© 2001 by CRC Press LLC Chapter Ten © 2001 by CRC Press LLC 10 Planned Life-Cycle Cost Estimates William E. Schwinkendorf Idaho National Engineering and Environmental Laboratory Idaho Falls, Idaho Introduction Selection and design of systems and technologies for treatment of mixed low-level waste (MLLW) requires knowledge and understanding of the expected costs, schedules, risks, performance, and reliability of the total engineered system. These factors are all related. For example, cost is a function of: Schedule. The longer the schedule required to treat a given quantity of waste, the greater the operating and maintenance cost. Reliability. The greater the system reliability, the lower the maintenance cost, the greater the system availability, and therefore the shorter the schedule. However, increased reliability may increase capital cost for more reliable equipment. A system with low reliability will increase operational and economic risk associated with increased probability of equipment failure, increased mainte- nance and a drawn-out schedule. Risk. Additional costs are required to mitigate environmental safety and health (ES&H) risks associated with handling and treating mixed waste. The design requirements for risk mitigation will depend on the waste content and the technologies used in the treatment process. Performance. A system that performs poorly in terms of meeting treatment goals and regulatory requirements may require post-treatment, re-treatment, or system modifications, all of which will increase cost and schedule. The purpose of this section is to provide the reader with insight into factors involved in determining the cost of a mixed waste treatment system, the relative cost of various treatment concepts, and the trade- offs that should be considered when developing an economic system design. This section is based on the results of an integrated process analysis project (Feizollahi et al., 1994; Feizollahi and Quapp, 1996; Biagi et al., 1997) commissioned by the Department of Energy (DOE), Office of Science and Technology (OST), to evaluate thermal and non-thermal treatment systems for DOE mixed low-level waste (MLLW). The purpose was to evaluate and compare the performance and cost of various treatment technologies in the context of a complete treatment system capable of treating the wide variety of mixed waste in the DOE complex. Subsequent to these initial studies, additional analyses were performed to obtain greater insight into the cost sensitivities and trade-offs associated with operating parameters that differed from those used in the initial studies. These studies did not include the time value of money, escalation for expenditures occurring at different times, or salvage value of the facility. Many textbooks on engineering economy and cost engineering are available that provide methods for taking these factors into account for commercial operations. © 2001 by CRC Press LLC Thus, costs identified in subsequent subsections are for specific systems designed to treat specific DOE waste streams for the integrated process analysis project. These costs should not be taken to represent the costs of different treatment systems designed to process other combinations of waste streams. Rather, the relative costs, their trends with respect to system parameters and waste characteristics, and the implications of these factors on life-cycle cost are the important factors to consider in evaluating the life- cycle cost of a mixed waste treatment facility. Standard Cost Factors Total life-cycle cost of a mixed waste treatment system is a function of six major work breakdown structure (WBS) components. Contingency should be included in all costs and generally should be higher for systems using less-developed technologies to reflect operational uncertainties. However, increased con- tingency cost for less-developed technologies is one factor that makes such technologies and associated systems less economically desirable than more mature technologies (Harvego and Schafer, 1997). The six cost components of the WBS are (Feizollahi et al, 1994; Feizollahi and Quapp, 1996): 1. Studies and bench-scale tests and demonstration. Costs for treatability studies and bench-scale testing include research personnel, equipment, facilities, and project management before Title I design. Demonstration costs include personnel, design and inspection, construction and equip- ment including construction management, project management, waste disposal, and decontami- nation and decommissioning. 