SALE OF SURPLUS GOVERNMENT PROPERTY

Notice Date

January 4, 2001

Contracting Office

U. S. Department of Energy, Oak Ridge Operations Office, P. O. Box 2001, Oak Ridge, Tennessee 37831

ZIP Code

37831

Response Due

January 29, 2001

Point of Contact

John E. Bailey (865)574-1107 Bechtel Jacobs Company, LLC, East Tennessee Technology Park (formerly K-25 Plant), Property Management Dept., K1310-DE, MS 7471, P.O. Box 4699, Oak Ridge, TN 37830

E-Mail Address

John E. Bailey; W. Terry Humphry (baileyje@bechteljacobs.org; humphryswt@bechteljacobs.org)

Description

The Transportable Vitrification System (TVS) demonstration came about as a result of the Department of Energy's (DOE's) desire to move waste processing technologies from the laboratory to the field. The TVS is specifically designed for the treatment of mixed wastes that contain both hazardous and radioactive materials. Although these wastes are a significant waste management challenge to the DOE complex, a large number of them have been shown to be suitable for treatment by vitrification through laboratory and small-scale melter demonstrations on both actual and surrogate wastes. The TVS was developed by Westinghouse Savannah River Company (WSRC) as part of a program that would result in use of the vitrification technology on a large, field-scale process. The demonstration was conducted to support the DOE Mixed Waste Focus Area. The East Tennessee Technology Park (ETTP), formerly the K-25 Site, Oak Ridge, Tennessee was selected as the first TVS demonstration site for treating mixed wastes. The TVS is a large-scale, fully integrated vitrification system for the treatment of low-level mixed waste in the form of sludges, soils, incinerator ash, and other waste streams. The unit is designed to be transportable and easily decontaminated. Equipment primarily is housed in modules that can be sealed for over-the-road transportation. Major modules include feed preparation, melter, offgas, and control systems. Slurried or dry feed is introduced to the feed preparation module where it is blended with glass formers. A slurry system then pumps the waste/additives mixture to the melter. The melter module contains a joule-heated cold-top melter manufactured by Envitco, Inc., and is based on their proprietary technology. The refractory-lined melter has a separate chamber for the glass drain. Offgas is processed in a separate emissions control module. The glass product is poured into steel containers, which after cooling are stored for eventual disposal. While primarily intended for waste demonstration activities, the TVS is large enough to completely treat small- to medium-sized DOE waste streams. A demonstration processing mixed waste was completed in the fall of 1997. Waste to be processed is delivered to the Waste and Additives Module as either dry or slurried waste. Slurried waste can be pumped directly to the Blend Tank, while dry waste must be dumped first into the Waste Hopper where a screw feeder then transports it to the Blend Tank. Glass-forming additives are supplied in bulk bag containers ("supersacks") and transported to the Blend (Mix) Tank by a metering screw feeder. Water is added as necessary. The Blend Tank is placed on load cells to aid the operator in achieving the proper mix of waste and additives. An agitator in the Blend Tank homogenizes the feed. Once the batch is ready, it is pumped to the Surge (Feed) Tank, which is also provided with an agitator. A recirculation loop transports the slurried feed to the melter where a side stream is drawn off and metered for introduction into the melter. The melter is constructed of refractory blocks and a refractory superstructure (lid) and is divided into three chambers. The largest is the main, central processing chamber, which contains the primary electrodes. Glass temperature in the melter is measured in the center of the main melter chamber by a molybdenum-sheathed thermocouple. The melter is capable of generating glass temperatures between 1000 and 1400 C. Slurried feed is introduced into the main chamber and forms a "cold-cap" on the surface of the molten glass. This cap helps reduce heat loss and emissions of volatile metals. Convective currents in the glass, set up by the electrodes, draw fresh material from the cold-cap into the glass pool where the vitrification process takes place. Glass is drawn through a refractory-lined "throat" into the second or glass drain chamber. Here a nuclear-level gauge allows the operator to determine glass level in the melter and control it by moving