Nuclear HAZMAT Event – Uncontained Radiation Source (Cs 137): Prince William County, Woodbridge, Virginia
Nuclear Event in USA on Thursday, 29 December, 2016 at 15:40 [ET] est.
AGREEMENT STATE REPORT – APPARENT UNCONTAINED RADIATION SOURCE DETECTED
The following information was received via facsimile:
“On December 29, 2016, the Office of Radiological Health (ORH) was notified that radiation had been detected on a local law enforcement officer’s personal radiation detector at the intersection of Route 123 and the I-95 southbound exit ramp in Woodbridge, Virginia. The Prince William County HazMat unit responded and identified the source as cesium-137 using a radioisotope identifier. The source was present in the grassy knoll in the median of the interchange. ORH and other agencies, including the Virginia State Police, Virginia Department of Emergency Management and FBI, participated in the initial investigation. The Virginia Department of Transportation, which had representatives at the location, has responsibility for this area and has been requested to arrange for mitigation of the source through the services of a radiation consulting company. Radiation levels were measured at about 10 mR/hr at 1.5 feet above the apparent location of the source and between 30 mR/hr and 50 mR/hr at ground level. Based on the radiation levels and the source location, no radiation exposure occurred to members of the public. The source is apparently below ground and will remain isolated and undisturbed until the Virginia Department of Transportation can arrange for the consultant to remove the item, analyze it, and arrange for its disposal. The consultant is enroute and expected to begin mitigation and disposal efforts late this afternoon. ORH is continuing its investigation and will update this notification when additional information is obtained.”
Virginia Event Report ID No.: VA-16-015
* * * UPDATE AT 1451 EST ON 12/30/16 FROM CHARLES COLEMAN TO JEFF HERRERA * * *
The following update was received from the Virginia Radioactive Materials Program via facsimile:
“On December 29, 2016, the Office of Radiological Health (ORR) was notified that radiation had been detected at the intersection of Route 123 and the I-95 southbound exit ramp near Woodbridge, Virginia. The Virginia Department of Transportation (VDOT) took mitigation action. VDOT contacted a radiation safety consulting firm which arrived at the scene that evening. A metallic pellet was found after removal of about one inch of soil. The pellet was confirmed to be a cesium-137 source with an activity of about 8 millicuries and a contact exposure rate of 900 milliRoentgen per hour. It was approximately 7 millimeters in diameter and approximately 15 millimeters long. A field leak test of the source and surveys of the area after removal of the source indicated no contamination. The source was placed in a lead shield inside a DOT 7A Type A steel drum overpack. It was sent to the consulting firm’s facility for temporary storage pending disposition. This notification will be updated if additional information becomes available.”
Notified the R1DO (Lilliendahl), NMSS (Henderson), ILTAB (Tucker) and NMSS Events (email).
IAEA Categories of Radioactive Sources
Category 1 – Extremely dangerous to the person: This source, if not safely managed or securely protected, would be likely to cause permanent injury to a person who handled it or who was otherwise in contact with it for more than a few minutes. It would probably be fatal to be close to this amount of unshielded radioactive material for a period in the range of a few minutes to an hour
Category 2 – Very dangerous to the person: This source, if not safely managed or securely protected, could cause permanent injury to a person who handled it or who was otherwise in contact with it for a short time (minutes to hours). It could possibly be fatal to be close to this amount of unshielded radioactive material for a period of hours to days.
Category 3 – Dangerous to the person: This source, if not safely managed or securely protected, could cause permanent injury to a person who handled it or who was otherwise in contact with it for some hours. It could possibly — although it would be unlikely — be fatal to be close to this amount of unshielded radioactive material for a period of days to weeks.
The size of the area to be cleaned up would depend on many factors (including the activity, the radionuclide, how it was dispersed andthe weather).
Reference: Categorization of Radioactive Sources, Table 3. Plain Language Descriptions of the Categories, 32