Office of
Research and Development
Washington, DC 20460
EPA/540/K-92/001
June 1992
P/EPA
Radioactive
Site Remediation
Technologies Seminar
Speaker Slide Copies
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EPA/540/K-92/001
June 1992
Radioactive Site Remediation
Technologies Seminar
Speaker Slide Copies
Summer 1992
Printed on Recycled Paper
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TABLE OF CONTENTS
Page
Approaches to Sampling Radioactive Heterogeneous Waste 1
Soil Characterization Methodology for Determining Application of Soil Washing 3
VORCE (Volume Reduction/Chemical Extraction) Program 15
Treatment of Radioactive Compounds in Water 19
Polymer Solidification of Low-Level Radioactive, Hazardous, and Mixed Waste 23
In Situ Vitrification of Soils Contaminated With Radioactive and Mixed Wastes 31
Decontamination of Contaminated Buildings 37
Incineration of Radioactive Waste 47
In Situ Stabilization/Solidification With Cement-Based Grouts 51
Environmental Restoration and Waste Management 53
Removal of Contaminants From Soils by Electrokinetics 55
Treatment, Compaction, and Disposal of Residual Radioactive Waste 63
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APPROACHES TO SAMPLING RADIOACTIVE HETEROGENEOUS WASTE
Mr. Terence Grady
U.S. Environmental Protection Agency
Las Vegas, Nevada
Both the U.S. Environmental Protection Agency and the U.S. Department of Energy are faced with
characterizing and remediating sites contaminated with hazardous chemicals and/or radionuclides.
Much of the waste on these sites is of varied composition ranging from uncontainerized waste in landfills
to drummed or boxed waste. Investigators experience severe difficulties when attempting to design
sampling strategies, collect representative samples, and identify and select appropriate field and
laboratory methodologies for radioactive heterogeneous waste. The problem of method selection is
further compounded by personnel safety considerations.
Recent work at the Environmental Monitoring Systems Laboratory-Las Vegas developed a logical
approach to designing a sampling and analysis program for debris and heterogeneous wastes, both
hazardous and radioactive. The approach begins with determining data quality objectives (DQOs) and
progresses through formulating a site model, statistical considerations of sampling design and, finally,
selecting sampling and measurement procedures. Recommended for this last phase are semi-invasive
sampling followed by fully invasive sampling if sufficient information is not obtained by semi-invasive
procedures. The use of pilot sampling is recommended as a guide to planning future sampling activities.
The process is illustrated by reference to actual sampling situations.
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Intentionally Blank Page
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SOIL CHARACTERIZATION METHODOLOGY FOR
DETERMINING APPLICATION OF SOIL WASHING
Dr. James Neiheisel
U.S. Environmental Protection Agency
Washington, D.C.
The Office of Radiation Programs (ORP), in compliance with the Superfund Amendments and
Reauthorization Act (SARA) of 1986, has evaluated radioactively contaminated soils from sites on the
National Priority List (NPL) for potential application of soil washing as a viable remediation technology.
In these investigations, a laboratory methodology for soil characterization has been developed which is
essentially an additional step to existing RI/FS procedures. This methodology separates representative
soil samples from the site into several size fractions with each soil fraction tested for mineralogical,
physical, and radionuclide content by detailed petrographic and radiochemical techniques. The protocol
provides (1) a grain size distribution curve which relates weight percent versus particle size, (2)
relationship of specific radionuclide activity levels versus particle size, (3) identification of the mineral/
material composition of the radioactive contaminant waste forms and their physical properties, and (4)
mineral/material identification of the host medium and its specific physical properties. Differences found
in the physical and chemical properties of the radioactive contaminants and host materials are used in
providing essential data to determine the potential feasibility of volume reduction by soil washing.
The application of the soil characterization protocol for radioactive soils is described for the potential
remediation of thorium contaminated soils at the Wayne and Maywood, New Jersey, FUSRAP sites and
for the radium contaminated soils of the Maywood and Glen Ridge, New Jersey, sites on the National
Priority List.
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SOIL CHARACTERIZATION
METHODOLOGY FOR
DETERMINING APPLICATION
OF SOIL WASHING
James Neiheisel
EPA Office of Radiation Programs
Washington, D.C.
During the FS process, soil characterization assists in
the detailed analysis of individual remedial alternatives
against the 9 NCR evaluation criteria:
Protection of human health and the environment
Compliance with ARARS
Long-term effectiveness/permanence
ซ Reduction of toxicity, mobility, or volume
Short-term effectiveness
Implementability
Cost
State Acceptance
Community Acceptance
Innovative Soil Characterization Protocol for Radioactive
Contaminated Soils has Application to all tasks of the
RI/FS Process
> Utility has been demonstrated at Wayne/
Maywood, NJ, FUSRAP sites and Montclair/
Glen Ridge, NJ, NPL sites.
Potential application for additional
NPL sites (45) and FUSRAP sites (26).
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[Standard RI/FS
I on Bulk Samplei
Addition
Soil Fractions by Water Wash ;
Petrographic & Radiochemical j
Analysis of Soil Fractions I
Identifies mineral/material
composition and physical
properties of contaminant
and host materials
Identifies particle size
of contaminants
Utility of Protocol Data for RI/FS Tasks
Determination of potential effective-
ness of soil remediation alternatives.
Grain size in relation to Radioactivity Levels
Minerals or materials containing radionuclides
Minerals or materials comprising host media
Physical properties of contaminants and host
media
GRAIN SIZE DISTRIBUTION CURVE
HISTOGRAM OF THE SANDY SOIL
-------
STAGES OF PETROGRAPHIC EXAMINATION
Tier 1
Course (0.60 mm and greater) Megascopic
Medium (0.038 mm to 0.60 mm) Petrographic Microscope
Fine (less than 0.038 mm) X-Ray Diffraction
Tier 2
Additional Size Fractions
Sedimentation and Centrilugatjon for Fine Fractions
SEM/EDX of Fines
K'.uIiiKKtivity vs Carlidc Si/c
I'll r licit Si/c (itini)
-------
Application of Protocol to Radioactive Sites on NPL
and Formerly Utilized Sites Remedial Action Program
(FUSRAP) Sites
Wayne and Maywood, NJ, FUSRAP sites
Montclair and Glen Ridge, NJ, NPL
sites
Sample Heceipl and IVeparaliun
Scretn for Kadioaclivity
Vigorous \Vas,h
I }
Wtl Sitvint' Vtrlical Column
Pelrographic Analysis
I
Radiochrmislry
I
Report
Wayne and Mavwood. NJ. FUSRAP Sites
Prior to March '91 March '91
Standard RI/FS Procedures Protocol Additions
No knowledge of:
Mineralogy or physical
nature of contaminants
Grain size range of
contaminants
Protocol Key Additions-.
Identification of
Monazite and Zircon
as contaminants
Size range of
contaminants
Feasibility of volume
reduction
-------
100 H
n /0 ^
0*
**ป
4*
1
o
0(
Cumulative Weight Percent vs Particle Size
"xT*^
>^^ -o
-^
X >^
NX
\
\
j
*_
---ป*--
\
A
ซ. v^
"T*. "-.
1
Maywood
Wayne
\
"--,_'"-..,
*
k<* '
clปy *"* jju *"* S""<1 ' ' If"
Parlklc Silt (mm)
3
Radioaclivily vs I'arliclc Si/.c Afler VOKCE VVc( Separation
Ci*y
sand
('article Si/f (mm)
Mineral and Material Composition - Wayne
f. r\
DU
50 -
|2 40 ~
tj
If 30 -
o
So
c 20 -
u
u
a.
