Hazardous and Radioactive Waste Treatment Technologies Handbook - Chapter 10 (end) ppsx

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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.
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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.
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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.
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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 units 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.
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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 DOEs 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.
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Operating Efficiency
Significant cost savings are possible by increasing the operating efficiency or system availability. However,
managements ability to affect significant life-cycle cost savings with relatively small investments in capital
or other resources diminishes exponentially as the project evolves beyond the conceptual design phase
and into development, construction, and operation. Typically, 40 to 70% of the life-cycle cost of high-
technology systems have been locked in by the end of the conceptual design phase (Michaels and Wood,
1989) whereas only 3% of the project funds have been spent. As indicated in Figure 10.2, there is an
optimal period when timely management action can provide significant savings.
The optimum reliability (or mean time between failure) is indicated by the minimum in the curve for
acquisition cost plus operational cost, as shown in Figure 10.3. (Lamb, 1995). Improving reliability 
and therefore system availability  reduces the time required to treat a given quantity of waste as well
as maintenance and operational costs. However, acquisition costs must generally increase to achieve
higher reliability. Thus, the objective is to find the optimum balance between investing in improved
reliability during system conceptual design and development and reducing operations and maintenance
costs so that life-cycle cost is minimized.
FIGURE 10.2 Percent of total life-cycle costs vs. locked-in costs. (Adapted from Arsenault and Roberts, Reliability
and Maintainability of Electronic Systems, Computer Science Press, Potomac, MD, 1980.)
FIGURE 10.3 Reliability optimization to minimize life-cycle cost.
Life Cycle Cost
Operational Cost
Reliability
Acquisition Cost
Life Cycle Cost
© 2001 by CRC Press LLC
Operational availability is defined as the fraction of time that the plant or its subsystems are physically
able to perform their intended function as defined in Equation (10.1). It is the mean time between
maintenance (MTBM) divided by the sum of the MTBM and the mean maintenance downtime (MMDT).
MTBM includes the mean time between failure, which is a measure of system reliability (or the probability
of successful operation for a specified time interval), and the time between planned or preventive
maintenance. MMDT is also a probability distribution, providing a measure of the time required for a

failed or shutdown subsystem or piece of equipment to be restored to service.
(10.1)
Thus, availability is characterized as a probability distribution associated with the plant operating
conditions. The plant does not need to be shut down to experience reduced availability. For example, a
failure might result in a reduced production level in which availability at the desired production level is
lost although the plant continues to produce. Thus, additional costs are incurred due to lost productivity
and increased time required to process a given quantity of waste.
Alternatively, when a plant has two pieces of equipment with one as a spare, when one fails the other
is placed into service. Although the plants real production level is not reduced, the probability of
maintaining that production level is significantly reduced during the time that the first item is being
repaired and until the first item becomes available for service. Other than the presence of the failed item,
the reduction in availability is not visible in plant performance. However, the expectation of meeting
plant production levels is now lower (Lamb, 1995).
Various methods exist for improving system availability including increased component and system
reliability through improved design or redundancy, or decreased maintenance time  all of which have
an associated cost. Thus, it is important to understand the costs incurred vs. the cost savings realized by
improving the system availability. Reliability, availability, and maintainability (RAM) analysis early in the
design phase can significantly increase the probability of success of any waste treatment system and/or
innovative technology, and provide significant cost savings over the lifetime of a treatment system through
increased availability.
Using the systems analyzed in the integrated process analysis project, the effect of improved system
availability is shown in Figure 10.4 (Schwinkendorf and Cooley, 1998). In this case, treatment costs are
compared for rotary kiln systems that differ only in the type of final waste form produced: vitrified waste,
grouted waste, or waste stabilized in phosphate bonded ceramic (PBC). For equal availability, there is
little difference in the treatment costs for these systems. The major cost differences would be in disposal
costs due to differences in final waste-form volume. However, there is a significant decrease in cost for
all processes as system availability is increased.
The results of improving system availability for a rotary kiln system from 46 to 67% are also seen in
Figure 10.5 (Cooley, Schwinkendorf, and Bechtold, 1997). Increasing the availability increases the oper-
ating hours of the plant from 4032 to 5850 hr/yr with a decrease in total years of operation from 20 to

