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Emerging Technologies for the Treatment of Organic and Aqueous Waste Streams: International and U.S. Department of Energy Case Studies Dennis Kelley, Pacific Nuclear Solutions. Objectives of Presentation.
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Emerging Technologies for the Treatment of Organic and Aqueous Waste Streams:International and U.S. Department of Energy Case StudiesDennis Kelley, Pacific Nuclear Solutions
Objectives of Presentation • Examine several case studies that describe polymer solidification technology for use on complex liquid waste streams: • STMI-Areva, France • British Nuclear Group, Sellafield, U.K. • Cernavoda, Romania; Krsko, Slovenia & OPG Canada • Khlopin Radium Institute, St. Petersburg, Russia • China Institute of Atomic Energy, Beijing, China • U.S. DOE Rocky Flats, Colorado • U.S. DOE Mound, Ohio
Nochar Polymer Technology • ABsorbent, mechanical process; not an ADsorbent material (surface collector) • Not an encapsulation technology • Minimal volumetric increase: 5% or less • No leaching / no liquid release • Solidification time: 1 hour to 48 hours depending on waste stream composition • Mechanical / chemical reaction; no heat build-up, no heat release • Polymers reduce the risk of fire; suppress vapor
Polymer Technology • Stability of Solidification: Cobalt 60 gamma • 270 million rad on organic / acid waste • 90 million rad on organic waste – TBP • 75 million rad on aqueous waste – 14.2 pH • Helps to immobilizes heavy metals • Safe / simple process: mixing or no mixing, depends on composition of waste stream • Final product for short, intermediate or final storage / burial • Incineration: less than .02% ash • Combined with grout / cement for monolithic matrix possible
Polymers • N910: styrene block co-polymer • styrene-ethylene/butylenes-styrene • N960: 100% cross linked, co-polymer of acrylamide
France • Partner: STMI (Areva Group) • 2003, analyzed 20 year old tank waste • 4 phase complex organic / aqueous waste stream, with alcohol and solid material • Good characterization made testing easy • Polymer formulas created according to each phase • 2 : 1 bonding ratio for each phase • Encapsulation of polymer waste in cement
France • Cementation tests – passed ANDRA requirement, but not cost effective • ANDRA does not accept sorbent (organic) materials • Incineration at Centraco • 2007 project at AREVA – Marcoule • Complex aqueous waste stream with low pH • 2010 project at AREVA SICN Veurey • DU, oils & solvents + low amount of water, classified as “liquid muds”
U.K. Contacts • Sellafield • NNL, Workington • AWE, Aldermaston • UKAEA, Harwell • LLWR / NDA • Magnox stations, Berkeley • British Energy • AMEC • NSG Environmental
United Kingdom - Sellafield • Oil immobilization program initiated by British Nuclear Group: 2006 • Waste oil, non-standard waste stream, treatment and disposal issues on site • Waste Characterization & Clearance group and PNS conducted 3 experimental campaigns • Small scale test program: 90+ oil types
Experimental Methodology • Polymers: N910, N935, N960 • 1.5 : 1 ratio (liquid to polymer by weight) • Light mixing applied if “pooling” occurred on surface, due to quick solidification • Curing period: 24 – 48 hours • Polymers blended, depending on waste composition • Compositions unknown
Results of Experiments:British Nuclear Group Analysis • Polymer systems proved effective in immobilization of waste oil into a solid product • No leaching of liquid on compression • Need to test for compatibility of polymers to waste and assess ratios on case by case basis • 2 : 1 ratio is optimum for economic and security reasons
Cementation Test Program • UK Conditions for Acceptance for LLW disposal call for compressive strength minimum • Consider cement encapsulation of polymer solidification to be suitable for final disposal • Tests demonstrated oil solidification + grout can form a safe, non-compactable matrix suitable for final disposal
U.S. Department of Energy’s Initiatives for Proliferation Prevention in Russia:Results of Radioactive Liquid Waste Treatment Project, Year 1 Y. Pokhitonov, V. Kamachev V.G. Khlopin Radium Institute, Russia D. Kelley Pacific Nuclear Solutions, USA
Russia since 2002 • Partner: Khlopin Radium Institute, St. Petersburg • Over 60 tests conducted on complex liquid waste streams: Gatchyna and RADON – Sosnvoy Bor NPP • Sludge types from decontaminating solutions • Several forms of TBP from extraction facility for spent fuel reprocessing • Spent extractant solutions with heavy metal content
Oil Sludge Nitric Acid with Plutonium
Purpose of Project • Program sponsored by DOE to engage Russian weapons scientists in peaceful use of existing and newly developed technologies • DOE’s IPP program is a mechanism for U.S. private sector companies to enter Russian market: radwaste treatment • Introduce USA environmental technology to weapons sector and seek joint technologies • Investigate solutions for Russia & USA liquid radwaste problems resulting from Cold War • DOE compensates scientists to participate in program • Long-term, commercialize project, employ scientists
Project Participants • Russia • Russian State Atomic Energy Corporation (ROSATOM) • VG Khlopin Radium Institute (project manager) • Seversk (SCC ), Zheleznogorsk (MCC), Ozersk (MAYAK), Gatchyna • 90+ participants, 68 weapons scientists • USA • Department of Energy (GIPP) • Argonne National Lab • Pacific Nuclear Solutions (project manager) • International Science & Technology Center (ISTC) • Project administrator, Moscow
