Environmental aspects of Uranium Enrichment

Presentation for Finnish Young Generation

Helsinki, 3 November 2006

Pieter Kleerebezem

Chair Dutch Young Generation

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Content

• Introduction

• The Urenco Group

• Nuclear energy cycle

• Environmental aspects

• Safety aspects

• Summary / Conclusion

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The Urenco Group

Urenco Enrichment

Company Ltd

Urenco Inc.

Urenco Investments Inc.

100 % 100 %

50 %50 %

Enrichment Technology

Company Ltd

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Fuel cycle, overview

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Fuel cycle, mining

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Conversion factories:

• Comurhex (France)• ConverDyn (USA)• Cameco (Canada)• BNFL (UK)• Minatom (Russia)

Fuel cycle, conversion

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Enrichment with Gas centrifuges or Gas diffusion,

Laser is not (yet) feasable

Fuel cycle, enrichment

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Fuel cycle, how the centrifuge works

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Fuel cycle, the cascade

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Fuel cycle, players on the enrichment market 2005

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Fuel cycle, plant & storage

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Environmental aspects

• Containment, normal operation

• Lack of containment

- What can happen

- How serious can it be

- We talk about a safety issue

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Environmental aspects, the cascade

Cooling

Cooling

Hot box with UF6 transport

container

Separation in Centrifuge Cascades

Compressor

Depleted UF6

Cooling box with transport container with enriched UF6

Compressor

Enriched UF6

UF6

Sub-atmospheric Pressure

Heating

Cooling box with transport container with depleted UF6

2.000 kg

10.000 kg

10.000 kg

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Enviromental aspects, the cascade

Cooling

Cooling

Hot box with UF6transport container

Separation in Centrifuge Cascades

Compressor

Depleted UF6

Cooling box with transport container with enriched UF6

Compressor

Enriched UF6

UF6

Sub-atmospheric Pressure

Heating

Cooling box with transport container with depleted UF6

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Environmental aspects, emissions of the cascade

UF6 (Feed)

Electricity

Water

GasTails (depleted UF6)

Radiation

Cooling

Cooling

Hot box with UF6transport container

Separation in Centrifuge Cascades

Compressor

Depleted UF6

Cooling box with transport container with enriched UF6

Compressor

Enriched UF6

UF6

Sub-atmospheric Pressure

Heating

Cooling box with transport container with depleted UF6

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Environmental aspects, enrichment

• Input

- UF6, Electricity

• Output

- Tails, Product

- Radiation

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Environmental aspects

• Enrichment of uranium has minimal influence on the environment in normal operation because there is a “containment” (closed loop system)

• What if “lack of containment”, then a safety issue

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Safety aspects

• Criticality

• Lack of containment

• Prevention

• Radiation of UF6 is minimal, it’s chemic toxic!

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Safety aspects, criticality

• A system with fissionable material is critical ifselfsustaining fission occurs

• Prevent criticality by design/process or doublecontingency

Double contingency: at least a combination of twounlikely and independend events must take place before safety limits can be exceeded

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Safety aspects, criticality prevention

• Safe geometry / Process- D˜ 200mm or H˜ 100mm or Volume˜ 20liter,

if not exceeded the critical mass can not be reached

• Double contingency- Enrichment < 1%, no reaction can occur

- Container and < 12 liter water

- Water and < 15 kg uranium

Remark: all values depend on percentage of enrichment

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Safety aspects, lack of containment

• Content UF6 in a cascade, 10 kg

• Airplane crash

• Consequenses

- Detectable on area of Urenco, or outside

- Effect on people

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Safety aspects, lack of containment

Cascade content, airplane crash

• Reaction of UF6 with air/water

• 4HF is gasseous, hydrogen fluoride and is a poissonous gas forhumans.

• UF6 starts to smoke if it reacts with atmosphere

• UF6 cannot explode if it reacts with atmosphere

HFFUOOHUF 426 222 +⇒+

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Safety aspects, containers

• The Feed, Tails and Product containers are testedaccording to international standards.

- Fire test

- Drop test

- Pin test

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Summary / Conclusion

• Environmental impact of enrichment is minimal (containment)

• Safety measures are high in enrichment proces

• Airplane crash, local impact but severe

• UF6 reacts with H2O => chemic toxic gas, not explosive

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Questions?

Sources: ET NL, Urenco website, interview Urenco employees