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