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Curie Reduction of Liquid Effluent at Nuclear Power Plants. Presented by Tim Carraway. Technologies. Two Primary Types of Liquid Waste Processing Technologies Membranes for BWR’s? Demineralization with Chemical Injection for PWR’s?. Over 1 Billion Gallons Processed by end of 2004.
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Curie Reduction of Liquid Effluent at Nuclear Power Plants Presented by Tim Carraway
Technologies • Two Primary Types of Liquid Waste Processing Technologies • Membranes for BWR’s? • Demineralization with Chemical Injection for PWR’s? Over 1 Billion Gallons Processed by end of 2004
Key Steps for Technology Selection • Do Not Prematurely Conclude a Specific Technology Will Provide a Solution • Detailed Assessment is Required to Determine the Best Fit Solution • Plant Operating Philosophy Typically Requires Changes to Ensure Overall Success
Perform Detailed Influent Assessment • Characterize All Sources • Equipment Drains • Floor Drains • Miscellaneous Sources (Lab Drains, Resin Transfer Water, Various Storage Tanks) • Consider Condensate System Inputs (BWR) • Do Not Rely on a Single “Snapshot” • Include Outage and Non-Outage Chemistry • Also Consider Evolutions Such as Condensate System Backwashes and URC’s
Typical Influent Parameters • Identify the Range for Each Parameter • The Analysis Must Be Complete • Ensure Unusual Plant Evolutions Are Considered
Identify Effluent and Performance Goals • Curies • Is Zero Curie Discharge Desirable? • Is Lowering Curie Discharge Desirable? • Recycle Water Chemistry • TOC • Conductivity • Sulfates • Chlorides • Others • Waste Generation • Operator Dose
Understand the Total Costs • Confirmatory Testing • Plant Modifications • Equipment Installation • Equipment • Operations • Maintenance • Process Waste Disposition • Training • When Comparing Costs to Existing Processes Ensure All Costs are Considered
Understand There is Not a Single Generic Solution • The Proposed Technology Must Consider Influent Chemistry and Plant Goals • System Components Must be Configured Based on Specific Plant Conditions • Consider Testing With Scaled Down Equipment to Verify Performance • Another Way to Mitigate Risk
Post Implementation Keys to Success • Continually Track, Trend and Analyze Performance Data • Use Data to Define Improvements and Optimize System Performance • Maximize Filter Run Times, Media Throughput, Membrane Life • Measure Effectiveness of Changes to Any Plant Operating Philosophies
Goals • PWR’s • Minimize curie discharge • Minimize waste generation • BWR’s • Minimize or eliminate curie discharge • Produce reactor grade make-up water • Allows 100 % recycle of water processed • Minimize waste generation
PWR’s • Demineralization with Chemical Addition • Cost effective • Provides similar effluent activity results as membrane based technology • Demin Systems are simple and less expensive to operate and maintain • Provides versatility and the ability to “target” specific radionuclides (such Co-58 and Sb-125)
BWR’s • Membrane Based Technology : • Provides “zero” curie discharge capability • Provides reactor grade quality make-up water • Produces less waste generation than Demin Systems Curie Definition
History of Membrane Technology • Membrane Technology has been in Operation Since 1995 • 45 Million Gallons Processed Annually with Membrane Technology • Currently, Membrane Technology is in operation at 4 Nuclear Power Plants • 9 Mile One (First to Operate Technology in 1995) • 9 Mile Two • Pilgrim Station • TVA’s Brown Ferry Station Over 100 Million Gallons Processed at Pilgrim Station
Contaminants Dissolved Suspended
DISSOLVED SUSPENDED 0.01 Micron 0.1 Micron 1 Micron 10 Micron 100 Micron 1000 Micron 0.0001 Micron 0.001 Micron Particle Filtration Colloids Metal Ions Microfiltration Aqueous Salts Ultrafiltration Beach Sand Bacteria Nanofiltration Reverse Osmosis
Colloids • col·loid noun (plural col·loids) a suspension of small particles dispersed in another substance • Due to the small size of colloidal particles, the natural movement of water molecules does not allow them to settle. Even in static conditions, colloidal particles will Never settle out in solution.
Membrane Based System • System Primary Components • Reverse Osmosis Membrane Skids • Granular Activated Carbon Beds • Process Feed Tank • Filters • Demineralizer
Polisher GAC Vessels Control Module Plant 2nd Pass RO F-1 Process Feed Tank F-2 1st Pass RO
Membrane System Results • Processed over 280 Million Gallons Total • Average 45 Million Gallons per Year • Achieved 100 % recycle for all water processed, resulting in “zero curie” discharge • Produces close to theoretically pure water
Reactor Feedwater Conductivity Near theoretically pure water
Reactor Feedwater TOC Exceptionally low level of organic contaminants.
Waste Generation Cubic Ft.
Annual Savings These savings also include the cost of our services Does Not include savings such as substantial ANI insurance reductions
Demins with Chemical Injection • System Primary Components • Granular Activated Carbon Beds • Demineralization Vessels • Filters • Chemical injection allows targeting of specific isotopes • Duratek Systems Currently in use at 11 Plants
Carbon Vessels Carbon Vessels Carbon Vessels Cation Resin Carbon Vessels Anion Resin Control Module Charge Detector Polymer Injection AIMTM Chemical Injection System
DISSOLVED SUSPENDED 0.01 Micron 0.1 Micron 1 Micron 10 Micron 100 Micron 1000 Micron 0.0001 Micron 0.001 Micron Particle Filtration Colloids Metal Ions Microfiltration Aqueous Salts Ultrafiltration Beach Sand Bacteria Nanofiltration Reverse Osmosis
Demin/Chemical Injection Results • Processed over 500 Million Gallons Total • Average 20 Million Gallons per Year • Minimizes Curie Discharge • Provides 1st Quartile Curie Discharge Results • Average Effluent Activity: 2.6E-6 uCi/ml • Average DF: > 2,000 • Average Waste Generation: < 200 cu.ft./yr
Definition cu·rie [ kyree, kyoor ] (plural cu·ries) noun unit of radioactivity: a unit of radioactivity equal to 3.7 times 1010 disintegrations per second[Early 20th century. Named for the French physicists Pierre Curie (1859–1906) and Marie Curie, who studied radioactivity.]