Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
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.
9004040223
.
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.
.ENDEND
