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