14. Increasing the availability produces savings of $380 million for a rotary kiln with vitrification and
$415 million for a rotary kiln with grout. Thus, designs should be developed for maximum improved
equipment reliability. However, the estimated operating efficiency and the cost of increased reliability
must be determined from actual operating experience, detailed component RAM analysis, or extrapola-
tion from similar systems.
As mentioned previously and discussed in detail later, as long as the operating efficiency is comparable
among technology systems, there are significant incentives for vitrification. This is due to typically high
waste loading, high density, and the resultant significant waste volume reduction associated with the slag
waste form. However, referring to Figures 10.4 and 10.5, if the operating efficiency of a system using
vitrification is less than a system producing grout, the cost advantages of vitrification can be decreased
significantly.
A
MTBM
MTBM MMDT+

=
© 2001 by CRC Press LLC
The effects of differences in system availability on TLCC are shown in Figure 10.6. At equal availability
of 46%, the treatment cost of a rotary kiln system with grout is about $60 million greater than the
treatment cost of a rotary kiln system with vitrification, primarily due to the higher final volume of
grouted waste and the associated cost of certifying and shipping this waste for disposal. The treatment
cost is shown on the ordinate at zero disposal cost. The TLCC of the two systems diverges with increased
unit disposal cost. However, if the grout system availability is greater than the availability of the vitrifi-
cation system, the relationship between TLCC changes.
If the grout system availability is increased from 46 to 60%, the treatment cost decreases from $2.2
billion to $1.9 billion, as shown by the intercept for zero unit disposal cost in Figure 10.6. The TLCC for
the grout system (with 60% availability) remains less than that for the vitrification system (with a 46%
availability) until the unit disposal costs reach $6700/m
3
($190/ft

3
), at which point the economic advan-
tage of volume reduction become greater than the advantage of greater availability. If the grout system
availability can be increased to 70%, it retains an economic advantage over a vitrification system with
46% availability until the disposal cost reaches $10,600/m
3
. This illustrates the importance of process
FIGURE 10.4 Treatment cost as a function of system availability source. (From Schwinkendorf, W.E. and Cooley,
C.R. 1998. Costs of mixed low-level waste stabilization options. Waste Management 98 Conference Proceedings. WM
Symposia, Inc., Tucson, AZ.
FIGURE 10.5 System availability is an important factor in system cost. (Reprinted from The Journal of the Franklin
Institute, 334A(2-6), C.R. Cooley, W.E. Schwinkendorf, and T.E. Bechtold, Integrated process analysis of treatment
systems for mixed low level waste, 303-325, Copyright 1997. (With permission from Elsevier Science.)
$1,500
$2,000
$2,500
$3,000
$3,500
$4,000
$4,500
20% 30% 40% 50% 60% 70% 80% 90%
Treatment Cost ($millions)
Grout System
Vitrification System
PBC System
Availability
$0
$500
$1,000
$1,500

$2,000
$2,500
Treatment Cost (million)
Rotary Kiln with Vitrification Rotary Kiln with Grout
46% Availability 67% Availability
$2,170
$1,790
$2,230
$1,815
© 2001 by CRC Press LLC
reliability and system availability (Cooley, Schwinkendorf, and Bechtold, 1997). Thus, the objective of
any system design should be to achieve the optimum operating efficiency as illustrated in Figure 10.3.
Facility Capacity and Treatment Schedule
The effect on cost of treating the 236 million pounds of DOE MLLW in 10 years rather than 20 years
was evaluated using scaling factors to estimate the costs of a facility with twice the capacity. The system
availability was assumed to be the same in both cases and only throughput or system capacity is increased.
The effect on cost as a result of increasing capacity depends on the scaling factor used in the exponential
scaling relation in Equation (10.2), where C
1
is the cost of a treatment facility of capacity q
1
; and the cost
of a similar treatment facility of capacity q
2
is given by C
2
, where n is the scaling factor (Perry and Green,
1984). A scaling factor between 0.6 and 0.7 is typically used in industry for a processing plant.
(10.2)
The results of this scaling of capacity are shown in Figure 10.7 for a rotary kiln system with vitrification

