This workshop featured a range of expert briefings as well as extensive discussion sessions. The workshop was organized into three sessions, reflected in Chapters 2, 3, and 4 of this volume as follows:
- Challenges to regulatory flexibility and risk-informed decision making;
- Holistic approaches to remediation; and
- Incorporating sustainability into decision making for site remediation.
Each session followed a similar format: the subject matter was introduced by an expert followed by a set of presentations highlighting case studies on that subject. After each presentation, a discussion session was held. All workshop presentations are available online: http://sites.nationalacademies.org/PGA/sustainability/PGA_085849.
This summary was written by a rapporteur to present the various ideas and suggestions that arose in the workshop. It does not include conclusions or recommendations, nor does it cover the full spectrum of issues around this topic.
The remainder of this chapter is based on a white paper (Brose and Heimberg 2013) distributed to the workshop participants and is intended to provide the reader with background information regarding regulatory history and status of environmental cleanup of nuclear legacy sites, relevant National Research Council (NRC) reports, and sustainability frameworks.
The nuclear weapons industrial complex, which grew out of the Manhattan Project and the Cold War, is massive by any number of measures. More than $450 billion was spent and hundreds of thousands of workers were employed to support nuclear material production, weapon assembly, and nuclear testing (DOE 1995).1 More than 100 sites spanning 31 states, 1 territory, and 2.3 million acres were developed. One hundred and twenty million square feet of buildings were utilized (DOE 1995; NRC 2010). By the end of the Cold War, the United States had produced about 994 metric tons of highly enriched uranium and more than 100 metric tons of plutonium (DOE 1995). A large portion of this industrial complex was devoted to the production of the nuclear materials required for weapons. In 1939, physicists Niels Bohr and John Wheeler hypothesized that a specific, rarely occurring isotope of uranium (U-235) was more fissile than the more naturally abundant U-238 and was required to sustain the nuclear chain reaction (Bohr and Wheeler 1939). Because U-235 occurs in less than 1 percent of natural uranium, which itself occurs in concentrations of 2 to 5 parts per million in mined ore, Bohr expressed deep doubt that a nuclear bomb could be made “unless you turn the United States into one huge factory” (DOE 1995, p. 2).
Uranium has multiple uses in the production of nuclear weapons; it can be used for bomb material or as a fuel and target in plutonium production. Several processing steps are required to enrich uranium: It is first mined from rock and refined to natural uranium (also called yellow cake), converted to uranium hexafluoride (UF6), enriched to increase the required U-235 content, and then converted to metal. The mining and milling of uranium ore for the Manhattan Project and Cold War took place at more than 400 locations within the United States. Approximately 60 million tons of ore were mined (DOE 1995). The conversion and enrichment primarily took place in Tennessee (Oak Ridge), Ohio (Portsmouth), and Kentucky (Paducah). About 700,000 metric tons of UF6 were produced. Conversion to nuclear fuel for plutonium production and metal (for weapons) took place at Fernald, Ohio. Over its operational lifetime, the Fernald plant produced 250,000 tons of uranium metal products (WM 2011).
Plutonium-239 is also used in nuclear weapons and does not occur naturally in useful abundance; it is created by bombarding uranium fuel and targets with neutrons usually in a nuclear reactor. Pu-239 is later extracted from the irradiated uranium fuel. Plutonium production and separation of Pu-239 from the irradiated uranium targets (i.e., reprocessing) took place in Hanford, Washington, and Aiken, South Carolina, near the Savannah River. The Hanford and Savannah River Sites housed a total of 14 produc-
1 Adjusted for 2013 dollars.
tion reactors, encompassed nearly 1,000 square miles, and produced more than 100 tons of plutonium (Gephart 2003). When Bohr later joined the Manhattan Project and learned the extent of its operations, he confirmed his earlier prediction, “I told you that you would have to turn the United States into a factory. You have done just that,” (DOE 1995 p. 2).
