On April 26, 2010, while the licensee, Particle Drilling Technologies out of Houston,
Texas was performing a scheduled shutter operation check, the shutter on a Ronan Model SA1 nuclear
gauge failed to close. They were at a remote drilling site in the Pinedale, Wyoming when this occurred and was using the
gauge as generally licensed material under its
Texas license. The
gauge contains 20 millicuries of
Cesium (Cs) 137 (S/N #6198CN). The
gauge is in its normal operating position and a radiation survey conducted by the licensee indicated that radiation levels are normal. The
gauge was leak tested and the test sent for analysis. The licensee stated that there is no risk of additional exposure to their workers. The licensee is working with the manufacturer to schedule the repair of the
gauge on May 18, 2010. The licensee reported this incident to the NRC Operations Center on April 27, 2010, and it was logged until it could be determined whether this incident should be reported to the State of
Texas or the NRC. It was determined that since the event occurred in Wyoming, it is an NRC report.
On May 1, 2010, the licensee was performing shutter checks when they discovered two more shutters were stuck in the open position. These are also Ronan Model SA1
gauges that contain 20 mCi
Cs-137 sources. Their serial numbers are 6115CN and 5808CN. The vendor is still scheduled for onsite repairs on May 18.