using a scaling factor of 0.6 (Cooley et al., 1997). In this case, costs were scaled uniformly. However, it
may be appropriate to vary the scaling factor for each individual cost component. For example, although
partially dependent on the size of the equipment, the operating and maintenance costs likely do not scale
to the same magnitude as the equipment costs. Further, the calculated treatment cost is a significant
function of the scaling factor, which must be chosen carefully for less developed technologies and
equipment used in mixed waste treatment.
For the example in Figure 10.7, where the system capacity is doubled, increased equipment costs offset
decreased operating costs; thus, there was little difference in treatment cost for the same operating time
per year for this scaling factor. In this case, a scaling factor of 0.58 is the break-even point where the
treatment cost for operating for 10 years is the same as the baseline system operating for 20 years. If costs
were scaled using a factor less than 0.58, then the 10-year treatment cost would be less than the baseline
system treatment cost operating for 20 years (Harvego and Schafer, 1997). Although the shorter processing
time does not affect treatment cost significantly, it appears attractive to minimize storage costs, either
prior to or during treatment. This assumes that the logistical and transportation problems are manageable
over this shorter operating period.
A cost for storage is incurred until the stored waste is completely treated, as shown in Figure 10.7.
Treatment of 236 million pounds of waste in 20 years incurs a treatment cost of $2167 million and a
cost of $216 million to store the waste as it is being treated, assuming a storage cost of $207/m
3
/yr
FIGURE 10.6 Improved operating availability decreases treatment cost and total life-cycle cost.
$1,500
$1,700
$1,900
$2,100
$2,300
$2,500
$2,700
$2,900
$0 $2,000 $4,000 $6,000 $8,000 $10,000

Total Life Cycle Cost (millions)
Unit Disposal Cost ($/m
3
)
Vit. with 46% Availability
Grout with 60% Availability
Vit. with 70% Availability
Grout with 46% Availability
Grout with 70% Availability
Grout with 90% Availability
67% Waste Loading in Slag
33% Waste Loading in Grout
C
2
C
1
q
1
q
2



n
=
© 2001 by CRC Press LLC
(Shropshire et al., 1995). Decreasing the time required for treatment to 10 years increases the cost of
treatment slightly to $2197 million, but the storage cost decreases to $108 million. Thus, treatment of
waste in 10 years as opposed to 20 years could save approximately $78 million. However, shortening the
schedule may have significant repercussions on the supporting infrastructure that must be considered.

This shortened operating period required to treat the baseline stored waste allows scheduling of the
facility to process additional future waste through the same facility. Additional wastes arise from processes
that generate new waste, including clean-up operations such as site remediation and the decontamination
and dismantling of facilities. Doubling the capacity and operating for 20 years to treat twice the total
waste (e.g., 472 million pounds) increases the treatment cost but decreases the unit cost from the baseline
of $9.18/lb ($20.24/kg) to $6.85/lb ($15.10/kg).
Scaling of capacity can also be used to evaluate the effect of multiple facilities to treat the same quantity
of waste. In the integrated process analysis project, a single facility was assumed. As illustrated in Table
10.4, constructing and operating two facilities to treat 236 million pounds of waste over 20 years results
in a 38% increase in treatment cost. Five regional facilities incur a 113% increase in treatment cost
(Harvego and Schafer, 1997).
Although transportation costs will be less for shipping waste to multiple facilities, the transportation
of waste to a single large facility is small  less than 1% of the baseline life-cycle cost. Thus, transportation
cost provides little incentive for selecting one versus multiple facilities. However, non-economic factors
such as the ability to transport across state boundaries may favor multiple facility locations.
Effect of Present Value Analysis
Up to this point, the discussion has been based on a summation of costs over the life of a treatment
facility. The time value of money is taken into account by calculating the present value of costs in order
to compensate for differing cash outlays or expenses at different times during the system life time. That
is, the value of a given sum of money depends on when it is received or expended. The economic worth,
or purchasing power, of money changes over time, with the preference being to receive dollars today
rather than some time in the future or, conversely, to spend the dollars later rather than earlier. This
preference is due to the cost of forgoing the opportunity to earn interest, or a return, on investments if
funds are spent today rather than later.
FIGURE 10.7 Cost of waste treatment and storage during treatment. (Reprinted from Cooley, C.R., Schwinkendorf,
W.E., and Bechtold, T.E. 1997. Integrated Process Analysis of Treatment Systems for Mixed Low Level Waste. The
Journal of the Franklin Institute. 334A(2-6):303-325. (With permission from Elsevier Science.)
$0
$500
$1,000