The end of the Cold War in 1991 and a nuclear weapons test moratorium in 1992 brought an end to large-scale production of nuclear materials for weapons within the United States. The diversity and extent of lands in which facilities were built are vast. The surface topography, climate, subsurface geology, and hydrology of these sites vary widely (Figure 1-1; NRC 2000). Population densities and cultural uses of the lands around these sites have changed with time. In some cases, population densities increased to support the operations at the facilities (e.g., Hanford, Oak Ridge, Los Alamos); in other cases, they increased because of expansion of
FIGURE 1-1 A schematic illustration of historical waste management practices in the DOE nuclear industrial complex and contaminant pathways to the environment. This schematic also shows the geologic features at the surface and subsurface and their relationship to the sources of waste. The contaminants in the soil and groundwater shown above are light and dense non-aqueous phase liquids (LNAPLs and DNAPLs, respectively), technetium (T c), chromium (Cr), cesium (Cs-137), plutonium (Pu), mercury (Hg), strontium (Sr-90), uranium (U), and lead (Pb).
SOURCE: NRC 2000.
suburbs around cities previously considered far removed from the site (e.g., the Rocky Flats site near Denver; DOE 1995).
Since the creation of the Office of Environmental Management (EM) in 1989, the diversity and magnitude of the wastes and contamination have become well known, including approximately 88 million gallons of radioactive wastes stored in tanks, 1,000 tons of spent nuclear fuel, more than 10,000 containers of plutonium and uranium, more than 5,000 contaminated facilities, millions of cubic meters of contaminated soil, and 1 billion gallons of contaminated ground water (DOE 2013). Cleanup efforts have cost approximately $190 billion to date (NRC 2010); remediation of the remaining sites is expected to cost more than $300 billion and take an additional 40 years (DOE 2013). The cost of the cleanup efforts could ultimately exceed those for the development of the nuclear weapons.
1.2 REGULATORY HISTORY
Beginning with the Atomic Energy Act in 1954, laws have been enacted to control and regulate the cleanup of radioactive and hazardous waste to protect human health and the environment.2 Two of the main laws are the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA, also known as Superfund) and the Resource Conservation and Recovery Act (RCRA). CERCLA, which typically applies to releases from facilities that are no longer operating, allows for broad federal authority to respond to releases or threatened releases of hazardous substances (including radioactive substances) that endanger public health or the environment. The law has subsequently been amended, by the Superfund Amendments and Reauthorization Act of 1986 (SARA), and the Small Business Liability Relief and Brownfields Revitalization Act of 2002. RCRA, which applies to active or planned facilities, focuses on disposal of hazardous wastes, including some of the chemical by-products of nuclear weapons production. Both laws require that DOE and other federal and state regulators enter into interagency agreements to address site remediation (CERCLA section 120, and 3008(h) and RCRA section 6001).
Federal Facility Agreements and Consent Orders have been established between Department of Energy (DOE), the Environmental Protection Agency (EPA), and state regulators to satisfy CERCLA and RCRA requirements. Also called tri-party agreements, they define agreed-upon and legally enforceable milestones toward achieving compliance with laws and reaching site closure. The tri-party agreements for the states with the largest and most problematic waste issues are Washington (1989 and 2003), Idaho
(1991), and South Carolina (1993), and define what DOE cleanup efforts must accomplish, timelines for the accomplishments, and in many cases, the means by which the accomplishments are to be achieved (NRC 2005a).
1.3 CURRENT STATUS OF CLEANUP EFFORTS
Since cleanup activities began in 1989, DOE has conducted an accounting of the number of sites requiring cleanup, begun characterization of wastes and contamination, and initiated cleanup activities. Currently, 90 out of 107 sites have completed cleanup activities required by those sites’ tri-party agreements (Figure 1-2). Completed cleanup does not necessarily mean that the site has been returned to pre-contamination conditions or has been approved for unrestricted public use. Many of the 90 completed sites have wastes remaining on site and restrictions on future use; these sites require long-term monitoring to ensure that the existing remedies continue to protect human health and the environment. When wastes remain on a site, CERCLA requires 5-year reviews to provide an opportunity to evaluate the implementation and performance of a remedy to determine whether it remains protective of human health and the environment. For example, the sites in Rocky Flats, Colorado, and Fernald, Ohio, have restrictions on future uses because wastes remain on site. For Fernald, the On-Site Disposal
FIGURE 1-2 Location of principal sites within the DOE nuclear industrial complex. The four major DOE sites are labeled.
SOURCE: Modified from NRC 2000.