the spindle of a submerged drain valve. When this valve is open, glass drains by gravity into glass receptacles placed on a conveyor. Continuous glass production rates of 50 to 150 kg/h can be maintained. After filling, the containers are allowed to cool and are removed by a forklift truck for storage or disposal. The third chamber, which has a separate drain mechanism, is designed to remove salts/sulfates that may collect on the glass pool surface. The processing of some waste streams may result in the accumulation of metals in the main melter chamber; therefore, a third "metals drain" is provided for this eventuality. Neither the salts nor the metals drains have been used to date. Offgas from the melter is drawn off through a refractory-lined duct to the emission control module. The offgas system consists of a quencher, packed bed cooler, variable throat venturi scrubber, mist eliminator, reheater, high-efficiency particulate air (HEPA) filters, and fans. Treated offgas is released through a 15-m stack, with provisions for Environmental Protection Agency approved particulate and gas sampling. The Control and Services (Power) Module contains the control room for the TVS, as well as the power supply and conditioning equipment for the melter. A standard programmable logic control system is used to control most of the operations of the TVS from the control room. Envitco completed construction of the TVS in July 1995 at the facilities of Dreicor, Inc., in Erwin, Tenn. Dreicor is a subsidiary of the company that owns Envitco. An acceptance test was completed at the TVS fabrication site and the unit was disassembled and transported to Clemson, S.C., where it was reassembled for surrogate testing by WSRC and Clemson University Environmental Systems Engineering personnel. The TVS was operated from December 1995 through early March 1996. Modifications at Clemson associated with Oak Ridge site-specific requirements and repairs were then completed and the TVS was disassembled for transport to the ETTP. Thirteen tractor-trailer loads were required for the move, which took place in late May and early June 1996. Lockheed Martin Energy Systems, Inc., assumed responsibility for TVS assembly, which was completed in September 1996. WSRC provided technical assistance. The TVS was started up in September 1996 for shakedown and surrogate testing, and operated until early November 1996. The unit was placed in cold shutdown to address permitting issues, make refractory modifications, and prepare for processing of mixed waste. Processing of mixed waste was initiated on September 24, 1997, and completed on October 20, 1997. The mixed wastes processed by the TVS were the dewatered B&C pond sludge (approximately 96% solids) and the Central Neutralization Facility (CNF) sludge (approximately 20% solids). The B&C pond sludge was a fine, dry sludge generated from the Pond Waste Management Project. The sludge had a high silica content and was used as a partial substitute for the silica glass additive. The CNF sludge was a wet sludge and was mixed with the B&C pond sludge. These sludges were considered a challenge for controlling glass chemistry because of the high iron content in the B&C pond sludge and the high phosphorus content in the CNF sludge. The vitrified waste was poured into 8 cubic foot stainless steel boxes. The boxes were made from recycled radioactively contaminated scrap metal. A total of 16,159 lb of mixed waste was processed (8372 lb of B&C, 7787 lb of CNF). This produced a total of 17,338 lb of vitrified waste (glass). The volume of waste treated was 276 cubic feet, for a total of 112 cubic feet of vitrified waste. This represents a volume reduction of approximately 60%. Buyer must be NRC licensed to handle radioactively contaminated equipment. The TVS will be offered "where is -- as is", with all faults and in the current condition. Components considered being Limited Rights Data (LRD) or Restricted Rights Data (RRD) will require licensing through the manufacturer or will not be released as a sale item. The Buyer will be responsible for proper licensing along with disassembly, characterizing, packaging, loading, arranging for transportation, and transporting the TVS to the buyer's facility. The Buyer shall be required to follow all federal, state and BJC requirements for disassembly, characterizing, packaging, loading, and transporting the TVS to the buyer's facility. Interested parties may contact the POC listed above for more information.

Record

Loren Data Corp. 20010108/SUMSC002.HTM (W-004 SN50A0W1)