Despite some concerns, a Department of Energy contractor at the Hanford Site in Washington state received good marks from an independent assessment of its pretreatment of radioactive wastes prior to vitrifying the waste into a more stable glass form.
The DOE’s Office of Enterprise Assessments conducted the review of Hanford’s Tank Side Cesium Removal (TSCR) project. The system uses ion exchange columns to filter out undissolved solids and radioactive cesium from liquid waste before sending the stream to the Waste Treatment and Immobilization Plant’s Direct-Feed-Low-Activity Waste facility.
DOE and Bechtel, which is building the plant, plan to start turning some low-activity tank wastes into glass by December 2023, although a revised legal settlement has pushed the milestone into 2024 to make up for time lost during the COVID-19 pandemic.
The independent review by the Office of Enterprise Assessments follows upon an October 2021 contractor readiness assessment of TSCR operation. The Defense Nuclear Facilities Safety Board staff watched contractor Washington River Protection Solutions remove an ion-exchange column from TSCR and replace it with a new one. This is a process that must be repeated every few months.
The DNFSB staff said there was damage to the “threaded connections” or couplers used to connect the ion exchange columns to the system. The DNFSB staff concluded the contractor’s evaluation and repairs don’t meet requirements of the American Society of Mechanical Engineers for nuclear quality assurance.
Subsequently on Oct. 26, the Office of Enterprise Assessment published its independent review of TSCR operations. The written assessment followed an onsite visit in July.
In the report, Enterprise Assessments voiced concerns about written procedures not being technically accurate — meaning they cannot be accomplished as written. Also, checklists at the TSCR’s at-the-controls area were not controlled as required. That means there was no method to verify accurate guidance is provided to new shifts.
“WRPS manages and maintains a generally effective conduct of operations program,” according to the Enterprise Assessments office. Operations were effectively implemented, “with a few notable exceptions described in this report.”
The report gave WRPS high marks for managing personnel, training, employees understanding their duties, good communications and correct labeling of components.
The DOE Office of Environmental Management declined comment on the report.
The tank side system began operating in January 2022 and has thus far pretreated 380,000 gallons of waste during two batch runs.