Facility (OSDF) contains low-level radioactive wastes and contaminated groundwater. The Fernald Preserve, now managed by DOE’s Office of Legacy Management, has a public visitors center and hiking trails with access restrictions (e.g., excluding access to the OSDF). At Rocky Flats, contaminated surface soils and groundwater remain, and the site has been transferred to the Department of Interior’s Fish and Wildlife Service for use as a National Wildlife Refuge.
Long-term monitoring is required for both sites. Monitoring is usually performed using direct measurements of groundwater and soil collected at predetermined locations known as points of compliance. The points of compliance are usually at the perimeters of storage locations or groundwater plumes. Point-of-compliance testing requires sample collection, processing, analysis, and reporting. Other long-term monitoring activities include institutional controls, which are non-engineered instruments, such as administrative and legal controls, that help minimize the potential for human exposure to contamination and/or protect the integrity of the remedy. Although the majority of DOE sites have completed cleanup, the largest and most technically challenging sites remain. Each has unique terrain, subsurface geology, contaminants and wastes, regulations, and tri-party agreements. Wastes will remain on site, and future land use will likely be restricted. As such, all remaining sites are faced with long-term monitoring until either technologies can be developed to effectively address the contamination or the radioactive wastes decay through natural processes.
1.4 CHARACTERIZATION OF WASTE AND CONTAMINATION
To determine an achievable end state and the actions needed to reach that end state, it is necessary to understand the extent of the cleanup task. A thorough characterization of the wastes and the contamination is needed at each site. Characterization of the wastes can be difficult because of poor accounting and documentation practices for wastes and waste discharges during the early days of the Manhattan Project (e.g., tank waste). Characterization of the contamination of groundwater and soil is difficult because of the challenges of measuring the subsurface hydrology and a full understanding of the contaminants’ interaction with different media (i.e., soil or water) (NRC 1998, 1999).
The NRC has offered advice to DOE on many of these topics. Reports on the characterization of waste include advice on tank waste retrieval and processing, which concluded that sufficient characterization has taken place to extract wastes from the tanks but that more detailed characterization would be needed before final processing (NRC 2006). The importance of characterizing transuranic and high-level waste is captured in several reports (NRC 2001c, 2002a, 2004, 2005b). NRC reports on soil and
groundwater contamination focus on improving models, technologies, and characterization methods. The main message from many of these reports is that better characterization is still needed for contaminated soil and groundwater—especially the subsurface geological structures (e.g., better characterization of wastes/chemicals transport in the subsurface). Also, many reports conclude that the majority of the problematic sites will not be remediated to the level of unrestricted use (NRC 1999, 2007, 2013a). One NRC report states, “Effective technologies do not exist for treating the contamination to soil and groundwater even for the most common contaminants” (NRC 1999, p. 1). Unfortunately, this remains true today (NRC 2013a). Other notable challenges are listed below:
- Measurements from monitoring may be near background levels and have large uncertainties—communicating measurements that exceed background levels to regulators and the public will be challenging (NRC 2007).
- Pumping groundwater for treatment is marginally effective for some common contaminants with no viable alternatives (NRC 1999, 2013a).
- Remediation through natural attenuation is appropriate for only a few contaminants and is an acceptable solution only when the process can be proven effective and sustainable (NRC 2000).
1.5 TECHNOLOGIES AND DECISION MAKING
DOE has requested the advice of the NRC on its research and development programs throughout the years (NRC 1997, 2000, 2001a, 2001b, 2001d, 2002b, 2009, 2010, 2011a). It is understood that new technologies are still needed to close capability gaps to address cleanup issues. The most difficult issues remaining are soil and groundwater contamination. The NRC report Groundwater and Soil Cleanup: Improving Management of Persistent Contaminants provides an overview of the existing technologies and their limitations in this area (1999, pp. 5-6, 8-9).
The NRC report Risk and Decisions about Disposition of Transuranic and High-level Radioactive Waste provides a summary of studies and programs starting in 1988 aimed at incorporating risk into decision making (2005a). A chronological overview of DOE’s decision-making programs is also included. Risk-based decisions have a technical component that characterizes the scientific aspects of the problem by quantifying risk. However, many of the NRC committees (NRC 1997, 2000, 2001a, 2001b, 2001d, 2002b, 2009, 2010, 2011a) stress the following general characteristics of risk-based decision making that are not technical or scientific in nature:
- Risk assessment is not risk management; assessment of risk should guide but not make decisions;
- A formalized decision-making process provides consistency and transparency in agency decisions;
- Meaningful stakeholder involvement and communication between interested parties are needed early and throughout the risk analysis and decision-making processes; and
- Risk to human health is important but is one of many other considerations that should be incorporated into decisions.
