WASTE R&D AT ORNL
This article also appears in the Oak Ridge National Laboratory
Review (Vol. 25, No. 2), a quarterly research and development
magazine. If you'd like more information about the research
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In the past few years efforts to clean up hazardous waste at sites
across the country, including Department of Energy facilities, have
increased dramatically. Vast economic and personnel resources are
being devoted to environmental restoration. Sometimes problems can
be solved quickly using available techniques; however, solving many
old environmental problems requires new methods and technologies.
Creating these new approaches is the task of the Office of
Technology Development (OTD) within DOE's Office of Environmental
Restoration and Waste Management.
The success of this task depends to a considerable degree on
maintaining open lines of communication between OTD and its
counterparts, the Office of Environmental Restoration and the
Office of Waste Operations. These organizations are involved in the
nuts and bolts work of restoration, remediation, and waste
management, often responding to crisis situations. During the
course of this work, some areas are found to have cleanup and waste
management needs that cannot be met with existing technologies.
OTD's mission is to be attentive to these areas, seek out possible
solutions, and nurture their development so they can be implemented
in the field.
At ORNL, innovative environmental restoration and waste management
techniques for OTD are being developed in the following areas:
- Characterization--developing advanced models, field
measurement and sensing methods, and data acquisition and
analysis systems for mapping and determining the contents of
a waste site;
- Bioremediation--developing microorganisms to "eat" or
otherwise stabilize selected organic contaminants, such as
trichloroethylene (TCE) and polychlorinated biphenyls (PCB),
and inorganic species, such as uranium and lead, in situ (in
place) or in process;
- Treatability--developing methods for treating soils
contaminated with volatile organic compounds and low levels
of radioactive substances;
- Robotics--developing robotic systems and remote technology
to characterize and clean up waste without exposing workers
to a hazardous environment;
- D&D--decontamination and decommissioning of metals and
concrete to assist in disassembling old facilities and in
replacing several major facilities in the Defense Programs
Reconfiguration;
- Transportation--performing evaluations of transportation
needs for on-site and off-site transfer of hazardous and
mixed waste (hazardous and radioactive waste combined); and
- Technology transfer--promoting the transfer of technologies
developed at ORNL that potentially could improve program
effectiveness, reduce costs, and save time for federal
agencies, industry, academia, and the international
community.
All these activities involve developing new remediation and waste
management methods or modifying existing techniques to create
cost-effective, energy-efficient waste-minimization technologies.
CHARACTERIZATION
Finding more economical ways to clean up soil and groundwater
contaminated by radioactive and hazardous chemicals is a priority
in environmental restoration and waste management. The first step
toward reducing the cost of cleaning up sites is reducing the cost
of collecting and analyzing soil and groundwater samples. The
process of collecting and analyzing samples is not only costly, but
it also delays cleanup efforts because of the time required to
obtain results. The Office of Technology Development is currently
supporting a number of projects at ORNL addressing these problems.
For example, ORNL researchers Marcus Wise, Cyril Thompson, and Mike
Guerin, all of the Analytical Chemistry Division, have developed a
portable, real-time, direct-sampling ion-trap mass spectrometer
that can detect hazardous organic compounds at extremely low
concentrations. This device reduces sample processing time to less
than half that required using conventional analytical methods (see
the article on "New Waste Technologies" in this issue).
The improved Derivative Ultraviolet Absorption Spectrometer (DUVAS)
system developed by John Haas of the Health and Safety Research
Division measures groundwater contamination directly and, as a
result, is able to more accurately characterize any such
contamination. The system may have additional applications in the
monitoring of manufacturing discharges and chemical process streams
(see the article on "New Waste Technologies" in this issue).
