The
NIST (National Institute of Standards and Technology) determined that 24.9 microCuries of
Cf-252 is being considered lost after performing an examination of inventory records. The missing material was identified during a leak test conducted on Wednesday August, 9, 2017. After identification of the missing material,
NIST performed a physical inspection of all laboratories and examined physical inventory records.
NIST has identified that there is a potential for this material to have been shipped to the Department of Energy and is still awaiting a response to verify that information.
NIST has performed a courtesy notification to the NRC R1 (Ullrich) and PM (Naquin) regarding this incident.
- * * RETRACTION AT 1631 EDT ON 8/16/2017 FROM MANUEL MEJIAS TO MARK ABRAMOVITZ * * *
The purpose of this communication is to provide additional details surrounding the circumstances that have led to location of the Cf-252 source reported as missing under 10CFR20.2201(a)(i) at 14:54EDT on 8/14/2017. A call to the Ops Center was made today at 16:31EDT. The purpose of the call was to retract Event #52900 after successfully locating the source with NIST unique identifier number RS75-0086 (known by the Department of Energy as NS-86). The source was located inside a restricted area, the same room where the empty storage container was located.
After reporting event #52900, at my direction as Radiation Safety Officer and with the support of NIST Senior Management, multiple efforts were started to investigate the probable disposition of the source (also as directed by 10CFR20.2201(b)(iii)). During those efforts, all records for shipments of Cf-252 were reviewed and colleagues at the DOE were contacted to exhaust the possibility that the material had been transferred out of NIST. Having no record of the source departing the facility, a new round of radiological surveys was started of the restricted facilities where the source had been previously authorized. After removal of all other neutron-emitting shielding containers from the immediate area, a residual field of neutron radiation was detected. This seemed indicative of the presence of a source. At this time it was observed that a radioactive source was outside of the storage containers. This source is/was of very small dimensions [approximately one inch in diameter]. The source matched the description and nearby was found the hazards information tag that corresponded to RS#75-0086.
Given that the source was always in a restricted area with low-occupancy, we have determined that no hazards to individuals have resulted from this source misplacement.
Notified ILTAB (Ahern), R1DO (Gray), and NMSS Events Resource (via e-mail).
THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL
Sources that are "Less than
IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as
moisture density gauges or thickness
gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to
http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf