Environmental Protection: Research and Development of Plasma Arc Technology Used to Treat Hazardous Waste

Published by the Government Accountability Office on 1999-02-16.

Below is a raw (and likely hideous) rendition of the original report. (PDF)

      United States
GAO   General Accounting Office
      Washington, D.C. 20548

      National Security and
      International Affairs Division


      February 16, 1999

      The Honorable Larry E. Craig
      United States Senate

      Subject: Environmental Protection: Research and Development of Plasma Arc
               Technology Used to Treat Hazardous Waste

      Dear Senator Craig:

      As you requested, we are providing information on three selected research and
      development initiatives using a technology called plasma arc’ to treat waste
      materials. As agreed with your office, our objective was to compare
      characteristics of the largest of the Department of Energy initiatives and both
      Department of the Navy shore and ship initiatives.


      The high heat of a plasma arc causes fundamental changes in materials exposed
      to it. For example, some materials become a molten mass, which hardens into
      a rock-like substance, while others are vaporized. Such heat was first used in
      metal processing about 100 years ago. Beginning in the 1980s the Departments
      of Energy and Defense began research for treating hazardous waste using heat
      from a plasma arc torch designed to reduce some hazardous compounds to
      benign basic elements. Some elements might remain hazardous but could be
      trapped in a hardened rock form. Gases and particles that are given off during
      the process may require further treatment.


      In summary, the three initiatives use a similar source of heat to treat waste, but
      have different goals and equipment designs. Although the initiatives’ goals and

      ‘Plasma arc technology involves the conversion of electrical energy into an
      intensely hot gas of several thousand degrees centigrade. Plasma is the term
      given to the condition of the gas at the highest temperature in the arc. The arc
      is like a sustained lightning discharge and does not require oxygen in the way
      that a fire does.
      1                                           GAOMXAD-99-51R Environmental Protection
designs for systems’ inputs, furnaces, and outputs differed, the contractor
responsible for the Energy and Navy shore initiatives incorporated technology
from prior Energy research into the Navy shore initiative. Table 1 shows major
characteristics of the three initiatives. See enclosure I for information on the
plasma arc process in hazardous waste treatment and details on the Energy and
Navy initiatives.

Table 1: Characteristics of Selected Energy and Navy Initiatives
 Characteristic          Energy             Navy shore              Navy   ship

 Phase               Research            Development            Research
 Goal                Obtain research     Treat hazardous,       Treat
                     data, including     nonradioactive         nonhazardous
                     data on             waste on shore         waste on ships
                     radioactive waste
 Input               Individual 55       Up to 5-gallon         Feed from other
                     gallon drums        containers             waste systems
  Furnace            6.5-foot square     S-foot diameter        3-foot by l-foot
                     fured-hearth with   rotating-hearth with   diameter hearths
                     a movable 1.Z       a movable .75-         with two f=ed 175
                     megawatt torch      megawatt torch         kilowatt torches
  Output system      Treatment for       Treatment for wider    Treatment for
                     mostly benign       range of gases and     mostly benign
                     gases and           particles using a      gases and particles
                     particles           second plasma

Note: Defense and Energy waste categories include nonhazardous materials
such as food, paper, and glass; hazardous material such as paint, solvents, and
metals; radioactive elements such as plutonium and materials contaminated by
radioactivity; and mixed waste consisting of commingled hazardous and
radioactive waste.


We obtained information on plasma arc research and development initiatives at
the headquarters of the Departments of Defense (Washington, D.C.) and Energy
(Germantown, Maryland) and at pertinent Defense, Energy, and government
contractors’ locations. To compare Energy and Navy initiatives, we included
the highest-cost Energy initiative and both the Navy shore development and the
Navy ship research initiatives cited in the request. We focused on the goals of
the initiatives and designs for equipment inputs, furnaces, and outputs. The
primary Department of Defense (DOD) offices were the Directorate of Defense

 2                                             GAO/N3AD-99-51R Environmental Protection

Research and Engineering and the program offices for the Environmental
Security Technology Certification Program and the Strategic Environmental
Research and Development Program.

We also talked with staff from the offices of the Naval Sea Systems Command,
Naval Facilities Engineering Command, and Naval Research.

We performed our work from June through December 1998 in accordance with
generally accepted government auditing standards.