The colloidal borescope previously developed by Tom Cronk and Pete
Kearl, both of ORNL's Grand Junction, Colorado, office, is being
adapted to measuring the velocity of groundwater flow. This
instrument offers the potential for improved site characterization,
design of faster and more cost-effective remediation strategies,
and improved monitoring of the remediation process. Meanwhile,
nondestructive assay and nondestructive examination methods using
a linear accelerator have been developed for characterizing
remote-handled transuranic (RH-TRU) waste by Fred Schultz of the
Office of Environmental and Health Protection Compliance.
Tuan Vo-Dinh of the Health and Safety Research Division is
developing a luminescence spot test for rapid screening of soils to
find out if they contain PCBs. In this technique, the presence and
concentration of PCBs adsorbed on chemically treated filter paper
and exposed to light are determined by detecting and measuring
their resultant luminescence. Advantages of the technique are that
the simple instrumentation can be easily set up and used in the
field and that it can analyze samples more rapidly and at a lower
cost than conventional methods.
Some effort at ORNL has been devoted to developing technologies for
analyzing air, water, and soil in place, thus reducing considerably
the cost, time, and hazards associated with extracting,
transferring, and analyzing contaminated samples.
Haas has been building a fiber-optic probe and monitoring system
using DUVAS to provide fast, cost-effective in situ sampling of
groundwater to identify its contaminants. At the same time, Roger
Jenkins of the Analytical Chemistry Division is developing an
arrayed multisorbent sampler--an array of tubes packed with layers
of various materials that adsorb volatile organics--for in situ
collection of volatile species at depths up to 38 m (125 ft). An
example of such an organic pollutant is TCE, a solvent that had
been widely used to remove grease from metal. The samplers will
provide temporally and spatially resolved chemical information
concerning the impact, effectiveness, and zone of influence of
candidate remediation technologies.
Considerable time and money can be saved by identifying the
technologies already available and establishing procedures for
their use. Wayne Griest, Gary Sega, and Bob Schenley, all of the
Analytical Chemistry Division, are adapting analytical methods
already approved by regulatory agencies to the characterization of
mixed wastes and radioactive environmental samples.
BIOREMEDIATION
A number of hard-to-degrade volatile organic compounds, such as
TCE, have been identified as groundwater and soil contaminants at
DOE sites. These contaminants are of particular concern not only
because of their potential toxicity but also because of their
movement through soils as vapors and in water. New technologies are
needed to remove these contaminants from groundwater and soil and
to safely dispose of them.
For example, the popular method of air stripping results either in
the discharge of TCE to the atmosphere or its capture on activated
carbon, which itself must then be disposed of. In either case, the
TCE is not actually destroyed. A more viable solution seems to be
bioremediation, which is based on the use of organisms to destroy
the contaminant at the site, thus avoiding the risks to worker
safety of handling, transporting, treating, or storing contaminated
residuals.
Two types of contaminants, perchloroethylene (PCE) and PCB, are
effectively nondegradable under aerobic (oxygen-rich) conditions,
but they may be broken down into harmless substances in an
anaerobic (oxygen-free) environment. At least two OTD projects at
ORNL are focused on developing techniques to break down these
chemicals in anaerobic environments. For instance, Terry Donaldson,
Thomas Klasson, and Betty Evans, all of the Chemical Technology
Division, are working to identify and cultivate naturally occurring
anaerobic bacteria that break down PCB molecules by eating and
digesting them (see the article on "New Waste Technologies" in this
issue). Likewise, Steve Herbes and Mike Morissey, both of the
Environmental Sciences Division, are exploring methods to assist
cleanup at the Savannah River Site by anaerobically degrading PCE
and other organic compounds resistant to biological treatment using
existing commercial processes.
Because bioremediation approaches that exploit existing bacteria or
green plants are more socially acceptable than using engineered
microbes, Barbara Walton and Nelson Edwards, both of the
Environmental Sciences Division, are studying the effects of
vegetation on the bioremediation of soils contaminated with TCE and
PCE. In particular, they will determine whether certain plant
species and fertilizers speed up the rates at which TCE and PCE
decompose in soil. Meanwhile, Tony Palumbo of the same division is
coordinating a soil bioremediation team including scientists from
both the University of Tennessee and the University of Minnesota.