! 0 -
1 n
J I
tl
1
i J<1 ._ i-t _ L_
1
j~i
i~
L
I
Q Sandstone
Q Gronmc Rock
B Quortzite
0 Bosolt
D Quartz
Feldspar
j^ Heavy nmerols
D Other
Grovel Coarse Sand Fine Sand Silt and Cloy
Size Cta&s
-------
Heavy Mineral Composition
B
t .0
Q
Wayne fine band Wayne Sill Maywooo I me SJ..O naywooo b
Wayne and Maywood, NJ, Sites Application of ORP Soil
Characterization Data in Relation to RI/FS Process
Task
J Task 3
Monazite identified as highly insoluble source of Thorium
Predictor of :. Applicable to risk Applicable to
Retention onsite ; assessment parameters V0|ume reduction
Groundwater free
from Contamination ;
Thorium, Radium, and Uranium contaminants have high
density and are concentrated in the smaller; soil particle
size fractions (generaffy farger than 10 micron size)
i Application to inhalation. Applicable to soil wash
ingestion. and soil to of coarse particles from
; air resuspension fines and concentration
; of contaminants
65% of Maywood soil & 50% of Wayne soil less than 5 pCi/g
--- Applicable to volume
reduction remedial design
-------
Mnntdair and Glen Ridge, New Jersey
Radium ( un(amina(cd NI*K Si'lev
Sieve No
4
10
50
60
I 4 0
? 0 0
270
Siie(mm)
25.00
12.50
4.75
2.00
.30
.25
.106
.075
.050
.015
.005
.002
-.0005
Soil Size
Sand
Sill
Clay
Sizing Melhod
Gition
Vibrator
Screener
Sedimentation
Centrifugalion
Separation Method
Bromoform and
Tetrabromoethane
Sink Float Method
(heavy mineral
Heavy Liquid
Linear Density Method
(high activity
separation)
Gamma Spectroscopy
Alpha Spectroscopy
Magnetic Properties
Gamma Spectroscopy
Alpha Spectroscopy
Pelrographic Microscopy
Chemistry
Gamma Spvctroscopy
Alpha Spectroscopy
X-Ray Diffraction
w/X-Ray Analyzer
Laboratory Methods for Characterization or Radium Contaminated Soils
lOO-i
90
80-
TJ
I 70
n
ซ; 6o-
at
& 50-
4j
]ง 40-
1 30
O
20-
10-
Monlclair soil sample
-5 -4 -3 -2
01234
0 Scale
10
-------
Mineral and Material Composition
of Montclair Soil
Percentage of Size Class
Stag
1 ] GUsJ/Trtsh
d3 Clay Mineral*
5 % or Total Soil Ra228
GLEN RIDGE SITE. ANALYSIS BY PNL.
Wt% DEN SI
'6 pCI I7.3(
*.S90pCi/0 LOMpCl
GLEN FtlDCE tO-IO MiCnO" SIZE
J.10-1.2!
U*4nl
I.IS-J-7
GI.EH niOCE i-10 MICRON SIZE
31.M J.OIOpCl'B BJ7pD
11
-------
of 10-20 micron size material.
TYPES OF RADIUM CONTAMINANTS
AT MONTCLAIR SITE
15% Natural Uranium Minerals - Carnotite, Uraninite,
and minor others in medium sand to coarse silt
size
85% Anthropogenic Radium Materials
50 Radiobarite - medium sand to fine silt
size
23 Amorphous Silica - silt to clay size
2 Uraninite in Coal Ash - all sizes
4 Furnace Fired Slag/Cinders - gravel and
coarse sand
6 Adsorbed on Illite and other materials - silt
to fine clay size
Result: Vigorous water wash/wet seiving laboratory scale tests reduced 30-40% of Montclair
and Glen Ridge soil to a target level of 12 - 15 pCi/g (Ra-226). The wash water can be
recycled.
Activity Versus Grain Size
12
-------
Summary Soil Characterization Protocol
Additions to RI/FS Process
Identifies, the physical form and mineral/material
composition of radioactive contaminants and
activity levels on the various size fractions.
Data applicable to prediction of retention or transport
of contaminant and impact on groundwater.
Provides explicit site specific data to key parameters
in risk assessment evaluations.
Provides data to evaluate feasibility of Volume Reduction
technologies.
13
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Intentionally Blank Page
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VORCE (Volume Reduction/Chemical Extraction) PROGRAM
Mr. Mike Eagle
U.S. Environmental Protection Agency
Washington, D.C.
The EPA Office of Radiation Programs (ORP) developed the VORCE (Volume Reduction/Chemical
Extraction) Program to conduct treatability studies for the volume reduction of Superfund soils contami-
nated with radionuclides. The VORCE Program has developed a laboratory screening process (including
an innovative soil characterization protocol), a bench-scale testing process, and a pilot plant. The pilot
soil washer is currently being tested to reduce the volume of radioactive soils at two Superfund sites in
New Jersey (Montclair and Glen Ridge). The pilot plant completed the first round of testing with soil from
the sites. The result was a 30% volume reduction of 9 picoCurie per gram soil, with the clean portion at
6 picoCurie per gram. The pilot plant also achieved a steady-state operation for 4 hours at the rate of
almost 2 tons per hour. Presently, the plant is being optimized in preparation for the second round of
testing.
15
-------
GENERA
Contaminated ^
Soil ^
Contaminated g
Volume "
L FLOW DIAGRAM
Separation -^ Liberation
(
4: t
1 4 Clean Volume
1 r 4
1
Dewatering <4- Separation
TIER 2, BENCH-SCALE TESTING
Particle Liberation Unit Operations
- detach clean particles from contaminated particles
- washing
- scrubbing
- attrition
- crushing and grinding
Particle Separation Unit Operations
- divide mixture of soil particles into two or more volumes
- sieving
- wet classification
- density separation
- magnetic separation
- flotation
Dewatering
- remove water from contaminated fraction of soil (fines)
- centrifugation (future)
- gravity sedimentation
- evaporation (future)
VORCE PROGRAM
FOUR TIERS OF TREATABILITY STUDY
Soil Characterization
- Designed to quickly and inexpensively determine if volume
reduction is feasible.
4 Bench-scale Testing
- Designed to verify whether a volume reduction technology can
meet the performance goals for the site.
4 Process Development Unit (PDU)
- Developed to demonstrate volume reduction on-site at a small-
scale (150 Ibs/hr).
4 Pilot Plant
- Designed to provide detailed cost, design, and performance
data.
16
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TABLE PARTICLE LIBERATION TECHNIQUES
Technique
Basic Principles
General Equipment
Lab Test Equipment
Washing
water action
trommel, washer,
screw classifier
stining units.
trommel, eluirialion
column
Scrubbing
panicle/panicle
aaion
irommel, screw
classifier
Hummel
AraitioQ
vigorous
partkle/particlt
action
trommel, mill
uomrotl
Crushing
siซ reduction
Surface DC-
Boading
surfactant action
irommel, mill
trommel
Technique
Also Called
Basic Principle
Major Advantage
Major Disadvantage
GeueraJ Equipment
Lab Test Equipage ot
TABLE 2: PARTlCI-E SEPARATION TECHNIQUES
Sizing j Settling Velocity
screening
various diameter
openin|s
mtxperfiive
screens can plug.
fine screens are
fragile, dry screens
produce dust
screens, sieves
sieve/screen,
irommel screen
classification
faster vs. slower
settling graias
cominuous
processing, long
history, reliable,
inexpensive
difficuliy with
clayey, sandy, and
bumus soils
mechanical, non-
mechanical,
hydraulic classifiers
elutriaiion columns
Specific Cravify
gravity separation
differences in
density, size,
shape, and weight
of grains
ecor.omicaJ, simple
to implement, long
history
ineffective for fines
jigs, shaking tables,
UOugts, sluices
jig, shaking table
.Magnetic Properties
magnetic
magnetic
susceptibility
impiemcni
high operating costs
magnetic separators
lab magnet*
Flotation
f:o:a'.ion
suspend fines by air
agilalion. add
promoler/ collecior
agents, skirr. oil
froth
very effective for
some grain sizes
be srnali fraaion of
total volume
flotation machines
i
17
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Intentionally Blank Page
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TREATMENT OF RADIOACTIVE COMPOUNDS IN WATER
Mr. Thomas J. Sorg
U.S. Environmental Protection Agency
Cincinnati, Ohio
Currently, the EPA has maximum contaminant levels (MCLs) for only two specific radionuclides in
drinking water, radium-226 and radium-228. On July 18, 1991, the Agency proposed revisions to the
radionuclides in drinking water regulations to change the MCLs for radium and to add MCLs for uranium
and radon-222. All of these radionuclides occur naturally and are frequently found in drinking water
sources, primarily groundwaters.
Although limits have not been established for other specific radioactive elements in drinking water, the
Agency has limits for a variety of other natural and man-made radionuclides under a group heading listed
as gross alpha emitters and beta and photon emitters. Included under the category of alpha emitters,
in addition to radium-226, uranium and radon are isotopes of bismuth, polonium, thorium, and plutonium,
most of which are naturally occurring. Under the proposed revised regulations, the gross alpha in drinking
water cannot exceed 15 pCi/L, excluding the contribution of radium-226, uranium, and radon-222.
The MCL for gross beta and photon emitters is 4 mrem ede/yr (excluding the contribution of radium-228).
The regulation states that gross beta emitters in drinking water cannot produce a radiation dose of more
than 4 mrem per year to the total body or to an individual internal organ. The majority of beta emitters
are man-made radioactive elements and include tritium and isotopes of carbon, cobalt, strontium,
cesium, barium, and iodine. These radionuclides are not normally found in natural drinking water
sources.
