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Office of Science and Office of Environmental Management; Office of Science Financial Assistance Program Notice 01-16: Environmental Management Science Program: Basic Science Research Related to High Level Radioactive Waste

Note: EPA no longer updates this information, but it may be useful as a reference or resource.


 [Federal Register: January 16, 2001 (Volume 66, Number 10)]
[Notices]
[Page 3564-3571]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16ja01-44]

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DEPARTMENT OF ENERGY


Office of Science and Office of Environmental Management; Office
of Science Financial Assistance Program Notice 01-16: Environmental
Management Science Program: Basic Science Research Related to High
Level Radioactive Waste

AGENCY: Office of Science and Office of Environmental Management,
Department of Energy (DOE).

ACTION: Notice inviting grant applications.

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SUMMARY: The Offices of Science (SC) and Environmental Management (EM),
U.S. Department of Energy (DOE), hereby announce their interest in
receiving grant applications for performance of innovative, fundamental
research to support specific activities for high level radioactive
waste; which include, but are not limited to, characterization and
safety, retrieval of tank waste and tank closure, pretreatment, and
waste immobilization and disposal.

DATES: The deadline for receipt of formal applications is 4:30 p.m.
E.S.T., March 8, 2001, in order to be accepted for merit review and to
permit timely consideration for award in Fiscal Year 2001.

ADDRESSES: Formal applications referencing Program Notice 01-16 should
be sent to: U.S. Department of Energy, Office of Science, Grants and
Contracts Division, SC-64, 19901 Germantown Road, Germantown, MD 20874-
1290, ATTN: Program Notice 01-16. This address must be used when
submitting applications by U.S. Postal Service Express, commercial mail
delivery service, or when hand carried by the applicant.

FOR FURTHER INFORMATION CONTACT: Dr. Roland F. Hirsch, SC-73, Mail Stop
F-237, Medical Sciences Division, Office of Biological and
Environmental Research, Office of Science, U.S. Department of Energy,
19901 Germantown Road, Germantown, MD 20874-1290, telephone: (301) 903-
9009, fax: (301) 903-0567, E-mail: roland.hirsch@science.doe.gov, or
Mr. Mark Gilbertson, Office of Basic and Applied Research, Office of
Science and Technology, Office of Environmental Management, 1000
Independence Avenue, SW., Washington, DC 20585, telephone: (202) 586-
7150, E-mail: Mark.Gilbertson@em.doe.gov. The full text of Program
Notice 01-16 is available via the World Wide Web using the following
web site address: http://www.sc.doe.gov/production/grants/grants.html.

SUPPLEMENTARY INFORMATION: The Office of Environmental Management, in
partnership with the Office of Science, sponsors the Environmental
Management Science Program (EMSP) to fulfill DOE's continuing
commitment to the clean-up of DOE's environmental legacy. The program
was initiated in Fiscal Year 1996. Ideas for basic scientific research
are solicited which promote the broad national interest of a better
understanding of the fundamental characteristics of highly radioactive
chemical wastes and their effects on the environment.
    The DOE Environmental Management program currently has ongoing
applied research and engineering efforts under its Technology
Development Program. These efforts must be supplemented with basic
research to address long-term technical issues crucial to the EM
mission. Basic research can also provide EM with near-term fundamental
data that may be critical to the advancement of technologies that are
under development but not yet at full scale nor implemented. Proposed
basic research under this Notice should contribute to environmental
management activities that would decrease risk for the public and
workers, provide opportunities for major cost reductions, reduce time
required to achieve EM's mission goals, and, in general, should address
problems that are considered intractable without new knowledge. This
program is designed to inspire ``breakthroughs'' in areas critical to
the EM mission through basic research and will be managed in
partnership with SC. The Office of Science's well-established
procedures, as set forth in the Office of Science Merit Review System,
available on the World Wide Web at: http://www.science.doe.gov/
production/grants/merit.html will be used for merit review of
applications submitted in response to this Notice. Subsequent to the
formal scientific merit review, applications that are judged to be
scientifically meritorious, will be evaluated by DOE for relevance to
the objectives of the Environmental Management Science Program and for
relevance to the technical focus of this solicitation (see ``Relevance
to Mission'' section below). Additional information can be obtained at
http://emsp.em.doe.gov. Additional Notices for the Environmental
Management Science Program may be issued during Fiscal Year 2001
covering other areas within the scope of the EM program.

Purpose

    The purpose of the EMSP is to foster basic research that will
contribute to successful completion of DOE's mission to clean-up the
environmental contamination across the DOE complex.
    The objectives of the Environmental Management Science Program are
to:
    1. Provide scientific knowledge that will revolutionize
technologies and clean-up approaches to significantly reduce future
costs, schedules, and risks;
    2. ``Bridge the gap'' between broad fundamental research that has
wide-ranging applicability such as that performed in DOE's Office of
Science and needs-driven applied technology development that is
conducted in EM's Office of Science and Technology; and
    3. Focus the Nation's science infrastructure on critical DOE
environmental management problems.

Representative Research Areas

    Basic research is solicited in areas of science with the potential
for addressing problems in the clean-up of high level radioactive
waste. Relevant scientific disciplines include, but are not limited to,
chemistry (including actinide chemistry, analytical chemistry and
instrumentation, interfacial chemistry, and separation science),
computer and mathematical sciences, engineering science (chemical and
process engineering), materials science (degradation mechanisms,
modeling, corrosion, non-destructive evaluation, sensing of waste
hosts, canisters), and physics (fluid flow, aqueous-ionic solid
interfacial properties underlying rheological processes).

