2
Framing DOE’S Transuranic and Mixed Waste Challenges

The accumulation of radioactive waste materials began in the 1940s with the development of the atomic bomb and continued with the large-scale refining and production of fissile materials such as uranium and plutonium during the Cold War. Processes included separation and enrichment of special isotopes, reactor fuel fabrication, dissolution and chemical separation of irradiated materials, and fabrication (casting, machining, plating) of weapons components. During this period, emphasis was placed on production and little attention was given to reducing the volume or variety of wastes. The wastes were managed using practices analogous to those used in other process industries, including on-site disposal in landfills and the use of ponds and lagoons to manage large volumes of wastewater.

Wastes generated by production operations ranged from slightly contaminated trash to highly radioactive liquids from processing irradiated fuels. Frequently these wastes contained both radioactive and hazardous chemical substances. This chapter provides a context for the Department of Energy’s (DOE’s) challenges in managing wastes contaminated with both hazardous chemicals and low levels of radioactive fission products (mixed low-level waste [MLLW]) and wastes contaminated with transuranic isotopes (TRU waste)—see Sidebar 2.1. Research challenges for managing DOE’s high-level radioactive waste and spent nuclear fuels and for remediating subsurface contamination are described elsewhere (NRC, 2000a, 2001a, 2002a) and are not dealt with in this report.

During most of the time this study was in progress, the Transuranic and Mixed Waste Focus Area (TMFA), a part of the DOE Environmental Management Office of Science and Technology (EM-OST), was responsible for ensuring that technologies were available to manage this waste. Organizational changes within EM-OST that occurred as this report was being finalized are described in Appendix A.



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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes 2 Framing DOE’S Transuranic and Mixed Waste Challenges The accumulation of radioactive waste materials began in the 1940s with the development of the atomic bomb and continued with the large-scale refining and production of fissile materials such as uranium and plutonium during the Cold War. Processes included separation and enrichment of special isotopes, reactor fuel fabrication, dissolution and chemical separation of irradiated materials, and fabrication (casting, machining, plating) of weapons components. During this period, emphasis was placed on production and little attention was given to reducing the volume or variety of wastes. The wastes were managed using practices analogous to those used in other process industries, including on-site disposal in landfills and the use of ponds and lagoons to manage large volumes of wastewater. Wastes generated by production operations ranged from slightly contaminated trash to highly radioactive liquids from processing irradiated fuels. Frequently these wastes contained both radioactive and hazardous chemical substances. This chapter provides a context for the Department of Energy’s (DOE’s) challenges in managing wastes contaminated with both hazardous chemicals and low levels of radioactive fission products (mixed low-level waste [MLLW]) and wastes contaminated with transuranic isotopes (TRU waste)—see Sidebar 2.1. Research challenges for managing DOE’s high-level radioactive waste and spent nuclear fuels and for remediating subsurface contamination are described elsewhere (NRC, 2000a, 2001a, 2002a) and are not dealt with in this report. During most of the time this study was in progress, the Transuranic and Mixed Waste Focus Area (TMFA), a part of the DOE Environmental Management Office of Science and Technology (EM-OST), was responsible for ensuring that technologies were available to manage this waste. Organizational changes within EM-OST that occurred as this report was being finalized are described in Appendix A.