2. Facility capital costs. This cost element consists of five subcomponents described below that involve design, equipment costs, and building costs. Design, inspection, management, and indirect costs are dependent costs that are calculated as a fraction of the purchase costs for the building structure and equipment. a. Design: preliminary and detailed designs b. Inspection: this includes engineering support during construction c. Project management: management costs incurred by site management and the contractor d. Construction: Facility construction costs are developed from the preconceptual design package and include site development, construction of buildings and structures for alpha and non- alpha waste, processing and material handling equipment, installation, and indirect costs such as subcontractor overhead and fees e. Construction management: this includes material and services procurement and control activ- ities, allowances for project scope change, management reserve, and contingency reserves to reduce the impact of missed cost or schedule objectives 3. Operations budget funded activities. These are preconstruction and preoperational activities. This cost element includes conceptual design, safety assurance, National Environmental Policy Act (NEPA) compliance efforts for government projects, permitting, preparation for operations, and project management. Conceptual designs may consist of process functional diagrams, facility layouts, equipment lists, personnel requirements, and material mass balances. 4. Operating and maintenance costs. This cost element includes operating labor, utilities, consumable materials, maintenance (parts, equipment and labor), and transportation. Transportation costs include transportation of wastes to the treatment facility and transportation of treated waste to a disposal site. Allowances for management reserve and contingencies should be included. 5. Decontamination and decommissioning costs. These costs include decontaminating the facility, removing the structures and equipment, and decontaminating the site. 6. Disposal. This cost includes the price charged by the disposal facility. This is usually a one-time cost based on the volume of waste to be disposed. However, the per-unit volume cost may vary, depending on the type and quantity of hazardous species and radionuclides remaining in the waste. © 2001 by CRC Press LLC Facility Design Issues Facilities handling MLLW are placed in Seismic Category 1 and are classified as moderate-hazard facilities (Kennedy et al., 1992). A major area of concern for ES&H and a major cost driver is the design for alpha containment. All systems and critical operations related to handling alpha-contaminated MLLW are classified according to safety. They should have high-quality, low-maintenance features to keep personnel exposure as low as reasonably achievable. Operations with alpha-MLLW should be confined, to the greatest extent practical, to remote cubicles. All process steps with potential for generating airborne alpha contamination should have a tertiary containment system. Thus, equipment used to process alpha-MLLW should be placed in triple confinement, airtight cells with personnel access through airlock doors. Such cells should operate at slightly negative pressure to avoid releasing contamination outside the units. Only two levels of containment are required for other processes involving materials with a limited potential for becoming airborne. However, this requirement should be carefully assessed to avoid potential worker inhalation risks. Personnel entering alpha cells must wear Level A protective equipment, including self-contained breathing equipment. The facility should be designed and equipment selected to minimize maintenance requirements and minimize the personnel exposure time while performing maintenance operations. Large corridors may be required next to each cell for equipment removal and maintenance. In this corridor, equipment may be disassembled, decontaminated (if required), and sent to the maintenance shop for further repair. There are two maintenance issues to be considered. The first issue is the basic maintenance costs (e.g., labor, equipment, parts and material, and lost production due to downtime, which can be minimized with a just-in-time supplier or an inventory of spare parts or replacement equipment). The second issue is the need to have sufficient staff to prevent any single individual from exceeding his/her daily or annual radiation exposure limits while performing maintenance functions. Facility concepts and confinement levels require detailed analysis and refinement when processing alpha-MLLW to determine the most cost-effective design that meets ES&H requirements. The risk of cost overruns may be high when the system is applied to alpha-MLLW because most system components must be further developed to allow ease of decontamination and maintenance for application in an alpha cell environment and to prevent the inadvertent release from processing systems. Of particular concern are high temperature processes and the entrainment of actinides in the off-gas. Facility Subsystems MLLW consists of organic and inorganic solids and liquids comprising a wide variety of materials contaminated with hazardous organics, toxic metals, and radionuclides. Such waste matrices may include any of those shown in Table 10.1 (Huebner et al,. 