The following information was received from the
Maine Radiological Control Program (
RCP) via phone and email:
On May 15, 2025, at 1142 EDT, Nine Dragons (ND) Paper contacted the Maine RCP and reported that the source shutter on a fixed nuclear level gauge was stuck in the open position and that the shutter on another gauge was failing to lock.
While doing routine shutdown activities to dismount a unit for pipe replacement, it was discovered that one of the fixed mounted source units (source serial number: 551-2-90, 30 mCi of Cs-137) was not able to rotate the shutter to the closed position due to the shaft spinning for the shutter mechanism. Based on this finding, the lock and tag out of the unit was stopped and all work that was planned for the pipe replacement was cancelled. There was not any exposure to any personnel and the systems are still secure in the normal operation mode. ND Paper personnel barricaded the source holder and pipe piece so there would be no unintentional work on the pipe the unit is mounted to. The pipe diameter is too small to allow personnel entry, eliminating exposure risks.
Later, while doing checks on other sources in the area it was discovered that another source (source serial number: 986-3-90, 20 mCi of Cs-137) was not able to lock its shutter. The shutter closes, as verified with a survey meter, but the locking mechanism will not operate to secure the shutter in the closed position. After discussing the issues with Berthold (the original equipment manufacturer), and mill operations, ND Paper decided to order a set of replacement holders and sources from Berthold. ND Paper will leave the units in place until Berthold is able to get replacement units and is able to schedule technicians to replace the malfunctioning gauges.
Maine RCP Event Report ID Number: ME (2025-003)