In 2003, DOE approved Policy 455.1 to include risk-based end states in a re-evaluation of cleanup activities. The policy specifically stresses the importance of stakeholder involvement in determining a risk-based end state vision. Stakeholder involvement and environmental end states have been highlighted by DOE and outside committees providing advice to DOE as important components of risk-based decisions. However, implementing an effective risk-based decision process that sufficiently incorporates stakeholder concerns has proven difficult. Sustainability principles are being explored as a method to better incorporate those concerns into the decision-making process.
1.6 OPERATIONALIZING SUSTAINABILITY
Sustainability has permeated all sectors of society—the private sector, federal, state, and local agencies, nongovernmental organizations (NGOs), and academia are all working on incorporating sustainability into their practices and operations. Sustainability is now being incorporated into what has been conventionally risk-based decision making at contaminated cleanup sites (Holland et al. 2011; Döberl et al. 2013). Although cleanup strategies for complex multi-contaminant sites remain site specific, the incorporation of sustainability principles at ongoing DOE sites, such as Hanford or Savannah River, could help move cleanup strategies forward in a way that addresses ongoing social, economic, and environmental concerns.
The NRC report Sustainability and the U.S. EPA (2011b) used the definition for sustainability from Executive Order 13514, where it is defined as “to create and maintain conditions, under which humans and nature can exist in productive harmony, that permit fulfilling the social, economic, and other requirements of present and future generations” (p. 8). The 1969 National Environmental Policy Act (NEPA) embodies sustainability, which requires an integration of social, environmental, and economic policies—the three pillars of sustainability. International acceptance of sustainability was spurred by the 1987 report of the World Commission on Environment and Development, Our Common Future (WCED 1987). In 1992, at the
United Nations Conference on Environment and Development in Rio de Janeiro, the United States and other countries endorsed a global plan of action for sustainable development and a set of principles to guide that effort (UNCED 1992). The 2011 NRC report for EPA further described sustainability as a process—because the United States and other countries are far from being sustainable—and a goal. Sustainability is achieved in particular places and contexts—it is a place-based approach—and it is necessary to maintain the conditions supporting it in the face of social, technological, environmental, and other changes.
As the private sector, federal, state, and local agencies, NGOs, and academia struggle to address cross-cutting, complex, and challenging issues, sustainability as an operational framework is being increasingly embraced and incorporated into decision-making processes. Several examples of sustainability frameworks have been developed, including those by the National Research Council (NRC) and the U.S. Sustainable Remediation Forum (SURF). In 2009, EPA requested that the NRC convene an expert committee to develop a framework for incorporating sustainability into the agency’s principles and decision making (NRC 2011b). The framework was intended to help the agency better assess the social, environmental, and economic impacts of various options as it makes decisions. In its Strategic Plan, EPA has made “working toward a sustainability future” a major cross-program goal, and it continues to develop an implementation plan for adopting the committee’s recommendations as it moves toward incorporating sustainability into its decision-making processes.
The resulting framework is organized into two levels (Figure 1-3). Level 1 consists of several components that define the agency-wide process: the social, environmental, and economic pillars of sustainability and the principles and legal mandates that feed into the process; EPA’s sustainability vision, goals, and organization; the Sustainability Assessment and Management (SAM) approach; and periodic evaluation and public reporting activities. Level 2 articulates the elements of the SAM approach, which is intended to be equally applicable to human health, ecological risks, and other challenges. The SAM approach is designed to be comprehensive, systems-based, and intergenerational and to solicit stakeholder involvement and collaboration. It is driven by sustainability principles and goals and involves setting, meeting, and reporting on measurable performance objectives (NRC 2011b).
The report states that the framework incorporates and goes beyond an approach based on assessing and managing the risks posed by pollutants that has largely shaped environmental policy since the 1980s. Although risk-based methods have led to many successes and remain important tools, as the report states, they are not adequate to address many of the complex problems that put current and future generations at risk, such as depletion
FIGURE 1-4 Conceptual Decision Framework. Four phases are shown, along with the relevant steps in each phase. The framework could be applied in creating either programs or projects related to sustainability.
