What is reprocessing?
Reprocessing is the separation and removal of fission products from the SNF
U, Pu may be separated and reused or stored
Fission products vitrified as HLW glass (ideally)
Many processes
wet dry transmutation
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Reprocessing
Spent Fuel
95% 238U 1% 235U 1% Pu 3% fission products
Reprocessing separates it into 3 groups
U Pu Waste
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Reprocessing
IAEA 6
Reprocessing
IAEA 7
Reprocessing
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What is the Wet Route?
shear, dissolve fuel in nitric acid clarify, solvent extraction partition U/Pu recover UO3, PuO2 powders
Purex variations most successful 99.8-99.9% recovery of U/Pu
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What are the Facilities?
Several large facilities for power reactor SNF All heavily shielded - 4 ft walls Cells, manipulators, remote operations
France - La Hague 2 plants, about 1,700 te/yr capacity running at 1,500-1,600 te/yr 1020 Bq vitrified HLW
UK - Sellafield 2 plants THORP - about 700 te/yr (800 capacity) 0.3 x 1020 Bq vitrified HLW
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Dry Reprocessing
Sometimes called pyroreprocessing, pyrometallurgical
Uses melting, electrolysis, volatilization to separate U/Pu from fission products
Proposed in transmutation schemes
Difficult to adapt to commercial fuels
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Transmutation
Perform nuclear processes and reactions on radioactive wastes to render them either non-radioactive or significantly less radioactive so that radiotoxic and disposal concerns are substantially reduced or eliminated.
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Why Transmutation?
Some Fission Products and Transuranics radioactive/hazardous for 10,000+ years and environmentally mobile
Why not transmute them into stable (nonradioactive) or short-lived materials?
Why not reduce quantities, isotopes, types going to disposal?
Ideally, only LLW disposal requirements needed Main focus on Actinides (Np, Pu, Am, Cm) Secondary focus on Tc, I, Ni, Zr Tertiary focus on Cs, Sr
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What does this mean?
Methods can reduce the risks of SNF/HLW disposal
Not obvious that any route can meet desired destruction % for LLW
All require significant money and take time
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World Commercial Reprocessing Capacity
Country Location LWR fuel
tonnes/yr
France La Hague 1,600
UK Sellafield (THORP) 1,200
Russia Chelyabinsk (Mayak) 400
Japan 90
Total 2,940
Other nuclear fuels:
UK Sellafield 1,500
France Marcoule 400
India 200
Total 2,100
Total civil capacity 5,040
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Reprocessing
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Reprocessing
Occurs 5 – 25 years after removal from reactor
Partitioning Separate individual radionuclides
Transmutation Neutron bombardment converts one
radionuclide into another with better characteristics
Radiotoxicity reduced within 1000 years
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Reprocessing
PUREX process Dissolving fuel Separation of U and Pu by solvent
extraction Remaining 3% is HLW – vitrified
pending disposal
UREX process Proposed by USA – only U recovered
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Reference
International Atomic Energy Agency, Postgraduate Educational Course in Radiation Protection and the Safety of Radiation Sources (PGEC), Training Course Series 18, IAEA, Vienna (2002)