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes SIDEBAR 2.1 WHAT ARE MIXED LOW-LEVEL AND TRANSURANIC WASTES? The committee used the following working definitions in preparing this report. They are based on the EPA Mixed Waste Glossary (EPA, 2002a). As noted, they were derived from detailed definitions in Congressional acts or developed by the federal agencies that regulate these wastes: the DOE, the Nuclear Regulatory Commission (USNRC), and the Environmental Protection Agency (EPA). Low-level radioactive waste (LLW) is defined in the Low-Level Radioactive Waste Policy Amendments Act of 1985, essentially by excluding other types of waste. Namely, LLW is not spent nuclear fuel, high-level radioactive waste from reprocessing spent nuclear fuel, or byproduct material. Most wastes in the DOE inventory that are designated as LLW are contaminated with small amounts of radioactive fission products, which are the isotopes that result from splitting (fissioning) the uranium nucleus. Hazardous waste is defined by the EPA in Title 40 of the Code of Federal Regulations, parts 260 and 261. This waste is toxic or otherwise hazardous because of its chemical properties. Waste can be designated as hazardous in any of three ways: It contains one or more of over 700 materials listed as hazardous by the EPA; It exhibits one or more hazardous characteristics, which include ignitability, corrosivity, chemical reactivity, or toxicity; It arises from treating waste already designated as hazardous. Mixed low-level waste (MLLW) meets the above definitions of both low-level waste and hazardous waste. It contains materials that are chemically hazardous and low levels of radioactive contamination. Transuranic waste (TRU) is defined by DOE Order 435.1 as waste that has a radioactivity of more than 100 nanocuries per gram that arises from alpha-emitting isotopes with atomic numbers greater than uranium (92) and half-lives greater than 20 years. Most TRU waste in the DOE inventory is contaminated with plutonium-239, which has a longer radioactive half-life (24,000 years) than most fission products. Mixed transuranic waste (MTRU) meets the definitions of both transuranic and hazardous waste. EPA estimates that more than half of DOE’s TRU inventory is MTRU (EPA, 2002a). Because all TRU wastes are destined for WIPP, DOE no longer distinguishes MTRU as a special category in its inventory (DOE, 2001a). The Department of Energy’s challenges in managing and disposing its transuranic and mixed wastes (TM wastes) arise primarily from three factors. One is the large and diverse waste inventory, which is incompletely characterized. A previous study (NRC, 1999a, p. 18) of TM wastes found: EM’s mixed waste inventory is sufficiently characterized that conceptual design of treatment processes . . . can proceed. However, the inventory is insufficiently characterized for detailed engineering design of treatment processes or process optimization.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes Another challenge is the complex and evolving regulatory constraints that are applied to these wastes. The earlier study (NRC, 1999a, p. 22) noted: The U.S. Environmental Protection Agency (EPA), U.S. Nuclear Regulatory Commission (USNRC), Department of Transportation (DOT), and individual states all exert measures of control over treatment, transport, and disposal of mixed waste. . . . [T]he range of regulatory approaches and resulting regulations create substantial challenges for treatment and disposal of mixed wastes. There is public concern about, and often opposition to, technologies that are unfamiliar or that might change agreed-upon cleanup plans. An international review of waste management programs (NRC, 2001c, p. 3) found the following: Today the biggest challenges to waste disposition are societal. Difficulties in achieving public support have been seriously underestimated in the past, and opportunities to increase public involvement and to gain public trust have been missed. Based on its fact finding, the committee believes that these conclusions remain valid. Through their impact on site technology needs, challenges arising from the diverse waste inventory, multiple evolving regulations, and public concerns will significantly affect any research agenda developed by the Environmental Management Science Program (EMSP). These factors, which frame DOE’s TM waste challenges, are discussed in this chapter. DOE’s Transuranic and Mixed Waste Inventory Managing and disposing of DOE’s TM waste inventory presents technical challenges and research opportunities because the inventory is large and diverse. This section provides an overview of the inventory with emphasis on wastes that led the committee to its research recommendations. Appendix B gives a detailed description of the inventory. Inventory Description Information on DOE’s waste inventory is given in a summary report published in April 2001 (DOE, 2001a). DOE compiled much of the inventory data from its fiscal year 2000 Central Internet Database.1 1   See http://cid.em.doe.gov.