By law, the EPA must list the Best Available Technology (BAT) for each MCL established. Both current
and proposed BAT for radium-226 and radium-228 are ion exchange, lime softening, and reverse
osmosis. The BAT proposed for uranium is coagulation/filtration, ion exchange, lime softening, and
reverse osmosis. Although granular activated carbon (GAC) has been shown to remove significant
amounts of radon-222, only aeration has been proposed for BAT. GAC was not listed because of the
"long empty bed contact time" which was considered to be impractical for large water utilities. However,
GAC has been demonstrated to be effective for application on small systems and, therefore, would be
practical for site contamination problems.
Because the MCL's for alpha and beta emitters apply to groups of radioactive contaminants, selecting
one technology for all is not easily done. For alpha emitters, reverse osmosis was proposed for BAT
because it provides the highest removal efficiencies for the most common alpha emitters. For beta
emitters, ion exchange (cation and anion exchange) and reverse osmosis were proposed for BAT. The
selection of cation exchange, anion exchange, or mixed bed treatment depends on the specific
contaminants found in the contaminated water. Cation exchange has been found to be effective for
isotopes of barium, cadmium, cesium, lanthanum, and strontium. Anion exchange resins have inhibited
high removal for niobium, tungsten, zirconium, and yttrium. If the contaminated water contains both
cations and anions, mixed bed treatment or reverse osmosis would be required.
19
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DRINKING WATER REGULATIONS
(RADIONUCLIDES)
MAXIMUM CONTAMINANT LEVEL GOAL
(MCLG)
"O" CONCENTRATION FOR ALL
RADIONUCLIDES
DRINKING WATER REGULATIONS
(RADIONUCLIDES)
CURRENT AND PROPOSED MCL'S
Radionuclide Current Limit
Proposed Limit
(July 1991)
Combined Ra-226
and Ra-228 5 pCi/L
Ra-226
Ra-228
Rn-222
U (Total)
20 pCi/L
20 pCi/L
300 pCi/L
20 pCi/L (30
DRINKING WATER REGULATIONS
(RADIONUCLIDES)
CURRENT AND PROPOSED MCL'S
Radionuclide
Current
Proposed
(July, 1991)
Gross Alpha
Beta particle and
photon emitters
(man-made radio-
uclides)
15 pCi/L
(including
Ra-226, but not
Rn nor U)
4 m rein/year
(dose to body
or any internal
organ)
15 pCi/L
(excluding
Ra-226, U,
and Rn-222)
4 m rem/year
(does to body
or any internal
organ)
20
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RADIONUCLIDES
CHEMICAL FORM IN WATER
Radium Cation - Ra+2
Rn (Gas) Gas - Rnฐ
Uranium pll <2.5 Cation - UO2+
pll 2.5-7 Neutral - UO2 (CO3)ฐ
pll 7-10 Anion - UO2 (CO,),'2
- U02(CO,)3-4
RADIONUCLIDES
ALPHA
EMITTERS
BETA & PROTON
EMITTERS
Bismuth
Polonium
Thorium
Plutonium
Radium-226
Uranium
Radon
Tritium
Carbon
Cobalt
Strontium
Cesium
Barium
Iodine
Radium-228
I5EST AVAILABLE TECHNOLOGY
SDWA
R:idionuclide(s)
BAT
Ra-226/Ra-228
Rn-222
U
Alpha uniillcrs
Beta and pholon
emitters
Cation Exchange
Lime Softening
Reverse Osmosis
Aeration
Coagulation/Filtration
Ion Exchange (Anion/Cation)
Lime Softening
Reverse Osmosis
Reverse Osmosis
Ion Exchange
Reverse Osmosis
21
-------
REMOVALS - PERCENT
Contami- Ion Lime Coagulation Reverse
nant Exchange Softening Filtration Osmosis Aeration
Radium
Uranium
Radon
Beta
Emitters
Cs-137
I -131
Sr-89
65-97
65-99
95-99
95-99
75-95
85-99
80-95
90-99
90-99
90-99
87-98
98-99
up to 99
TREATMENT SELECTION CRITERIA
~ PERCENT REMOVAL REQUIREMENTS
~ COST OF TREATMENT
~ TYPE, QUANTITY, AND COST OF
DISPOSAL OF WASTE PRODUCTS
22
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POLYMER SOLIDIFICATION OF LOW-LEVEL RADIOACTIVE,
HAZARDOUS, AND MIXED WASTE
Mr. Paul D. Kalb
Brookhaven National Laboratory
Upton, New York
The Department of Energy (DOE) has generated large volumes of low-level radioactive (LLW),
hazardous, and mixed waste as a result of its research and defense activities over the last 50 years.
These include a broad range of waste types (such as evaporator concentrate salts, sludges, dry solids,
incinerator ash, and ion exchange resins) encompassing diverse chemical and physical properties. The
most common practice at DOE and commercial facilities is to solidify waste using hydraulic cement such
as portland cement. Cement solidification processes are limited, however, because cement hardens by
means of a chemical hydration reaction that is susceptible to interference with the waste. These
interactions can limit the types and amount of waste that can be solidified and can lead to waste form
degradation under anticipated disposal conditions.
BNL has developed two thermoplastic processes for improved solidification of radioactive, hazardous,
and mixed wastes. Both the polyethylene and modified sulfur cement encapsulation processes result
in durable waste forms that meet current Nuclear Regulatory Commission and Environmental Protection
Agency regulatory criteria and provide significant improvements over conventional solidification sys-
tems. For example, the polyethylene process can encapsulate up to 70 wt% mixed waste nitrate salt,
compared with a maximum of about 20 wt% for the best hydraulic cement formulation. Modified sulfur
cement waste forms containing as much as 43 wt% mixed waste incinerator fly ash have been formulated,
whereas the maximum quantity of this waste in hydraulic cement is 16 wt%. Data for waste form testing
are presented including compressive strength, water immersion testing, freeze-thaw cycling, radioactive
and hazardous constituent leachability, biodegradation, and radiation stability. These data indicate that
waste form performance far exceeds minimum regulatory standards. Both processes have completed
bench-scale development. Production-scale feasibility has been established for the polyethylene
process using process equipment with a maximum output of 900 kg/hr (2000 Ib/hr). A full-scale
technology demonstration is planned in which surrogate wastes similar to actual waste in chemical and
physical composition will be processed under plant conditions.
23
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\Sraolih3ven Nlliontl latlorltory
Polymer Solidification
of Low-Level Radioactive, Hazardous,
and Mixed Wastes
Paul D. Kalb
Presented at the EPA/DOE
Technology Transfer Seminar Series
on Radioactive Site Remediation
Waste Management Research & Development Group
Radiological Sciences Division
Department of Nuclear Energy
Brookhaven National Laboratory
Overview
Introduction
Background
Polyethylene Encapsulation Process
Modified Sulfur Cement Encapsulation Process
Summary/Conclusions
\Btootfitven Nltiontt Laboratory
Program Support
In FY 1992, the DOE Office of Technology Development
(DOE OTD) is supporting three programs in this area:
ซ Polymer Solidification
Technology Demonstration and Transfer
Coordination of national efforts to develop polymer
solidification technology
BF Polymer Solidification Support for Rocky Flats Plant
ซ* Polyethylene Encapsulation of Single Shell Tank Low-
Level Wastes (at Westinghouse Hanford)
24
-------
\Brgokhtvซn National labor* tofy
Background
** DOE is a major generator of
hazardous and mixed wastes
Many are "problem wastes":
- difficult to solidify
- poor quality w~ste forms
Annual U.S. Production of LLW
BNL is investigating new and innovative techniques for
improved encapsulationof mixed wastes
/i Ntliontl itbontofy
Objectives
To develop materials and processes that:
*& have potential to encapsulate problem mixed wastes
*ป* minimize potential for release of toxic materials
* comply with applicable regulatory requirements
ซ result in durable waste forms
CF are simple to operate, easy to maintain and economical
MATERIALS USED AT BNL FOR THE IMMOBILIZATION OF
RADIOACTIVE AND MIXED WASTE STREAMS
Portland
Masonry cement
Cement-sodium silicate
Pozzolanic
High alumina
Portland blast furnace slag
Latex modified cement
Polymer modified gypsum
Polymer-impregnated concrete
THERMOPLASTIC
Bitumen
Polystyrene
Polymethylmethacrylates
Polyethylene
Sulfur cement
THERM.OSETTING
Vinyl-ester styrene
Polyester styrene
Water extendable polyester
Epoxy resins
25
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BNL EXPERIENCE WITH ENCAPSULATION/SOLIDIFICATION OF
RADIOACTIVE AND MIXED WASTE STREAMS
Aqueous and Dried Nitrate Salt Waste
Chrome Sludge from Y-12
Incinerator Ash
Vacuum Pump Oils
Mixed Organic Solvents
Sodium Sulfate Evaporator Concentrates
Boric Acid Evaporator Concentrates
Mi-.cd Bed Spent Ion-exchange Resins
Mixed Waste Contaminated Soils
Aqueous Tritiated Waste
n Ntliontl Ittionlofy
Polyethylene Encapsulation Process
Technology Description
Encapsulation of LLW, hazardous, and mixed wastes in
polyethylene, an Inert thermoplastic material.
