The following information was obtained from the State of
Illinois via email:
The Radiation Safety Office for the licensee reported a second device at their facility had a shutter mechanism failure. The shutter was found stuck in the open position on March 26, 2012 during continuation of their routine maintenance check and survey. The gauge is near the top floor of a coker drum away from any routinely occupied work station. The device/area has been posted with appropriate warning notices. Measured radiation levels appear normal for this type of device with the shutter open. There are two other gauges on this vessel which are operating normally. Operators in the area have been informed of the situation and vessel access is prohibited. The area is subject to high humidity and rust build up is the suspected cause of the shutter failure. In the past, the manufacturer has recommended covers for these devices but none are available. The licensee's consultant and the vendor have been called. Both will be on-site again on March 30, 2012 as previously arranged to service a similar other device that failed last week. They will investigate this recent failure at that time.
The gauge is an Ohmart Corp. model number SHLG-2, serial number 2605CN and contains a 5 Ci Cs-137 source.
The previous failure was reported under NRC EN# 47759.
Illinois Item Number: IL12006