On January 22, 2005 a radiation protection technician discovered that a radiation detector calibration source was missing from its locked storage cabinet. An investigation was initiated and efforts to locate the source continue but the source has not been located. The source is approximately 2 inches in diameter in the form of a metal disc containing 0.0154 micro-curies of Thorium-230 that is used to calibrate SAC-4 alpha counters. The source is labeled and poses no radiological hazard to individuals that could unknowingly be in close proximity to it. The source was last used to calibrate a SAC-4 alpha counter on 1/20/2005.
10CFR20.2201(a)(1)(ii) requires a telephone report to the Operations Center in accordance with 10CFR50.72 within 30 days of the loss of licensed material in a quantity greater than 10 times the quantity specified in Appendix C to Part 20. The quantity specified in Appendix C for Thorium-230 is 0.001 micro-curies; therefore, this report is required.
The licensee notified the NRC Resident Inspector.