Contaminants are immobilized in stable, monolithic solid
waste forms with high solidification efficiencies and
excellent performance in disposal environment
Application of single-screw technology
Developed at BNL using bench-scale extruder (16 kg/hr);
Feasibility demonstrated at production-scale (900 kg/hr)
Technology Demonstration at BNL planned
Comparison of Polyethylene and Cement
for Waste Encapsulation
{riSfipStuhjfB'Siru'S
Solidification assured
Compatible with wide range
of waste types
High solidification efficiency
(more waste/drum)
Lower product density
(reduced shipping & disposal
costs)
&SM
-------
Bench-scale polyethylene extruder
Polyethylene Encapsulation Process
Technology Demonstration
Production-scale (114 mm) extruder with output capacity of 900
kg/hr will be used to demonstrate processing of surrogate nitrate
waste at BNL
Polyethylene Encapsulation System
Process Flow Diagram Oui^ui Scale
27
-------
Biookhavan Httiontl Lfboftory
Pilot-scale polyethylene waste form produced during scale-up
feasibility test containing 60 wt% sodium nitrate
\Brool
,khปv*n Nttiontl Lปborปtory
Polyethylene vs. Portland Cement
Maximum Waste/Drum
600
soo-
400-
300-
200 '
100-
Waste Types
Economic Analysis for
Rocky Flats Plant
Nitrate Salt Encapsulation
28
-------
Broofituvan National laboratory
Waste Form Performance Testing
NRC Test Criteria
Compressive Strength
Water Immersion
Thermal Cycling
Radionuclide Leachability
Biodegrada tion
Radiation Stability
EPA Test Criteria
Toxic Leachability
DOT Test Criteria
Oxidizers
Test Method
ASTM D-695, C-39
90 day
ASTM B-553
ANS 16. 1
ASTM G-21, G-22
70i rad
Test Method
Taxicity Characteristic
Leaching Procedure (TCLP)
Test Method
Solid Oxidizer Test
n tJtiionfl Laboratory
Modified Sulfur Cement
Thermoplastic material developed by U.S. Bureau of
Mines to utilize by-product sulfur (>5 million tons/year}
*sf Commercially manufactured and available under license
from USBM ($0.17/lb)
ซ* Stable, resistant to extremely harsh environments,
forms strong, durable waste forms
Advantages Over Hydraulic Cement
Chemical reaction not required for set
Full strength attained within hours rather than weeks
Greater compressive and tensile strengths are possible
Resistant to attack by most corrosive acids and salts
29
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\BfOQkhivan Ntv'ontf lปt>arttofy
Portland cement Sulphur concrete
concrete
Comparison of INEL and BNL Formulations
for Encapsulation of INEL Fly Ash
?akh*v8fi Niltont! laboratory
Summary /Conclusions
Polyethylene and Modified Sulfur Cement have
successfully completed bench-scale development and
will be demonstrated at full-scale
Compared with conventional hydraulic cement, these
thermoplastic binders provide:
- improved compatibility with wide range of wastes,
- improved waste loadings (more waste/drum) that
result in lower overall costs,
- improved waste form performance.
30
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IN SITU VITRIFICATION OF SOILS CONTAMINATED WITH
RADIOACTIVE AND MIXED WASTES
Mr. James L. Buelt and Mr. Leo Thompson
Battelle, Pacific Northwest Laboratory
Richland, Washington
In Site Vitrification (ISV) is a patented thermal treatment process for the in-place destruction and
immobilization of contaminants in soil. ISV melts contaminated soil by introducing an electrical current
among four graphite electrodes, achieving temperatures of about 1600 degrees centigrade. The molten
soil zone grows outward and downward during processing, and consolidates soil and compressible
materials into a voidless mass. Organic materials are destroyed and/or removed by the process. Most
of the radionuclides and heavy metals are retained within the molten soil which, when allowed to cool,
forms a relatively nonleachable glass and crystalline material similar to obsidian or basalt. Organic and
paniculate contaminants that are evolved with the gaseous effluents are captured in a hood overlying the
site and directed to an off gas system for treatment. The subsidence region that forms from the
consolidation of soil particles and compressible wastes in the soil is backfilled with clean fill after
processing.
ISV, which was conceived in 1980 and patented in 1983, has been tested and demonstrated under a
variety of conditions for several types of contaminants. It has been demonstrated at two past practice
units at the Department of Energy's (DOE's) Hanford, Washington reservation. It has also been tested
on a variety of soils from around the country, including tests at the Idaho National Engineering Laboratory
(INEL) and Oak Ridge National Laboratory (ORNL). Radionuclide, heavy metal, and organic contami-
nants (including PCBs) have been successfully vitrified or destroyed in these tests and demonstrations.
As a result of this testing and demonstration program, established capabilities and limitations of the ISV
technology have been identified, along with technical and regulatory issues that need to be resolved for
successful implementation of the technology at DOE sites. The ISV Integrated Program was created by
DOE's Office of Technology Development to help resolve these issues and promote deployment of the
technology in the field.
The near term priority issues directed for resolution include the following:
Develop methods that accurately predict, measure, and achieve significantly greater melt depth
and control of the melt shape. Presently, the ISV process has been demonstrated to a depth of
5 m. Significantly greater depths (i.e., up to 10 m) are needed for broad implementation.
Improve the understanding of and empirically verify volatile organic contaminant (VOC) behavior.
Implementation of ISV would be enhanced if the behavior of VOCs, such as carbon tetrachloride
or trichloroethylene that may coexist with other contaminants at some sites, were better defined.
Determine the potential for transient gas release events while vitrifying relatively low permeability
soils. Operating limits are being better defined to ensure containment and treatment of off gases
during processing.
Resolve secondary waste generation and handling concerns as they relate to the volatilization
of 137Cs from contaminated soils with unusually high Cs concentrations (multiple curies per
setting). Cesium recycle or volatility suppression techniques will be developed.
31
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ISV Glass Durability
Soxhlet Leach Rate <1 x 10-5g/cm2/day
Vitrified
Soil
MCC-1 Test
Weathering
Fracture
2345
Soxhlet Corrosion Rate (g/cmz-d x 10s)
<2 x TO'7 g Pu/cm2/day
<1mm/10,000 years
Conchoids)
TCLP RESULTS OF VITRIFIED PRODUCT
Concentration. mg/L
1000
LEGEND
Glass
Max Allowable
Arsenic Barium Cadmium Chromium Lead Mercury
Strength Comparison
Compressive
Strength (psi)
Splitting Tensile
Strength (psi)
Concrete
3,000 to
8,000
400 to
600
Vitrified Soil
35,000 to
45,000
4,000 to
8,000
32
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In Situ Vitrification (ISV)
RESIDUAL WASTE FORM QUALITIES
No organics present
Incorporated/immobilized inorganics
Excellent mechanical properties
Unaffected by weathering (freeze/thaw, wet/dry)
Superior resistance to chemical leaching
Acceptable biotoxicity
Pacific Northwest
Laboratory
ISV COST COMPARISONS WITH ALTERNATIVES
Cost, S/Ion
3500
3000
2500
2000
1500
1000
500
0-
TranSI
Transportation UHBK
Incineration iBmiJI
Chemical Stabilization BSBjJi
Excavation ISV i^Ks!
LOW COST RANGE HIGH COST RANGE
In Situ Vitrification (ISV)
CURRENT ISV APPLICABILITY
Soil Properties
- All Textures - Sand, Silt, and Clay; Sludge; and
Sediment (Low permeability soils, <10~3 cm/s,
require special monitoring or testing)
- Broad Chemical Compositions (with a minimum of
1.4 wt% of Na or K and 30 wt% silica)
- Depths up to 5 meters
- Varying Moisture Content up to 50 wt% (exclusive of
permeable aquifers)
Pacific Northwest
Laboratory
33
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In Situ Vitrification (ISV)
CURRENT ISV APPLICABILITY
ปContaminants
- Transuranics (up to established criticality limits of
~30 kg Pu per setting)
- Fission Products (up to 1000 Ci of Cs per setting)
- Inorganic Chemicals (volatiles, such as chlorides
and sulfates, removed and treated in off gas)
- Organic Contaminants and Materials up to 7 wt%
(limited field experience)
Pacific Northwest
Laboratory
In Situ Vitrification (ISV)
CURRENT ISV APPLICABILITY
(continued)
Soil Inclusions
- Metals up to 25 wt% (with Electrode Feeding)
- Concrete, Rubble, Rock, and Debris up to 50 wt%
(Mixed with Soil)
- Solid Combustibles up to 7 wt% (Limited Field
Experience)
- Not Ready for Sealed Containers
Pacific Northwest
Laboratory
In Situ Vitrification (ISV)
NEAR TERM PRIORITIES
Increase Achievable Depth from ~5 m to
Greater Than 10 m.
