Robotic Technology Gives Idaho a Hand in Waste Drum Scans to Positive Reviews

Use of ultrasonic technology could lead to potential taxpayer savings of $20 million

IDAHO FALLS, Idaho — An innovative robotic technology has confirmed the integrity of most legacy transuranic waste drums at the Idaho National Laboratory (INL) Site screened so far, enabling their safe and compliant shipment to the Waste Isolation Pilot Plant (WIPP) for disposal and saving taxpayers a potential $20 million.

Since testing and implementation of the ultrasonic testing began in March, team members with Idaho Cleanup Project contractor Idaho Environmental Coalition (IEC) have scanned more than 2,000 drums of lower-contaminated contact-handled transuranic waste. Only 14% of them don’t meet minimum thickness requirements or have other anomalies, and must be placed in overpack containers prior to their shipment to WIPP.

Personnel are encouraged by these results midway through the ultrasonic testing campaign.

“We’re very pleased that we’ve surpassed the expectations of previous estimates,” said Mark Henderson, Production Planning manager for IEC. “Based on past testing of a small number of drums, it was estimated that as many as 40% of the legacy waste drums would fail inspection.”

The technology was deployed to ensure about 4,400 100-gallon drums — in storage for four or more years — meet U.S. Department of Transportation minimum thickness requirements — comparable to the width of automotive sheet metal.

If the drums meet those requirements, they can be loaded directly into shipping casks without overpacking. An overpack is a container designed to provide additional protection.

Based on results so far, Henderson estimates there is a potential $20 million savings over the cost of overpacking all 4,400 legacy waste drums.

During testing, a robotic arm with an affixed ultrasonic testing probe and high tech software scans each waste drum, providing real time data. The equipment scans more than 95% of the impact area of the drum bottom followed by the lower one-third of the drum. Just as gel is used for conventional ultrasonic testing scans, water is used to displace the air during ultrasonic testing, providing a more effective scan.

“The ultrasonic testing system is very robust,” said Henderson. “As long as we’ve kept up on preventative maintenance, it has been mechanically and electronically flawless.”

The need for this technology stems from two 2022 incidents where supercompacted waste packaged in 100-gallon drums developed pinholes and leaked while in transit to the underground waste repository in New Mexico. Both shipments were returned to the Advanced Mixed Waste Treatment Project at the INL Site for the removal of their contents and decontamination of the shipping casks.

Engineering studies indicated that drums more than five years old have the potential to develop pinholes and breach during their transport. As a conservative measure, IEC halted shipments of waste drums older than four years old, resulting in thousands of drums remaining in storage.

This work is being performed under the Resource Conservation and Recovery Act and in support of the 1995 Idaho Settlement Agreement, which requires stored legacy transuranic waste be shipped out of Idaho.

-Contributor: Erik Simpson