SOURCE: NRC 2013b.
of natural resources, climate change, and loss of biodiversity. The report also stated that EPA could benefit from formally developing, adopting, and publishing a set of broad “Sustainability Principles” that underlie all agency policies and programs. These principles would guide the agency’s implementation of regulatory mandates and discretionary programs in ways that optimize benefits as they relate to the social, environmental, and economic pillars. Examples of such principles could include those of public administration, such as openness and transparency, reliability, accountability, efficiency, and effectiveness. The most widely cited and used set of principles are the sustainable development principles from the Rio Declaration of 1992. The report recommended that some of the key dimensions of the principles that EPA should consider including are intergenerational and intragenerational equity, justice, and a holistic-systems approach to environmental problems and solutions.
The NRC report Sustainability for the Nation (2013b) provides an analytical framework for decision making related to linkages of sustainability across all federal agencies (Figure 1-4). The framework is divided into four distinct phases: (1) preparation and planning; (2) design and implementation; (3) evaluation and adaptation; and (4) long-term outcomes (NRC 2013b).
The report describes each phase as follows (NRC 2013b):
- Phase 1: Preparation and planning. This phase has three major steps that need to occur prior to the actual program or project design: (1) frame the problem (determine baseline conditions, key
drivers, metrics, and goals based on these metrics); (2) identify and enlist partners; and (3) develop a project management plan.
- Phase 2: Design and implementation. This phase has three main steps, including (1) define goals; (2) design action plan; and (3) implement plan.
- Phase 3: Evaluation and adaptation. This phase focuses on realizing short-term outcomes, assessing outcomes, and adjusting actions. Outcomes are assessed and evaluated relative to the baseline conditions established in Phase 1.
- Phase 4: Long-term outcomes. Long-term outcomes are on the scale of several years or more and should closely track the goals identified in the first phase. Using outcome measures developed under Phase 2, at this stage evaluations are conducted to see if short- and long-term outcomes are meeting goals. Ideally, this evaluation should be able to be compared to the baseline evaluation finalized in Phase 2. Based on this evaluation, necessary changes to the team, goals, outcomes and measures, management plans, design, implementation, or maintenance are made.
SURF recently offered another sustainability framework. SURF was initiated in 2006 as a private-sector effort to incorporate sustainability into decisions on remedial actions at contaminated sites. In 2011, SURF developed a framework “to enable sustainability parameters to be integrated and balanced throughout the remediation project life cycle, while ensuring long-term protection of human health and the environment and achieving public and regulatory acceptance” (Holland et al. 2011). Because sustainability is a cross-cutting issue, this framework integrates sustainability throughout the entire remediation system. SURF describes sustainable remediation as “balancing the impacts and influences of the triple bottom line of sustainability (i.e., environmental, societal, and economic) while protecting human health and the environment.” Over the past few years, remediation practitioners have incorporated sustainability parameters more frequently during remedy selection and implementation; however, methodologies have been inconsistent, partly because of a lack of a broad, widely applicable sustainable remediation framework.
To address this need, SURF developed a framework to mirror each phase of a traditional remediation project: investigation, remedy selection, remedial design and construction, operation and maintenance, and closure (Figure 1-5). The framework can be thought of as interconnected components of the wider remediation system, which interact with each other as the project progresses. Practitioners are encouraged to look both prospectively and retrospectively throughout the project to integrate sustainability improvements. Some benefits of using the framework, according to SURF,
include fewer impacts on the environment and enhanced relationships with and investments in the local community. The framework is intended to be accessible to all stakeholders involved in or affected by a remediation project, regardless of prior sustainable remediation experience. It is process-based and adaptable over time. The framework is designed to assist practitioners to (1) perform a tiered sustainability evaluation, (2) update the conceptual site model based on the results of the sustainability evaluation, (3) identify and implement sustainability impact measures, and (4) balance sustainability and other considerations during the remediation decision-making process. The framework can complement and build upon existing sustainable remediation programs developed by government agencies, industry associations, and the regulated communities. The framework allows for goal-oriented outcomes but also introduces additional opportunities for incorporating sustainability parameters throughout the remediation project.