Develop Cesium Recycle/Suppression
Techniques
Improve Understanding of VOC Behavior
Better Define Operational Constraints in
Low Permeability Soils
Develop Technique for Subsurface Vitrified
Barriers
Pacific Northwest
Laboratory
34
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IN SITU VITRIFICATION INTEGRATED PROGRAM SCHEDULE
Obtain Funding Partner for Field Demonstrations
Obtain Funding Partner(s) (or Applied R&D
V _ y
Resolve Key, Near-Term Issues (Vapor-
Release, VOC Migration, Depth, Cs Volatility)
VOCs, Low* Compressible High Cesium Buried
Complete ER Field '""'^ " ฐ ' 'L "ป ซ "
Demonstrations * - * - * - * - *-
Resolve Remaining Issues
(Barriers, Product Performance) ^7
Develop Technology for Advanced Applications,
it Warranted (Buried Wastes, Tank Residuals)
' Proposed, potential Industrial collaboration
35
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DECONTAMINATION OF CONTAMINATED BUILDINGS
Mr. Jerry M. Hyde
U.S. Department of Energy
Washington, D.C.
The decontamination of contaminated buildings may pose risks to both human and environmental health.
The objectives of decontamination activities are: to minimize the potential contamination to workers, the
general public, and the environment; to generate the least amount of secondary waste possible; and to
maximize the quantity of building materials that can be recycled after they are decontaminated.
The deactivation and decommissioning of a building is the construction process in reverse. The systems
and components that are installed last in the construction process (ventilation systems, insulation, and
electrical wiring) are the first items to be decontaminated. The process of selecting methods for these
activities should be driven by the recycle and the disposal decisions.
The activities to deactivate and decommission a building can be divided into seven categories:
characterization
decontamination
dismantlement
material disposition
robotics/automation/artificial intelligence
regulatory compliance
planning
Today, each site has its own list of accepted methods for these activities.
Characterization of contaminated buildings begins with the identification and mapping of the contami-
nants present within the building.
Decontamination activities reduce radiation levels or remove radioactive contamination in or on
structures, equipment, and materials. The primary emphasis of decontamination today is pollution
prevention.
Dismantlement of contaminated buildings attempts to contain the contamination, and at the same time,
protect the workers.
Material disposition activities address the issues of release criteria for the reuse of construction
materials and the waste form criteria for storage and disposal.
All the other groups are supported by robotics, automation, and artificial intelligence activities. The
objective here is to protect the workers.
Regulatory compliance activities attempt to establish standards for Below Regulatory Concern for
waste disposal and De Minimus for material release.
Recently, a group of experts met to identify the technology needs within the seven categories. Based
on these needs, technology development activities have been identified.
Using these methods in the future, the decontamination of a contaminated building will be safer, faster,
and less costly, and will produce less secondary waste than the accepted group of activities selected
today.
37
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Decontamination Methods
for Contaminated Buildings
Jerry Hyde
U.S. Department of Energy
Office of Environmental Restoration
and Waste Management
General Approach
Building selected for decommissioning
What it means to decontaminate a building
How we would decontaminate a building with today's
methodology
- By activity area
-Total package
ซ Needs identified during decontamination and
decommissioning workshop
How we would decontaminate a building in the future
- By activity area
- Total package
What It Means To Decontaminate A Building
Decontamination and Decommissioning activity areas
- Characterization
- Type of contaminants
- Levels of contaminants
- Decontamination
- Surface contamination
- Bulk contamination
- Dismantlement
- Green field condition
- Material deposition
- Recycle and reuse (De Minimus standards)
- Disposal (Below Regulatory Concern standards)
- Regulatory compliance
- Robotics, automation, and artificial intelligence
38
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Characterization of Buildings, Equipment, and Waste
Chemical analysis techniques
Instrumentation
- Field instruments
- Laboratory Instruments
- Monitors and sensors
Decontamination of Buildings, Equipment,
and Waste
In Situ Decontamination
Methodologies for metal bulk and surfaces
Methodologies for surface layer removal
Reagent recycle technology
Secondary waste minimization
Dismantlement of Buildings and Equipment
Contamination containment
Special problems associated with high radiation areas
Worker protection
39
-------
Material Disposition
Recycle and release for reuse of valuable materials
Storage
Waste disposal
Recycle Projects Support Decontamination and
Decommissioning
Recycle Disposal
" Reuse
Regulatory Compliance
Below Regulatory Concern and De Minimus levels
for release
Cost
End point scenarios
Environmental statutory requirements
Mixed wastes
Public perception
Risk assessment
40
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Robotics, Automation, and Artificial Intelligence
Characterization
Decontamination
Dismantlement
Materials information management
Packaging
Available Characterization Methods
Field deployable monitors
- Alpha, Beta, Gamma counters
Infrared analyzers
Photoionization and ionization flame detectors
- Measurements include radiation levels, total
organic exposure
Laboratory analysis
- Gamma spectroscopy
Inductively coupled mass spectroscopy
X-ray fluorescence
Samples include bulk materials, surface swipes,
air filters, traps
Available Decontamination Methods
Manual methods
- Scraping, scrubbing, wiping
Abrasive methods
High pressure water/steam
Grit blasting
Chemical methods
Foams, gels, pastes
- Hard chemical (greater than 5 percent)
solutions
Electrochemical methods
Electrorefining
41
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Available Dismantlement Methods
Concrete demolition
Headache ball
Jack hammers
Metal/pipe cutting
- Abrasive cut off saws
Plasma torches
Asbestos removal
Automatic cutters and knives
- Wetting agents
Worker protection
Area radiation monitors
Robotics equipment
Available Material Disposition Methods
Treatment
Packaging
Storage
Disposal
Burial
Recycle versus disposal costs
Treatment for purposes of volume reduction
Existing Methodology for Decontaminating Buildings
Field deployable instruments to measure radiation
level and total organic exposure
Samples sent to mobile and permanent laboratories
High pressure water for concrete surfaces
Headache ball for walls and ceilings
Jack hammers for floors
Abrasive saws for metal/pipe cutting
Package all wastes and transport for burial
42
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Identified Characterization Needs
Instrumentation to determine nature, concentration, and
extent of contamination before, during, and after
decontamination
- Techniques that are certifiable by regulatory
agencies for release of facilities, recycle and reuse
of materials, and evaluation of exposure to the
public and the environment
Benefits
- Reduce worker exposure to radiation and hazardous
materials
- Minimize time lost waiting on analysis
- Better definition of public and environmental
exposure
- Support to De Minimus and Below Regulatory
Concern standards
Identified Decontamination Needs
Technology to remove radioactive and hazardous
substances from concrete surfaces and metal equipment
and structures
- Decontaminate surfaces, equipment, and structures
sufficiently to permit release, reuse, recycle, or
disposal as Below Regulatory Concern
Benefits
- More material can be recycled and reused
- Reduce radioactive and hazardous waste disposal
requirements
Identified Dismantlement Needs
Choice of technology may be highly site and
application specific, is influenced by the types and
levels of contamination present, and by the facility
size and configuration
- Will only be feasible through the use of robotics
and automation
- Some available technologies generate large
quantities of mixed waste
Benefits
- Produces a larger fraction of materials which are
recyclable
- Improves worker protection systems
43
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Identified Material Disposition Needs
Activities needed to recycle valuable materials and to
dispose of materials which cannot be reused cost
effectively utilizing methods that protect human health and
the environment
- Need treatment methodologies to support material
disposition
Benefits
- Establish reasonable health based standards for
recycle of materials (De Minimus) and disposal
(Below Regulatory Concern) of slightly contaminated
materials
- Cost recovery through the recycle of materials
Characterization Development Activities
Integrated analysis system for real time analysis of
organic and mercury compounds
Passive monitors for measuring surface alpha
contamination
Portable real time polychlorinated biphenyl sensors
Surface characterization technologies for monitoring
metal and concrete
Decontamination Development Activities
Concrete decontamination by electro-osmosis
Electropolishing of irregular shapes
Gas phase decontamination
High speed cryogenic pellet decontamination
In Situ cleaning of pipes and drains
Laser decontamination with recycle of metals
Liquid phase decontamination
Microwave concrete decontamination system
44
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Dismantlement Development Activities
1 Cutting and breaking of concrete structures
> High velocity pellet cutting
> Improved portable modular shielding systems
Material Disposition Development Activities
De Minimus limits and Below Regulatory Concern
standards
System method analysis of decontamination and
decommissioning options
Treatment and recycle of cleaning waters for water and
steam decontamination systems
Future Methodology for Decontaminating Buildings
Real time monitoring of process
Real time field analysis of all samples
Microwave scabbling for concrete surfaces
Laser melting for metal surfaces
High velocity pellet cutting for walls, ceilings,
and floors
On site concrete rubble recycling
Package all homogeneous waste and transport for
burial
45
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Recycle of Metal Into Containers
Utilizing Private Sector Capabilities
Summary
Developing technologies to permit the decontamination
and decommissioning of excess Department of Energy
facilities while minimizing waste generation and exposure
of workers, the public, and the environment to hazardous
and radioactive materials
Improved technology must be developed in a timely
manner
- Fernald Plant 7 is scheduled to begin
decontamination in 1993
- Oak Ridge gaseous diffusion plant is scheduled to
begin decontamination in 2003
Technologies will emphasize recycle and reuse of as
much material as practical
46
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INCINERATION OF RADIOACTIVE WASTE
Dr. H.W. "Bud" Arrowsmith
Scientific Ecology Group, Inc.