Project Renewals

    Lead Principal Investigators of record for Projects funded under
Office of Science Notice 98-08, Environmental Management Science
Program: Research Related to High Level Radioactive Waste, are eligible
to submit renewal applications under this solicitation.

Program Funding

    It is anticipated that up to a total of $4,000,000 of Fiscal Year
2001, Federal funds will be available for new Environmental Management
Science Program awards resulting from this Announcement. Multiple-year
funding of awards is anticipated, contingent upon the availability of
appropriated funds. Award sizes are expected to be

[[Page 3565]]

on the order of $100,000-$300,000 per year for total project costs for
a typical three-year award. Collaborative projects involving several
research groups or more than one institution may receive larger awards
if merited. The program will be competitive and offered to
investigators in universities or other institutions of higher
education, other non-profit or for-profit organizations, non-Federal
agencies or entities, or unaffiliated individuals. DOE reserves the
right to fund in whole or part any or none of the applications received
in response to this Notice. A parallel announcement with a similar
potential total amount of funds will be issued to DOE Federally Funded
Research and Development Centers (FFRDCs) and may be accessed on the
World Wide Web at http://www.science.doe.gov/production/grants/
LAB01_16.html. All projects will be evaluated using the same criteria,
regardless of the submitting institution.

Collaboration and Training

    Applicants to the EMSP are strongly encouraged to collaborate with
researchers in other institutions, such as universities, industry, non-
profit organizations, federal laboratories and Federally Funded
Research and Development Centers (FFRDCs), including the DOE National
Laboratories, where appropriate, and to incorporate cost sharing and/or
consortia wherever feasible. Refer to http://www.sc.doe.gov/production/
grants/Colab.html for details.
    Applicants are also encouraged to provide training opportunities,
including student involvement, in applications submitted to the
program.

Applications

    Applicants are expected to use the following format in addition to
following instructions in the Office of Science Financial Assistance
Program Application Guide. Applications must be written in English,
with all budgets in U.S. dollars.
     SC Face Page (DOE F 4650.2 (10-91))
     Application classification sheet (a plain sheet of paper
with one selection from the list of scientific fields listed in the
Application Categories Section)
     Table of Contents
     Project Abstract (no more than one page)
     Budgets for each year and a summary budget page for the
entire project period (using DOE F 4620.1)
     Budget Explanation. Applicants are requested to include in
the travel budget for each year funds to attend the annual National
Environmental Management Science Program Workshop, and also for one or
more extended (one week or more) visits to a clean-up site by either
the Principal Investigator or a senior staff member or collaborator
     Budgets and Budget explanation for each collaborative
subproject, if any
     Project Narrative (recommended length is no more than 20
pages; multi-investigator collaborative projects may use more pages if
necessary up to a total of 40 pages)
     Goals
     Significance of Project to the EM Mission
     Background
     Research Plan
     Preliminary Studies (if applicable)
     Research Design and Methodologies
     Literature Cited
     Collaborative Arrangements (if applicable)
     Biographical Sketches (limit 2 pages per senior
investigator)
     Description of Facilities and Resources
     Current and Pending Support for each senior investigator

Application Categories

    In order to properly classify each application for evaluation and
review, the application must indicate the proposer's preferred
scientific research field, selected from the following list.

Field of Scientific Research

1. Actinide Chemistry
2. Analytical Chemistry and Instrumentation
3. Separations Chemistry
4. Engineering Sciences
5. Geochemistry
6. Geophysics
7. Hydrogeology
8. Interfacial Chemistry
9. Materials Science
10. Other

Application Evaluation and Selection

Scientific Merit

    The program will support the most scientifically meritorious and
relevant work, regardless of the institution. Formal applications will
be subjected to scientific merit review (peer review) and will be
evaluated against the following evaluation criteria listed in
descending order of importance as codified at 10 CFR 605.10(d):

1. Scientific and/or Technical Merit of the Project
2. Appropriateness of the Proposed Method or Approach
3. Competency of Applicant's Personnel and Adequacy of Proposed
Resources
4. Reasonableness and Appropriateness of the Proposed Budget.

    The evaluation will include program policy factors such as the
relevance of the proposed research to the terms of the announcement and
the Department's programmatic needs. DOE shall also consider, as part
of the evaluation, program policy factors such as an appropriate
balance among the program areas, including research already in
progress. External peer reviewers are selected with regard to both
their scientific expertise and the absence of conflict-of-interest
issues. Non-federal reviewers may be used, and submission of an
application constitutes agreement that this is acceptable to the
investigator(s) and the submitting institution.

Relevance to Mission

    Subsequent to the formal scientific merit review, applications
which are judged to be scientifically meritorious will be evaluated by
DOE for relevance to the objectives of the Environmental Management
Science Program and for relevance to the technical focus of the
solicitation (see section below).
    ``Researchers are encouraged to demonstrate a linkage between their
research projects and significant clean up related problems at DOE
sites. Researchers could establish this linkage in a variety of ways--
for example, by elucidating the scientific problems to be addressed by
the proposed research and explaining how the solution of these problems
could improve remediation capabilities.'' (National Research Council,
Board on Radioactive Waste Management, December 1998)
    DOE shall also consider, as part of the evaluation, program policy
factors such as an appropriate balance among the program areas,
including research already in progress. Research funded in the
Environmental Management Science Program in Fiscal Year 1996 through
Fiscal Year 2001, can be viewed at  http://www.doe.gov/em52/science-
grants.html.

