NORM in Scrap Metal'''

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NORM in Scrap Metal...

• Richard van Sonsbeek
• Röntgen Technische Dienst bv
• Dept. Radiation Protection Services
• P.O. Box 10065
• 3004 AB Rotterdam
• The Netherlands
• Phone [phone]
• Fax [phone]
• e-mail r.van.sonsbeek_at_rtd.nl

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The Dutch approach
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Melting radioactive material with scrap metal

• Health risk for workers and public (neighbours,
  users of products)
• Contamination of foundries and the environment
• Financial consequence for company that is held
  liable
• Especially with strong artificial sources

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Measures to avoid risks

• Adding clauses in contracts stating that loads of
  scrap metal should be free of radioactive
  materials
• Check incoming loads of scrap metal for
  radioactive materials portal detectors, crane
  detectors, portable detectors
• Same precautions are taken by the (bigger) scrap
  metal traders

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Portal detector
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Legal framework

• Dutch Nuclear Energy act It is prohibited to
  possess, use, import, export, or dispose of
  radioactive substances without a license
• Suspicion to be in possession of radioactive
  substances without a license must be reported to
  the relevant authorities, i.e. VROM Inspectie,
  the Dutch Inspectorate for the environment

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Radiation Protection Ordinance

• Exemption, and clearance levels per radionuclide
  in terms of activity concentration, and total
  activity
• Summation rules for mixtures
• Distinction between practices (artificial
  sources), and work activities (sources of natural
  origin, i.e. NORM)

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Work activities

• Two limits for activity concentration
• One below which the radioactive substance is
  exempted from the regulations
• Another one, that is ten times higher, below
  which only reporting of the work activity is
  required

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Limits for work activities
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Guideline for Metal Recycling Industry

• First version drawn up in 1997
• After three revisions, and following the
  publication of the decree on radioactively
  contaminated scrap (January 2003), a completely
  new guideline has been published by VROM
  Inspectie.

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Advice in guideline

• Perform measurements on each incoming load of
  scrap with appropriate radiation detection
  equipment, and by sufficiently trained personnel

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Further investigation to be performed by the
trader

• background radiation level
• maximum dose rate
• extent, and shape of the radiation field
• origin, destination, transport company, weight
  quality, and description of the load
• If dose rate gt 20 ?Sv/h or 200 times background
  report directly to VROM Inspectie, and keep at a
  distance.

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Report to VROM Inspectie

• Result of the further investigation
• Scrap Metal trader shall propose a Solution

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Two possible solutions

• Return container to sender without opening it.
• Have load inspected, and sorted out

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Returning load to sender

• Only permitted if the maximum dose rate is
  smaller than 5 ?Sv/h
• No suspicion that the load contains a single
  concentrated source
• Declaration by sender that he will take back the
  load, and proof thereof
• Permission from VROM Inspectie
• A Dutch sender always has to have the load
  inspected, and sorted

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Inspection, and sorting

• Expert company with license (RTD)
• Plan of action must be approved by VROM Inspectie

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Plan of Action preparation

• Radiation expert, minimum level 3 with sufficient
  experience
• Appropriate radiation detection-, and personal
  protection equipment
• Packing material
• Shielding material (if necessary)
• Transport container

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Plan of action steps

• Perform radiation measurements on the outside of
  container
• Give instruction to assistants
• Put on Personal Protection Equipment
• Unload container in controlled way on liquid
  proof floor
• Check every batch that is unloaded
• Isolate radioactive objects

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Analysis of radioactive objects

• Dose rate measurements
• Contamination measurements
• Take Samples
• Take Pictures
• Record marks

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Final actions

• Pack radioactive objects or prevent radioactive
  material to disseminate
• Store radioactive objects on location, with
  appropriate instruction to the customer, or
• Transport radioactive objects for further
  analysis, or storage at RTDs premises
• Check used equipment, floor, and container for
  contamination

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Report

• Details of load
• Plan of Action
• Involved persons
• Used equipment
• Dose rates measured
• Contamination measured
• Result of laboratory analysis
• Dose to persons, and environment
• Conclusion, and advice

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Treatment of isolated radioactive objects -1

• Return to an original sender outside the
  Netherlands (transport regulations, international
  procedures, permission from VROM Inspectie,
  declarations from the sender)
• Re-use of the objects after decontamination by a
  licensed company, e.g. Reym

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Treatment of isolated radioactive objects -2

• Process the objects at Siempelkamp (Krefeld,
  Germany), if the criteria set by this company are
  met
• Dispose of the objects as radioactive waste
  directly to COVRA, the Central Organisation for
  Radioactive Waste in the Netherlands

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Number of incident reports

• Portal detectors are very sensitive
• Portal detectors do not distinguish between
  artificial radioactive sources and other
  radioactive material
• ? Lot of radioactive objects are intercepted that
  otherwise would not have been noticed, e.g NORM
  contaminated objects

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Summary of incidents1996-2002

• 1,497 reports to VROM Inspectie, of which
• 892 reports (60) concerned loads of scrap metal
• The last figure includes false alarms
• Most inspections have been performed by radiation
  experts of RTD

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Trends

• Number of reports on loads of scrap metal
  increased almost monotonously from 39 in 1996 to
  208 in 2002, and is still increasing

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Maximum dose received by radiation expert

• Average effective dose roughly estimated to be
  maximum 25 ?Sv per job (10 ?Sv due to external
  irradiation, and 15 ?Sv due to internal
  contamination)
• Total dose received by radiation expert lt 0,25
  mSv/year (also due to other radiological work)

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NORM in scrap metal

• In 2001, and 2002, about 70 of the reports on
  loads of scrap metal, concerned NORM contaminated
  objects
• About 25 to 35 of these reports concerned
  objects containing radioactive slag-wool

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Contaminated beer barrels
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Information on beer barrels

• Load originated from Turkey
• 28 contaminated barrels between other
  contaminated objects
• max. dose rate on surface of barrel 6.5 ?Sv/h
• It was decided to make an x-ray before opening
  one of the Barrels

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X-ray of one beer barrel
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Content beer barrel
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Results

• Cans contained Ra-226 scale with an activity
  concentration of 131 Bq/g
• Wilful action to illegally dispose of radioactive
  material and / or harm a competitor
• The barrels were processed at Siempelkamp

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Conclusion -1

• In the Netherlands a method has been developed in
  which loads of scrap metal are inspected, and
  sorted out safely
• Radiation dose received by workers, and general
  public due to radioactively contaminated loads
  has been very limited

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Conclusion -2

• The chance that radioactively contaminated scrap
  metal is intercepted has become higher
• More portal detectors (at the end of 2002 at
  least 66 companies have installed one or more)
• Introduction of crane detectors

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Decree on radioactively contaminated scrap

• Obligation to perform measurements, and keep
  registry of these measurements
• Obligation to train personnel

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Test protocol Portal detectors

• In a separate regulation the minimum requirements
  for radiation detection equipment are stated.
• RTD performed inter-comparison measurements on 32
  portal detectors
• All, or almost all fulfil the requirements for
  sensitivity, i.e. to be able to detect a Co-60
  source that causes a dose rate of 20 nSv/h

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Training of personnel

• Currently the training provided by RTD is the
  only one that is acknowledged by the Dutch
  authorities
• Up to an including April 2004, about 100
  employees of scrap metal traders followed our one
  day course on radiation protection

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Thats all folks!!!