$1,500
$2,000
$2,500
$3,000
Treatment/Storage Cost ($millions)
20 Years
10 Yea rs
Years of Operation
$2,383
$2,167
$2,305
$2,197
Treatment (millions) Storage (millions)
© 2001 by CRC Press LLC
The result of performing a present value analysis on the systems analyzed in the integrated process
analysis project is that the present value of the cost for completing the earlier phases of the treatment is
a greater percentage of the TLCC, whereas the present value of the costs for completing the later phases
is a smaller percentage of the TLCC. When compared to simply adding the life-cycle costs over time, the
present value comparison shows that construction costs increase as a percentage of TLCC, whereas the
operating costs decrease as a percentage of TLCC (Harvego and Schafer, 1997).
Although present value analysis demonstrates that cash outlays in the later phases of the life-cycle of
a treatment system are more economically favorable than cash outlays in the earlier phases, it does not
change any previous conclusions regarding relative costs or trends between projects assuming the timing
of expenses is similar.
The time value of money is also important in evaluating the cost benefit of early completion of a
treatment project; for example, doubling the capacity and treating a given quantity of waste in 10 years
versus 20 years, or increasing capital expenditures to increase system availability and decrease the time
required for treatment. For a GOCO facility, there is no direct revenue to counterbalance the costs of
construction and operation. Thus, the preference, from a present value perspective, may be to postpone
the expenditure as long as possible to maintain the earning power of the dollars. However, storage costs

being incurred immediately may tip the scales in the other direction, indicating a present value benefit
to early treatment. Penalties for non-compliance with regulations or agreements with federal or state
regulators may also impact the present value cost/benefit evaluation.
Effect of Stabilization Processes and Final Waste Form Volume
Assuming equal system availability, the use of a high-temperature vitrifier rather than grout stabilization
can provide significant savings in disposal costs and certification and shipping costs. Disposal costs
constitute about 20% of the TLCC for non-thermal waste forms and about 11% for thermal waste forms.
A volume reduction factor (input volume divided by output volume) of 3.4 was generally predicted for
all of the waste being treated and stabilized in a high-temperature vitrified waste form (slag) with an
assumed waste loading of 67 wt%. However, the volume reduction for the rotary kiln with grout was
zero to 1.5, assuming a 33 wt% waste loading. The effect of final waste form volume on disposal cost
and the cost of handling the final waste form through certification and shipping are shown in Table 10.5
(Cooley et al., 1997).
TABLE 10.4 Waste Distribution and Total Treatment Costs for Multiple Facilities (0.5 scaling
factor)
System
Capacity
(%)
Capacity
(million pounds)
Total Treatment Cost
($Millions)
Unit Treatment Costs
($/lb)
Baseline 100 236 $2167 $9.18
Two Regional Facilities
Eastern Facility 66 156 $1781 $11.42
Western Facility 34 80 $1208 $15.10
Total Cost $2989 $12.66
a

Five Regional Facilities
Oak Ridge 60 141 $1703 $12.00
INEEL 20 47 $1028 $21.80
Rocky Flats 10 24 $758 $32.10
Hanford 5 12 $568 $47.30
Savannah River 5 12 $568 $47.30
Total Cost $4625 $19.60
a
a

