Crews should within a couple weeks begin demolition of the most contaminated portion of the Hanford Site’s most hazardous building, the Plutonium Finishing Plant.
Tom Teynor, Department of Energy manager for the Plutonium Finishing Plant (PFP), provided the update on the highly contaminated canyon of the plant’s Plutonium Reclamation Facility on Tuesday at a committee meeting of the Hanford Advisory Board.
The PFP was used for decades to shape plutonium produced at Hanford into a hockey-puck form that could be inserted into nuclear weapons. Skinny pencil tanks up to 22 feet long once hung on racks in the tall, narrow area of the facility known as the canyon, used in recovery of plutonium from scrap material that would have otherwise been waste.
Demolition is underway on the Plutonium Reclamation Facility built onto one end of the plant near the canyon area, Teynor said. When heavy equipment starts to tear down the canyon, no more than one 2-foot-wide, vertical slice of the canyon will be removed each day, at least initially, he said.
The 17,150-square-foot Plutonium Reclamation Facility stood four stories high with a two-story penthouse on top of that. The canyon within it is three stories high, or 34 feet tall, and is 30 feet wide by 66 feet deep.
Data from extensive characterization of the canyon was fed into air dispersion models developed by the Pacific Northwest National Laboratory to set safe parameters for the demolition. There will be some air contamination, but it will be within regulatory limits, said Tom Rogers of the Washington state Health Department.
The latest schedule calls for the Plutonium Reclamation Facility to be demolished by mid-to-late June.
The main portion of the Plutonium Finishing Plant could be ready for the start of demolition at the end of May, Teynor said. Among challenges there are 10 glove boxes that remain in the plant. Three are expected to be removed before demolition starts, but that will require some coordination with other cleanout work as some interior walls are opened up to move the glove boxes toward a door.
Of the seven others, four have been cleaned out enough that they can be characterized as low-level radioactive waste and come down with the building, Teynor said. The remaining three have transuranic waste contamination and will be taken out whole, possibly in July, and shipped to nearby PermaFix Northwest to be cut into pieces and then stored until they can be shipped to DOE’s Waste Isolation Pilot Plant in New Mexico.
The current DOE schedule calls for the plant to be torn down to slab on grade by the end of September, meeting a revised Tri-Party Agreement milestone. The state last summer gave DOE an additional year to complete the job following unanticipated contamination, accidents on the job, and equipment troubles.
DOE Richland Operations Office Manager Doug Shoop acknowledged earlier this year that demolition could extend past Sept. 30, due to lost work days from a harsh winter and a radioactive contamination incident that temporarily halted work. If DOE faces unexpected challenges on the remainder of the project it will be in contact with Tri-Party agencies: DOE, the Environmental Protection Agency, and the Washington state Ecology Department, Teynor said.