Oak Ridge, Tennessee
The incineration of low level radioactive waste in the United States is now making a major contribution
to the effort of reducing waste volumes requiring burial and is also improving waste forms. This
contribution is primarily being made by the world's largest radioactive waste incinerator, which is housed
and operated at the Scientific Ecology Group (SEG) facilities in Oak Ridge, Tennessee. The SEG
incinerator is an automated, controlled air incinerator capable of burning waste consisting of 70% plastic,
with smaller amounts of paper, cloth, rubber, wood, sludges, and ion exchange resin, at the rate of 1000
pounds per hour. Volume reductions of at least 100:1 are regularly obtained when burning these
mixtures. The incinerator was built in Denmark by Envikraft, the off gas system was built in Holland by
American Air Filter, and the system was integrated by SEG.
The SEG incinerator consists of a primary chamber, a secondary chamber, and a third burning chamber.
Waste charges, averaging two hundred fifty pounds, are charged into the primary chamber through a
vertical airlock system every fifteen minutes. The charged waste falls onto a burning pile in the primary
chamber, which is operating at an average temperature of 1000 degrees centigrade. Most of the waste
is converted by pyrosis into burnable gases which are then transported to the secondary chamber for
burning. In the secondary chamber, excess oxygen is added and the gases are burned at a temperature
ranging from 1000-1200 degrees centigrade. After burning, the gases are transported to the third
chamber where they are reburned at temperatures ranging from 1000-1300 degrees centigrade. The
transit time required for gases to travel through the primary chamber and exit the third chamber is 2
seconds.
Waste from the incinerator includes bottom ash, fly ash, scrubber salt, and boiler ash. Bottom ash is
removed from the incinerator using augers, and is then collected at 50 degrees centigrade 12 hours from
the time the original waste entered the incinerator. Baghouse dust is collected and treated to reduce the
leachability of the heavy metals, which are volatilized in the primary chamber. Scrubber salts are
concentrated from the scrubber liquor and dried. The bottom ash, treated fly ash, and dried scrubbersalts
are all disposed of as radioactive waste.
The incinerator off gas system consists of a boiler to reduce gas temperatures, a baghouse to remove
a high percentage of the particulate entrained in the gas stream, a 3 stage filter, including a HEPA filter,
a quench tower, and a packed tower scrubber. This off gas system is very efficient in removing the non
volatile radioactive nuclides and it efficiently removes the acid gases from the incinerator exhaust. In
1991, the SEG incinerator burned 5.3 million pounds of low level radioactive waste and produced an
estimated dose of only 0.027 mr/year to the nearest resident, compared to natural background radiation
levels of approximately 150 mr/year.
47
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BENEFITS OF INCINERATION
REDUCED WASTE VOLUME REQUIRING BURIAL
IMPROVES THE WASTE FORM
REDUCES BURIAL GROUND SUBSIDENCE
RADIOACTIVE WASTE MATERIALS
THAT ARE INCINERATED
PAPER
WOOD
RUBBER
FIBERGLASS
ION EXCHANGE RESIN
ANIMAL CARCASS
OILS
PLASTIC
CLOTH
CANVAS
CHARCOAL
SLUDGES
OILS
HEPA FILTERS
INCINERABLE WASTE PROCESSING
RECEIPT
WASTE TRACKING IDENTIFICATION
SORTING
PACKAGING
INCINERATION
PACKAGE ASH FOR BURIAL
48
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INCINERATOR WASTES
WASTE TYPE HAZARDOUS CATEGORY
BOTTOM ASH
BOILER ASH
FLY ASH
SCRUBBER SALT
SOMETIMES CHARACTERISTIC
ALWAYS CHARACTERISTIC
ALWAYS CHARACTERISTIC
NON HAZARDOUS
REDUNDANT INCINERATOR FEATURES
DRAFT FANS
AIR SUPPLY FANS
GAS MONITORS
OPACITY DETECTORS
HEPA FILTERS
NEGATIVE AIR PRESSURE CONTROLLERS
EMERGENCY POWER
WASTE CHARGING PERMISSIVES
TIME FROM LAST CHARGING
OPACITY AFTER BOILER
PRIMARY CHAMBER AND SECONDARY CHAMBER
WASTE LEVEL IN PRIMARY CHAMBER
OXYGEN CONTENT AFTER THIRD CHAMBER\
49
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BENEFICIAL USE OF WASTE ENERGY
OPERATE EVAPORATOR FOR SCRUBBER UQUIR
REHEAT STACK GASES
PROVIDE ENERGY FOR RESIN DRYING
HEAT BUILDINGS
50
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IN SITU STABILIZATION/SOLIDIFICATION WITH
CEMENT-BASED GROUTS
Mr. T. Michael Gilliam
Oak Ridge National Laboratory
Oak Ridge, Tennessee
The cement-based grout stabilization/solidification (CGSS) systems currently in use are actually derived
from work begun in the 1950s with low-level radioactive waste (LLW). CGSS systems have become the
most widely used hosts for the immobilization of LLW streams because (1) the cost of the materials is
low; (2) the processes are run at low temperature, use standard "off-the-shelf" equipment, and are
adaptable to a wide variety of disposal scenarios; (3) the resulting waste forms can be highly resistant
to chemical, biological, thermal, and radiation degradation; and (4) high waste loadings are achieved with
a minimum waste-volume increase when the waste-host formulas are tailored to the specific waste
streams. The positive characteristics of the CGSS products that made them acceptable for disposal of
LLW have also proved desirable for disposal of some hazardous wastes. Indeed, the Environmental
Protection Agency (EPA) has specified CGSS as the Best Demonstrated Available Technology (BOAT)
for selected hazardous wastes (e.g., F006 and K046) or for residuals from other BDATs (e.g., K001 and
K022).
In general, the CGSS systems are batch processes where the waste is removed, the materials is
processed through the CGSS system, and the product is either placed where the original waste was
located or elsewhere. However, in situ (i.e., in place) grouting, involves solidification/stabilization (S/S)
or the waste without removal and processing through the CGSS system. There are two general types
of in situ S/S processes: (1) those in which the reagents are mixed with the waste using a rotary device
such as an auger and (2) those that involve the physical encapsulation of the waste by pressure injecting
the reagents into the accessible void spaces around the waste. The EPA has performed several
evaluations of this technology under the auspices of its Super-fund Innovative Technology Evaluation
(SITE) program.
Both batch and in situ processes require laboratory-scale "treatability studies" to establish the matrix
design (i.e., the composition of the mix of reagents to be used). These studies must not only address
compliance with required performance objectives, such as concentration of the leachate from the Toxicity
Characteristic Leaching Procedure (TCLP), but must also determine compatibility with both process and
site-specific constraints. This compatibility assessment may require the determination of characteristics
such as density, particle size, settling rate, rate of set, compressive strength, viscosity, and bulking factor.
In general, these characteristics determine the limitations of a specific in situ process, and the site
characteristics and specific performance objectives determine the applicability of the in situ S/S option.
51
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ENVIRONMENTAL RESTORATION AND WASTE MANAGEMENT
Dr. Rashalee Levine
Office of Technology Development
U.S. Department of Energy
Washington, D.C.