1994). Treatment of such a wide variety of waste streams requires a complex treatment system consisting of many subsystems to handle separate waste matrices and, in some cases, specific contaminants. The types of subsystems that may be required are as follows. 1. Front-end handling. Waste is received and characterized. Instrumentation can include real-time radiography (RTR), gamma-spectroscopy, and passive/active neutron (PAN) assay. The waste is removed from the incoming drums, sorted, separated, size reduced, and transferred to the next process. Contaminated empty drums can be decontaminated for reuse, melted for metal recovery, or compacted for disposition, depending on the waste content and residual contamination. 2. Primary treatment. For thermal systems, primary treatment generally consists of a single process to destroy the organic waste components, and in some cases to vitrify the inorganic components (incinerator, plasma furnace, steam reformer, etc.), although some variations may exist. For non- thermal systems, the primary treatment consists of a treatment train such as a separation process (thermal desorption or washing) to remove organics from inorganic waste matrices and a chemical oxidation process to destroy organic waste. © 2001 by CRC Press LLC 3. Aqueous waste. All aqueous waste, including secondary waste generated internally (e.g., from washing or decontamination processes or from off-gas scrubbers, etc.), will require treatment. 4. Air Pollution Control (APC). APC systems may be required for various subsystems such as the primary treatment unit, stabilization process, metal melter, or decontamination system. Details and size of the air pollution control system depend on the specific process and contaminants in question. The components of thermal and non-thermal APC systems are similar and perform similar functions. However, because approximately an order of magnitude more non-toxic gases are emitted from thermal systems than from non-thermal systems, more fume, particulates, and contaminants can be carried over with the off-gas from the thermal systems. Thermal systems are also more likely to generate specific hazardous compounds and volatile off-gas constituents (e.g., dioxins/furans, NO x , Cd, Pb, Hg, etc.). Thus, the off-gas from thermal systems requires more complex treatment and the APC system must be much larger and more effective than that for non-thermal systems to achieve the same level of performance. 5. Metal recovery. Melters can be used to produce ingots from ferrous metal wastes that cannot be decontaminated for subsequent recycle or disposal. Metal and lead decontamination can use an abrasive water jet or CO 2 pellets to decontaminate the metals. Mercury can be removed from inorganic wastes with a retort or by a leaching process. TABLE 10.1 Mixed Waste Matrices and Contaminants Aqueous Liquids and Slurries Soils Acidic wastewaters and aqueous slurries • Organic contaminated soils (halogenated or nonhalogenated) Basic wastewaters and aqueous slurries • RCRA metal contaminated soils Cyanide wastewaters • Soils with debris Organic Liquids Debris Waste Aqueous/halogenated or nonhalogenated organic liquids • Metal debris Pure halogenated or nonhalogenated organic liquids • Concrete PCBs • Glass Ceramic/brick Asbestos • Combustibles (plastic/rubber, wood, paper/cloth/trash) Graphite Biological Composite filters Asphalt Solid Process Residues Special Waste Inorganic particulates Reactive metals Ash Components (contaminated with reactive metals) Sand blasting media Pyrophoric fines Absorbed aqueous or organic liquids Explosives/propellants Ion exchange media Compressed gases/aerosols Calcined solids Inorganic sludges Wastewater treatment sludges Plating waste sludges Inherently Hazardous Waste Paint waste-liquids/sludges, chips/solids Elemental mercury RCRA metal salt wastes Elemental lead Activated carbon (halogenated or nonhalogenated) Beryllium Organic resins (halogenated or nonhalogenated) Batters Cd/Pb/Hg Organic absorbents (halogenated or nonhalogenated) Batters Cd/Pb/Hg Organic sludges (halogenated or nonhalogenated) Cadmium metal/alloys Organic particulates (halogenated or nonhalogenated) Biological materials Organic Chemicals (halogenated or nonhalogenated) © 2001 by CRC Press LLC 6. Stabilization. Several stabilization options are available as indicated in previous portions of this Handbook. Stabilization is generally required to meet Resource Conservation and Recovery Act (RCRA) Land Disposal Restriction (LDR) requirements. 