Application Guide and Forms

    Information about the development, submission of applications,
eligibility, limitations, evaluation, the selection process, and other
policies and procedures may be found in 10 CFR Part 605, and in the
Application Guide for the Office of Science Financial Assistance
Program. Electronic access to the Guide and required forms is available
via the World Wide Web at: http://www.sc.doe.gov/production/grants/
grants.html. DOE is under no obligation to pay for any costs associated
with the preparation or submission of applications if an award is not
made.

[[Page 3566]]

Technical Focus of the Solicitation

    This research announcement has been developed for Fiscal Year 2001,
along with a development process for a long-term program within
Environmental Management, with the objective of providing continuity in
scientific knowledge that will revolutionize technologies and clean-up
approaches for solving DOE's most complex environmental problems. A
general description of the high level waste problem can be found in the
Background section of this Notice. Detailed descriptions of the
specific technical (science) needs and areas of emphasis associated
with this problem area are available on the Tanks Focus Area web site
at http://www.pnl.gov/tfa.

Long Term Research Agenda for High Level Radioactive Waste

    The National Academy of Science's National Research Council was
requested to assist the DOE in developing a long-range science plan for
the management of radioactive high-level waste at DOE sites. The
Committee empanelled to study that issue determined that some High
Level Waste related problems will require further research and
development to minimize risk and program cost and to improve the
effectiveness of clean-up. Their recommendations in four topic areas
are the focus of this solicitation and are described below. More
detailed descriptions of the specific technical (science) needs in
these four topic areas are available on the Tanks Focus Area web site
at: http://www.pnl.gov/tfa.

1. Long-Term Issues Related to Tank Closure

    An example of research activities to address this issue is
innovative methods for in situ characterization of the High Level Waste
remaining in the tanks after retrieval to facilitate tank closure.

2. High-Efficiency, High-Throughput Separation Methods That Would
Reduce High-Level Waste Program Costs Over the Next Few Decades
Including

    a. High-efficiency separation, and
    b. Minimization of the volume of secondary waste.
    Applications on separation sciences addressing these two areas are
encouraged. The projects should address all types of separations:
solids from liquids from gases, High Level Waste from low level waste,
and radionuclides from organic compounds.
    An example of a project addressing separation issues could be
research on processes that remove multiple radionuclides in a single
step.

1. Robust, High Loading, Immobilization Methods and Materials That
Could Provide Enhancements or Alternatives to Current Immobilization
Strategies including

    a. Alternatives to borosilicate glasses using slurry-fed electric
(Joule) melter as an immobilization matrix, and
    b. Alternatives melter techniques.
    As an example, a research project might study alternative
immobilization matrixes, tailored to either High Level Waste or low
level waste, such as cement or crystalline ceramics. Applications to
conduct research on alternative melter techniques that would increase
the processes available to address different waste streams leading to
more efficient immobilization results are encouraged.

4. Innovative Methods To Achieve Real-Time, and, When Practical, in
situ Characterization Data for High Level Waste and Process Streams
That Would Be Useful for all Phases of the Waste Management Program
With Emphasis on

    a. Characterization of the waste after retrieval, for instance in
process streams and melter feeds.
    Applications aimed at developing techniques to achieve shorter
turn-around times for the analytical results, which in turn would allow
better control of High Level Waste processing are encouraged. An
example of such a project is research on fiber-optical interrogation to
characterize process streams.
    Attendant to paragraph 1. above, there was another area highlighted
by the National Research Council regarding long-term issues related to
characterization of surrounding areas including radionuclide and metal
contamination problems in the near-field around the tanks, and
engineered surface or subsurface barriers. These topics will be a
matter of a future solicitation for research regarding subsurface
contamination.

Specific High Level Waste Science Needs

    Detailed information on the specific high level waste technical
(science) needs within the general topic areas of this solicitation are
available from the Tanks Focus Area Home Page at: http://www.pnl.gov/
tfa. Relevance to mission reviews will consider responsiveness to the
four topic areas of this solicitation and these corresponding specific
technical needs. Additional general science research needs and
information is also available at: http://emsp.em.doe.gov/
focus_area.htm.
    The aforementioned areas of emphasis do not preclude, and DOE
strongly encourages, any innovative or creative ideas contributing to
solving EM High Level Waste challenges mentioned throughout this
Notice.
    For further information regarding the Tanks Focus Area please
contact: Mr. Theodore P. Pietrok, Tanks Focus Area, U.S. Department of
Energy, P.O. Box 550, Mail Stop K8-50, Richland, WA 99352, telephone:
(509) 372-4546, Fax: (509) 372-4037, E-mail: Theodore_P_Pietrok@rl.gov.

