United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 90-24: Transportation of Model Spec 2-T Radiographic Exposure Device

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
              OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
                           WASHINGTON, D.C.  20555

                               April 10, 1990


Information Notice No. 90-24:  TRANSPORTATION OF MODEL SPEC 2-T 
                                   RADIOGRAPHIC EXPOSURE DEVICE 


Addressees:  

All NRC licensees authorized to use, transport, or operate radiographic 
exposure devices and source changers. 

Purpose: 

This information notice is provided to alert licensees of a recent change in 
the NRC Certificate of Compliance No. 9056, which imposes more restrictive 
requirements for proper transportation of the model SPEC 2-T radiographic 
exposure device. 

It is suggested that licensees review this information for applicability to 
operations involving transportation of radiography devices, and distribute 
it to persons responsible for proper transport of devices.  However, this 
notice does not constitute new NRC requirements, and no written response is 
required. 

Description of Circumstances: 

A certificate of compliance is issued by the NRC when a specific package 
meets the requirements of 10 CFR Part 71 and is approved by the NRC for 
transport of radioactive material.  Conditions for proper transportation of 
the model SPEC 2-T radiographic exposure device are stated in NRC 
certificate of compliance (COC) No. 9056 (Attachment 1).  These conditions 
augment the requirements of the U.S. Department of Transportation and 10 CFR 
Part 71 of the Commission's Regulations for the transportation of 
radioactive materials. 

Prior to this recent change, the COC specified that for transportation of 
more than 110 curies of iridium-192, the radiographic exposure device must 
either be within a protective overpack or transported by exclusive use 
shipment in accordance with the requirements of 49 CFR 173.441(b).  The 
purpose for this condition was to assure that the radiation dose rate on the 
surfaces of the radiographic exposure device or its overpack did not exceed 
200 millirem per hour.  






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                                                            IN 90-24 
                                                            April 10, 1990 
                                                            Page 2 of 2 


The NRC was informed that the surface dose rate on the radiography device 
could exceed 200 millirem per hour when loaded with 110 curies of 
iridium-192.  Apparently, the radiation measurements used to determine the 
110 curie maximum activity were not corrected for the distance between the 
surface of the device and the effective center of the radiation measurement 
instrument.  This correction was because of the small dimensions of the 
model SPEC 2-T depleted uranium shield. 

Discussion: 

The staff evaluated the information obtained from previous radiation 
measurements and determined that the dose rates had been underestimated.  
The maximum activity in the model SPEC 2-T device that corresponds to a 
surface dose rate of 200 millirem per hour is 45 curies of iridium-192.  As 
a result, conditions 8 and 9 of the NRC's COC No. 9056 were amended to 
specify 45 curies instead of 110 curies.  Also, the maximum quantity of 
iridium-192 per package was reduced from 240 curies to 225 curies. 

Users of the model SPEC 2-T device should be aware of the enclosed amended 
COC No. 9056 issued on February 21, 1990.  Users should also note that a 
radiation survey must be made prior to each shipment to ensure that the 
external radiation levels of the devices or the overpack do not exceed the 
limits specified in 10 CFR 71.47, and 49 CFR 173.441. 

This information notice does not require any written response to the NRC.  
If you have any questions about this matter, please contact the appropriate 
NRC regional office or this office. 




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

Technical Contact:  Steven L. Baggett, NMSS
                    492-0542

Attachments:
1.  NRC Certificate of Compliance
      No. 9056.
2.  List of Recent NMSS Information Notices.
3.  List of Recent NRR Information Notices.
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