Scientists meet to solve IWTU issues

The Integrated Waste Treatment Unit is located at the Idaho Nuclear Technology and Engineering Center west of Idaho Falls.

Scientists from around the country met in Idaho Falls this week to try and solve technical problems that continue to plague the Integrated Waste Treatment Unit.

U.S. Department of Energy officials said Wednesday they hope this week’s “chemistry summit” will lead to a solution for clogging issues at the radioactive waste treatment facility. The first-of-its-kind plant has remained in testing mode for several years, unable to begin treating some 900,000 gallons of liquid radioactive waste due to various clogs and glitches.

The facility was supposed to have the job finished in 2012, using steam to transform the sodium-bearing liquid into a safer powder form. But the treatment technology continues to face challenges during test runs, DOE officials told the INL Site Environmental Management Citizens Advisory Board at its Wednesday meeting.

Officials were careful to note that they have not given up on the plant, and remain hopeful it can begin safely treating waste before a Sept. 30 deadline mandated by the Idaho Department of Environmental Quality.

“We wouldn’t be doing this if we didn’t think it would work,” said Joel Case, DOE’s director for the project.

Scientists and experts from DOE, Idaho National Laboratory, Savannah River National Laboratory, National Energy Technology Laboratory and several government contractors were involved in this week’s chemistry meetings regarding the plant. They included Thor Treatment Technologies, the company that initially developed and demonstrated the treatment technology with a one-tenth scale pilot plant in Golden, Colo.

The primary problem to solve is the clogging issue. A formation that resembles tree bark builds up in part of the system each time simulant — a material that mimics real waste — circulates through. If bark formed during real waste treatment, the plant would require frequent shutdowns for cleaning, which potentially could be dangerous for workers.

“We want to see what recommendations we get from this chemistry summit,” Case said.

Recommendations may include altering the chemical makeup of the simulant so it won’t clog up. Those changes would then be duplicated on the real waste.

So far there have been three simulant test runs totaling about 90,000 gallons that have circulated through the system. The latest test run came in November, and was halfway finished when officials decided to shut the plant down to evaluate the bark problem. More issues were discovered after the test run, including warping and erosion of some of the system’s metal components, Case said.

Case said officials plan to begin the next simulant run in April, which will be followed by another outage period to address any more problems identified during testing.

About $3 to $5 million continues to be spent on the facility each month, Case said, much of which pays for project personnel. Between 120 and 200 people are involved in the project at any given time, he said.

Cost overruns on the project stand at roughly $300 million.

DOE officials in October said that they would begin examining treatment alternatives in case the current technology was never able to safely treat the waste. But the department’s message to the citizens board Wednesday was that there are no plans or timelines for abandoning the current design.

“Most of the plant equipment is operating reliably and as designed,” a PowerPoint presentation from Case said. “The list of significant issues is being narrowed largely to two: bark and erosion.”

“I’m not thinking about plan B,” Case said.

Luke Ramseth can be reached at 542-6763. Twitter: @lramseth