7. Certification and shipping. The physical and radiological properties of the packaged waste are certified in accordance with transportation, storage, and disposal requirements. The containers of packaged waste are weighed, examined with an RTR to ensure that the matrix is homogeneous and contains no free liquid, and beta and gamma radioactivity is assayed. 8. Administration and support. This includes all technical and administrative functions required to manage the operation of a waste management facility. These functions include security, access control including personnel decontamination, maintenance of uncontaminated areas and equip- ment, health physics and radiation badges, sanitary facilities, work control and personnel support, public relations communications, emergency response provisions, analytical laboratory, environ- mental field sampling, environmental regulatory reporting, and records management. Treatment systems that accept fewer types of waste matrices, contaminants, or wastes with low levels of contamination will naturally require fewer subsystems. However, most treatment systems will require some form of sorting and segregation of the waste to prevent accidents, inadvertent releases or equipment damage. Many waste treatment technologies have limits on feedstream chemical content, physical com- position, and particle size. Systems using a rotary kiln or plasma furnace for primary thermal treatment require the least feed preparation. In contrast, fixed-hearth controlled-air incinerators, indirectly fired pyrolizers, and non-thermal systems require a well-sorted feed. In general, it is undesirable for materials such as bulk lead and mercury to enter a thermal treatment unit because they are particularly hazardous volatile materials that are difficult to collect in the off-gas system. If these materials can be found using RTR performed on containers of intact waste, the containers should be emptied and the prohibited items removed and treated separately. Similarly, if RTR detects other bulk metals (e.g., steel, and aluminum), these metals should also be removed to minimize challenges to the shredder and physical damage to the thermal treatment units refractory. These constraints, coupled with the nature of the waste, dictate at least some degree of feed material sorting and separation and, if there is a limitation on particle size, some level of shredding may be required. The extent to which waste feed must be sorted and shredded to produce an acceptable feedstock has a significant impact on system cost. Manual sorting is labor intensive, and automated sorting requires highly sophisticated and costly instrumentation and involves high programmatic risk. Trade-offs between manual sorting by direct contact, or using telerobotics and automated sorting, will depend on several factors, including labor costs, costs associated with sufficient personnel on staff to meet daily exposure limits, and the cost of personnel protective equipment. These costs can be compared to the labor costs of operating telerobotic or automated equipment, the reliability of identifying waste items to be sorted, capital cost and maintenance cost of the equipment, and equipment reliability and availability. Excessive shredding is mechanically demanding and significantly increases maintenance cost. Low- speed shredders have been identified as the best candidates because they can tolerate the widest variation in waste feedstreams, are the least costly, and are least prone to operational problems (Soelberg and Reimann, 1994 ). However, commercial low-speed shredders reduce waste to 1 to 12 in. in size too large for many potential MLLW treatment technologies. The reaction rate for most non-thermal processes is surface-area limited; thus, such processes require particle sizes of 0.5 in. or less. The maximum feed size for molten salt oxidation and supercritical water oxidation is approximately 0.125 in. To achieve these small particle sizes requires low-speed shredding followed by high-speed sizing, typically a hammer mill. It has been estimated that separating and shredding combustible waste to a size range of 1 to 12 in. at a rate of 1 ton/hour would cost $700/ton. Reducing the maximum particle size to 0.125 in. would raise the cost to $1600/ton with the incremental cost attributable to the hammer mill, its inert gas system, © 2001 by CRC Press LLC additional separation equipment and maintenance requirements. Reducing the particle