The Energy Department and Hanford Site contractor CH2M Plateau Remediation have asked the Washington state Ecology Department for permission to uproot two drained waste tanks at the Plutonium Uranium Extraction Plant, according to a permit modification request dated July 11 and posted online Monday.
The plant, known as PUREX, is located in the 200 East Area in the site’s central plateau. The tanks to be removed are the 106,000-gallon TK-P4 and the 65,000-gallon TK-40, according to the permit modification request DOE’s Richland Operations Office filed with the state.
“Tank removal will be completed within 180 days after approval of the Permit modification incorporating this closure plan,” the permit modification request says. It could take another 60 days after that for DOE and the contractor to confirm the job was done right, and process the necessary paperwork.
Beginning Monday, there are 105 days worth of mandatory public comment before the state may grant the modification, which include weekends and holidays. That means the soonest the tanks could be removed is late April, 2017. Add another 60 days for closeout and paperwork, and the job would stretch out to late June, according to the modification request.
The tanks have to come out of PUREX before workers at the site can continue demolishing the rest of the building, which was once used to extract plutonium for the Pentagon’s nuclear arsenal from spent uranium fuel rods irradiated on site, DOE said.
Permit modification requests are routine, under the Tri-Party Agreement, as the specific plan for any given demolition job is seldom written into the original permit held by DOE and its contractors.
“A permit modification is required anytime work is not already covered in the existing permit,” a DOE spokesperson wrote in a Thursday email. “This is a normal and frequently used procedure.”
Once Washington state grants the permit modification, the department and its contractor will start ripping out the tanks, associated equipment such as plumbing, secondary containment structures made of concrete, and up to 1 meter of soil beneath each tank structure. Once removed from PUREX, the tanks will be cut up into smaller pieces and disposed of, along with the associated material, at Hanford’s Environmental Restoration Disposal Facility.
Tank TK-P4 stored recovered uranyl nitrate hexahydrate, a byproduct of recovering plutonium from spent uranium fuel rods, while tank TK-40 stored contaminated tributyl phosphate, an organic solvent, according to the permit modification request.
Under the Tri-Party Agreement that governs Hanford cleanup, DOE’s permit modification request must go through a 60-day public comment period that concludes Sept. 16 and includes a public meeting scheduled for 5:30 p.m. Aug. 31, local time, at the Richland Library in Richland, Wash. After the 60-day public comment period, which is led by DOE, there will be a 45-day comment period concluding Oct. 31 and led by Washington state, according to the permit modification request.
CH2M Plateau Remediation 10-year Hanford Site Central Plateau Remediation prime contract is worth $5.8 billion and expires Sept. 30, 2018.
