The long-running cleanup of a 1950s-era nuclear research site in Niskayuna hit a milestone Thursday, project officials said.
The 14th and final shipment of solidified radioactive sludge left the former Separations Process Research Unit bound for a disposal facility in Texas.
Work resumed at the site less than a year ago. Cleanup stopped in late 2010 after a series of incidents at the site. The SPRU site is located at the Knolls Atomic Power Laboratory in Niskayuna.
“The radioactive sludge constituted one of the highest risks at SPRU,” federal site project director Steven Feinberg said in a statement. “The successful solidification of the sludge marks major progress in our environmental cleanup project and enables us to put our full attention on moving ahead with the active decontamination and demolition of unused buildings on the site.”
Cleanup at the site resumed last June after completion of two environmental enclosures ordered to be built after the accidental release of radioactive dust in September 2010. Better systems and backups were put in place after discharge the following month of 630 gallons of contaminated water into the Mohawk River.
In both incidents, officials have said, there was no risk to workers or the public. The incidents, though, were still of concern to federal energy officials, who halted the project and demanded further safeguards.
In all, two large, steel-frame enclosures were built, one over a part of the project called Building G2, the other over a part called Building H2. A new subcontractor was also brought in to take key positions in the wake of the 2010 incidents.
Erosion caused by tropical storms Irene and Lee in August and September 2011 helped delay design and construction of the added safety measures.
Workers now must remove equipment, tanks and piping. Interior ventilation system ductwork and interior non-load bearing walls also must be removed.
After that, remaining concrete surfaces must be decontaminated.
Only after all that is complete will the safety enclosures be removed, officials said.
All wastes generated will be disposed off-site.
The SPRU focused on research into recovering uranium and plutonium from spent nuclear fuel. It operated for less than three years and closed in 1953. KAPL then shifted from a general-purpose lab to a concentration on nuclear-powered ships.
Officials last year gave late 2014 or early 2015 for possible completion dates. A spokesman Thursday only said that the Department of Energy and contractor URS Corp. are in negotiations over final cost and schedule.
The Department of Energy’s Office of Environmental Management is responsible for the cleanup project and currently manages the facilities and land areas, which make up about 15 acres of the entire 170-acre Knolls site.