PLEASE DO NOT REMOVE FRCM LIBRARY REPORT OF INVESTIGATIONS/1995 Evaluation of the Three-Phase, Electric Arc Melting Furnace for Treatment of Simulated, Thermally Oxidized Radioactive and Mixed Wastes (In Two Parts) 1. Design Criteria and Description of Integrated Waste Lk3 dt.!H':.(ll J '; Mil .~ " Treatment Facility f $ 1 ;~ *.,;;::wr')oMFp.·:~ '" ,,~ ~~f . \N," 00<?0 ,- , l By L. L. Oden, W. K. O'Connor, P. C. Turner, and A. D. Hartman UNITED STATES DEPARTMENT OF THE INTERIOR BUREAU OF MINES u.s. Department of the Interior Mission Statement As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally-owned public lands and natural resources. This includes fostering sound use of our land and water resources; protecting our fish, wildlife, and biological diversity; preserving the environmental and cultural values of our national parks and historical places; and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to ensure that their development is in the best interests of all our people by encouraging stewardship and citizen participa­ tion in their care. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration. Cover. ThenntJl waste tret1lment facility. T- ~---------- ~1 H Report of Investigations 9528 'I Evaluation of the Three-Phase, Electric Arc Melting Furnace for Treatment of Simulated, Thermally Oxidized Radioactive and Mixed Wastes !' ( (In Two Parts) 1. Design Criteria and Description of Integrated Waste Treatment Facility By L. L. Oden, W. K. O'Connor, P. C. Turner, and A. D. Hartman I; UNITED STATES DEPARTMENT OF THE INTERIOR I' Bruce Babbitt, Secretary BUREAU OF MINES Rhea L. Graham, Director International Standard Serial Number ISSN 1066-5552 CONTENTS Page Abstract .......................................................................... 1 Introduction ....................................................................... 2 Design criteria ..................................................................... 2 Description of waste treatment facility .........................................•........... 3 Feed system ....................................................................... 3 Electric arc melting furnace and power supply ............................................ 4 Furnace description ............................................................. 4 Furnace refractories . 5 / \ Furnace and transformer cooling ................................................... 5 Power supply ................................................................ : .. 6 Air pollution control system ......................................................... 6 Data management system ........................................................... 13 Arc furnace analyzer and electronic data logger . 13 Manual data logs ............................................................... 13 Summary ......................................................................... 15 References ........................................................................ 16 ILLUSTRATIONS 1. Diagram of integrated waste processing facility . 4 2. Receiving bin and charge hopper ..................................................... 5 3. Design drawing for water-cooled feed tubes ................•............................ 6 4. Furnace roof • . • • . .. 7 5. Cooling water circuit diagram ................ '. 8 6. Furnace, plumbing, and fiowmeters .................................... ,.............. 9 7. Line drawing for electric arc melting furnace power supply .......... 10 8. Design drawing for quenching air inlet system ........................................... 11 9. Furnace and air pollution control system within the building ................................ 12 10. Air pollution control system outside the building. 14 TABLE 1. Power supply characteristics ................................•................. ~ . 6 UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT Metric Units A ampere mm millimeter cm centimeter min minute g/cm3 gram per cubic centimeter MPa megapascal h hour MW megawatt kg/h kilogram per hour Pa pascal kY·A kilovolt ampere pct percent ! kW kilowatt s second kW·h kilowatt hour t metric tons kW.h/mt kilowatt hour per metric ton t/h metric ton per hour L liter Y volt L/s liter per second var volt x ampere x reactance m meter W watt m/s meter per second JLm micrometer m3 cubic meter °C centimeter u.s. Customary Units acfm actual cubic foot per minute Ib pound ft foot Ib/ft3 pound per cubit foot ft3 cubic foot lb/h pound per hour ·1 ft/min foot per minute psig pound per square inch, gauge gal gallon scfm standard cubic foot per minute gal/min gallon per minute st short ton hp horsepower st/h short ton