size to less than 0.004 in. would increase the pretreatment costs to approximately $2100/ton due to additional screening and recycling of waste through the hammer mill, and higher hammer mill operating and maintenance costs. The processing rate also affects sizing costs; reducing the processing rate by a factor of 10 increases the pretreatment unit costs by a factor of 4 to 5 because most of the equipment is the same so fixed capital costs are spread over less waste. Other required subsystems include primary treatment to destroy the hazardous organic components in accordance with EPA requirements, and the nonhazardous organics to decrease the volume of waste to be disposed. Under EPA regulations, residues and secondary wastes will require treatment and/or stabilization before disposal if leachability standards are not met. Variations of the stabilization process include vitrification, polymers, and cement or grout. Thus, operations are needed to stabilize the treat- ment residues, unregulated organics that have not been destroyed, inorganic materials, and radionuclides prior to disposal in a MLLW disposal facility. In general, systems that require complex mechanical, thermal or chemical processes, or precise control of these processes, are difficult to operate and subject to frequent failures resulting in low operating efficiency, low availability and reliability, and high maintenance. Cost confidence is achieved using proven technologies. Conversely, technologies based on innovative or untested concepts pose a high risk of overruns. Other factors contributing to system economics are availability of construction materials, system size, and the use of commercial equipment. Volume reduction is also a principal cost consideration due to the costs associated with packaging, shipping, and disposing of secondary wastes. However, the cost of achieving significant volume reduction can exceed the savings depending on the complexity of the system and its reliability and availability. Cost Comparisons Systems conceptualized in the integrated process analysis project consisted of all facilities, subsystems, equipment, and methods needed to treat and dispose of the MLLW stored in the DOE complex, including waste receiving, characterization, sizing, organic destruction, air pollution control, metal recovery, and secondary waste residue processing for eventual disposal. A generalized configuration is shown in Figure10.1. Various technologies were assembled into 30 different conceptual systems: 20 thermal systems (Feizol- lahi et al., 1994; Feizollahi and Quapp, 1996), 5 non-thermal systems (Biagi et al., 1997), and 5 enhanced non-thermal systems (Biagi, Schwinkendorf, and Teheranian, 1997). The thermal systems used inciner- ation or other thermal processes for organic destruction, and vitrification, grout, or polymer for stabi- lization. The non-thermal systems used wet oxidation processes operating at less than 350 ° C, such as acid digestion for organic destruction, and grout, phosphate bonded ceramic, or polymer for stabilization. The enhanced non-thermal systems included non-thermal organic destruction and vitrification for stabilization. These systems were compared to understand risks, cost and performance (Schwinkendorf, 1996). Material mass balances were prepared using the Aspen Plus computer code (Aspen Technology, Inc., 1994) to analyze preconceptual system designs. The resulting equipment sizes, the space footprint, and associated operating and maintenance staff requirements were estimated to develop the total life-cycle cost (TLCC) that covered everything from current storage through final disposal and release of effluents in accordance with expected regulations. A comparable basis among the various systems was made possible by maintaining the following assumptions throughout all of the studies. 1. The same waste characteristics and distribution of constituents were used for all analyses. 2. A single, centralized government-owned and contractor-operated (GOCO) facility capable of treating all DOE MLLW was assumed. 3. About 70% of the current DOE MLLW inventory, or 236 million pounds (107 million kilograms), of waste was treated over the system lifetime of 20 years. © 2001 by CRC Press LLC 4. Waste was treated at a rate of 2930 lb/hr (1330 kg/hr) with 46% online availability (4030 hr/yr of operation out of 8760 hr) due to uncertain equipment life and maintenance requirements with radioactive operations. 5. Because the treatment systems are used for alpha and non-alpha waste, a tertiary containment system was used for all process steps from waste sorting through stabilization. 