They are using innovative methods of monitoring microbial activity
in the soil to measure the effectiveness of bioremediation of TCE-
and PCE-contaminated soil and water deep underground at the
Savannah River Site.
TREATABILITY
Waste retrieval and waste processing currently constitute the
largest segment of the mission of DOE's Office of Environmental
Restoration and Waste Management. Current technologies for treating
contaminated materials to eliminate their toxicity or removing them
from sites and processing them into a suitable form for shipping or
disposal are often inadequate and expensive. In situ vitrification
is one promising technology that instantly destroys many hazardous
components and immobilizes the remainder by trapping them in a
block of glass or slag with minimal personnel exposure. Gary Jacobs
and Brian Spalding, both of the Environmental Sciences Division,
successfully demonstrated this technique on a trench containing
radioactive materials.
A Chemical Technology Division team consisting of Lloyd Youngblood,
Jr., Zane Egan, Klasson, and Donaldson is adapting previously
developed techniques for the chemical destruction of
PCB-contaminated cooling oils and electrical transformer oils to
the treatment of DOE's mixed wastes. Youngblood is also addressing
the concern about the integrity of aging tanks containing mixed
wastes by trying to determine the best method for removing the
sludge from these tanks before they begin to leak.
Mixed wastes offer plenty of tough problems for researchers to
solve. For instance, many aqueous mixed waste streams contain
concentrations of nitrate that exceed drinking water standards. Al
Mattus of the Chemical Technology Division is searching for ways to
chemically reduce the nitrates contained in these mixed waste
streams, producing gaseous ammonia and achieving acceptable nitrate
levels. At the same time, Chet Francis of the Environmental
Sciences Division is hot on the trail of a method for selectively
removing uranium from soils containing high concentrations of silt
or clay. Selectively removing the uranium would be much less costly
than transporting, storing, and monitoring of tons of contaminated
earth.
ROBOTICS
In the movies, robots are literally able to "boldly go where no one
has gone before" and save human adventurers from risking life and
limb. Real-life robots are being developed at ORNL and elsewhere to
help reduce or eliminate the risks of exposing personnel to
radioactive or hazardous wastes. Researchers are applying the
principles of robotics to develop servomechanical devices that
incorporate sensors, computer control, and human-machine interfaces
for efficient remote operations under hazardous conditions and for
improvements in productivity. Typically, a robot possesses
sufficient autonomous control capability to perform many of its
functions automatically, but more difficult tasks are supervised
and guided by a human operator who is remotely located--out of
harm's way.
ORNL researchers are focusing on developing a practical robotics
technology to reduce the hazards and costs of cleaning up DOE
sites. The work is being carried out by a research team headed by
Bill Hamel, who also serves as one of the National Robotics Program
coordinators. This team forms an important part of the Robotics
Technology Development Program in OTD. This national robotics
effort is addressing needs at many DOE laboratories and weapons and
materials production sites.
The ORNL team seeks to develop robotic technology for applications
involving underground storage tanks, buried wastes, waste
minimization, contaminant analysis automation, waste facility
operations, and decontamination and decommissioning associated with
DOE facilities.
Research efforts in the characterization and remediation of
underground storage tanks are led by Barry Burks of ORNL's Robotics
and Process Systems Division. Recently, a team led by Burks
achieved tremendous success in applying computer-based laser
imaging techniques to mapping the surface topology of
radon-emitting uranium ore residue stored in silos at what used to
be the Fernald Feed Materials Production Center in Ohio. The
accuracy of the surface maps has enabled workers to precisely apply
a foot-thick contaminant barrier of low-permeability clay over the
waste to reduce radon emissions, saving DOE millions of dollars in
remedial action costs (see the article on "New Waste Technologies
in this issue).