Background

    Environmental Management (EM) is responsible for the development,
testing, evaluation, and deployment of remediation technologies to
characterize, retrieve, treat, concentrate, and dispose of radioactive
waste stored in the underground storage tanks at DOE facilities and
ultimately stabilize and close the tanks. The goal is to provide safe
and cost-effective solutions that are acceptable to both the public and
regulators.
    Radioactive high level waste is stored at four sites across the DOE
complex:

1. Hanford Site near Richland, Washington
2. Savannah River Site (SRS) near Aiken, South Carolina
3. Idaho National Engineering and Environmental Laboratory (INEEL) near
Idaho Falls, Idaho
4. West Valley Demonstration Project (WVDP) in West Valley, New York

    At these sites, 282 underground storage tanks have been used to
process and store radioactive and chemical mixed waste generated from
weapon materials production and manufacturing. Collectively, these
tanks hold approximately 90 million gallons of high-level and low-level
radioactive liquid waste in sludge, saltcake, and as supernate and
vapor.
    Tanks vary in design from carbon or stainless steel to concrete,
and concrete with carbon steel liners. Two types of storage tanks are
most prevalent: the single-shell and double-shell concrete tanks with
carbon steel liners. Capacities vary from 5,000 gallons (19m3) to
1,300,000 gallons (4920m3). Most tanks are covered with a layer of soil
ranging from approximately 3 to 10 feet thick.
    Most of the waste is alkaline and contains a diverse mixture of
chemical constituents including nitrate and nitrite salts
(approximately half of the total waste), hydrated metal oxides,
phosphate precipitates, and ferrocyanides. The 784 MCi of radionuclides
are distributed primarily

[[Page 3567]]

among the transuranic (TRU) elements and fission products, specifically
strontium-90, cesium-137, and their decay products yttrium-90 and
barium-137. In-tank atmospheric conditions vary in severity from near
ambient to temperatures over 93 deg. C. Radiation fields in the tank
void space can be as high as 10,000 rad/h.
    Hanford has 177 tanks that contain approximately 53 million gallons
of hazardous and radioactive waste. There are 149 single-shell tanks
that have exceeded their original design life. Sixty-seven of these
tanks have known or suspected leaks. Due to several changes in the
production processes since the early 1940s, some of the tanks contain
incompatible waste components, generating hydrogen gas and excess heat
that further compromise tank integrity.
    Radioactive waste at SRS consists of 33 million gallons of salt,
salt solution, and sludge stored in 51 double-shell underground storage
tanks, two of which have been closed (emptied of all waste and filled
with grout). Twenty-three tanks are being retired, because they do not
have full secondary containment. Nine tanks have leaked detectable
quantities of waste from the primary tank to secondary containment.
    Unlike the other DOE sites, radioactive waste at INEEL was stored
in acidic conditions in stainless steel tanks rather than alkaline
conditions. The 11 stainless steel tanks at INEEL store approximately
1.2 million gallons of acidic radioactive liquids. Additionally,
approximately 4000 m3 of calcined waste solids are stored in seven
stainless steel bin sets enclosed in massive underground concrete
vaults.
    At the West Valley Demonstration Project nearly all of the original
600,000 gallon of HLW has been retrieved and vitrified. This site is
now in the process of cleaning the storage tanks and preparing for
closure.
    The general process for waste tank remediation involves a number of
critical steps including:
     Safe waste storage.
     Waste characterization.
     Retrieval of tank waste.
     Pretreatment and separation of tank waste.
     Waste immobilization.
     Tank closure, and
     Immobilized waste disposal.
    Tank remediation problems within these critical process steps are
described below. Several process steps are combined for the purpose of
describing related technical issues

Characterization and Safety

    DOE, contractors, and stakeholders have committed to a safe and
efficient remediation of HLW, mixed waste, and hazardous waste stored
in underground tanks across the DOE complex.
    Currently, there are only limited fully developed or deployed in
situ techniques to characterize tank waste. In situ characterization
can eliminate the time delay between sample removal and sample analysis
and aid in guiding the sampling process while decreasing the cost
(approximately $1 million is spent for one tank core extrusion) of
waste analysis. Most importantly, remote analysis eliminates sample
handling and safety concerns due to worker exposure. However, analysis
of extruded tank samples allows a more complete chemical and physical
characterization of the waste when needed. Knowledge of the chemical
and radioactive composition and physical parameters of the waste is
essential to safe and effective tank remediation.
    There are three primary drivers for the development of new chemical
analysis methods to support tank waste remediation: (1) Provide
analyses for which there are currently no reliable existing methods,
(2) replace current methods that require too much time and/or are too
costly, and (3) provide methods that evolve into on-line process
analysis tools for use in waste processing facilities.
    Characterization of the elemental and isotopic chemical
constituents in DOE tank waste is an important function in support of
DOE tank waste operation and remediation functions. Proper waste
characterization enables: safe operation of the tank farms; resolution
of tank safety questions; and development of processes and equipment
for retrieval, pretreatment, and immobilization of tank waste. All of
these operations are dependent on the chemical analysis of tank waste.
    Current techniques of tank waste analysis involve the removal of
core samples from tanks, followed by costly and time consuming wet
analytical laboratory testing. Savings in both cost and time could be
realized in techniques that involve in situ probes for direct analysis
of tank materials.
    Leakage from the single shell tanks at Hanford is among the safety
concerns. As indicated earlier many of the 149 single shell tanks are
known or suspected to leak. This presents a grave problem for retrieval
of waste from these tanks since the baseline method for retrieval is to
sluice thousands of gallons of water into the tank to dissolve and
suspend the waste. HLW waste leakage into the environment can threaten
the ground water. There is a need to develop instrumentation to
determine the location of a leak, measure the amounts of contamination
that may have leaked, and assess the environmental impact.
    Another safety concern is the long-term performance of waste forms.
Performance assessments of radionuclide containment rely primarily on
the geologic barriers (e.g., long travel times in hydrologic systems or
sorption on mineral surfaces). The physical and chemical durability of
the waste form, however, can contribute greatly to the successful
isolation of radionuclides; thus the effects of radiation on physical
properties and chemical durability of waste forms are of great
importance. The changes in chemical and physical properties occur over
relatively long periods of storage, up to a million years, and at
temperatures that range from 100 to 300 degrees Celsius, depending on
waste loading, age of the waste, depth of burial, and the repository-
specific geothermal agent. Thus, a major challenge is to effectively
simulate high-dose radiation effects that will occur over relatively
low-dose rates over long periods of time at elevated temperatures.
Similarly, there is a paramount need for improved understanding and
modeling of the degradation mechanisms and behavior of primary
radioactive waste hosts and/or their containment canisters, corrosion
mechanisms and prevention in aqueous and/or alkali halide containing
environments, and remote sensing and non-destructive evaluation.
    Examples of specific science research challenges include but are
not limited to: basic measurement science and sensor development
required for remote detection of low concentrations of hydrogen inside
tanks and in containers; basic analytical studies needed to develop new
methods for chemical and physical characterization of solid and liquids
in slurries and for development of advanced processing methodologies;
basic instrument development needed to perform in situ radiological
measurements and collect spatially resolved species and concentration
data; basic materials and engineering science needed to develop
radiation hardened instrumentation.

