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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 57087 | 22 April 2024 05:00:00 | Agreement State | Shutter Stuck Partially Open | The following was received from the Iowa Department of Public Health - Bureau of Radiological Health (Iowa HHS) via email: Arconic Davenport possesses an IMS Measuring System (model 5221-02 profile thickness gauge) for measuring thickness of aluminum on the production line. The C-frame gauge contains five independent source housings, with each housing containing a 5 curie, americium-241, sealed source. The C-frame gauge is constructed from steel and is suspended from a monorail which allows the device to be moved offline to a restricted access calibration area. The shutter (on each source) is opened and closed by a pneumatic cylinder that is controlled from a remote location. On the morning of April 22, 2024, it was determined that shutter number 1 of the C-frame gauge B had failed to fully close. This was determined (during) an automated attempt to close all 5 shutters on the gauge, and the computer indicated that shutter number 1 was not fully closed. Per the licensees procedures, the C-frame gauge was removed from the line using the monorail to the secured calibration house. Radiation surveys of the outside wall adjacent to the shutter 1 position were above background with a maximum dose rate of 0.1 mR/hr. The licensee has contacted their service provider to perform repair work (identify and fix the equipment problem) which is tentatively scheduled for same day or April 23, 2024. No reported overexposures have occurred because of this incident, no release or contamination of radioactive material occurred because of this incident (most recent negative leak test was November 2, 2023), and Iowa HHS will update this report once additional information is provided (cause, corrective actions, etc.). IA Event Number: IA240002 | ||
| ENS 56874 | 28 November 2023 06:00:00 | Agreement State | Partially Stuck Open Shutter | The following information was provided by the Iowa Department of Health and Human Services (HHS) via email: Arconic Davenport possesses an (Isotope Measuring Systems) IMS model 5221-02, profile thickness gauge for measuring thickness of aluminum on the production line. The C-frame gauge contains 5 independent source housings, with each housing containing a 5 curie, Americium-241 sealed source. The C-frame gauge is constructed from steel and is suspended from a monorail which allows the device to be moved off-line to a restricted access calibration area. The shutter is opened and closed by a pneumatic cylinder that is controlled from a remote location. In the afternoon of November 28, 2023, it was determined that shutter number 1 of the C-frame gauge had failed to fully close. This was determined when an automated attempt to close all 5 shutters on the gauge (failed), and the computer indicated that shutter number 1 was not fully closed. Per the licensee's procedures, the C-frame gauge was removed from the line using the monorail to the secured calibration house. Radiation surveys of the outside wall adjacent to the shutter 1 position were above background with a maximum dose rate of approximately 0.1 mR/hr. The licensee has contacted their service provider to perform repair work (identify and fix the equipment problem) which is tentatively scheduled for November 29, 2023. No reported overexposures and no release or contamination of radioactive material occurred because of this incident (most recent negative leak test was November 2, 2023). Iowa HHS will update this report once additional information is provided (cause, corrective actions, etc.). Iowa Item Number: IA230004 | ||
| ENS 56179 | 24 October 2022 05:00:00 | Agreement State | Stuck Shutter | The following report was received via email by the Iowa Department of Public Health: A fixed nuclear gauge was determined to have a stuck shutter on 10/24/2022 and reported to the Iowa Department of Health & Human Services (Iowa - HHS) on the evening that same day. The C-frame (IMS model 5221-02) profile thickness device contains five, 5-curie Americium-241 sources with each having its own shutter (total device activity is nominally 25 curie of Am-241). One of the five shutters (source holder number 2) was not working correctly. After troubleshooting (i.e., rebooting the gauge and failed standardizations) did not fix the computer error, the gauge was removed from the mill line and securely placed in the gauge house. Initial reported radiological surveys were 1.0 mR/hr directly under the shutter number 2 source holder and 11 inches above the receiver, and background around the perimeter of the secured gauge house. No personnel were overexposed from this incident, and Iowa HHS will gather additional information on what caused this equipment failure once it has been determined. The licensee's service provider was notified and is expected to be onsite for repairs on 10/25/2022. Iowa Event Number: IA220006 | ||
| ENS 56051 | 17 August 2022 00:42:00 | Agreement State | Stuck Shutter | The following report was received via email by the Iowa Department of Public Health: A fixed gauge (Isotope Measuring Systems, Inc., Model Number 5221-02, with an Am-241 5 Ci source) was given indications of improper function. When workers entered with the survey meter, they identified radiation levels were elevated, indicating a stuck shutter. The gauge and gauge assembly were rolled into an isolated and secured in a storage facility. Their service provider will be on scene tomorrow (8/18/22) to assess the fixed gauge. Initial cause is a partial closing of the shutter due to a faulty screw. The licensee in pursuing replacement of fixed gauges due to the age of the devices. Iowa Event Number: IA220005 | ||
| ENS 55763 | 2 March 2022 06:00:00 | Agreement State | Stuck Shutter Gauge | The following information was provided by the Iowa Department of Public Health via email: A stuck shutter was discovered Wednesday, March 2nd on the B-gauge, shutter 1. Entry to the gauge house has been prohibited per protocol. Measurements indicate an increase dose rate relative to background at the south side adjacent to the gauge and shutter 1 position, with a maximum reading of 0.11 mR/hr. The licensee's service provider, SenTek, has been requested to perform emergency repair work. The B-Gauge was repaired last night around 1900 CST. The shutter failed to close due to the solenoid valve that opens and closes the shutter, which would not vent pressure. The failed solenoid valve was replaced by a new valve. The project to replace these gauges with x-ray technology is ongoing and on track to be replaced by first quarter, 2023. Source/Radioactive Material: SEALED SOURCE GAUGE Manufacturer: Isotope Measuring Systems, Inc. Model Number: NOT KNOWN IAEA Category: 3 Serial Number: 2332-2336L Radionuclide: AM-241 Activity: 5 Ci (185 GBq) Iowa Event Number: IA220001 | ||
| ENS 55417 | 18 August 2021 05:00:00 | Agreement State | Stuck Open Gauge Shutter | The following information was obtained from the state of Iowa via email: On August 18, 2021, at approximately 1000 CDT, the DAV-015 #4 shutter was reported to be stuck in the open position. A survey meter measured a background level of 0.02 mR/hr outside of the gauge house, and 0.05 mR/hr inside the gauge house at that time. Locks were changed to the gauge house to prevent entry. The service company, SenTek, was notified and requested to provide service. They are expected to arrive on August 19, 2021, to provide service and repairs. This event will be updated after the service company determines the cause of the failure and the licensee provides a corrective action plan. The gauge was manufactured by Isotope Measuring Systems, Inc., model number 5221-02, serial number 2332-2336L, and contains 5 Curies of Am-241. NMED Number: IA210003
The following information was obtained from the state of Iowa via email: The SenTek service technician arrived onsite late afternoon on August 18, 2021 and determined that the bolts holding the shutter had sheared and needed to be replaced. All other shutter bolts were inspected and found to be satisfactory. As a corrective action, the licensee is implementing an annual preventative maintenance check to inspect and replace the bolts on all shutters. The licensee's intent is to replace these fixed gauging devices with x-ray tube devices. The State considers this event closed. Notified: R3DO (Riemer) and NMSS Events Notification via e-mail. |