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes FIGURE 2.1 Before 1970, transuranic and mixed wastes were buried in near-surface trenches. The waste was considered to be permanently disposed, and inventory data are lacking. Source: http://web.ead.anl.gov/techcon/images/ineel3.jpg. TM wastes are described in two categories, transuranic and MLLW. The summary report does not distinguish between TRU and mixed transuranic waste (MTRU) (see Sidebar 2.1). All inventory data refer to the waste volume unless noted otherwise. Since 1970, DOE sites have stored most TM wastes retrievably in 55-gallon drums or larger containers for future treatment, if needed, and disposal. Before 1970, DOE sites buried TM wastes in “shallow land” facilities, within about 30 meters of the surface.2 Most waste was buried in 55-gallon drums, some was buried in other containers, and some had no durable container (e.g., burial in plastic bags, cardboard boxes, or without containment); see Figures 2.1 and 2.2. At the time, DOE generally considered buried waste to be permanently disposed. Recently, DOE has recognized that at least some of its buried waste inventory may require retrieval and treatment (DOE, 2001a). Contaminated soils and sediments have resulted from previous DOE practices of discharging low-level liquid wastes to retention basins or 2   A fraction was buried at “intermediate” depths between 30 and 300 meters.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes FIGURE 2.2 Since 1970, DOE has required that sites store TRU waste so that it can be retrieved easily. TRU wastes at Hanford, which is in a very dry region, are stored in earthen mounds. Source: DOE Richland Operations Office. from leaks. DOE recognizes that some of these soils and sediments are sufficiently contaminated to warrant retrieval and describes these as “ex situ contaminated media” in its summary report. If they are retrieved, both the pre-1970 buried waste and the ex situ media will be considered newly generated waste (DOE, 2001a). Table 2.1 gives an overview of DOE’s current and expected inventories of TM wastes. Disposing of retrievably stored TRU waste, which contains an estimated 2.6 million curies of radioactivity, in the Waste Isolation Pilot Plant (WIPP) is a top priority for DOE (Triay, 2001). Buried TRU waste, with a volume comparable to the stored TRU, is estimated to contain about 400,000 curies. A large volume of buried MLLW is contaminated with alpha-emitting isotopes at levels below the regulatory threshold for TRU waste and is designated as α-L LW.3 DOE expects to continue generating TRU waste until about 2034 and MLLW until about 2070, mainly from facility deactivation and decommissioning. In addition, DOE expects to produce ex situ waste by recovery of a portion of the more contaminated soils and sediments at some of its sites. The diversity of the TM waste inventory is described in the Mixed Waste Inventory Report (MWIR [DOE, 1995]). This report was based on data compiled by DOE sites as a basis for developing their site treat- 3   The radioactivity from alpha-emitting isotopes is estimated to be between 10 and 100 nanocuries per gram of waste.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes TABLE 2.1 Overview of DOE’s Transuranic and Mixed Wastes   Volume Origin TRU (m3) MLLW (m3) Buried (pre-1970) 137,000 317,000a Retrievably stored (1970-1999) 111,000 44,500 Predicted new waste generation 60,000b 100,000c Recovered soils and sediments (2002-2010) 32,000 170,000 a α-LLW. b 2000-2034. c 2000-2070. SOURCE: DOE, 2001a. ment plans as mandated under the Federal Facility Compliance Act of 1992. The inventory was divided into five treatment groups: debris, inorganic homogeneous solids and soils, organics, unique wastes, and wastewaters (see Sidebar 2.2). The treatment technologies for these groups were reviewed in a previous NRC (1999a) report. Table 2.2 shows the relative amounts of retrievably stored wastes that fit into each of the treatment groups. Debris waste, which is very heterogeneous, comprises by far the largest category. Unique wastes make up a small fraction of the inventory. However, many unique wastes are problematic to treat and dispose, and their small volumes make them economically unattractive to site cleanup contractors.4 No information is available concerning the treatment needs for the previously buried waste. DOE’s production processes did not change with the prohibition of burial in 1970, so these materials are expected to have a composition similar to retrievably stored waste. The distribution profile of wastes into the treatment groups is unlikely to change appreciably if buried wastes are retrieved. The 1995 inventory also indicates DOE’s level of confidence in how well the wastes were characterized. In general terms, DOE has high or medium confidence that the physical nature (i.e., soil or sludge) of most wastes is correctly identified but lacks confidence in the existing quantitative data on the wastes’ chemical and radioactive constituents (see Appendix B for details). 4   The TMFA recognized that unique wastes could become an obstacle to site closure and formed a Waste Elimination Team to identify and plan disposition of these orphan and hard-to-treat wastes (Hulet, 2002).

