On October 8, 1993, personnel at the Sandia National Laboratory discovered a pig holding a one mCi plutonium-239 radiation source in an uncontrolled area. Health Physics technicians determined that the source contained no removable contamination, and returned it to a controlled storage area. Facility personnel reported that the source is occasionally used by an employee to calibrate a micro calorimeter, and, when not in use, the source is stored in the controlled area. Event investigators determined that the employee who uses the source does not wear a dosimeter and has not received radiation worker safety training. The employee was instructed to wear a dosimeter when working with the source and to request surveys from Health Physics before any movement. (ORPS Report ALO-KO-SNL-2000-1993-0006)
Research of the ORPS database indicated various events at this facility classified as a loss of control of radioactive materials. Examples of these events include the following.
On June 24, 1993, Health Physics technicians surveyed items in the display cases in the lobby of a building and discovered four radioactive items with activity levels ranging from 4,200 to 70,000 dpm/100cm2 beta/gamma fixed. (ORPS Report ALO-KO- SNL-9000-1993-0002)
On June 3, 1993, Health Physics personnel discovered five items (pieces of depleted uranium, a stainless steel part, and one military voltage arrester) with radiation readings located in and near an oscilloscope cart outside of a radiological controlled area. The uranium was discovered in the drawer of the oscilloscope cart. (The largest piece was 545.42 grams). The radioactive stainless steel part was located in a cardboard box on a pallet, and the voltage arrester was labeled as containing 30 micro curies of promethium-147. However, the isotope had apparently decayed as no indication of the nuclide was detected by measurement equipment. Activity levels of the four remaining items ranged from 5,000 to 15,000 dpm/100cm2 beta/gamma removable; 30,000 to 750,000 dpm/100 cm2 beta/gamma fixed; and 40,000 to 300,000 dpm/100cm2 alpha fixed. (ORPS Report ALO-KO-SNL-9000- 1993-0002)
On August 18, 1992, a Health Physics technician found a depleted, uranium- contaminated lithium/sulfur dioxide battery pack in an equipment cabinet outside of a radiological controlled area. The technician also discovered ten contaminated zip-lock bags and seven vials containing one percent uranium oxide in a workbench drawer. (ORPS Report ALO-KO-SNL-TA2IGLOO-1992-0004)
On June 27, 1992, Health Physics personnel discovered depleted uranium in an empty trash can in an uncontrolled area. Activity of the uranium measured by Health Physics personnel was found to be 6,000 dpm per direct frisk beta gamma fixed and 184 dpm/cm2 loose beta and 40 dpm/cm2 loose alpha contamination. Investigators concluded that the policy for handling and use of depleted uranium as a radioactive material was not adequate. (ORPS Report ALO-KO-SNL-TA2IGLOO-1992- 0003)
On June 26, 1992, personnel mistakenly used a tritium source for a study instead of a nickel-63 source. As a result, tritium contamination levels of 2,000 to 500,000 dpm/cm2 were found on the workbench and fume hood. After the event, facility personnel committed to revise the procedure for handling and storage of sources to include independent verification that sources are properly labeled.
The October 8, 1993, event underscores the importance of properly training personnel in basic radiation worker safety. Failure to wear dosimeters while working with radioactive sources can lead to unplanned and unmonitored exposures. All of the events highlight the need for strict accountability of sources and other radioactive items. In several incidents, procedures for administratively controlling radioactive materials were either deficient or non-existent, and contaminated items were not treated as hazardous material. NS reported in OE Weekly Summary 93-40 on several similar events involving loss of accountability of radioactive sources. A review of the ORPS database in regard to radioactive materials indicated numerous problems with incorrect labeling, improper disposal, inadequate postings for storage areas, access control weaknesses, training deficiencies, and lack of procedural guidance for controlling sources.