ORNL's efforts in remote characterization of buried waste sites are
being led by Brad Richardson and Mark Noakes, both of the Robotics
and Process Systems Division. Previous collaborative work with the
U.S. Army is now being extended toward development of a special
low-ferromagnetic signature vehicle that will significantly improve
the performance of subsurface mapping sensors, and a new ORNL-Army
collaboration is seeking to adapt a military backhoe to remote
excavation of buried waste trenches and contaminated soils.
Members of Hamel's team are working on robotics projects with
researchers at other DOE sites who are supported by the Robotics
Technology Development Program. These collaborations are expected
to result in significant progress in applying robotics and remote
technology to the cleanup of DOE sites.
TECHNOLOGY TRANSFER
The need to make the world a healthier, cleaner, and safer place to
live in has motivated people everywhere to join together to solve
a common problem--cleaning up the environment. Tom Gagnier,
coordinator of the Office of Technology Development environmental
technology transfer efforts at ORNL, plays a key role in this
effort by promoting the sharing of technologies among other federal
agencies, industries, educational facilities, and international
communities to improve efficiency, reduce costs, and save time in
environmental cleanup.
Tom Mayfield of the Office of Technology Transfer of Martin
Marietta Energy Systems, Inc., is already heavily involved in at
least two projects at ORNL that do just that. For instance, ORNL
scientists led by Brenda Faison of the Chemical Technology Division
have identified biosorbents--biological tissue that will bind
metal, removing it from solution--that significantly reduce levels
of uranium, strontium, cesium, lead, silver, iron, cadmium, and
copper in contaminated process fluids. The team is now putting
together a cooperative research and development agreement (CRADA)
with a U.S. firm to develop biosorbent technology for remediation
of 14 German sites where uranium mining and milling operations were
carried out from 1949 until they were closed in 1990. The
technology employed may also be customized for use at other sites,
including those in the United States.
The technical exchange goes both ways. ORNL has entered into a
collaborative agreement with a laboratory in Germany and several
other DOE facilities in which ORNL personnel led by Robert Siegrist
will have the opportunity to study unique technologies developed at
the University of Karlsruhe in Germany, including a groundwater
well system used to manipulate and treat contaminated soil and
groundwater and an in situ biotechnology treatment system. In
addition, the parties involved will study other approaches and
technologies that have potential applications in both
countries.Integration
Somehow, all of these diverse activities have to be brought
together. To make sure that important information does not fall
through the cracks, the ORNL team must interact not only with our
counterparts at the other Energy Systems sites but also with our
colleagues throughout the DOE complex. In addition, someone must
make sure that the research being conducted at ORNL is actually
implemented in the field. These tasks all fall under the
jurisdiction of the Office of Waste Research and Development
Programs, directed by Tony Malinauskas with the aid of Norm
Cutshall and Jan Pruett. The goal of this office is to ensure that
ORNL becomes a valuable source of model technologies for improving
the economics and effectiveness of DOE's waste management and
environmental restoration efforts.
BIOGRAPHICAL SKETCH
Diedre Falter is completing a year-long assignment in the Waste
Research and Development Program Office at ORNL, where one of her
first assignments was to write this article for the Review. After
working as a laboratory supervisor at Transducer Research, Inc., of
Naperville, Illinois, and receiving her B.S. degree in engineering
physics from Murray State University in 1986, she joined ORNL's
Instrumentation and Controls (I&C) Division. There she helped
develop detectors for use in radiation detection, genome
sequencing, radiometry, and high-temperature thermometry. She was
project leader of a team that received a 1990 Martin Marietta
Energy Systems Technical Achievement Award for development of a
microminiature infrared transmitter. As a result of that work, she
was awarded her first patent. She has spent several years
coordinating precollege (K-12) activities and internships for the
I&C Division. Her husband is an engineer in the I&C Division.
Diedre Falter
(keywords: waste management, hazardous waste)
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Date Posted: 2/7/94 (ktb)