August 31, 2020 | Susan Napier-Sewell

Quick-Thinking Team Prevents Significant Spread of Contamination

What caused the breach that triggered the alarm to alert the team?

Recently, a researcher was cleaning the interior of a glovebox window when a glovebox differential pressure alarm was activated. Remaining calm, the researcher visually surveyed the glovebox work area and realized the left glovebox support ring and glove he was working in had detached outward from the glovebox port creating an opening directly into the glovebox. The researcher was able to close the gap between the glove and glovebox by pressing his shoulder into the glove ring while simultaneously pulling the left glove into the box with his right glove. Another staff member in the room notified a Radiation Protection Technician (RPT), who immediately responded and re-seated the glove ring. With the assistance of several other RPTs, the researcher was then able to exit the glovebox safely and with minor contamination on his laboratory coat.

Breach prompts lab-wide requirement to install factory-optional locking rings

To better understand why the glovebox ring dislodged from the port, glovebox technicians recreated the event. The technicians discovered that putting significant stress on a glovebox glove could move and dislodge the support ring from the glovebox port. An extent of condition review revealed that PNNL has not consistently utilized locking rings deemed optional by the manufacturer. Use of a locking ring can validate the support ring and glove are installed properly and help keep the support ring and glove in place during operation. PNNL is in the process of updating Laboratory requirements to assure all gloveboxes with push through style glove rings and ports are equipped with locking rings now.

Lessons Learned

The differential pressure alarm (design feature) on the air glovebox was helpful in alerting the researcher of the abnormal event with the glovebox. Validate assumptions during design and operations for optional components or suggestions from manufactures or staff. In this case, the manufacturer didn’t require the use of locking rings but if installed, provide validation that the support ring is installed correctly and will prevent the glove support ring from coming out of the glovebox. Although all gloveboxes with push through style glove rings and ports will soon be equipped with locking rings, staff should be mindful that applying undue pressure on glovebox gloves can result in a breach. Glovebox users can limit stress put on the glove systems by:

  • Utilizing reach tools inside the glovebox,
  • Asking for assistance from a peer for transferring items,
  • Positioning equipment for ideal movement.

This Lesson Learned was published by Pacific Northwest National Laboratory (Richland WA), Richland, WA (PNNL) and disseminated by OPEXShare, The Department of Energy.

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