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes SIDEBAR 2.2 DIVERSITY OF TM WASTES For the purpose of developing site treatment plans for TM wastes, DOE established five treatment groups. The types of waste included in each group provide a perspective on the overall waste diversity. Debris Metal Debris: Metal with or without lead or cadmium Inorganic Nonmetal Debris: Concrete, glass, ceramic or brick, rock, asbestos, and graphite Organic Debris: Plastic or rubber, leaded gloves or aprons, halogenated plastics, nonhalogenated plastics, wood, paper, and biological matter Heterogeneous Debris: Composite filters, asphalt, electronic equipment, and other inorganic and organic materials Inorganic Homogeneous Solids and Soils Inorganic Homogeneous Solids: Particulate matter—such as ash, sandblasting media, inorganic particulate absorbents, absorbed organic liquids, ion-exchange media, metal chips or turnings, glass or ceramic materials, and activated carbon Inorganic Sludges: Wastewater treatment pond, off-gas treatment, plating waste, and low-level reprocessing sludges Other Inorganic Waste: Paint waste (chips, solids, and sludges), salt waste containing chlorides, sulfates, nitrates, metal oxides or hydroxides, and inorganic chemicals Solidified Homogeneous Solids: Soil, soil/debris, and rock/gravel Challenges in Managing the Inventory The current and projected volume of TRU waste will pose significant challenges for disposing of this waste. Several hundred thousand drums will have to be shipped to WIPP (see Table 2.1). The characterization required for shipping and acceptance at WIPP currently requires several hours and costs about four thousand dollars for each drum (DOE, 2001d).5 5   One cubic meter is equal to five 200-liter (55-gallon) drums, although WIPP can receive containers larger than 55-gallon drums.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes Organics Organic Liquids: Aqueous streams containing both halogenated and nonhalogenated organic compounds as well as pure organic streams containing halogenated and nonhalogenated compounds Organic Homogeneous Solids: Organic particulate matter (resins, organic absorbents), organic sludges (biological, halogenated, and nonhalogenated), and organic chemicals Unique Waste Lab Packs: Organic, aqueous, and solid laboratory chemicals and scintillation cocktails Special Wastes: Elemental mercury, elemental hazardous metals (activated and nonactivated lead, elemental cadmium), beryllium dust, batteries (lead acid, mercury, cadmium), reactive metals (bulk and reactive metal-contaminated components), pyrophoric fines, explosives or propellants, and compressed gases and aerosols All Others: Materials placed in a final waste form are included in this category Wastewaters Acidic, basic, and neutral aqueous liquids and slurries, including cyanide-containing wastewaters and slurries Source: DOE, 1995. Methods to streamline characterization are likely to save large amounts of time and money (see Chapter 3).6 Characterizing and treating MLLW, which has received relatively little attention compared to TRU waste, to meet Resource Conservation and Recovery Act (RCRA) disposal requirements will be a challenge. In spite of the lack of quantitative chemical characterization, most of the 6   Compositions of waste generated after about 1999 are well documented according to requirements of the WIPP permit (see next section). Additional characterization of this waste should not be necessary. TRU wastes will be generated until about 2035 (DOE, 2001a).

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes TABLE 2.2 Distribution (percent) of Inventoried Waste in Treatment Groups Group TRU MTRU MLLW Debris 95 71 57 Solids and soils 2 28 25 Organics 2 0.5 4 Unique 1 0.1 4 Wastewaters   0.1 9 NOTE: The MWIR distinguishes MTRU from TRU waste. About 2-4% of TRU and MTRU waste require remote handling. SOURCE: DOE, 1995. TABLE 2.3 Difficult-to-Treat Hazardous Components in DOE MLLW Percent of the Treatment Group that is Contaminated Type of Contamination Debris Organic Solids and Soils Unique Wastewater Metals 70 79 90 66 98 Solvents or other organics 77 90 75 23 27 Mercury 20 34 31 17 70   SOURCE: DOE, 1995 MLLW inventory is known to contain chemicals that are difficult to treat—heavy metals, solvents and other organics, and mercury (see Table 2.3). Further, there is considerable comingling of these classes of waste materials, making the selection of treatment options complicated. Some components in TRU waste are problematic for shipping or disposal in WIPP (see Appendix B). About half of DOE’S TRU waste contains organic materials that have posed shipping problems due to potential gas generation, especially hydrogen. However, recent revisions to the Safety Analysis for TRUPACT-II shipping containers have reduced but not eliminated the concern about hydrogen accumulation during shipment. Under the new revision, only about 2 percent of the TRU waste inventory (about 14,200 drum equivalents) continues to face shipping restrictions.7 Reactive and corrosive chemicals (including paint 7   Revision 19 to the Safety Analysis Report for Packaging for the TRUPACT-II (Curl et al., 2002).