We requested comments on a draft of this product from the Secretaries of
Defense and Energy or their designees. In oral comments, a DOD official in the
office of the Directorate of Defense Research and Engineering stated that DOD
concurred with our presentation of DOD information in the draft. DOD also
provided technical comments, which we have incorporated as appropriate. In
written comments, the Energy Department said that it had no issues with our
review. Enclosure II contains Energy’s written comments.

We are providing copies of this report to the Departments of Defense, the Navy,
and Energy. We will make copies available to other interested parties upon
request. If you have questions, please contact Charles Patton, Jr., Associate
Director, on (202) 512-8412 or Uldis Adamsons, Assistant Director, on
(202) 5124289. Other major contributors to this report were Bruce Brown,
Ed Soniat, Johnnie Phillips, and Peter tiaut.

Sincerely yours,

David R. Warren, Director
Defense Management Issues

Enclosures - 2

                                          GAOLKXAD-99-51REnvironmental Protection
ENCLOSURE I                                                                   ENCLOSURE I


Hazardous waste is present in numerous materials, including building materials, soiled
rags, solvents, paint, dirt, oil, lubricants, batteries, blast media, electroplating sludge,
incinerator ash, and adhesives, that present risks to human health and the environment.
Radioactive materials, such as plutonium or uranium, also present such risks. Research
has been funded using the plasma arc technology for treating one or a number of these
materials (including surrogates for radioactive materials).

The initiatives that we compared involve the treatment of hazardous waste in a furnace
heated by a plasma torch.’ The maximum heat is within a relatively small area
surrounding the arc, and furnace designs may move the hearth or the torch. Some
hazardous compounds may be carried in gases produced when the material is vaporized,
necessitating further treatment of the gases by filtering or other treatments.

Research initiatives for the treatment of hazardous waste have involved furnaces with
hearths ranging from less than 2 feet in diameter to 8 feet in diameter and electrical
power levels from 150 kilowatts to over 1 megawatt. They have involved continuous or
batch feed systems for small items or large 55-gallon drums of material. Research has
been conducted with fixed-hearth furnaces as well as with hearths that rotate.2 Gas
treatment has ranged from simple systems in the case of benign or less hazardous gases
to complex systems for wider ranges of gases or radioactive material.

Among various plasma arc research initiatives by Energy and Defense over the past 10
years for hazardous waste, only two in the United States have reached the
implementation stage. The two are the Navy shore project in&d&l in our comparison
and an asbestos destruction project that is ongoing at Port Clinton, Ohio. The others,
including the Navy ship project, are still in the research stage.

The following sections describe the largest of the Department of Energy plasma arc
initiatives, and both the Navy shore and ship initiatives.

‘Other plasma arc research involves treating contamination beneath the earth’s surface.
‘In addition to Energy’s fixed-hearth initiative which we compared to the Navy’s shore
initiative, the contractor also developed a rotating hearth furnace for Energy. The
contractor used the rotating hearth design for the Navy shore initiative.

4                                                      GAONXAD-99-51R Environmental Protection
ENCLOSURE I                                                                  ENCLOSURE I


The Energy Department’s research initiative involved a fixed-hearth furnace located at a
contractor site in Ukiah, California, and small-scale testing at other locations. The goal of
the projects was to gather research data on the treatment of radioactive waste,
nonradioactive hazardous waste, and mixtures of the two. The research involved limited
types of waste, primarily contaminated soil and construction material. Although the
research focused on radioactive waste, the experiments used surrogates to simulate the
radioactive materials. The initiatives began in 1991, became operational in 1996, and were
last funded in 1997. The Energy initiative’s total cost to date is $35 million.

The equipment input design provides for the feeding of 55-gallon drums of material into
the fixed-hearth furnace. The feeder is bolted shut and may be unbolted to receive the
next drum of material after the first moves out of the feeder. The hearth remains
stationary, while the torch is moved to apply heat uniformly. The hearth is equipped with
a tilt and pour system that can separate recoverable metals from other molten material.
The output system is designed to filter mostly benign gases that resulted from the


The Navy’s shore initiative involves constructing a rotating-hearth furnace system at the
Norfolk Naval Base to destroy mixed solid and liquid hazardous materials and to obtain
operational data to determine the cost-effectiveness of the process. The hazardous
material will come from the Norfolk Naval Base and from ships returning to the base.
The initiative began in 1995, and the Navy plans to complete the facility by 2000. Thus
far, $5.5 million has been obligated for the initiative. Another $4 million is planned before
facility operations begin.

