Information Notice No. 90-56: Inadvertent Shipment of a Radioactive Source in a Container Thought to Be Empty

                                UNITED STATES
                           WASHINGTON, D.C.  20555

                              September 4, 1990

                                   SOURCE IN A CONTAINER THOUGHT TO BE EMPTY 


All U.S. Nuclear Regulatory Commission (NRC) licensees. 


This notice is provided to inform licensees of a recent transportation 
incident that could have resulted in significant radiation exposures to 
workers or members of the public.  This notice also serves to remind 
licensees of their responsibilities when importing radioactive materials or 
when shipping packages. 

It is expected that licensees will review this information for applicability 
to their licensed activities and consider actions, as appropriate, to avoid 
problems when importing radioactive materials or shipping packages.  
However, suggestions contained in this notice do not constitute any new 
requirements, and no written response is required. 

Description of Circumstances: 

On March 8, 1990, Amersham Corporation (Amersham), Burlington, 
Massachusetts, an NRC licensee authorized to manufacture and distribute 
iridium-192 and cobalt-60 sealed sources for use in industrial radiography 
equipment, received a Model 500-SU source changer from its Korean product 
distributor.  In accordance with shipping documents, Amersham expected the 
source changer to be empty.  However, as an Amersham technician approached 
the source changer, his audible alarming dosimeter indicated increased 
radiation levels.  Radiation dose rates measured as high as 10 rem per hour 
at approximately 18 inches and 150 rem per hour on contact.  Amersham later 
discovered that the source changer contained a 2.4-curie, iridium-192 source 
capsule in an unshielded portion of the changer. Because the source changer 
was transported cross-country by domestic motor carrier, the potential 
existed for significant radiation exposure to a variety of individuals.  A 
more detailed description of the incident is enclosed in Attachment 1. 


NRC shares regulatory responsibility with the U.S. Department of 
Transportation (DOT) for transportation of radioactive materials.  NRC 
regulations for transportation of radioactive materials are codified in 10 
CFR Part 71, "Packaging and Transportation of Radioactive Material."  NRC 
regulations in 10 CFR 71.0(b) state, in part, "The packaging and transport 
of licensed material are also subject ... to the regulations of other 
agencies (e.g., the U.S. Department of Transportation and the U.S. Postal 
Service) having jurisdiction 


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over means of transport."  DOT's hazardous materials regulations are 
codified in 49 CFR Parts 100-180.  A provision of NRC regulations in 10 CFR 
71.5(a) effectively requires that all licensees (who transport or deliver to 
a carrier for transport), follow DOT's hazardous materials regulations in 
Title 49. 

NRC regulations in 10 CFR 110.27(a)(3), "Export and Import of Nuclear 
Equipment and Materials," authorizes any person to import byproduct material 
if that person is authorized to possess the materials under a specific 
license that has been issued by NRC or an Agreement State.  DOT regulations 
for the import and export of radioactive materials are specified in 49 CFR 
171.12, "Import and export shipments."  49 CFR 171.12(a) requires, in part, 
that each person importing a hazardous material into the United States shall 
provide the shipper (foreign exporter) and freight forwarder complete 
information as to the requirements of the DOT hazardous materials 
regulations that apply to the shipment within the United States. 

10 CFR 20.205 specifies package receipt and opening requirements for NRC 
licensees.  Pursuant to this section, licensees are required to report to 
NRC when receiving certain packages exhibiting excessive contamination or 
radiation levels.  In addition, pursuant to 10 CFR 71.95, NRC licensees are 
required to report "... any instance in which there is a significant 
reduction in the effectiveness of any NRC authorized packaging during use."  
DOT regulations in 49 CFR 171.15 and 171.16 require carriers to immediately 
report to DOT any incidents, during transport of hazardous materials, when 
there are fatalities, injuries involving hospitalization, $50,000 property 
damage, and, in the case of radioactive materials, "... fire, breakage, 
spillage, or suspected radioactive contamination...." 

Amersham provided an operations manual, with every Model 500-SU source 
changer, that included instructions to users for returning empty source 
changers.  These instructions described procedures for preparing an empty 
source changer containing depleted uranium (DU) shielding as an "excepted" 
package, provided the surface radiation level was below 0.5 mR/hr.  However, 
NRC determined that the surface radiation levels on the source changer 
involved in this incident exceeded the acceptable level.  The Amersham 
operation manual did not explain how to prepare the package (empty source 
changer), when the radiation level exceeds 0.5 mR/hr. 

The Model 500-SU operations manual also informed the user to "... assure 
that there is no source in the container."  However, the manual did not list 
specific procedures to make this determination.  Ordinarily, a visual 
examination would verify the presence (or absence) of a source assembly, as 
the connector end of the assembly would be evident.  However, a visual 
examination would not have revealed the source in this incident because the 
source was cut from the source assembly.  A surface radiation survey could 
also be used to detect a source in a changer.  However, NRC determined that 
even for a changer containing a 3-curie source, the surface readings would 
be indistinguishable from readings obtained from the DU shield of an empty 
source changer.  Amersham estimated that the minimum source activity 
detectable through the DU shielding of the Model 500-SU is 4 curies. 

The incident described in Attachment 1 could have resulted in significant 
radiation exposures to workers or members of the public.  The incident and 
the forementioned discussion demonstrate the importance of doing the 

                                                       IN 90-56 
                                                       September 4, 1990 
                                                       Page 3 of 3 

1.   Licensees who may be importing radioactive materials are advised to 
     review DOT's regulations in this area and are reminded of their 
     responsibility to inform foreign exporters of proper packaging, 
     labeling, and other requirements concerning transport of radioactive 
     materials in the United States.

2.   Licensees shipping packages that incorporate DU shields are reminded 
     that complete and accurate radiation surveys must be conducted to 
     verify proper shipping requirements, since DU containers may exceed 0.5 

3.   Licensees returning shielded packages that do not contain radioactive 
     material, especially those packages that incorporate DU shields, are 
     cautioned that complete and accurate radiation surveys must be 
     performed, and that a physical probe of the package may be necessary to 
     verify that the package does not contain radioactive materials.

4.   Manufacturers who receive returned packages should ensure that they 
     provide complete instructions to customers for properly verifying that 
     packages are empty as well as for meeting restrictions on surface 
     radiation levels.  Licensees that return such packages should ensure 
     that these procedures are strictly followed.

5.   Licensee are reminded of the need to evaluate incidents for their 
     actual and potential safety consequences.  Responsible individuals 
     should review even minor incidents for unexpected consequences and to 
     determine if there are any requirements for reporting the incident to 
     NRC or DOT.  Even if there does not appear to be an applicable 
     reporting requirement, or if there is some uncertainty about reporting 
     requirements, licensees are encouraged to discuss events with the 
     appropriate regulatory agency.  Transportation incidents should be 
     reported to DOT's National Response Center at (800) 424-8802. 

No written response is required by this information notice.  If you have any
questions about this matter, please contact the appropriate regional office 
or this office.  Questions concerning DOT requirements should be directed to 
Michael Wangler, Chief, Radioactive Material Branch, Office of Hazardous 
Materials Transportation, DOT (202) 366-4545. 

                                  Richard E. Cunningham, Director 
                                  Division of Industrial and 
                                    Medical Nuclear Safety 
                                  Office of Nuclear Material Safety 
                                    and Safeguards 

Technical Contact:  J. Bruce Carrico, NMSS
                    (301) 492-0634 

1.  Description of Incident
2.  Examples of a Source Assembly and
      a Model 500-SU Source Changer
3.  List of Recently Issued NRC Information Notices 

Page Last Reviewed/Updated Thursday, March 25, 2021