1. 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

2. 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.

3. 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

4. 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

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

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

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

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

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

10. 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

11. 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.

12. 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 to 65.5 nCi/g.

13. 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.

14. Sludge Removal & Solidification System

15. 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.

16. 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.

17. Solidified Sludge in Liner

18. First Liner Shipment

19. Disposal of First Liner

20. 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.

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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
(518)