Weighted average unit cost
© 2001 by CRC Press LLC
The difference between the total disposal cost of grout and high-temperature vitrified waste as a
function of the unit disposal cost is shown in Figure 10.8. A significant cost saving of $330 million is
achieved using vitrification rather than grout if the disposal cost is $240/ft
3
($8480/m
3
) and all other
operating parameters are kept the same. These savings assume a centralized facility treating 236 millions
pounds of waste and equal system availability (46%).
Use of contaminated soil as an additive to achieve vitrification can also provide a significant savings
(up to $120M in the integrated process analysis project) by avoiding the cost of separate soil treatment,
assuming that soil treatment costs $350/ton ($386/tonne) (DuTeaux, 1996). The use of soil also provides
a greater net waste loading and displaces additives thereby reducing the overall waste volume. The use
of contaminated soil as a glass former will likely require high-temperature melters (e.g., plasma or electric
arc furnaces) and would preclude the use of Joule-heated melters. However, high-temperature melters
are expected to have more volatile metals released from the melt, a higher volume of secondary waste
from the off-gas system associated with metal capture, and an increased uncertainty in the life of refractory
liners.

As shown in Figure 10.9, volume reduction can be achieved through increased waste loading in a final
waste form, or by stabilizing waste in a high-density waste form. This illustrates a variety of waste forms
available for stabilization of treated waste, including:
TABLE 10.5 Waste Form Volume Affects Disposal and Certification & Shipping Costs
System
Total
Disposal
Volum e
a
Disposal Cost
($Million) @ $243/ft
3

($8590/m
3
)
Certification &
Shipping Cost
($Million)
Disposal +
Certification &
Shipping Cost
($Million)
Rotary kiln with
Vitrification; volume
reduction = 3.4
1,096,700 ft
3
(31,040 m
3

)
270 210 480
Rotary kiln with Grout;
volume reduction = 1.5
2,507,900 ft
3
(70,970 m
3
)
610 370 980
a
Disposal volume of stabilized waste includes the volume of special waste and polymer stabilized waste, which are
approximately the same for these two systems. Slag waste loading is assumed to be 67 wt% and grout waste loading
is assumed to be 33 wt%.
Reprinted from Cooley, C.R., Schwinkendorf, W.E., and Bechtold, T.E. 1997. Integrated Process Analysis of Treatment
Systems for Mixed Low Level Waste. The Journal of the Franklin Institute. 334A(2-6):303325.
(With permission from
Elsevier Science.)
FIGURE 10.8 Vitrification can save disposal costs over grout stabilization for the same system availability. (Assumes
a total of 236 million lbs treated with a grout waste loading of 33 wt% and a slag waste loading of 67 wt%.)
$0.00
$100.00
$200.00
$300.00
$400.00
$500.00
$600.00
$700.00
$800.00
$0 $2,000 $4,000 $6,000 $8,000 $10,000 $12,000

Unit Disposal Cost ($/m3)
Disposal Cost (millions)
Glass Monolith Grout
© 2001 by CRC Press LLC
 Slag monoliths produced by high-temperature vitrification, with a density of about 188 lb/ft
3
and
an estimated waste loading between 50 and 70%.
 Glass monoliths produced by low-temperature vitrification, with a density of about 188 lb/ft
3
and
an estimated waste loading between 30 and 50%.
 Slag or glass marbles with 60% packing fraction and an overall effective density of about 113 lb/ft
3
.
Production of marbles limits the filling of the final volume of a container to about 60% of the
total available volume of the container (Cumberland and Crawford, 1987) thereby increasing the
total disposal volume from that of a vitrified monolith.
 Phosphate bonded ceramic produced by equipment similar to that used for cement mixing, with
a density of about 127 lb/ft
3
, and an estimated waste loading of 50 to 70%.
 Grout produced by equipment similar to that used for cement mixing, with a density of about
127 lb/ft
3
, and an estimated waste loading of 30 to 40%.
For vitrified waste, thick-walled steel containers may be required if the casting process involves pouring
molten glass directly into the waste container. It is assumed that these containers can be qualified to meet
Department of Transportation (DOT) and TRUPACT II criteria or equivalent. However, if these con-
tainers are degraded by the molten glass such that DOT requirements are not met, then an overpack will