6. Except where a Joule-heated melter is explicitly identified, all vitrification is performed in a high- temperature plasma furnace that produces a slag. 7. Waste loadings (i.e., mass of treated waste incorporated into the final waste form divided by the mass of the final waste form) of 67 wt% in high-temperature slag, 50 wt% in polyethylene, and 33 wt% in grout were assumed. 8. Disposal was in an RCRA engineered on-site disposal facility meeting land disposal restrictions with a disposal cost of $240/ft 3 ($8480/m 3 ). One of the primary products of these studies was the total life-cycle cost of these systems. It should be recognized that the actual costs of real systems will depend on the waste to be treated, the processes and technologies used, and the marketplace. However, the cost estimates developed in these studies are appropriate for system comparisons, identification of major cost elements, and identification of potential cost savings. Differences in the TLCC among systems of thermal technologies are minor. Likewise, only small differences were found among systems using non-thermal technologies. However, the cost of non-thermal systems was about 50% more than thermal systems. This difference appears significant because the studies should be within ± 30% owing to the comparative bases used. TLCC costs were estimated to be approximately $2.1 billion for a thermal metal melting system vs. $3.9 billion for a non-thermal acid digestion system. The unit costs for treatment (without disposal) vary between ~$8/lb ($17.60/kg) for thermal systems and $13/lb ($28.70/kg) for non-thermal systems. Tabl e 10.2 illustrates a typical distribution of subsystem costs for a rotary kiln system with vitrification and a non-thermal process with grout stabilization. Table 10.3 illustrates typical WBS cost components for the same systems. FIGURE 10.1 Generalized MLLW treatment system (*PBC = phosphate bonded ceramic). Aqueous Liquids Aqueous Waste Treatment Salts Salts Clean Metal & Lead to Recycle To Disposal To Disposal To Disposal Clean Metal to Recycle Discharge or Recycle Characterization Sorting Size Reduction Waste Feed 2927 lbs/hr Receiving & Preparation Combustible and Noncombustible Waste Metals with Entrained Contamination & Lead Primary Treatment Polymer Stabilization Stabilization Vitrification GroutPBC* Metal Melters Mercury Retort & Amalgamation Metal/Lead Decontamination Abrasive Blasting Special Waste Treatment Mercury Contaminated Waste Bulk Metals & Lead Special Waste Primary Waste Secondary Waste © 2001 by CRC Press LLC The non-thermal system costs are more than thermal systems because the operations and maintenance (O&M) costs are estimated to be 50% higher due to more waste sorting and preparation, and more unit operations requiring more personnel, equipment, and facilities. This is because non-thermal systems are limited to the types of waste and waste matrices that can be treated, require greater size reduction, and generate more secondary waste than thermal systems. Non-thermal systems, using grout for stabilization vs. vitrification used with thermal systems, produced more final waste form volume with the associated higher certification, packaging, and shipping cost and higher disposal costs. Non-thermal waste treatment technologies (e.g., alternative oxidation technologies such as acid diges- tion) are also immature technologies that have not been fully demonstrated and implemented in a variety of waste treatment applications. In contrast, incineration is a mature and proven technology that has generally been the primary choice of industry for destroying hazardous waste. The technical risks are low and the costs are well established. However, public opposition to incineration is well established and growing. Thus, there may be niche applications or site-specific applications where non-thermal technologies could be used economically or are necessary for treatment. Such applications might include difficult-to- treat wastes, orphan wastes that exist in small quantities and that cannot be transported to a centralized facility, or wastes that cannot be treated by incineration either due to safety or permitting issues or public opposition. O&M costs are the highest percentage (50 to 60%) of TLCC, followed by capital cost (23% of TLCC, most of which is facility cost), and then by disposal costs for systems that vitrify waste (11% of TLCC). Systems that use a non-thermal waste form (e.g., grout) have a significantly higher disposal cost approx- imately 20% of the TLCC. Because costs are only modestly affected by the choice of treatment technologies TABLE 10.2 Subsystem Cost Distribution for Thermal and Non-thermal Systems Thermal Subsystems Non-Thermal Subsystems Subsystem % Total Life-Cycle Cost Subsystem % Total Life-Cycle Cost Front-end handling 27 Front-end handling 