Retrieval of Tank Waste and Tank Closure

    Underground tanks throughout the DOE complex have stored a diverse
accumulation of wastes during the past fifty years of weapons and fuel
production. If these tanks were isolated in a manner that would
preclude the

[[Page 3568]]

escape of radiation into the environment for thousands of years, there
would be no reason to disturb them. However, a number of the storage
tanks are approaching the end of their design life, and 90 tanks have
either leaked or are suspecting of having leaked waste into the soil
and sediments near the tanks.
    Recently, dewatering processes have removed much of the free liquid
from the alkaline waste tanks. The tanks now contain wastes ranging in
consistency from remaining supernate and soft sludge to concrete-like
saltcake. Tanks also contain miscellaneous foreign objects such as
Portland cement, measuring tapes, samarium balls, and in-tank hardware
such as cooling coils and piping. Unlimited sluicing, adding large
quantities of water to suspend solids, is the baseline method for
sludge removal from tanks. This process is not capable of retrieving
all of the material from tanks. Besides dealing with aging tanks and
difficult wastes, retrieval also faces the problem of the tank design
itself. Retrieval tools must be able to enter the tanks, which are
under an average of 10 feet of soil, through small openings called
risers in the tops of the tanks.
    Retrieval of tank waste and tank closure requires tooling and
process alternative enhancements to mixing and mobilizing bulk waste as
well as dislodging and conveying heels. Heel removal is linked to tank
closure. The working tools and removal devices being developed include
suction devices, rubblizing devices, water and air jets, waste
conditioning devices, grit blasting devices, transport and conveyance
devices, cutting and extraction tools, monitoring devices, and various
mechanical devices for recovery or repair of waste dislodging and
conveyance tools.
    The areas directly below the access risers are often disturbed or
contain a significant amount of discarded debris. Therefore, evaluation
of tank waste characteristics by measurements taken at these locations
may not be representative of the properties of the waste in other areas
of the tanks.
    To monitor current conditions and plan for tank remediation, more
information on the tank conditions and their contents is required.
Current methods used at DOE tank sites are limited to positioning
sensors, instruments, and devices to locations directly below access
penetrations or attached to a robotic arm for off-riser positioning.
These systems can only deploy one type of sensor, requiring multiple
systems to perform more than one function in the tank.
    Currently, decisions regarding necessary retrieval technologies,
retrieval efficiencies, retrieval durations, and costs are highly
uncertain. Although tank closure has been completed on only two HLW
tanks (at Savannah River), the tank contents proved amenable to waste
retrieval using current technology. DOE has just begun to address the
issue of how clean a tank must become before it is closed. Continued
demonstration that tank closure criteria can be developed and
implemented will provide substantial benefit to DOE.
    A related problem that retrieval process development is examining
the current lack of a retrieval decision support tool for the end
users. As development activities move forward toward collection of
retrieval performance and cost data, it has become very evident that
the various sites across the complex need to have a decision tool to
assist end users with respect to waste retrieval and tank closure. Tank
closure is intimately tied to retrieval, and the sensitivity of closure
criteria to waste retrieval is expected to be very large.
    All the existing processes and technologies that could be used as a
baseline for tank remediation have not yet been identified. Identifying
these processes is one of EM's major issues in addressing the tank
problems. The overall purpose of retrieval enhancements is to continue
to lead the efforts in the basic understanding and development of
retrieval processes in which waste is mobilized sufficiently to be
transferred out of tanks in a cost-effective and safe manner. From that
basic understanding, data are provided to end users to assist them in
the retrieval decision-making process. The overall purpose of retrieval
enhancements is to identify processes that can be used to reduce cost,
improve efficiency, and reduce programmatic risk.
    Basic engineering and separation science studies are needed to
support tank remediation of liquids, which contain high concentrations
of solids.

