Department of Energy contractors at the Hanford Site in Washington state are making headway on remaining problems before crews can start turning some less-radioactive tank waste at the property into a solid glass form, the Hanford Advisory Board heard Tuesday.
After making a batch of non-radioactive test glass in December, DOE wants to start vitrification of direct-feed-low-activity-waste at the Bechtel-built Waste Treatment and Immobilization Plant in the first half of 2025. Among the remaining hurdles: re-treating some waste outside the plant to remove more cesium ahead of vitrification and starting up a second melter, said Brian Vance, DOE’s manager for Hanford.
“I believe we are on track to start Melter 2 heat up this month,” Vance said. The second melter was delayed due to “leakage” issues at the first melter, which have now been fixed, Vance said.
Meanwhile, DOE will retreat some waste in the Tank-Side-Cesium Removal (TSCR) project this spring to remove small amounts of remaining cesium that has lingered in the feeding tank for the vitrification plant. This clearing out of the AP-106 feed tank should occur in the March-April timeframe, Vance said.
After that, all the waste pre-treated through TSCR will meet the standards necessary for vitrification, he added.
After an early round of TSCR -pretreated waste was circulated inside AP-106, it dislodged some residual cesium stuck on tank walls from past years, making cesium levels in the treated waste too high for the vitrification plant, a Washington River Protection Solutions executive said in October. AP-106 was a waste storage tank before getting pressed into duty as a feeder for the Waste Treatment and Immobilization Plant.
DOE and contractor officials have said that TSCR itself is working as planned and that the excess cesium, which came from the walls of the AP-106, can be flushed out of the low-activity waste loop.
Editor’s note, Feb. 09, 2024, 11:23 a.m. Eastern time. The story was updated to clarify the source of the excess cesium in some treated waste.
