The following was received from the
Louisiana Department of Environmental Quality (
LDEQ) via e-mail:
On December 20, 2021, at approximately 1:55 pm, Central Standard Time, [the] Radiation Safety Officer for Rubicon, LLC, notified LDEQ of equipment malfunctions. Three Ohmart Model SH-F1 level/density gauges experienced shutter malfunctions, two installed on a vessel within the MDI-III process unit and one Model SH-F1 gauge installed on a vessel in the MDI-I processing unit. The gauges in the MDI-III unit possess two nominally 20 mCi sealed sources of Cs-137 and the gauge in MDI-I possesses a nominally 70 mCi sealed source of Cs-137. The above gauges were undergoing routine annual shutter tests when the above malfunctions were observed. The first gauge sealed source, 1566CG, installed on October 15, 2001, item 73 on the licensee's source inventory, is mounted on vessel MM-9303 in the MDI-3 unit. The second gauge source, 1567CG, installed on October 15, 2001, item 74 on the licensee's source inventory, is also mounted on vessel MM-9303. The third gauge source, 72930, installed on January 19, 1998, item 38 on the licensee's source inventory, is mounted on the P1 PI scrubber in the MDI-1 unit. [The] Zone Maintenance Coordinator, notified [the RSO] concerning the shearing of screws even with the top of each rotor on the two gauges in the MDI-III unit. [The Zone Maintenance Coordinator] also reported to the RSO that the source holder in the MDI-1 unit experienced a problem with the rotor mechanism not aligning with the shutter handle, which prevented the gauge shutter from closing fully. [The Zone Maintenance Coordinator] learned of the malfunctions during annual inventory work and reported the problem to the RSO on December 16, 2021 at approximately 2:30 pm. The situation with each gauge is under the licensee's control, and there were no exposures to members of the public approaching regulatory limits. Currently, the shutters on gauges, 73, 74, and 38 remain in the open position, as the gauge sources are needed to operate process control equipment. The gauges cannot be locked out in their current state. As a result, no vessel entries will be conducted on either vessel MM-9303 or the P1 PI scrubber vessel until the gauges are repaired by BBP Sales (BBP). Work orders have been written to correct the malfunction of all three devices. The licensee will continue to monitor the gauges and their status of repair. The licensee stated they would keep the LDEQ updated on progress of the repairs."
Louisiana Event Report ID No.: LA 210012