be required at least for shipment and possibly disposal. If this is the case, then the packing fraction will
be approximately 60% and the disposal volume of a vitrified monolith will be the same as vitrified
marbles.
Achievable waste loading depends on the contaminant in the waste, the ability to pass the EPAs toxicity
characteristic leaching procedure (TLCP) test, the disposal facilities waste acceptance criteria (WAC), or
the radionuclide content. Disposal cost is then determined by the volume of the final waste form and
the unit disposal cost (cost per unit volume of waste). Disposal costs for several waste forms, waste
loadings and unit disposal costs are shown 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 process.
This indicates that low-temperature vitrification that produces a glass waste form is expected to have
a higher disposal volume than high-temperature slag, and possibly higher than phosphate bonded
ceramic. This would be especially true if the waste form were produced in the form of glass marbles or
beads. Thus, for the specified waste loadings in Table 10.6, the lowest disposal cost waste form is the slag
monolith followed by phosphate bonded 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.
FIGURE 10.9 Disposal volume for various waste forms.
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
10% 20% 30% 40% 50% 60% 70% 80% 90%
Final Waste from Volume (m3)

Waste Loading (weight percent)
Polymer
Vitrified Beads
Grout
Vitrified Monolith
© 2001 by CRC Press LLC
Effects of Radionuclide Concentration
Changes in pricing for shipping and disposal may be such that the cost of shipping and disposal is based
not only on volume, but also on curie or hazardous material content or concentration because a particular
site may be limited in the amount or concentration of radionuclides or hazardous material it can accept.
Limitations may be imposed by regulators or safety professionals to limit the radiation at the surface of
the waste container for worker protection, or may be recognized through performance assessments that
predict the effects of migration from the disposal site. Thus, there may be step changes in the shipping
and disposal costs as the radionuclide content changes from Category A through Category C low level
waste, to alpha-contaminated waste, to transuranic waste, or the waste concentration causes the contact
radiation level to exceed 200 millirem/hour.
If volume reduction causes the contaminant concentration in the final waste form to increase beyond
the waste acceptance criteria for a disposal site, disposal may be more difficult and costly although the
waste volume has been decreased (Cooley, et al., 1997). Thus, the relationship between volume reduction,
contaminant concentration, waste loading, and disposal cost needs to be determined on a case-by-
case basis.
Using radionuclide concentration as an example, for an initial radionuclide concentration in the waste
of 350 Ci/m
3
, a 50% volume reduction during treatment leaves 700 Ci/m
3
in the residue prior to
stabilization. Assuming a residue density of 1280 kg/m
3
(80 lb/ft

3
), the concentration in the final waste
form increases linearly with waste loading as shown in Figure 10.10. For vitrified waste, the initial residue
concentration occurs at a waste loading of about 40 to 50wt%, whereas for grout or phosphate bonded
ceramic the initial residue concentration is reached at a waste loading of 60 to 70wt%. Thus, a higher
waste loading can be achieved in a grout or phosphate bonded ceramic before some critical concentration
is reached that may cause an increase in disposal cost.
The effect on waste disposal cost by consolidating radionuclides can be seen in Figure 10.11 where the
unit disposal cost is assumed to increase by an order-of-magnitude [from $20/ft
3
($707/m
3
) to $200/ft
3
($7070/m
3
)] when the radionuclide concentration increases above 700 Ci/m
3
. Although high waste loadings
and high-density materials decrease the volume of waste to be disposed (see Figure 10.9), for this example
(where the initial waste volume was assumed to be 10,000 m
3
), the disposal cost for high-temperature slag
(with a waste loading between 42 and 62 wt%) is significantly higher than the disposal cost for grout or a
cementitous type waste that can accept a high waste loading (e.g., phosphate bonded ceramic).
TABLE 10.6 Disposal Cost of Various Waste Forms for 236 Million Pounds of Original Waste
Unit Disposal Cost
Waste Form
Waste
Loading

Waste Form
Volume
Certification &
Shipping Cost
($millions)
$20/ft
3
($707/m
3
)
$100/ft
3
(3534/m
3
)
$240/ft
3
($8480/m
3
)
Total Disposal Cost ($millions)
High-temperature slag
monolith
67% 640,000 ft
3
(18,100 m
3
)
$169 $12.80 $64.00 $153.60
Slag beads 67% 1,067,000 ft