24 Stabilization 15 Stabilization 12 Primary treatment 7 Primary treatment 17 Disposal 11 Disposal 19 Administration 10 Administration 7 Air pollution control and aqueous waste treatment 11 Air pollution control and aqueous waste treatment 6 Certification and shipping 8 Certification and shipping 11 Metal recovery 10 Metal recovery 3 Special waste 1 Special waste 1 TABLE 10.3 Distribution of Cost Components for Thermal and Non-Thermal Systems Thermal Cost Components Non-Thermal Cost Components Cost Component % Total Life-Cycle Cost Cost Component % Total Life-Cycle Cost Operating and maintenance 56 Operating and maintenance 53 Capital (facility and equipment) 23 Capital (facility and equipment) 17 Disposal 11 Disposal 19 Pre-operational 4 Pre-operational 4 Test and demonstration 4 Test and demonstration 5 Decontamination and decommissioning 2 Decontamination and decommissioning 2 © 2001 by CRC Press LLC or equipment (i.e., equipment purchase costs less than 5% of TLCC), reliability, performance, and safety are the most important considerations in selecting equipment for treatment of MLLW. It is these equipment characteristics that will affect operating and maintenance costs. In all cases, energy costs are less than 1%of the treatment costs (i.e., TLCC without disposal costs). The hourly costs ranged from $80 to $200, with thermal treatment systems using electrical energy (metal melting and plasma systems) having the highest energy costs. Transportation costs were also found to be only 1% or less of the TLCC. Sensitivity Analysis Sensitivity studies were performed to determine the effects of varying the assumptions used in comparing treatment system costs. The sensitivity of system life-cycle costs was determined relative to changes in subsystem costs and WBS component cost, facility capacity, operating life, stabilization options and system availability. Effects of Changes in WBS Component Costs For all systems, the most cost-sensitive component is O&M. Because this is a major cost contributor to TLCC, a decrease in cost in these areas can have a significant impact on total system cost. When annual operating, utility, material, and maintenance costs are reduced by 50%, the treatment costs (costs without disposal) decrease by an average of 32% and total life-cycle costs (costs with disposal) decrease by 27%. This may amount to as much as $680 million over 20 years for a rotary kiln system with vitrification treating DOEs legacy MLLW. The second most cost-sensitive component is capital costs; a 50% decrease will result in a 12% decrease in treatment costs and a 10% decrease in total life-cycle cost. In this analysis, all dependent costs were changed; for example, design, inspection, and management costs are a percentage of building and equipment purchase costs. If these costs change, the dependent costs increase or decrease by the same percentage. As seen later, equipment reliability and system availability have a significant impact on TLCC as well as the choice of stabilization technology. Thus, an increase in equipment cost due to the purchase of higher reliability equipment should only have a marginal effect on dependent costs but significantly decrease O&M and total life-cycle costs. Effects of Changes in Subsystem Costs Front-end handling is the highest cost subsystem; thus, a decrease in cost in this area can also have a significant impact on total system cost. This subsystem has cranes and forklifts to unload waste containers from incoming vehicles, and various instruments to characterize the physical state of the contained waste. Computer software and barcode scanning record and track the waste. Containers not requiring sorting are moved directly to the appropriate treatment subsystem. If sorting is required, the container is opened and emptied onto a sorting table where the waste is segregated into treatment types. If required, the waste is size reduced. Opportunity exists for reducing front-end handling costs by reducing labor costs, the major O&M cost driver. For example, the integrated process analysis studies defined labor requirements for the receiving and inspection process to be three 28-person shifts per day to process approximately 150 55- gal drums of waste per day. In this case, each person processes 1.8 drums per day at 4.4 hr per drum. If improved technology allowed each person to process 5.4 drums per day at 1.5 hours per drum, then only one 28-person shift or three 7-person shifts would be required, for a savings of $235 million over 20 years (Harvego and Schafer, 1997). This indicates that time and motion studies on labor-intensive subsystems to identify rate-limiting steps can be an important tool to identify areas for process improve- ments and cost savings. [...]