The following information was received from the State of
Illinois via email:
On February 23, the licensee's radiation safety officer (RSO) called to advise that a sealed source of Cs-137 became separated from its handling rod within a fixed gauge and was now resting at the bottom of a seven foot 'well tube' within a nine foot conical reaction process vessel on their property. The well tube is centered on the vertical axis of the vessel and provides a protected environment for the source holder and rod. Previously the vessel had been emptied for routine maintenance and was being returned to service when the event took place. The current configuration is similar to that of its routine operating configuration other than the gauge is now 'always on' and cannot be returned to its normal shielded position, should the need exist. The plant plans on returning the vessel to service and refilling the vessel with reactants. This material should provide additional shielding such that accessible surface dose rates of the vessel are less than 1 mR/h.
The licensee is making arrangements with the manufacturer to come to the site and recover/dispose of the gauge and the source. Until that time, on site safety personnel and the process operating engineers have been advised of the situation and of the necessary precautions to observe should it become necessary to empty the vessel under emergency conditions. Under no circumstances will individuals be allowed access to the interior of the vessel without otherwise receiving explicit approval for the activity.
Pending recovery of the source by the manufacturer and receipt of the formal written report from the licensee, this matter remains open. No investigation by the Agency [Illinois Emergency Management Agency] is planned at this time.
Fixed Gauge Manufacturer: Kay-Ray/Sensall
Model Number: 7065
Serial Number: 28219
Source: Cs-137
Activity: 0.027 Ci
Illinois Incident #: IL16001