3
(30,200 m
3
)
$202 $21.30 $106.70 $256.00
Phosphate bonded
ceramic
67% 948,000 ft
3
(26,800 m
3
)
$192 $19.00 $94.80 $227.50
Low-temperature
glass monolith
33% 1,299,000 ft
3
(36,800 m
3
)
$223 $26.00 $130.00 $311.90
Glass beads 33% 2,166,000 ft
3
(61,300 m
3
)
$322 $43.30 $216.60 $519.80
Grou 33% 1,924,000 ft
3
(54,400 m

3
)
$290 $38.50 $192.40 $461.90
Reprinted from Cooley, C.R.: Schwinkendorf, W.E.; and Bechtold, T.E. 1997. Integrated Process Analysis of Treatment
Systems for Mixed Low Level Waste. The Journal of the Franklin Institute. 334A(2-6):303-325.
(With permission from
Elsevier Science.)
© 2001 by CRC Press LLC
Waste Container Size
The size of the container used for collection, transportation and disposal of MLLW can impact the post-
treatment cost of certification and shipping. Increasing the size of the container from a 55-gal drum to
a 6
×
4
×
4 (1.8
×
1.2
×
1.2 m) box will decrease the certification and shipping cost by about 90% due
to the decrease in the number of containers handled and associated decrease in labor. This assumes that
equipment costs for handling the larger boxes are the same as the costs for handling 55-gal drums
throughout the certification and shipping area, and the assay equipment (RTR, gamma and PAN) can
be designed to inspect the larger boxes at the same costs per container.
In the integrated process analyses, transportation costs alone were generally less than 1% of TLCC, or
$24 million, and the cost of transporting 55-gal drums should be about the same as transporting the
larger containers because the total volume and mass will be about the same. However, in addition to the
potential for decreased certification and shipping labor costs, several other potential advantages of large
containers include: capability to dispose large bulky waste in a large container and surround the waste
with other stable, solidified waste such as grout; the capability to include compacted empty drums for

disposal; economy in the number of post-treatment final characterizations required; and potential econ-
omy 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.
FIGURE 10.10 Radionuclide Concentration in the Final Waste Form Increases with Waste Loading and Volume
Reduction. Assumed initial waste loading of 350 Ci/m
3
with a 50% volume reduction leaving 700 Ci/m
3
in the residue
prior to stabilization. Assumed residue density = 1280 kg/m
3
(80 lbs/ft
3
).
FIGURE 10.11 Disposal Cost Varies as a Function of Radionuclide Concentration in the Final Waste Form. Unit
disposal costs are assumed to be $20/ft
3
($707/m
3
) for radionuclide concentrations less than 700 Ci/m
3
, and $200/ft
3
($7070/m
3
) for concentrations greater than 700 Ci/m
3
.
1600

1400
1200
1000
800
600
400
200
0
01020
30 40 50 60 70 80 90
Glass/Slag
Grout/PBC
Radionuclide Concentration
(Ci/m
3
)
Waste Loading (Weight Percent)
40
35
30
25
20
15
10
5
0
Glass
Grout
Disposal Cost ($million)
Waste Loading (Weight Percent)

0
20 40
60
80 100
© 2001 by CRC Press LLC
Container Disposal vs. Decontamination and Reuse
The integrated process analyses indicates that 25,200 55-gal drums per year containing 11.8 million
pounds of waste are delivered to a centralized treatment facility. Of these drums, it was assumed that
50% are undamaged and can be decontaminated for recycle or reuse at a cost of up to $72/drum or the
equivalent of $1.20/lb ($2.65/kg) of surface-contaminated metal (Kluk et al., 1996). The remaining drums
are assumed degraded to the point that they must be disposed or melted into ingots. Several options can
be considered for the 12,600 drums that are reusable. They can be decontaminated for reuse at an annual
cost of $900,000, or compacted and disposed. Assuming a 90% volume reduction of compacted drums,
and an 80% fill factor of compacted drums in 6
×
4
×
4 ft boxes, then 1086 large boxes will be required
to dispose of 12,600 compacted drums. The final package and disposal costs, including the cost of the
large boxes at $700/box, the cost of certification and shipping, and the cost of compaction, are shown
in Figure 10.12 as a function of unit disposal cost. This indicates that the disposal cost is greater than
the decontamination cost and that compaction costs have a negligible effect on treating and disposing
of drums.
Summary
This section has illustrated the relationships between costs, schedules, risks, performance, and reliability
of mixed waste treatment systems. Several conclusions can be drawn from the studies referenced in this
section:
1. Operations and maintenance (O&M) is the major cost element associated with a system designed
to treat MLLW.
2. Capital costs are the second highest cost element. However, the purchase cost of equipment is