... radioactive waste other than uranium mill tailings, transuranic waste, high-level waste, and spent nuclear fuel While most low-level waste is relatively short-lived and has low levels of radioactivity, some present a significant radiation hazard and require special treatment and disposal LLWs are classified as class A, B, or C, according to the concentration and the radionuclides contained in the waste. .. in Table 10. 6 (Cooley et al., 1997), along with the cost associated with waste handling for certification and shipping As expected, waste form loading and volume reduction also affect costs for certification and shipping of the final waste form Decreasing the volume of the final waste form will decrease the amount of waste that requires handling, certification, and shipping at the end of the treatment. .. life-cycle costs (TLCC): All costs associated with treating waste over the lifetime of a treatment system, including disposal costs Transuranic Waste: Waste contaminated with alpha-emitting radionuclides of atomic number greater than 92 and half-lives greater than 20 years in concentrations greater than 100 nCi/g Treatment Costs: All costs associated with treating waste over the lifetime of a treatment. .. J.V and Wood, W.P 1989 Design to Cost John Wiley & Sons, New York Perry, R.H and Green, D 1984 Perrys Chemical Engineers Handbook, 6th ed McGraw-Hill, New York Schwinkendorf, W.E 1996 Comparison of Integrated Thermal Treatment Systems and Integrated Nonthermal Treatment Systems for Mixed Low-Level Waste (INEL-96/0247) Idaho National Engineering Laboratory, Idaho Falls, ID Schwinkendorf, W.E and Cooley,... 100 ,000 50,000 0 10% 20% 30% 40% 50% 60% 70% 80% 90% Waste Loading (weight percent) FIGURE 10. 9 Disposal volume for various waste forms Slag monoliths produced by high-temperature vitrification, with a density of about 188 lb/ft3 and an estimated waste loading between 50 and 70% Glass monoliths produced by low-temperature vitrification, with a density of about 188 lb/ft3 and an estimated waste loading... for disposal; economy in the number of post -treatment final characterizations required; and potential economy in shipment and disposal operations due to the smaller number of containers that require handling Standardization of waste containers for all types of waste could provide significant cost savings by decreasing the type and quantity of handling equipment and operations required © 2001 by CRC Press... Swartz, V., Teheranian, B., and Vetromile, J 1997 Integrated Non-thermal Treatment System Study (INEL-9 6-0 273) Idaho National Engineering Laboratory, Idaho Falls, ID Biagi, C., Schwinkendorf, W.E., and Teheranian, B 1997 Enhanced Integrated Non-thermal Treatment Systems Study (INEL-9 6-0 473) Idaho National Engineering Laboratory, Idaho Falls, ID Cooley, C.R., Schwinkendorf, W.E.; and Bechtold, T.E 1997 Integrated... subsystem is front-end handling, which is associated with waste characterization, sorting, segregating, and size reduction 4 The life-cycle cost of non-thermal treatment systems is generally greater than that for thermal treatment systems, even when a low-volume final waste form (e.g., vitrification or phosphatebonded ceramic) is used This is due to the immaturity of such processes, and the need for... 1998 Costs of mixed low-level waste stabilization options Waste Management 98 Conference Proceedings WM Symposia, Inc., Tucson, AZ Shropshire, D., Sherick, M., and Biagi, C 1995 Waste Management Facilities Cost Information for Mixed Low-Level Waste (INEL-95/0014, Revision 1) Idaho National Engineering Laboratory, Idaho Falls, ID Soelberg, N.R and Reimann, G.A 1994 Radioactive Waste Shredding Preliminary... ceramic, and the highest disposal cost waste form is glass beads However, potential volume reduction is not the only factor to consider in determining cost-effectiveness © 2001 by CRC Press LLC TABLE 10. 6 Disposal Cost of Various Waste Forms for 236 Million Pounds of Original Waste Unit Disposal Cost Waste Loading Waste Form Volume High-temperature slag monolith Slag beads 67% Phosphate bonded ceramic Low-temperature . control and aqueous waste treatment 11 Air pollution control and aqueous waste treatment 6 Certification and shipping 8 Certification and shipping 11 Metal recovery 10 Metal recovery 3 Special waste. Idaho Introduction Selection and design of systems and technologies for treatment of mixed low-level waste (MLLW) requires knowledge and understanding of the expected costs, schedules, risks, performance, and reliability. design package and include site development, construction of buildings and structures for alpha and non- alpha waste, processing and material handling equipment, installation, and indirect costs