Three separate tests were conducted in 2003 and 2004 at the Plutonium Finishing Plant (PFP) at the Hanford, Washington site to determine if infrared imaging can be used to detect the presence of radioactive material in various storage containers. The tests were conducted at the two most common infrared wavelength ranges used for nondestructive evaluations, 3-5 microns and 8-12 microns. The results of the tests indicate that infrared imaging can be used to detect the presence of stored radioactive materials. However, the temperature difference between the end plates and the ambient temperature is generally not large, about 1?F. Some of the end plates were much hotter than others, probably due to the amount, type, and location of the material stored in them and any packing material also stored in the containers. Although there was consistency between the three tests, there were also some inconsistencies, probably due to reflections and emissivity differences in the surface of the end plates. There was excellent consistency between the random temperature measurements made with a contact thermocouple and the infrared image. In addition, testing with the radio-reflectors indicated that the presence of stored radioactive materials in the middle of the canister can be detected easier than at the end plate. It is recommended that infrared imaging continue to be explored as a possible method to determine the contents of the storage containers. The 64 rack-mounted Model 60 containers could be scanned from a distance in less than ten minutes, and this time could be decreased even further with a shorter focal length lens on the infrared cameras. This would greatly limit personnel exposure when taking inventory of the containers.
Revised: November 10, 2005 |
Published: May 15, 2004