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)