International Atomic Energy Agency IX.4.6. Management of disused sealed sources Technical options...

International Atomic Energy Agency

IX.4.6.IX.4.6.Management ofManagement of

disused sealed sourcesdisused sealed sources

Technical options and safety aspects


ScopeScope

• Introduction

• Integrated source management strategy

• Categorization of disused sources

• Conditioning and packaging of disused sources

• Storage of disused sources

• Disposal of disused sources

• Conclusions


IntroductionIntroduction

• Disused sealed radiation sourceA source permanently sealed in a capsule, or closely bonded and in a solid form, emitting ionizing radiation and that is no longer in use or intended to be used

• In use since 1901; until 1940 limited to radium used in medicine thus resulting in widespread storage of radium needles

• Today, widely used in medicine, industry, agricultural, research and consumer products

• Physically small, but contain high concentrations of radionuclides• Require heavily shielded containers for safe use, transport and

storage

• Give rise to serious safety problems if not managed properly


Introduction Introduction

• Poor management practices resulted in disused sources being stored in unsatisfactory conditions or no longer under regulatory control.

• Deliberate and malicious acts involving disused sources• Cs-137 container placed in Moscow park (1995) by terrorists

• Lithuania - persons arrested with Cs-137 in their possession (Vilnius, 2002)

• Accidents involving abandoned, lost or stolen gamma-radiation sources• Cobalt-60 in Juarez, Mexico, 1983

• Cesium-137 in Goiania, Brazil, 1987

• Others include accidents• Morocco (eight fatalilities)

• Shanxi Province in China (54 injured, 4 fatalities)


Activity ranges of radiation sources

Miscellaneous waste containing DSRS


Sr-90 radioactive sourcerecovered in the Rep. of Georgia Sources used in mobile caesium

irradiators in the former Soviet Union

Miscellaneous waste containing DSRS


The MessageThe Message

Clearly, an integrated strategy for lifecycle management of disused sealed radiation sources is needed.


Disused source

Characterising(potential use)

Non-usable source Usable source

Leaking source Non-leaking source

Packaging

Characterising(nuclide, half-life)

Return tosupplier

Transfer to another user

Potential use

Very short-lived Short-lived Long-lived

Clearancelevelsmet?

Decay storage

Transportation

LandfillDisposal?

Conditioning Conditioning

Long-terminterim storage

Transportation Transportation

Near-SurfaceDisposal?

GeologicalDisposal?

DS-160, Integrated SourceDS-160, Integrated SourceManagement StrategyManagement Strategy

• Establish a national inventory• Locate and transport disused sources to storage facilities TECDOC-804

• Characterize the sources and categorize them for storage TECDOC-1344

• Conditioning and packaging of sources for storage and/or disposal TECDOC-886

• Disposal of conditioned disused sources Draft TECDOC• Security of Sources, TECDOC-1355

• Code of Conduct


Categorization of disused sources (1)Categorization of disused sources (1)

• IAEA TECDOC 1344 (Categorization of radioactive sources)• To provide a simple, logical system for ranking radioactive sources

• Their potential to cause harm to human health

• Group practices in which sources are used into discrete categories

• To provide a fundamental and internationally harmonized basis for risk-informed decision making

• Used as an input to activities relating to the safety and security of radioactive sources

• Develop or refine (inter)national safety standards

• Develop or refine national regulatory infrastructures to meet the State’s requirements

• Optimize decisions about priorities for regulation within resource constraints

• Optimize security measures for radioactive sources, including potential malicious use

• Emergency planning and response

• Develop national strategies for improving control over radioactive sources

• Each category contains a mixture of radionuclides, half-lives


Storage of disused sources Storage of disused sources (1)(1)

Issues to consider• For many countries, it is the only option available

• Storage conditions not always satisfactory

• Most sources remain in storage pending the availability of a suitable disposal option

• Adequate final management option for sources containing short-lived radionuclides

• Centralized storage facility for a country/region

• Various options can be used as storage facilities• Shipping container

• Corrugated iron shed

• Below surface (basements)

• Boreholes

• Record keeping and radiation protection principles essential


Storage of disused sources (2)Storage of disused sources (2)


Disposal of disused sources (1)Disposal of disused sources (1)

Issues to consider• Specific activity of many disused sources exceed the waste acceptance

criteria for near-surface disposal facilities for low- and intermediate level waste

• Constitute high, localized concentrations (hot spots), resulting in unacceptable risk during human intrusion conditions

• Reasonable assurance of compliance with safety requirements not always adequately demonstrated in cases where it has been implemented

• Assumed institutional control not always the answer

• Disposal facilities providing higher levels of isolation is required

• Geological disposal is a possibility, but may not be available to many

• Countries lack an infrastructure for long-term waste management

• Borehole disposal of disused sealed radioactive sources

International Atomic Energy Agency IX.4.6. Management of disused sealed sources Technical options...

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