Bioremediation and biotreatment are key technology components of the mission of the Office of
Technology Development (OTD). OTD's overall mission is to: (1) rapidly develop, demonstrate, and
transfer needed technology to Defense Programs and the Office of Environmental Restoration and
Waste Management (EM); (2) minimize waste generation; and (3) obtain faster, better, cheaper, and
safer cleanup and disposal of waste.
The Bioremediation Program of OTD supports DOE's needs for environmental restoration and in-situ
cleanup. OTD conducts applied research in the areas of soil/groundwater and waste minimization/
processing on the hazardous and mixed (hazardous plus radioactive) wastes generated by DOE over
the past half-century. Biotechnology, as part of an interdisciplinary approach to waste stabilization and
waste reduction, could have less environmental impact than other methods and could be applied at less
cost. Wastes amenable to bioremediation include radioactive materials, heavy metals, organic materials,
and other wastes such as nitrates.
In situ Remediation: This sub-program is focused on bioremediation at the contaminated site.
Successful in situ bioremediation would eliminate the need for soil removal, transportation, off-site
treatment, and possible generation of secondary contamination. Projects underway include
biosorption of uranium tailings from leachate and groundwater, vapor-phase bioreactors for in situ
removal of vaporizable organic compounds from vacuum-generated waste streams in contaminated
soils, and modeling of subsurface fate and transport of heavy metals and radionuclides during in situ
bioremediation and nutrient injection.
Biotechnology for Characterization and Post-closure Monitoring: This sub-program is focused on the
use of non-invasive real-time biosensors and monitoring systems to identify and track hazardous
contaminants. Studies are underway to determine whether microbial and plant systems could be
used for bioremediation of contaminated soils with resulting improvement in underground water
quality.
Waste Minimization/Waste Processing: This sub-program is focused on reduction of hazardous and
mixed waste in on-going DOE industrial processes. An example of this program is a process
developed for the biological removal of nitrate from low level rad waste process streams which may
be successfully adapted to high level rad waste streams, thus significantly reducing the quantity of
waste generated.
DOE sites have many environmental restoration and waste management issues that can be addressed
by environmental biotechnology. Five high-priority areas were selected to address DOE's most pressing
needs. These areas are consistent and complementary to those identified in EPA's biotechnology plan
and integrate with existing DOE integrated programs and demonstrations.
Technologies will be developed for use in full-scale field operations at DOE sites in the short term (less
than 5 years). A strategic objective attainable within a 5-year period was developed for each of the five
areas.
53
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The five priority areas and the strategic objective of each are:
1. Hydrocarbons: Provide mature technologies for bioremediation of petroleum hydrocarbons in soils
(in situ and ex situ) within 3 years;
2. Chlorinated solvents: Demonstrate at several sites the use of environmental biotechnology to clean
up groundwater and soils contaminated with chlorinated solvents within 5 years;
3. Heavy metals/radionuclides: Perform pilot-scale demonstration of cost-effective concentration/
separation for several metals or radionuclides from water within 3 years;
Demonstrate in situ techniques in field plots for metals/radionuclides mobilization or immobilization
of priority metals within 5 years;
4. Mixed Waste: Provide a full-scale demonstration of biological denitrification of mixed waste within
4 years;
5. Characterization Assessment: Develop and transfer several characterization and assessment
technologies to EM within 5 years.
The current climate is good for development and acceptance of environmental biotechnology, whether
it is for in situ bioremediation, ex situ bioremediation when uniquely required, or biocharacterization to
demonstrate efficacy of cleanup or control in situ activities. What is needed is conduct of controlled efforts
that develop the data demonstrating the utility of these techniques at field scale, real world sites.
54
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REMOVAL OF CONTAMINANTS FROM SOILS BY ELECTROKINETICS
Dr. Yalcin B. Acar
Louisiana State University
Baton Rouge, Louisiana
Bench-scale studies conducted at Louisiana State University and other institutions demonstrate that
ionic species of heavy metals, selected organic contaminants (phenol, BTEX compounds below
solubility, and trichloroethylene), and radionuclides (uranyl and thorium ions) can be removed efficiently
from fine-grained deposits by application of electrical currents in the order of 25 to 1000 M-A/cm2 across
electrodes inserted in a soil mass. A pore fluid is also supplied at the electrodes during the process. This
technique, electrokinetic soil processing, results in generation of an acid front at the anode and a base
front at the cathode by the electrolysis reactions. The acid front flushes across the soil mass by diffusion,
migration, and advection due to electro-osmosis. The advance of the acid front coupled with the
chemical, hydraulic, and electrical potential differences generated across the soil mass results in
contaminant desorption, transport, collection, and removal. Different types of conditioning fluids may be
used at the electrodes to enhance removal.
The objective of this presentation is to provide the fundamentals of the electrokinetic remediation
process. The efficiency of the technique in soil remediation, energy requirements, and guidelines for its
implementation are discussed. Outlines of the ongoing large-scale laboratory study and the pilot-scale
field study are also presented. The advantages, shortcomings, and the complicating features of the
technique are reviewed and the implications of the results of the bench-scale, large-scale, and field-scale
studies on field implementation of the electrokinetic remediation process are provided.
55
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REMOVAL OF CONTAMINANTS
FROM SOILS
BY ELECTROKINETICS
Yalcin B. Acar
Louisiana State University
CONTENT I
ELECTROKJNETIC PHENOMENA IN SOILS
POTENTIAL USE
FUNDAMENTALS OF EK REMEDIATION
BENCH-SCALE STUDIES
PI LOT LARGE-SCALE / FIELD STUDIES
SUMMARY
ELECTROKJNETIC PHENOMENA I
IN SOILS I
ELECTROOSMOSIS
ELECTROPHORESIS
SEDIMENTATION POTENTIAL
MIGRATION POTENTIAL
ELECTRO-OSMOSIS
^"
= -
<
-
ELECTRO-OSMOTIC HEAD ^
ELECTRO-OSMOTIC FLOW
Saturated Soil
DC CURRE
^
-
ST/VOLTAGE
1
0
ELECTRO-PHORESIS
Particle Movement
Anodt
+
Clay Suspension
DC CURRENT
ll
SEDIMENTATION POTENTIAL
MIGRATION POTENTIAL
HYDRAULIC HEAD
POTENTIAL USE OF
ELECTROKINETIC PHENOMENA
IN REMEDIATION
56
-------
LEAK DETECTION IN CONTAINMENT BARRIERS
Flow Across Barrier
I LJ
FLOW BARRIERS IN CLAY LINERS
TRANSPORT OF CONTAMINANTS
BV HYDRAULIC AND CHEMICAL POTENTIAL GRADIENTS
I I I I I I I I
(D O O GT (J
CLAY BARRIER
O . O Q 0.0.0
I I I I I I t I
OPPOSING FLUXES BY ELECTRICAL GRADIENTS
I'LfME DIVERSION SCHEMES
MIGRATION DIRECTION
Q = k i A
h h h
Q = Flow under Hydraulic Gradients
h (cm3/s)
k = Hydraulic Conductivity
h (cm/s)
i = Hydraulic Gradient
h
A = Area (cm2)
Q = k i A
e e e
Q = Flow under Electrical Gradients
e (cm3/s)
k = Electroosmotic Coefficient of Permeability
e ( cm/s)/ (V/cm)
i = Electrical Gradient (Volt/cm)
e
A = Area (cm2)
Q
k i
e e
Q k i
h h h
FROM FINE SANDS TO CLAYS
-3 -10
k = 10 to 10 cm/sec
h
-4 -6
k =10 to 10 (cm/s) / (V/cm)
57
-------
Q=k i A = k EA/L = k(RA/L)I = (k/o)I
e e e e e e
k = k / a
i e
k = 0 to 1.5 gallons/A-h
i
Maximum Values
Low Activity Clays
High Water Contents
Low Electrolyte Concentrations
Initial Stages of the Process
ENERGY EXPENDITURE!
