The first scaled proof-of-principle cold crucible induction melter (CCIM) test to process a multiphase ceramic waste form from a simulated combined (Cs/Sr, lanthanide and transition metal fission products) commercial used nuclear fuel waste stream was recently conducted in the United States. X-ray diffraction, 2-D X-ray absorption near edge structure (XANES), electron microscopy, inductively coupled plasma-atomic emission spectroscopy (and inductively coupled plasma-mass spectroscopy for Cs), and product consistency tests were used to characterize the fabricated CCIM material. Characterization analyses confirmed that a crystalline ceramic with a desirable phase assemblage was produced from a melt using a CCIM. Primary hollandite, pyrochlore/zirconolite, and perovskite phases were identified in addition to minor phases rich in Fe, Al, or Cs. The material produced in the CCIM was chemically homogeneous and displayed a uniform phase assemblage with acceptable aqueous chemical durability.
Through its annual process of identifying technology deficiencies associated with waste treatment, the Department of Energy's (DOE)Mixed Waste Focus Area (MWFA) determined that the former DOE weapons complex lacks efficient mixed waste stabilization technologies for salt containing wastes. These wastes were generated as sludge and solid effluents from various primary nuclear processes involving acids and metal f~s h i n g ; and well over 10,000 cubic meters .exist at 6 complex sites. In addition, future volumes of these problematic wastes will be produced as other mixed 'waste treatment methods such as incineration and melting are deployed.The current method used to stabilize salt waste for compliant disposal is grouting with Portland cement. This method is inefficient since the highly soluble and reactive chloride, nitrate, and sulfate salts interfere with the hydration and setting processes associated with grouting. The inefficiency results fi-om having to use low waste loadings to ensure a durable and leach resistant final waste form.The approach for addressing this deficiency is based on system engineering principles developed specifically for the MWFA'. Based on these principles, requirements for resolution were identified and a technology development . plan was prepared.The requirements, formulated with technical, regulatory, and stakeholder input, specify the performance levels expected for each salt waste stabilization process selected for development. The development plan documents the MWFA strategy for selecting and testing the various alternative stabilization technologies. The plan also defines the schedule and scope needed to ensure timely and cost effective delivery of adequate solutions to potential end users. Based on this strategy, the following five alternative salt waste stabilization technologies were selected for MWFA development funding in FY97 and FY98: 1) Phosphate Bonded Ceramics, 2) Solgel, 3) Polysiloxane, 4) Polyester Resin, and 5) Enhanced Concrete. 'Comparable evaluations were planned for the stabilization development efforts. Under these evaluations each technology stabilized the same type of salt waste surrogates as specified by the MWFA. Final waste form performance data such as compressive strength, waste loading, and leachability can then be equally compared to the requirements originally specified.In addition to the selected test results provided in this paper, the performance of each alternative stabilization technology, will be
This test plan covers test AFY14CCIM-GC1which is the first of two scheduled FY-2014 test runs involving glass ceramic waste forms in the Idaho National Laboratory's Cold Crucible Induction Melter Pilot Plant. The test plan is based on the successes and challenges of previous tests performed in FY-2012 and FY-2013. The purpose of this test is to continue to collect data for validating the glass ceramic High Level Liquid Waste form processability advantages using Cold Crucible Induction Melter technology. The major objective of AFYCCIM-GC1 is to complete additional proposed crucible pouring and post tapping controlled cooling experiments not completed during previous tests due to crucible drain failure. This is necessary to qualify that no heat treatments in standard waste disposal canisters are necessary for the operational scale production of glass ceramic waste forms. Other objectives include the production and post-test analysis of surrogate waste forms made from separate pours into the same graphite mold canister, testing the robustness of an upgraded crucible bottom drain and drain heater assembly, testing the effectiveness of inductive melt initiation using a resistive starter ring with a square wave configuration, and observing the tapped molten flow behavior in pans with areas identical to standard High Level Waste disposal canisters. Testing conditions, the surrogate waste composition, key testing steps, testing parameters, and sampling and analysis requirements are defined.
This plan covers test BFY14CCIM-C which will be a first-of-its-kind demonstration for the complete non-radioactive surrogate production of multiphase ceramic (SYNROC) High Level Waste (HLW) forms using Cold Crucible Induction Melting (CCIM) Technology. The proof of principle test will occur in Idaho National Laboratory's (INL) CCIM Pilot Plant and is tentatively scheduled for the week of September 15, 2014. The purpose of the test is to begin collecting qualitative data for validating the ceramic HLW form processability advantages of using CCIM technology-as opposed to existing ceramic-lined Joule Heated Melters (JHM) currently producing accepted, but less durable, borosilicate glass (BSG) forms. The objectives of BFY14CCIM-C are to complete crystalline melt initiation with a new joule heated resistive starter ring, sustain inductive melting at temperatures between 1500 to 1700 O C for two different relatively highly conductive materials representative of the SYNROC formation inclusive of a HLW surrogate, complete melter tapping and pouring of molten ceramic material in to a preheated 4 inch graphite canister and a similar canister at room temperature. Other goals include assessing the performance of a new crucible specially designed to accommodate the tapping and pouring of pure crystalline forms in contrast to less recalcitrant amorphous glass, assessing the overall operational effectiveness of melt initiation using a resistive starter ring with a dedicated power source, and observing the tapped molten flow and subsequent relatively quick crystallization behavior in pans with areas identical to standard HLW disposal canisters. Surrogate waste compositions with ceramic SYNROC forming additives and their measured properties for inductive melting, testing parameters, pre-test modifications, key testing steps, data collection requirements, and sampling/post-demonstration analysis requirements for the produced forms are provided and defined. iii
Sponsored by the Department of Energy Nuclear Energy's Fuel Cycle Research and Development Program, the Cold Crucible Induction Melter is being developed as the next generation of melter technology for High Level Liquid Waste's efficient immobilization in highly durable glass ceramic and ceramic forms. Concentration of the radioactive High Level Liquid Waste generated from the proposed future recycling of spent nuclear fuel, after the fuel's dissolution in nitric acid, is necessary to take advantage of the inherent attributes of Cold Crucible Induction Melting technology. Based on a range of commercial spent nuclear fuel fission product composition data and its expected High Level Liquid Waste composition data as provided in oxide form, an analysis was completed to estimate a reliable concentration level for the waste. The analysis involved using nitric acid vapor liquid equilibrium data over a range of boiling temperatures and performing spreadsheet calculations to concentrate the High Level Liquid Waste through evaporation. The results will provide a concentrated nonradioactive surrogate High Level Liquid Waste feed recipe for testing in Idaho National Laboratory's Cold Crucible Induction Melter Pilot Plant. This testing will generate data to begin verification of the relatively high feed rates of Cold Crucible Induction Melters compared to those of ceramic lined Joule Heated Melters.
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