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes FIGURE 2.3 Manual sorting of waste inside a containment (glovebox) facility is required to remove items that are prohibited by shipping or disposal restrictions. Sorting and repacking the waste are time-consuming, expensive, and present risks to workers. Source: DOE Richland Operations Office. spray cans, which are often found in waste drums) cannot be accepted at the WIPP, and they are removed by sorting through the waste (see Figure 2.3). Waste that is contaminated with polychlorinated biphenyls (PCBs), about 1 percent of the inventory, cannot currently be accepted by the WIPP. Approximately 2 to 4 percent of the TRU waste inventory produces enough penetrating radiation from fission product contaminants that it requires remote handling (RH-TRU), rather than hands-on operator contact. The requirement for remote handling greatly increases the difficulty of characterizing, treating, and packaging or repackaging this waste. Meeting per-drum limits on heat generation and fissile material content can require repackaging the waste (Curl et al., 2002; Moody, 2002). In addition to increasing the waste volume, repackaging to meet drum limits is expensive, time consuming, and creates a potential for worker exposure. Current and Evolving Regulatory Constraints All waste handling and disposal operations are governed by regulatory requirements. However, DOE faces a particular challenge in

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes managing TM waste due to the number of agencies that regulate this waste and the generally prescriptive nature of their regulations. At the federal level, TM wastes are the regulatory responsibility of DOE, the Environmental Protection Agency, and the U.S. Nuclear Regulatory Commission. Department of Transportation requirements apply to shipping the waste as well as packaging the waste for shipment. The Federal Facility Compliance Act of 1992 (FFCA) requires that DOE facilities comply with all federal, state, and local laws and regulations pertaining to hazardous waste. TM waste is thus subject to hazardous waste requirements promulgated by EPA under the Resource Conservation and Recovery Act of 1976 and subsequent revisions. The EPA has delegated its authority to many states, which may add additional requirements of their own. The FFCA did not alter the separation between DOE and the USNRC. DOE is legally self-regulating for radioactive wastes (or the radioactive components of wastes) according to the Atomic Energy Act of 1954. However, DOE follows USNRC guidelines as a practical matter.8 Additionally, the USNRC has licensing authority over commercially operated waste disposal facilities in which DOE is disposing of MLLW. For some of this waste, the states regulate in place of the USNRC.9 Transuranic Waste Currently, DOE’s TRU waste disposal efforts are focused on maximizing the utility of the Waste Isolation Pilot Plant, which is located deep underground in a salt formation in southeastern New Mexico. In 1992, the WIPP Land Withdrawal Act transferred control of the land at the site from the Department of Interior to the DOE. Subsequent amendments exempted WIPP from RCRA treatment standards and land disposal regulations (NRC, 1996). WIPP operates under a permit issued by the State of New Mexico, which allows it to receive only TRU waste resulting from the nation’s defense programs. DOE has committed in its permit application to manage all TRU waste as though it were mixed waste. In fact, the WIPP Waste Acceptance Permit (the Permit) specifically prohibits DOE from 8   DOE Order 435.1 Radioactive Waste Management meets and extends provisions of USNRC waste management and radiation protection regulations, which are described later in this section. 9   Under the Low-Level Radioactive Waste Policy Amendments Act of 1985, an “agreement state” is a state that has entered into a formal agreement with the USNRC and has the authority to regulate disposal of low-level radioactive waste within the state.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes disposing non-mixed TRU waste unless the waste has been characterized in compliance with applicable provisions of the Permit. This is to avoid any question of New Mexico’s having authority to regulate radioactive waste that is not subject to RCRA. The Permit recognizes two classes of TRU waste: retrievably stored and newly generated. Retrievably stored refers to waste generated after 1970 but before the characterization requirements of the Permit were implemented at DOE sites (in about 1999). Newly generated refers to waste generated more recently. If wastes buried before 1970 or contaminated soils are retrieved, they will be considered as newly generated waste upon retrieval (see Table 