NORM in Scrap Metal Richard van Sonsbeek The

NORM in Scrap Metal. . . Richard van Sonsbeek The RTD Group Röntgen Technische Dienst bv Dept. Radiation Protection Services P. O. Box 10065 3004 AB Rotterdam The Netherlands Phone +31 (0)10 2088229 Fax: +31 (0)10 4158022 e-mail: r. van. sonsbeek@rtd. nl

The Dutch approach The RTD Group

Melting radioactive material with scrap metal The RTD Group § 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

Measures to avoid risks The RTD Group § 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

Portal detector The RTD Group

Legal framework The RTD Group § 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

Radiation Protection Ordinance The RTD Group § 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)

Work activities The RTD Group § 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;

Limits for work activities The RTD Group

Guideline for Metal Recycling Industry The RTD Group § 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.

Advice in guideline Perform measurements on each incoming load of scrap with appropriate radiation detection equipment, and by sufficiently trained personnel The RTD Group

Further investigation to be performed by the trader The RTD Group § 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 > 20 Sv/h or 200 times background: report directly to VROM Inspectie, and keep at a distance.

Report to VROM Inspectie § Result of the further investigation § Scrap Metal trader shall propose a Solution The RTD Group

Two possible solutions § Return container to sender without opening it. § Have load inspected, and sorted out The RTD Group

Returning load to sender The RTD Group § 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

Inspection, and sorting § Expert company with license (RTD) § Plan of action must be approved by VROM Inspectie The RTD Group

Plan of Action: preparation The RTD Group § Radiation expert, minimum level 3 with sufficient experience § Appropriate radiation detection-, and personal protection equipment § Packing material § Shielding material (if necessary) § Transport container

Plan of action: steps The RTD Group § 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

Analysis of radioactive objects The RTD Group § § § Dose rate measurements Contamination measurements Take Samples Take Pictures Record marks

Final actions The RTD Group § 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 RTD’s premises § Check used equipment, floor, and container for contamination

Report The RTD Group § § § § § 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

Treatment of isolated radioactive objects -1 The RTD Group § 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

Treatment of isolated radioactive objects -2 The RTD Group § 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

Number of incident reports The RTD Group § 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

Summary of incidents 1996 -2002 The RTD Group § 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

Trends § Number of reports on loads of scrap metal increased almost monotonously from 39 in 1996 to 208 in 2002, and is still increasing; The RTD Group

Maximum dose received by radiation expert The RTD Group § 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 < 0, 25 m. Sv/year (also due to other radiological work)

NORM in scrap metal The RTD Group § 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

Contaminated beer barrels The RTD Group

Information on beer barrels The RTD Group § 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

X-ray of one beer barrel The RTD Group

Content beer barrel The RTD Group

Results The RTD Group § 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

Conclusion -1 The RTD Group § 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;

Conclusion -2 The RTD Group § 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

Decree on radioactively contaminated scrap § Obligation to perform measurements, and keep registry of these measurements; § Obligation to train personnel The RTD Group

Test protocol Portal detectors The RTD Group § 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 n. Sv/h

Training of personnel The RTD Group § 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

That’s all folks!!! The RTD Group