Pretreatment and Separation Processes for Tank Waste

    About 90 million gallons of HLW are stored in tanks at four primary
sites within the DOE complex. It is neither cost-effective nor
practical to treat and dispose of all of the tank waste to meet the
requirements of the HLW repository program and the Nuclear Waste Policy
Act. The pretreatment area seeks to address multiple needs across the
DOE complex. The primary objectives are to reduce the volume of HLW,
reduce hazards associated with treating LLW, and minimize the
generation of secondary waste.
    The current baseline technology systems for waste pretreatment at
DOE's tank waste sites are expensive, and technology gaps exist. Large
volumes of HLW will be generated, while there is limited space in the
planned Nuclear Waste Repository for HLW from DOE. Even if adequate
space were made available, treatment and disposal of HLW is still very
expensive, estimated to be about $1 million for each canister of
vitrified HLW. Only a small fraction of the tank waste, by weight, is
made up of HLW radionuclides. The bulk of the waste is chemical
constituents intermingled with, and sometimes chemically bonded to, the
radionuclides. The chemicals and radionuclides can be separated into
HLW and LLW fractions for less costly treatment and disposal.
    Most of the tank waste was generated as a result of nuclear fuel
processing for weapons production. In that process, irradiated fuel and
its cladding were first dissolved, uranium and plutonium were recovered
as products, and the highly radioactive fission product wastes were
concentrated and sent to the tanks for long-term storage.
    Fuel processing at SRS did not change substantially from the
beginning of operations in about 1955 to the present. While these
wastes are fairly uniform, they still require pretreatment to separate
the LLW from HLW prior to immobilization. Liquid waste at INEEL is
stored under acidic pH conditions in stainless steel tanks. The
original liquid high level waste has been calcined at high temperature
to a dry powder. At Hanford, several processes were used over the years
(beginning in 1944), each with a different chemical process. This
resulted in different waste volumes and compositions. Wastes at Hanford
and SRS are stored as highly alkaline material so as not to corrode the
carbon steel tanks. The process of converting the waste from acid to
alkaline resulted in the formation of different physical forms within
the waste.
    The primary forms of tank waste include sludge, saltcake, and
liquid. The bulk of the radioactivity is known to be in the sludge
which makes it the largest source of HLW. Saltcake is characteristic of
the liquid waste with most of the water removed. Saltcake is found
primarily in older single-shell tanks at Hanford.
    Saltcake and liquid waste contain mostly sodium nitrate and sodium
hydroxide salts. They also contain soluble radionuclides such as
cesium. Strontium, technetium, and transuranics

[[Page 3569]]

