June 25-26, 2002D&D Lessons Learned Workshop1 Tritium Decontamination Techniques and Technology C. A. Gentile, J. J. Parker D&D Lessons Learned Workshop June 25-26, 2002 PPPL

June 25-26, 2002D&D Lessons Learned Workshop2 Oxidative Chemistry Employed for Tritium Removal 1.H2O2 (hydrogen peroxide) liquid phase 2.O3 (ozone) gas phase Technology Overview Reduce tritium surface (and bulk) contamination on various components and items Remove contamination by chemically reacting elemental T to tritium oxide (purge reaction effluent to TCS or stack) Control via implementation of specific concentrations, catalytic parameters, and/or process conditions

June 25-26, 2002D&D Lessons Learned Workshop3 Introduction Expendable items de-tritiated to activity levels at or slightly above background level Re-usable items de-tritiated to free release levels (< 1000dpm/100cm2, and for use in controlled areas) Oxidative Tritium Decontamination System (OTDS) capital cost and operation cost is relatively low, compared to other decontamination methods

June 25-26, 2002D&D Lessons Learned Workshop4 Background O3 and H2O2 decontamination processes both employ oxidative chemistry Process was implemented on contaminated RF Feedthrough components (copper, stainless steel) Post H2O2 process activity levels dropped significantly (< 1% initial activity) No discernable surface regrowth was noted after approximate 8 month hold time

June 25-26, 2002D&D Lessons Learned Workshop5 Background Stainless Steel RF Feedthrough Components Copper Internal Conductor Component

June 25-26, 2002D&D Lessons Learned Workshop6 Background

June 25-26, 2002D&D Lessons Learned Workshop7 System Configurations Oxidative Tritium Decontamination System Rotary Stationary

June 25-26, 2002D&D Lessons Learned Workshop8 Rotary System Configuration

June 25-26, 2002D&D Lessons Learned Workshop9 Stationary System Configuration

June 25-26, 2002D&D Lessons Learned Workshop10 Piston-Cylinder Configuration V o = X C o = [O 3 ] V f = 0.5X C f = 2[O 3 ] uncompressed compressed

June 25-26, 2002D&D Lessons Learned Workshop11 Reaction Chemistry

June 25-26, 2002D&D Lessons Learned Workshop12 Secondary reactions (promote additional release of hydrogen isotopes) oxidation of carbon via ozone and/or diatomic oxygen to yield CO2 (and CO) reaction of nitrogen (if present in system) with tritium to yield tritiated ammonia oxidative dissociation of polymer chains Reaction Chemistry

June 25-26, 2002D&D Lessons Learned Workshop13 Required duration of O3 exposure dependant upon: concentration of pure O3 in feed residence time in reaction chamber These parameters are controlled via the following: concentration of diatomic oxygen in gaseous supply to ozone generator volumetric flow rate (output) of ozone generator volume of reaction chamber Reaction Chemistry

June 25-26, 2002D&D Lessons Learned Workshop14 Desiccation/drying of feed supply Lowers relative humidity within reaction chamber, thus facilitating evaporation of HTO (tritium oxide) Reduces possibility of formation of hydroxyl radicals, which can hinder the primary reaction mechanism Desiccation/drying of feed supply yields shorter system run-time Reaction Chemistry

June 25-26, 2002D&D Lessons Learned Workshop15 Decomposition of Excess Ozone Following Oxidation Process in OTDS HVAC ductwork, in most cases, is constructed of ferrous metal, which exhibits corrosion when exposed to strong oxidizing agents Ozone will degrade polymer-composite seals present in HVAC systems It is necessary to significantly reduce the release of ozone into these systems

June 25-26, 2002D&D Lessons Learned Workshop16 Decomposition of Excess Ozone Following Oxidation Process in OTDS Thermal Decomposition Activated Carbon Decomposition Hopcalite Catalyst Decomposition

June 25-26, 2002D&D Lessons Learned Workshop17 Thermal Decomposition Ozone must be held at temperatures exceeding 300 degrees Celsius for an approximate 3 second duration for adequate conversion to occur

June 25-26, 2002D&D Lessons Learned Workshop18 Activated Carbon Decomposition Design of activated carbon bed must allow for an approximate 3 second residence time for adequate conversion to occur

June 25-26, 2002D&D Lessons Learned Workshop19 Hopcalite Catalyst Decomposition MnO2 (manganese dioxide) based catalyst Not consumed during ozone decomposition Approximate second residence time >99% conversion of up to ppm ozone

June 25-26, 2002D&D Lessons Learned Workshop20 Efficient Removal of HTO HTO formed via this reaction mechanism is not removed through chemical process Majority of HTO remains as condensate on material surfaces A physical process (i.e. evaporation) must be implemented to facilitate HTO removal

June 25-26, 2002D&D Lessons Learned Workshop21 Efficient Removal of HTO

June 25-26, 2002D&D Lessons Learned Workshop22 Results

June 25-26, 2002D&D Lessons Learned Workshop23 Results