ENS 46205
ENS Event | |
|---|---|
14:15 Aug 24, 2010 | |
| Title | Level Detection Gauge Shutter Control Rod Disengaged |
| Event Description | After completion of casting operations at our #1 Slab Caster, a trained worker proceeded to the mould strand area to remove the Berthold Co-60 rod source from the mould and place it in proper storage. The source is 3.97 mCi and is used to measure mould level of liquid steel. After properly securing the source into its shielded source holder, the trained worker began transporting the holder to the storage cabinet. During transport, the holder fell over and hit the ground. When it hit the ground, the steel 'D' arm (for lifting the holder) structure on the outside of the holder was bent.
Also, the device is designed such that the source insertion/removal rod is stored on the outside of the holder. It actually slides through openings on the 'D' arm and screws into the shutter door when in the closed position. After the fall, the threaded portion of the shutter door which receives the insertion rod broke. I immediately removed the rod and replaced it with a positive lock. During this event, the source rod and its shielding were not compromised and there was no exposure to employees. Also, we are making immediate modifications to the transporting device to prevent this from recurring. The shutter was closed throughout this event.
The licensee is retracting this report based on the following text provided by the ArcelorMittal Burns Harbor Radiation Safety Officer (RSO): Further investigation has revealed new information which we feel warrants a retraction of the reported event as a non-reportable event. Originally, we stated that the Co-60 source rod was removed from the mould and safely inside the holder (post-casting) when the holder fell over, however, it was actually not in the holder. The source rod had actually been properly installed in the mould (pre-casting), and the employee was actually returning the empty holder to the storage cabinet when the holder fell over. I also have three very important attachments. One is our Steel Producing department's preliminary investigation report which reveals more accurate facts of the event. The second is a quote from Berthold's Source and Device Registry document which can be interpreted as indicating that the insertion rod screwing into the shutter 'door' is not part of a safety design function of the device (see attached photo). The photo shows a positive lock installed on a separate portion of the shutter 'door' which serves as the actual safety locking function. The insertion rod screwed into the shutter 'door' serves merely as a storage location for the insertion rod when the device is not in use. Therefore, the damaged (de-threaded) opening on the shutter 'door' which receives the insertion rod is strictly for insertion rod storage only. Also, the insertion rod and its threading were not damaged in this event. The insertion rod itself is still able to be installed into its stored position (without being screwed-in) and can be used in operations if necessary. Lastly, we would have redundancy of insertion rods if necessary. Further, there was no loss of functionality to the source holder, Co-60 source rod, or shutter mechanism as a result of this event, and the shutter is still lockable. The device is fully functional and no safety features have been breached. Nonetheless, I have taken the device out of service and secured it in a location controlled by me as RSO. I've begun the process of having the manufacturer repair the device. The above information was discussed with the NRC Region III staff prior to submittal as a retraction. Notified R3DO (Lara) and FSME (McIntosh). |
| Where | |
|---|---|
| Arcelormittal Burns Harbor Burns Harbor, Indiana (NRC Region 3) | |
| License number: | 13-32670-01 |
| Organization: | Arcelormittal Burns Harbor |
| Reporting | |
| 10 CFR 30.50(b)(2), Licensed Material Protection Equipment Failure | |
| Time - Person (Reporting Time:+19.58 h0.816 days <br />0.117 weeks <br />0.0268 months <br />) | |
| Opened: | Chris Sarvanidis 09:50 Aug 25, 2010 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Aug 26, 2010 |
| 46205 - NRC Website | |
Arcelormittal Burns Harbor with 10 CFR 30.50(b)(2) | |
WEEKMONTHYEARENS 511222015-06-04T12:30:0004 June 2015 12:30:00
[Table view]10 CFR 30.50(b)(2) Stuck Gauge Shutter ENS 463412010-10-18T11:00:00018 October 2010 11:00:00 10 CFR 30.50(b)(2) Stuck Gauge Shutter ENS 462052010-08-24T14:15:00024 August 2010 14:15:00 10 CFR 30.50(b)(2) Level Detection Gauge Shutter Control Rod Disengaged ENS 461542010-07-22T06:30:00022 July 2010 06:30:00 10 CFR 30.50(b)(2) Nuclear Gauge Dislodged from Steel Caster and Later Retrieved 2015-06-04T12:30:00 | |