are also present in varying concentrations. The radionuclides must be
removed; leaving a large portion of waste to be treated and disposed of
as LLW and a very small portion that is combined with HLW from sludge
for subsequent treatment and disposition.
    Over the years, tank waste has been blended and evaporated to
conserve space. Although sludge contains most of the radionuclides, the
amount of HLW glass produced (vitrification is the preferred treatment
of HLW) could be very high without pretreatment of the sludge.
Pretreatment of the sludge by washing with alkaline solution can remove
certain nonradioactive constituents and reduce the volume of HLW.
Pretreatment can also remove constituents that could degrade the
stability of HLW glass. The pretreatment area seeks to address multiple
needs across the DOE complex. The primary objectives are to reduce the
volume of HLW, reduce hazards associated with treating LLW, and
minimize the generation of secondary waste.
    The concentration of certain chemical constituents such as
phosphorus, sulfur, and chromium in sludge can greatly increase the
volume of HLW glass produced upon vitrification of the sludge. These
components have limited solubility in the molten glass at very low
concentrations. Some sludge has high concentrations of aluminum
compounds, which can also be a controlling factor in determining the
volume of HLW glass produced. Aluminum above a threshold concentration
in the glass must be balanced with proportional amounts of other glass-
forming constituents such as silica. There are estimated to be 25
different types of sludge at Hanford distributed among more than 100
tanks. Samples from 49 tanks would represent approximately 93 percent
of the sludge in Hanford tanks. Testing of enhanced sludge washing, the
combination of caustic leaching and water washing of sludge, on all of
these samples is needed to determine whether enhanced sludge washing
will result in an acceptable volume of HLW glass destined for the
repository and will allow processing in existing carbon steel tanks at
Hanford and SRS.
    The efficiency of enhanced sludge washing is not completely
understood. Inadequate removal of key sludge components could result in
production of an unacceptably large volume of HLW glass. Improvements
are needed to increase the separation of key sludge constituents from
the HLW.
    Enhanced sludge washing is planned to be performed batch-wise in
large double-shell tanks of nominal one million gallon capacity. This
will generate substantial volumes of waste solutions that require
treatment and disposal as LLW. Settling times for suspended solids may
be excessive and the possibility of colloid or gel formation could
prohibit large-scale processing. Alternatives are needed that will
reduce the amount of chemical addition required and prevent the
possibility of colloid formation. Sludge at SRS and Hanford will be
washed to remove soluble components prior to vitrification. Removing
suspended solids from the wash solutions is inherently inefficient due
to long intervals required for the solids to settle out.
    Approximately 1.2 million gallons of acidic liquid waste are stored
in single-shell, stainless steel, underground storage tanks at INEEL.
In 1992, a Notice of Noncompliance was filed by the State of Idaho
stating that the tanks did not meet secondary containment requirements
of the Resource Conservation and Recovery Act. Subsequently, an
agreement was reached between DOE, the Environmental Protection Agency,
and the Idaho Department of Health and Welfare that commits DOE to
remove the liquid waste from all underground tanks by the year 2015.
Recent discussions with the state of Idaho have accelerated this date
to 2012.
    The baseline treatment for INEEL liquid and calcine waste was
recently reviewed as part of the site's Environmental Impact Statement
process. The site is now developing a revised roadmap to pursue direct
vitrification of the liquid waste and determine the best path to treat
the calcine.
    The transuranic extraction process for removal of actinides, or
transuranics, from acidic wastes has been tested on actual Idaho waste
in continuous countercurrent process equipment. The strontium
extraction process shows promise for co-extraction of strontium and
technetium and also has been demonstrated on Idaho waste in continuous
countercurrent operation.
    DOE's underground storage tanks at Hanford, SRS, and INEEL contain
liquid wastes with high concentrations of radioactive cesium. Cesium is
the primary radioactive constituent found in alkaline supernatant
wastes. Since the primary chemical components of alkaline supernatants
are sodium nitrate and sodium hydroxide, the majority of the waste
could be disposed of as LLW if the radioactivity could be reduced below
Nuclear Regulatory Commission limits. Processes have been demonstrated
that removed cesium from alkaline supernatants and concentrate it for
eventual treatment and disposal as HLW.
    At Hanford, cesium must be removed to a very low level (3 Ci/m3) to
allow supernatant waste to be treated as LLW and disposed of in a near-
surface disposal facility. The revised Hanford Federal Facility
Agreement and Consent Order, or Tri-Party Agreement (between DOE,
Environmental Protection Agency and the Washington State Department of
Ecology) also recommends treatment of LLW in a contact-maintained or
minimally shielded vitrification facility to speed remediation and
reduce costs. Cesium removal performance data are needed to estimate
dose rates for this process and provide input to the design of an LLW
pretreatment facility for Hanford supernatants.
    At SRS, cesium removal from saltcake waste was planned to be
accomplished through use of an in-tank precipitation process. Due to
safety and technical challenges, that process was abandoned. Three
alternatives including alkaline solvent extraction, cesium ion exchange
using crystalline silicotitanate and small tank tetraphenylborate
precipitation are currently being evaluated for use in treating the SRS
saltcake waste. Cesium removal may also be needed to separate cesium
from Defense Waste Processing Facility recycle, or offgas condensate,
to greatly reduce the amount of cesium that is routed back to the waste
storage tanks.
    Technetium (Tc)-99 has a long half-life (210,000 years) and is very
mobile in the environment when in the form of the pertechnetate ion.
Removal of Tc from alkaline supernatants and sludge washing liquids is
expected to be required at Hanford to permit treatment and disposal of
these wastes as LLW. The disposal requirements are being determined by
the long-term performance assessment of the LLW waste form in the
disposal site environment. It is also expected that Tc removal will be
required for at least some wastes to meet Nuclear Regulatory Commission
LLW criteria for radioactive content. To meet these expected
requirements, there is a need to develop technology that will separate
this extremely long-lived radionuclide from the LLW stream and
concentrate it for feed to HLW vitrification.
    A number of liquid streams encountered in tank waste pretreatment
contain fine particulate suspended solids. These streams may include
tank waste supernatant, waste retrieval sluicing water, and sludge wash
solutions. Other process streams with potential for suspended solids
include evaporator products and ion exchange

[[Page 3570]]

feed and product streams. Suspended solids will foul process equipment
such as ion exchangers. Radioactive solids will carry over into liquid
streams destined for LLW treatment, increasing waste volume for
disposal and increasing the need for shielding of process equipment.
Streams with solid/liquid separation needs exist at all of the DOE tank
waste sites.
    Some examples of specific science research challenges include but
are not limited to: fundamental analytical chemical studies needed for
improvement of separation processes; materials science of waste forms
germane to their performance; elucidation of technetium chemistry;
basic engineering and separation science studies required to support
pretreatment activities and the development of solid/liquid
separations; fundamental separations chemistry of precipitating agent
and ion exchange media needed to support the development of improved
methods for decontamination of HLW; fundamental physical chemistry
studies of sodium nitrate/nitrite needed for HLW processing; basic
materials science studies concerned with the dissolution of mixed oxide
materials characteristic of calcine waste needed to design improved
pretreatment processes; basic chemistry of sodium when mixed with rare
earth oxides needed for the development of alternative HLW forms.