per hour in inch OF degree Fahrenheit in we inch water column EVALUATION OF THE THREE-PHASE, ELECTRIC ARC MELTING FURNACE FOR TREATMENT OF SIMULATED, THERMALLY OXIDIZED RADIOACTIVE AND MIXED WASTES (In Two Parts) 1. Design Criteria and Description of Integrated Waste Treatment Facility By L. L. Oden, W. K. O'Connor, P. C. Turner, and A. D. Hartman ABSTRACT The U.S. Bureau of Mines and the Department of Energy (DOE), through its contraCtor EG&G Idaho Inc., are collaborating on a multiyear research project to evaluate the applicability of three-phase, electric arc furnace melting technology to vitrify materials simulating low-level radioactive and mixed wastes buried or stored at the Idaho National Engineering Laboratory and other DOE sites. The metter' is a sealed, 1-t (1.1-st), three-phase, 800-kV· A electric arc melting furnace with lO.2·cm- (4-in·) diam­ eter graphite electrodes, water-cooled roof and sidewalls, and four water-cooled feed tubes. A water­ cooled copper f1X1:ure provides for continuous tapping of slag. An instrumented air pollution control system (APCS) with access ports for analysis and a feeder based on screw conveyors and a bucket eleva­ tor are dedicated to the facility. Test data are provided by an arc furnace analyzer and by sensors in­ dicating feed rate; slag temperature; and temperature, pressure, and velocity in the APCS. These data are received by a data logger, digitized, and transmitted to a personal computer for storage and display. This unique waste treatment facility is available for public and private use on a cost~sharing basis. 1 Research chemist. 2Chemical engineer. 3Supetvisory metallurgist. 4Chemical engineer. Albany Research Center, U.S. Bureau of Mines, Albany, OR. 2 INTRODUCTION The U.S. Bureau of Mines (USBM) and the Depart­ operated with power levels to over 100 MW processing ment of Energy (DOE), through its contractor EG&G oyer 130 t/h (143 st/h). Sealed furnaces have been built, Idaho Inc., are -collaborating on a multiyear research and furnaces processing materials at very high tempera­ project to evaluate' existing three-phase, electric arc tures 2,000 °C (3,632 OF) operate routinely. The objectives furnace melting technology to vitrify simulated mixed of this research program are.to ~dapt and demonstrate the wastes and soils contaminated 'with transuranic (TRU) application of existing arc melting furnace technology to elements and other hazardous organics and metals listed thermal processing of TRU-contaminated mixed wastes in the Resource Conservation and Recovery Act (RCRA) and soils, with the ultimate objective of preparing a that are buried or stored at the Idaho National En­ nonleachable final waste form that is stable over geologic gineering Laboratory (INEL) and other DOE sites. Over time frames. 57,000 m3 (+2,000,000 ft3) of buried waste is located at the The current program, the first year of an anticipated Subsurface Disposal Area of the Radioactive Waste Man­ 3-year effort, is directed to processing simulated, thermally agement Complex at lNEL, and roughly four times that oxidized mixed wastes. Simulated, actual, as-retrieved amount of potentially contaminated soil is intermingled waste mixtures containing combustible materials will be with the original wastes. These buried wastes represent a processed during the following years, with the ultimate highly heterogeneous mix of combustible organics, reactive goal of determining design parameters for a pilot-scale, materials, metal oxides, sludges, metals, and contaminated on-site waste processing facility. soils. An equal volume of similar waste is located in re­ The current research program required significant mod­ trievable above-ground storage at the INEL Transuranic ification of a melting facility originally constructed to vitrify Storage Area. Similar types and quantities of buried and residues from municipal waste combustion (1).5 This mod­ stored wastes exist at DOE's Hanford, WA site. ification consisted of adding water-cooled feed tubes to the Commercially available arc melting technology is well existing furnace; altering the air pollution control system developed for industrial pyrometallurgical smelting and (APCS) to cope with condensable fume in the offgas; and melting applications, which routinely process large volumes adding a data management system to log test parameters of heterogeneous materials similar to the buried mixed electronically characterizing the feed system, the APCS, wastes and soils. Electric arc furnaces are avaihible in and the electric furnace. FoUQwing is a summary of design many design configurations including direct current and criteria and a description