dE
2
I R
I V I
dt
A L A L A e
P= Power/unit volume
I = Current (constant)
R = Resistance
A = Area
L = Length
i = Electrical Gradient
ELECTRODE REACTIONS
I ANODE I
*>
!DC CurrenI
p .4e *2H
fiaป Cซnfni(K,n
II.dmgrnRtkaK
YT 7
AOVECTIufii I ELECTRO-OSMOSIS JICW MIGRATION
-------
IJAIA ACQUISITION
Pb(II) -Georgia Kaolinile Adsorption Isothtrm
a
< 1000
J
o 100 t '
} I 10 100 1000 10000
EQUILIBRIUM CONCENTRATION (PPM)
100 200 300 400 500 600 700 600
TIME (h)
ELECTRO-OSMOTIC COEFFICIENT OF PERMEABILITY
10 '
200 .100 600 800
TIME ELAPSED (h)
59
ELECTRO-OSMOTIC WATER TRANSPORT EFFICIENCY
1
0.8
0.6
0.4
0.2 -
0
0 100 200 300 400 500 600
TIME ELAPSED (h)
NORMALIZED DISTANCE FROM ANODE
IN-SITU AND PORE FLUID pH PROFILES
ACROSS THE CELL IN TEST 01 AND TEST 05
TEST 01. 388 A-hW bitMfun Fluid PH
TEST 05 . 1962 A.h/mJ
D D D p D
PORK FLUD ITLST 01, *- O
Initial In-iiiupN
D ;
a :
o ฐ :
. a " " ';
o - - :
-a -
889ฃ "'S1T1' CTEST "' '^^ ;
NORAULIZED DISTANCE FROM ANODE
- 10
z
.. ..ir
-------
|ฃl.5
* 0.5 '
V
0 0.2 0.4 0.6 0.8 1
NORMALIZED DISTANCE FROM ANODE
ฃ so
~ 40
NORMALIZED DISTANCE FROM ANODE
1'blll) [120-14fug/g] MASS BALANCE
o
IS
<
CONCENTRATION I'ROFILES IN rb(II) TESTS
0 O.Z 0.4 0.6 0.8 1
NORMALIZED DISTANCE FROM ANODE
60
Pb [1,000 ug/g] MASS BALANCE
02
TEST NUMBER
O
L
55
o
o
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
CD(II) REMOVAL EFFICIENCY
0.2 0.4 0.6 0.8 1
NORMALIZED DISTANCE FROM ANODE
_
.ง 10
fiซOR ('
D CATHODE r
O SPECIMEN |:
COOZ CD03
TEST NUMBER
ACTIVITY PROFILES IN URANIUM REMOVAL
1
0.2 0.4 0.6 0.8
NORMALIZED DISTANCE FROM ANODE
-------
URANIUM-1,500 ug/g-MASS BALANCE
TEST NUMBER
3 PHENOL REMOVAL FROM KAOLINITE
(500 ug/g)
1 2 3
PORE VOLUMES OF FLO"'
"2
ฃ
""' 16
r-
^ ,-,
O 12
^
O
i 4
0
PHENOL (500 ug/g) MASS BALANCE
_
D SPECIMEN
D EFaUENT
J_
MH^Hl
I
_J_
ERROR
ii 1 1 .
*~^^am.
0] o: 03
TEST NUMBER
<
a
ui
753.1,0.;
753-1,06
0.02 0.04 0.06 0.08 0.1 0.12 0.1-1
CURRENT DENSITY (mA/cm:)
RESEARCH AND DEVELOPMENT!
BASIC RESEARCH
CONDITIONING FLUIDS
SURFACE CHEMISTRY
ELECTRODE TYPES
LARGE-SCALE MODEL (LSU)
THEORETICAL MODEL (LSU)
DESIGN / ANALYSIS SCHEMES (EK)
IMPLE MENTATION GUIDELINES (EK)
CONSTRUCTION PROCEDURES (EK)
PILOT-SCALE TESTS |
ELECTROKINETICS / LSU (USA)
Pb(II) 4, 000- 36, 000 ug/g
GEOKJNETICS (NETHERLANDS)
Zn 5.120 ug'g
As 385 ug'g
Pb 500 ug/g
Cu 1,150 ug'g
61
-------
Samples SD-S27 wjj) be taken at specified grid
locations within one ft intervals down to a depth
of 4 ft
SUMMARY |
BENCH-SCALE AND LIMITED PILOT-SCALE TESTS
REMONSTRATE THAT ELECTROKINETIC SOIL
PROCESSING IS A FEASIBLE AND EFFICIENT
TECHNOLOGY IN REMEDIATION OF (FINE-GRAINED)
SOILS FROM INORGANIC, SELECT RADIONUCLIDES
AND SOME ORGANIC CONTAMINANTS
SUMMARY (continued)
THE PROCESS REMOVES CONTAMINANTS
FROM SOILS BY ELECTRO-OSMOTIC AD-
VECTION AND ELECTRICAL MIGRATION
COUPLED WITH THE DESORPTION GENE-
RATED BY THE ADVANCING ACID FRONT
AND/OR ANY CONDITIONING FLUIDS INTRO-
DUCED AT THE ELECTRODES UNDER AN
ELECTRICAL POTENTIAL DIFFERENCE
SUMMARY (continued) |
TYPE OF CONTAMINANTS
- INORGANIC IONIC SPECIES
As, Cd, Cr, Cu, Pb, U, Zn
Th &Ra (Precipitation)
- ORGANIC CONTAMINANTS
Phenol, BTEX Compounds (Below Solubility Limits)
O-Nitrophenol
Hexachloroburadienne (failed at 1, 000 ppm)
(Micellic removal is investigated)
SUMMARY (continued) !
CURRENT/VOLTAGE LEVELS
BENCH-SCALE TESTS
- 10 ,uA/cm2 to 1000 (,iA/cm2
- 1 to 2 V/cm
- Preferrable (< SO |aA/cm2)
PILOT-SCALE TESTS
- up to 4 mA/cm2 or
- up to 2 V/cm
SUMMARY (continued)
ELECTRODE DETAILS / LAYOUT
TYPE
- ANODE INERT
- CATHODE OTHER
- SHEETS / RODS OR COATED
DISTANCE
- UP TO 4m (6m?)
LAYOUT
- l-D CONDITIONS PREFERRED
SUMMARY (continued)
ENERGY EXPENDITURE
BENCH-SCALE TESTS
18-100 kW-h/m3
PILOT-SCALE TESTS
100-400 kW-h/m3
|
62
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TREATMENT, COMPACTION, AND DISPOSAL
OF RESIDUAL RADIOACTIVE WASTE
Mr. Walter M. Hipsher
Scientific Ecology Group, Inc.
Oak Ridge, Tennessee
The remediation of a facility or site that has radioactive contaminants will result in the generation of
secondary radioactive waste, such as anticontamination clothing, and radioactive waste that is to be
removed from the site. These materials need to be processed to reduce disposal costs, to meet disposal
site acceptance criteria, or to meet NRC waste form stabilization requirements. Treatments applied by
industry to prepare these materials for either release or disposal are broken down into three categories
and discussed in this presentation.
The first category is that of decontamination of materials either to reduce the activity for unrestricted
release or to reduce the radiation levels of the materials for future handling and storage. Techniques to
accomplish this task include manual cleaning, chemical cleaning, abrasive cleaning, pressurized water,
and various combinations of these techniques. Any of these techniques could be used for removal of
contaminants that result in the unrestricted release of the materials.
The second category is that of treatment to reduce the volume and/or cost for disposal of the materials.
The primary technique utilized is to volume reduce the materials by compaction. Recently, incineration
has become the primary choice for combustible materials as it reduces both weight and volume. Other
volume reduction techniques such as the removal of liquids by suction dewatering and/or drying are used
for specialized waste forms such as dirt, resins, and some sludge.
The third category is the processing of materials to assure that the waste form meets specific NRC and/
or disposal site acceptance criteria. The process may involve some of the techniques previously
discussed that are used as pretreatment steps and the addition of techniques to assure that specific
waste form criteria are achieved. Ashes may be solidified or compacted to meet the receipt requirements
that they be non-dispersible in air. Higher activity sludge, liquids, soils, and resins may be placed in
specialized disposal containers or solidified with specialized stabilization agents. Characteristic mixed
wastes may be solidified to remove the hazardous waste characteristic so that the material may be
disposed of as radioactive.
63
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RADIOACTIVE SITE REMEDIATION
TREATMENT, COMPACTION, DISPOSAL
I. TYPICAL DRY ACTIVEJWASTE (DAW)
SOIL
ANTI-C's
RESIN
BUILDING RUBBLE
II. COMPACTION
PREPACKAGED DRUMS/BINS
BULK MATERIALS
LIMITATIONS
RADIOACTIVE SITE REMEDIATION
TREATMENT, COMPACTION, DISPOSAL
III. INCINERATION
WEIGHT REDUCTION
VOLUME REDUCTION
RESIN
COMBUSTIBLES
LIMITATIONS
RADIOACTIVE SITE REMEDIATION
TREATMENT, COMPACTION, DISPOSAL
IV. RADIOLOGICAL DECONTAMINATION
METALS
LIQUIDS
SOILS
LIMITATIONS
64
-------
RADIOACTIVE SITE REMEDIATION
TREATMENT, COMPACTION, DISPOSAL
V. DISPOSAL
BEATTY, NV
RICHLAND, WA
BARNWELL, SC
DOE
NARM
65
&V.S. GOVERNMENT PRINTING OFFICE: 1992 - 64S-O03/4I84I
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