Waste Immobilization and Disposal

    Waste immobilization processes convert radioactive waste into solid
waste forms that will last in natural environments for thousands of
years. DOE tank wastes requiring immobilization include LLW such as the
pretreated liquid tank waste and HLW such as the tank sludge. There are
also a number of secondary wastes requiring immobilization that result
from tank waste remediation operations, such as resins from cesium and
technetium removal operations.
    The baseline technologies to immobilize radioactive wastes from
underground storage tanks at DOE sites include converting LLW to either
grout or glass and converting HLW to borosilicate glass. Grout is a
cement-based waste form that is produced in a mixer tank and then
poured into canisters or pumped into vaults. Glass waste forms are
created in a ceramic-lined metal furnace called a melter. Tank waste
and dry materials used to form glass are mixed and heated in the melter
to temperatures ranging from 1,800 F to 2,200 F. The molten mixture is
then poured into log-shaped canisters for storage and disposal. The
working assumption is that the LLW will be disposed of on site, or at
the Waste Isolation Pilot Plant if transuranic elements are present.
The HLW will be shipped for off-site disposal in a licensed HLW
repository, such as the one proposed at Yucca Mountain, Nevada.
    Methods are needed to immobilize the LLW fraction resulting from
the separation of radionuclides from the liquid and high-level calcine
wastes at INEEL. LLW is to be mixed with grout, poured into steel
drums, and transferred to an interim storage facility, but alternatives
are being considered. Tests must be conducted with surrogate and actual
wastes to support selection of a final waste form. SRS has selected
saltstone grout (pumped to above ground concrete vaults and solidified)
as the final waste form for LLW.
    DOE sites at Hanford, SRS, and INEEL will remove cesium from the
hazardous radioactive liquid waste in the underground storage tanks. If
cesium is removed, it costs less to treat the rest of the waste.
However, cesium removal from tank waste, while cost-effective, creates
a significant volume of solid waste that must be turned into a final
waste form for ultimate disposal. The plan is to separate cesium from
the liquid waste using ion exchange or other separations media, treat
the cesium-loaded separations media to prepare it for vitrification,
and convert the cesium product into a glass waste form suitable for
final disposal. Personnel exposures during processing and the amount of
hazardous species in the offgases must be kept within safe limits at
all times.
    The effectiveness of advanced oxidation technology for treating
organic cesium-loaded separations media prior to vitrification is not
proven. After a suitable melter feed is obtained, vitrification of the
cesium-loaded media must be demonstrated. Technology development is
needed because: (1) Compounds are in the separation media that must be
destroyed or they will cause flammability problems in the melter and
decrease the durability and waste loading of the final waste form; (2)
High beta/gamma dose rates are associated with handling cesium-
containing waste; and (3) Cesium volatizes in the melter and becomes a
highly radioactive offgas problem.
    Confidence and assurance that long-term immobilization will be
successful in borosilicate glass warrants research and improved
understanding of the structural and thermodynamic properties of glass
(including the structure and energetics of stable and metastable
phases), systematic irradiation studies that will simulate long term
self-irradiation doses and spectra, (including archived glasses
containing Pu or Cm, and over the widest range of dose, dose rate and
temperature) and predictive theory and modeling based on computer
simulations (including ab initio, Monte Carlo, and other methods).
    Some examples of specific science research challenges include but
are not limited to: fundamental chemical studies needed to determine
species concentrations above molten glass solutions containing heavy
metals, cesium, strontium, lanthanides, actinides, with and without a
cold cap composed of unmelted material; materials science studies of
molten materials that simulate conditions anticipated during
vitrification and storage in vitrified form of HLW needed to develop
improved processes and formulations; fundamental physical chemistry
studies of sodium nitrate/nitrite mixtures needed for HLW
stabilization.

References for Background Information

    Note: World Wide Web locations of these documents are provided
where possible. For those without access to the World Wide Web, hard
copies of these references may be obtained by writing Mark A.
Gilbertson at the address listed in the FOR FURTHER INFORMATION
CONTACT section of this Notice.

    DOE. 2000. DOE's Research and Development Portfolio for FY 2001.
http://www.osti.gov/portfolio/.
    DOE. 2000. Paths to Closure--A collection of documents on
accelerating clean-up. http://www.em.doe.gov/closure/.
    DOE. 2000. Tanks Focus Area References and Bibliography http://
www.pnl.gov/tfa/back/reference.stm.
    DOE. 2000. Environmental Management Dynamic Organization Chart.
http://www.em.doe.gov/orgchart.html.
    DOE. 2000. Environmental Management Science Program. http://
www.em.doe.gov/.
    DOE. 2000. Office of Science and Technology (EM-50). http://
ost.em.doe.gov/.
    NRC. 2000. Long-Term Research Needs for High-Level Waste at
Department of Energy Sites: Interim Report. http://www.nap.edu/catalog/
9992.html.
    NRC. 2000. Alternatives for High-Level Waste Salt Processing at the
Savannah River Site. http://www.nap.edu/books/0309071941/html/.
    NRC. 1999. Disposition of High-Level Radioactive Waste Through
Geological Isolation: Development, Current Status, and Technical and
Policy Challenges.

[[Page 3571]]

http://books.nap.edu/books/0309067782/html/1.html.
    NRC. 1999. Interim Report--Committee on Cesium Processing
Alternatives for High-Level Waste at the Savannah River Site. http://
books.nap.edu/books/NI000350/html/index.html.
    NRC. 1999. Alternative High-Level Waste Treatments at the Idaho
National Engineering and Environmental Laboratory. http://
books.nap.edu/books/030906628X/html/129.html.

(The Catalog of Federal Domestic Assistance Number for this program
is 81.049, and the solicitation control number is ERFAP 10 CFR Part
605.)
    Issued in Washington, DC, on January 9, 2001.
John Rodney Clark,
Associate Director of Science for Resource Management.
[FR Doc. 01-1184 Filed 1-12-01; 8:45 am]
BILLING CODE 6450-01-U 

 
 


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