small relative to facility and dependent costs. The cost associated with purchasing equipment with
high reliability and ease of maintenance is small relative to the savings achieved through lower
O&M costs.
3. The highest cost 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 phosphate-
bonded ceramic) is used. This is due to the immaturity of such processes, and the need for extensive
FIGURE 10.12 Cost of compacting and disposing of drums. Total cost of drum disposal includes compaction,
certification & shipping, and disposal in a 6
×
4
×
4 ft Type A box. No decontamination is required. From Cooley,
C.R.: Schwinkendorf, W.E.; and Bechtold, T.E. 1997. Integrated Process Analysis of Treatment Systems for Mixed
Low Level Waste. The Journal of the Franklin Institute. 334A(2-6):303-325. (With permission from Elsevier Science.)
$0 $2,000 $4,000 $6,000 $8,000 $10,000 $12,000
Annual Drum Disposition Cost
(millions/year)
Unit Disposal Cost ($/m3)
Compaction Cost = $1.50/lb ($3.21/kg)
Compaction Cost = $0.50/lb ($1.10/kg)
Decontamination Cost @ $1.20/lb ($2.65/kg)
$40.00
$35.00
$30.00
$25.00
$20.00
$15.00
$10.00

$5.00
$0.00
© 2001 by CRC Press LLC
waste sorting and size reduction. However, there are some waste streams that are difficult to treat
thermally (e.g., wastes with mercury or plutonium contamination); and there is increasing diffi-
culty in permitting thermal processes, making, non-thermal processes attractive in certain situa-
tions.
5. Reliability, performance, and safety are the most important considerations in selecting equipment
for treatment of MLLW. These are also factors that have a major influence on system cost.
Depending on unit disposal cost, poor system availability can overcome the cost benefits associated
with low disposal volumes. System designs should optimize efficiency and availability, usually
through redundancy, readily available spare parts, or improved equipment reliability.
6. High-temperature vitrification can provide significant savings in certification and shipping costs
and disposal costs relative to grout due to the lower volume of the final waste form.
7. Disposal costs are affected by a variety of factors, including final waste form volume, final waste
form type and performance, packaging and transport limitations, waste acceptance criteria, and
radionuclide concentration.
Defining Terms
Alpha-MLLW: Mixed low-level waste containing greater than 10 nanocuries per gram (nCi/g) but less
than 100 nCi/g of alpha-emitting radionuclides.
Availability: As used in this section, the term availability refers to operational availability, which is the
probability that a system or equipment, when used under specified conditions in an operational
environment, will operate in a satisfactory manner when called upon.
Leachability standards: Concentration-based extraction test performed in accordance with the EPAs
toxic characteristic leaching procedure (TCLP).
Level A protective equipment: Fully encapsulating chemical protective suit: positive-pressure, full face-
piece, self-contained breathing apparatus; inner and outer chemical resistant gloves; chemical
resistant boots with steel toe and shank.
Low-level waste (LLW): LLW includes all 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. These classifications determine the requirements for
handling, packaging, shipping, and disposing of LLW.
Maintainability: A characteristic of system design and installation expressed in terms of probabilities of
maintenance frequency, maintenance time (i.e., elapsed times and labor hours), and maintenance
cost.
Reliability: The probability that a system will perform in a satisfactory manner for a given period of time
when used under specified operating conditions.
Total 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 system, excluding
disposal costs.
Triple confinement: Operating areas with independent, fully contained ventilation system surrounded
by a second independent, fully contained system surrounded by a third containment system where
pressures are controlled so any leakage will be inward toward the more highly contained system.
Wa s te l o ad i n g : The percentage of waste, on a weight basis, contained in a stabilized waste form ready
for disposal. Equal to the weight of the treated waste incorporated into the final waste form divided
by the weight of the final waste form.
© 2001 by CRC Press LLC
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