The input design provides for the continuous feed of mixed liquid and solid hazardous
waste. Up to 5-gallon containers of hazardous material can be manually loaded into a
shredder that feeds material into the hearth by means of a screw feed mechanism, while
liquids can be poured into a separate opening. The furnace hearth rotates during the
treatment of the hazardous material, while the torch is moved to apply heat. The output
system includes a chamber with a second plasma torch that is intended to treat a wide
range of gases and particles generated in the initial treatment phase. In addition to the
second torch, the system includes filters to remove remaining hazardous particles carried
by the gases.

5                                                    GAONSAD-99-51R Environmental Protection
ENCLOSURE I                                                                 ENCLOSURE I

The Navy’s ship initiative is to develop a compact unit to treat and reduce the volwne of
solid nonhazardous waste on ships. Development of the unit is projected to be completed
by 2004, and the unit is planned for installation on a ship by 2005. The project began in
1995, and $3.6 million has been obligated to date. Although the initiative was not funded
during fiscal year 1998, funding is anticipated for fiscal 1999. An additional $13.2 million
is planned for fiscal years 1999 to 2001, and no estimate has been made for costs for 2002
and beyond.

The planned input design provides for separate continuous feeders and separate hearths-
one for organic solids such as food and paper and one for inorganic solids such as glass
or metal. The Navy plans to use existing shredders and pulpers to process such material
before heat treatment. Although the ship system would require substantial space, the
hearths are smaller than Energy and Navy shore systems and the Navy reports that its
design is on the order of one-tenth the weight and one-third the volume of conventional
marine incinerators of the same throughput. The output system is to include a second
chamber, where gases and particles generated after the initial treatment of nonhazardous
materials would be treated.

 6                                                    GAODEXAD-99-51REhironmental   Protection
ENCLOSURE II                                                                                     ENCLOSURE II


                                      Department       of Energy
                                          Washington, DC 20585

                                                FEE       4 1998

           Mr. David R Warren, Director
           Defense Management Issues
           U.S. General Accounting Office
           Washington, D.C. 20548

           Dear Mr. Warren:

           We have reviewed the January 1999 draft General Accounting Office (GAO) report,
           “‘ENVIRONMENTAL PROTECTION: Research and Development of PlasmaArc
           Technology Used to Treat Hazardous Waste,” in which Department of Energy
           (DOE) work was used for comparative information during GAO’s review of research
           involving plasma arc technology in the Department of Defense and of high-heat
           systems by the Navy.

           We have no issueswith the review results described in the drafI report, which points
           out the differences in goals and equipment designs of the three initiatives. The report
           also points out that technology from DOE research was leveraged in the Navy
           development project.

           If you need additional information, please contact me or Lana Nichols of my stafFon


                                                 Gerald G. Royd           ’
                                                 Acting Deputy Assistant Secretary
                                                  for Science and Technology
                                                 Office of Environmental Management


7                                                                GAO/NSIAD-99-&R         Environmental   Protection
Ordering     Information

The first copy of each GAO report and testimony is free.
Additional   copies are $2 each. Orders should be sent to the
following address, accompanied by a check or money order
made out to the Superintendent     of Documents, when
necessary. VISA and Mastercard      credit cards are accepted, also.
Orders for 100 or more copies to be mailed to a single address
are discounted 25 percent.

Orders by mail:

U.S. General Accounting    Office
P.O. Box 37050
Washington, DC 20013

or visit:

Room 1100
700 4th St. NW (corner of 4th and G Sts. NW)
U.S. General Accounting Office
Washington, DC

Orders may also be placed by calling (202) 512-6000
or by using fax number (202) 512-6061, or TDD (202)       512-2537.

Each day, GAO issues a list of newly available reports and
testimony.   To receive facsimile copies of the daily list or any
list from the past 30 days, please callf202)   512-6000 using a
touchtone phone. A recorded menu will provide information         on
how to obtain these lists.

For information on how to access GAO reports on the INTERNET,
send an e-mail message with “info” in the body to:


or visit    GAO’s World Wide Web Home Page at:

United States                              Bulk Rate
General Accounting    Office         Postage & Fees Paid
Washington,   D.C. 20548-0001                 GAO
                                       Permit No. GlOO
Official   Business
Penalty    for Private   Use $300

Address    Correction    Requested