Experiments • Stability (Differential Thermal Analysis) • Irradiation • Gas generation • * Polymer solidification /capacity / evaporation • * Leaching / water contact • * Encapsulation in cement * Represents test data / results published in paper
Differential Thermal Analysis Polymers: N910, N930, N960 Solidified samples with nitric acid and sodium nitrate possess high thermal stability
Irradiation Tests / Results • Extensive irradiation testing conducted, required for ROSATOM certification • All high dose rates • Cobalt 60 gamma irradiator • One example: nitric / organic solution 30 rad per second 30 days = 77 M Rad + 73 days = 270 M Rad • Brittle, size reduction, no degradation / leaching • Conducted for gas generation tests
Stability and Irradiation Cobalt 60, gamma installation, dose rate 3.9·10⁶ gray N960 polymer, HNO₃, 1M, after irradiation N910 polymer, oil + TBP, after irradiation
Gas Generation Tests • Preliminary tests, more testing and analysis is required • Tests required to determine fire and explosion safety conditions • Tests carried out under static conditions in sealed glass ampoules • N960 polymer + nitric solution: no changes in the solidification and no gas release • N910 polymer + TBP / oil: variable results • Preliminary judgment: polymers are not gas generators
Rate of gas release during irradiation of sample: N910 polymer + 50%-TBP / 50%-oil
Solidified sample after addition of waterSolution: HNO₃ 1,0M No volumetric increase
Polymer Solidification/ Capacity / Evaporation: Conclusions • Polymer technology is irreversible, liquid permanently immobilized in polymer matrix • Advantage: direct application of polymer to waste without conditioning / additives • Little or no volumetric increase in the process • Appreciable volume reduction through evaporation; no measurement of water vapor • Polymers slow evaporation process • Polymers are versatile, solidify aqueous / organic waste of varying acidities, specific activities, suspensions and sludge types & salts
Chemical Stability – Leach Test • Various leach tests conducted • samples with cesium and water contact • samples mixed with cement • Aqueous polymer has capacity limits, water contact will cause leaching • Cementation may be required by regulators • Cementation tests not conducted properly; precise bonding ratios are necessary • Results: • Immediate contact with water after solidification caused leaching • Better results when sample had aged 1 month
Encapsulation of Polymer Solidification • Cementation tests at AREVA & Sellafield successfully completed, with 90% organic / 10% aqueous streams • When aqueous is above 10%, new technique for encapsulation is required • Encapsulation research underway: • additives to solidification • additives to cement • tests with inorganic materials encouraging
Applications • Waste in above ground & underground tanks • Small containers / drums / self-contained generator (Yttrium -90) • Direct application to closed vessels to prevent leakage • Emergency spills at NPPs • Decommissioning sites, legacy waste
Markets • Weapons production sites • Nuclear power plants • Submarine decommissioning • Toxic chemical industrial complexes • Research institutes • Uranium mining • Medical waste • Land & water remediation projects
Year 2: Work Plan • Polymer certification • Required to import & sell polymer in Russia • Licenses required for health / safety, fire / explosion, irradiation / stability • Final certification issued by ROSATOM • Commence sub-site test work • Active solutions • Problematic waste streams • Continuation of experiments
Cernavoda, Romania • Cernavoda NPP approval – 2005 • CNCAN approval – early, 2007 • Waste streams to be solidified: • mineral oil with tritium / cesium, 200+ drums completed • machine oil with tritium • scintillation fluid • Interim storage on-site (20+ years), plan to incinerate at Studsvik, Sweden
Krsko, Slovenia • First Nochar user in Europe, 2002 • Oil with tritium / solvents • Waste transported to Studsvik Nuclear, Sweden for incineration • Incineration with excellent results • Safety booms in power plant for emergency spills
Ontario Power Generation - Canada • 2010 test program • FRF, Fire Resistant fluid for turbine governing system • Paint, latex (used N930) • Glycol (used N935) • Kodak developer (used N960) • Solvents, machine oil
China • China Institute of Atomic Energy, Beijing • Test program 2004-2005 • Formal paper published • Waste treatment regulations to be changed • Repository conditions, similar as WIPP-DOE, desert conditions • 1st large scale project underway
Waste Streams • Six simulant waste streams tested: • Tri-butyl phosphate: 30% TBP / 70% kerosene • Acidic (nitric) solution: less than 0 pH • Alkaline solution: more than 14 pH • Ion exchange resin: anion to cation – 2:1 • Sodium type-beads, chlorine type-beads & 50% water • Vacuum pump oil • Scintillation fluid
1:1 Ratio after 6 weeks 3:1 Ratio after 6 weeks
Irradiation Tests • Objectives of irradiation tests of solidified waste streams: • Evaluate degradation of waste form and polymers • Leaching • Durability • Waste sealed in individual ampoules • Cobalt-60, gamma source irradiator • Dose rate: 28 rad per second / 70 million rad • All samples exposed to same dose rate • Loose polymers also irradiated at same dose rate
IR Spectra-graph Tests/Results • Objective: check for degradation of polymers resulting from irradiation • 100,000 rad for 100 hours = 10,000,000 rad • Conclusion: Little or no degradation of polymer
IR Spectra-graph of N910 Red represents after irradiation Blue represents before irradiation
IR Spectra-graph of N960 Red represents after irradiation Blue represents before irradiation