Separations Process Research Unit (SPRU) Decommissioning Project Hugh Davis, Ph.D. U.S. Department of Energy SPRU Field Office LLW Forum Meeting, November 2016, Saratoga Springs, NY

History The Separations Process Research Unit (SPRU) is located near Schenectady, New York, adjacent to the Mohawk River and occupies approximately 5 acres of land. SPRU was operated from 1950 to 1953 as a pilot plant to research the REDOX and PUREX chemical processes to extract uranium and plutonium. SPRU research supported operations at the Hanford Site (Washington State) and Savannah River Site (South Carolina). The research was performed on a laboratory scale; SPRU was not a production plant.

SPRU Facility is Primarily Two Connected Buildings Building G2 housed the laboratories, hot cells, and separations process testing equipment Building H2 was used for liquid and solid waste processing

DOE-SPRU Decommissioning Project 2004 DOE SPRU Field Office established to oversee cleanup of the SPRU facilities and land areas By 2010, completed radiological and chemical cleanup of SPRU land areas (30 acres) Currently undergoing Decontamination and Decommissioning (D&D) of G2 and H2 Buildings by AECOM (formerly URS) HEPA ventilated enclosures constructed over G2 & H2 Conducting characterization and removal of piping, equipment, contaminated concrete and debris Goal: decontaminate under HEPA enclosures to levels that allow safe, open-air demolition Conduct open-air demolition of structures, remove any contaminated soil and restore the site

SPRU Building Enclosures HEPA ventilated enclosures for decontamination prior to open air demolition G2 H2 Slide enclosures

G2 Cell 1 Pre-Decontamination G2 Cell 1 prior to equipment removal and decontamination

G2 Cell 1 Post-Decontamination G2 Cell 1 after equipment removal and decontamination

Application of Fixative Pre-Demolition G2 Cell 1 sump after application of fixative

Open Air Demolition G2 Building After decontamination, building is demolished with heavy equipment Significant volumes of water used for dust suppression

SPRU D&D Waste Streams Two D&D waste streams covered in presentation: H2 Tank Sludge—9700 gallons Contaminated Water—1.5 million gallons since 2011

Sludge Waste Remained in the Tanks in H2 Vault Residual waste (sludge) in 7 stainless steel tanks in the SPRU H2 Tank Vault, where liquid radioactive waste was stored for processing during operations. Processing technology chosen: stabilization of sludge in “liners,” using a cement/fly ash/slag mixture. In 2010, sludge consolidated into a single tank (509E) for sludge waste processing and disposition.

SPRU Sludge Waste Characteristics 9,700 gallons of sludge processed Included fission products and long-lived transuranic (TRU) radionuclides Curie content based on in-process sampling--36 Ci 31.3 Ci (87%) Cs-137 and Sr-90 4.5 Ci (12.5%) TRU (primarily Pu-239) TRU content in final waste form--11.5 to 65.5 nCi/g.

SPRU Sludge Waste Characteristics Early project characterization data indicated sludge would likely be a RCRA characteristic waste Total mercury was over 1% and sludge contained elevated total lead and chromium However, TCLP tests concluded levels were at 0-3% of regulatory levels, due to low solubility of metals The final waste forms were sampled and found to be less than 100 nanocuries per gram (nCi/g) long-life TRU radionuclides, and thus were classified and shipped as Class C LLW.

Sludge Removal & Solidification System

Primary Process Steps - 1 A pump was used for mixing of the contents of Tank 509E (solids were mobilized). After a minimum recirculation time of two hours, a batch of sludge was pumped to a “day tank.” The day tank was mixed with the internal paddle mixer; recirculation occurred through a sample loop Radiation dose readings were taken from the top to the bottom of the day tank. When the dose profile was stable, mixing was complete and a sample was taken for on-site analysis.

Primary Process Steps - 2 The batch was transferred to the solidification liner and the cement/fly ash/slag mixture was added. The mixture was periodically checked by a penetration test to determine when it was solidified. Additional cement was added to address any free water. The liner was moved into a shielded temporary storage area and then shipped off-site for disposal.

Solidified Sludge in Liner

First Liner Shipment

Disposal of First Liner

Sludge Processing Overview Began Sludge Processing September 9, 2013 Completed Shipments on February 27, 2014 28 liners solidified and shipped to Waste Control Specialists in Texas. Removed more than 50% of SPRU radionuclide inventory from site. Upon completing the sludge solidification project, the SPRU Disposition Project had achieved more than 2¾ years and more than 1.1 million safe work hours without a lost- time accident or injury.

What Were the Challenges? Facility and waste stream decades old, difficult to access and sample Tanks more than 20 feet below grade, in concrete vaults with 10’ soil cover The top of the facility had been demolished, and work was performed in tight conditions in enclosures Seven tanks with heels; each with different characteristics Mobilizing sludge tank heels was challenging Overall volume of waste expanded with water addition Solids mobilized in liquids required continual mixing to keep homogenous Mixing and extraction became more difficult as the process proceeded Initial uncertainty over final waste types (hazardous, TRU) Significant effort to ensure samples were representative and to ensure final waste forms not above TRU thresholds

SPRU Waste Water SPRU D&D Water continual challenge and expensive to manage and disposition Waste water can be a significant driver for the project cost and schedule—cannot underestimate planning needed to manage water Discuss two sources of project water at SPRU H2 Building Footer Drain Dust suppression water

H2 Footer Drain Water Footer drain water with low levels of radioactivity Annual amounts ranging from 150,000gal to more than 600,000gal Water flows by gravity year round, even during dry periods Effective in depressing water table and capturing contaminated water Collected in a sump Sump was strengthened after 2011 Hurricane Season Pumped from sump to multiple 18,000 g fractionation tanks Year-round operations require daily inspections and comprehensive freeze protection measures Efforts to treat on-site and discharge locally were not successful Water shipped by tanker truck for treatment and disposal out-of-state at considerable expense Off-site treatment/disposal locations must be vetted to ensure proper and compliant management Options for alternate treatment/disposal sites are necessary

Demolition Dust Suppression Water Water is used at SPRU during open air demolition for dust suppression “Dust Boss” produces a mist that knocks down particles Fire hoses produce higher volumes to wet down materials Measures must be taken to prevent run-off and capture water Dust suppression water is potentially contaminated with radioactivity and chemical constituents Water in contact with concrete debris can have elevated pH; potentially higher than 12.5, which would render it RCRA hazardous Dust suppression can generate large daily water volumes—at SPRU, at the high end, 10,000 gallons/per day Need be prepared to handle water and volumes May require interaction with State, if hazardous constituents potentially present

Final Lesson Learned on Water Management Water management systems can introduce contaminants PVC pipes/manifold systems can introduce volatile organic constituents (e.g., acetone, toluene), primary from cements Once VOCs are found in water samples, questions arise What is the origin of contamination? Were previous volumes of water contaminated? Do trace chemicals affect disposition options? Safety Data Sheets may not include information on volatile organics at levels below 1% in products Chemical testing of products may be necessary to determine if chemicals that come into contact with water are present

Next Steps at SPRU Project goals in next two years Complete open-air demolition of G2 Building Conduct demolition of H2 Building under enclosures; complete in open air Fill in excavations and finish landscaping Restore facility and turning over SPRU areas for continued government use QUESTIONS? Hugh Davis DOE-SPRU Field Office Hugh.davis@spru.doe.gov (518) 395-4956