2.1). Within each waste class, the Permit further categorizes three broad groups related to the physical form of the waste: homogeneous solids, soils and gravels, and heterogeneous debris (see Table 2.2). Under the Permit, every retrievably stored waste container undergoes either radiography or visual examination to identify the physical form of the waste and to ensure that prohibited materials are absent.10 Headspace gas analysis to determine the presence of volatile organic compounds (VOCs) must be performed on every container. Containers are assayed to be sure that their heat generation and fissile material content are within Permit limitations. In addition, some homogeneous solids and soil or gravel wastes must be sampled to establish the concentrations of VOCs, semi-VOCs, and metals for hazardous waste characterization. Currently, the Permit is limited to wastes that produce a radiation dose rate of less than 200 millirem per hour at the surface of the container. This waste is called contact-handled TRU waste (CH-TRU) because it is deemed safe for direct handling by workers. Waste that produces more then 200 millirem per hour, about 2 to 4 percent of the TRU inventory, is designated remote-handled TRU waste. Because RH-TRU presents a potential hazard to workers, DOE is seeking regulatory changes to simplify its characterization. The State of New Mexico and the EPA have not yet approved a DOE plan to characterize RH-TRU waste.11 As noted later in this chapter, EMSP research will be especially important if DOE’s expected regulatory changes to simplify characterizing RH-TRU and dealing with other problematic wastes are not forthcoming. 10   Prohibited materials include liquids, compressed gases, PCBs in concentrations of 50 parts per million or more, and ignitable, corrosive, or reactive materials. 11   Another NRC committee is assessing characterization requirements for remote-handled TRU waste (NRC, 2002b).

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes Mixed Low-Level Waste Unlike TRU waste, MLLW has no special exemptions from regulatory controls. DOE is relying primarily on private contractors and commercial facilities to meet EPA and USNRC requirements for treating and disposing of its MLLW. MLLW cannot be disposed in WIPP because it does not qualify as TRU waste.12 The EPA has developed regulations for hazardous waste management and disposal principally under the authority of RCRA enacted in 1976.13 RCRA has been amended several times, with the most significant amendments passed in 1984 as the Hazardous and Solid Waste Amendments. RCRA provides for cradle-to-grave control of hazardous wastes by imposing management requirements on generators and transporters of hazardous waste and on owners and operators of treatment, storage, and disposal facilities. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, also known as Superfund) of 1980 addresses threats to public health and the environment from abandoned or active sites contaminated with hazardous or radioactive materials. Reauthorized by Congress in the Superfund Amendments and Reauthorization Act (SARA) of 1986, CERCLA gives EPA the authority to require remediation of hazardous waste previously disposed at DOE sites. Compliance with CERCLA may require the retrieval of some previously buried mixed wastes. The EPA’s hazardous waste regulations apply to more than 500,000 companies and individuals throughout the United States (Case, 1991). Thus, the EPA uses a prescriptive approach to develop regulations that are almost universally applicable and contain straightforward numerical criteria that are relatively easy to understand and enforce. The EPA defines hazardous waste, specifies treatment standards that must be met prior to disposal, and specifies standards for construction and operation of hazardous waste disposal sites. For DOE MLLW, which includes relatively small quantities of many wastes that are diverse and heterogeneous, this universal prescriptive approach poses problems. A Memorandum of Understanding (MOU) between DOE and EPA to help resolve these problems was signed in February 2000 (Eaton and Carlson, 2002). Under the auspices of this memorandum, DOE and EPA have established several joint agency work groups to address issues 12   The basis for excluding MLLW is legal rather than technical. 13   A history of EPA regulation of mixed waste beginning in 1976 can be found on the EPA Mixed Waste Team home page: http://www.epa.gov/radiation/mixed-waste/.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes such as alternatives to incineration, mercury-waste treatment and disposal, HEPA (high-efficiency particulate arresting) filter monitoring, and generally difficult technical issues where mixed waste does not fit well with the land disposal restriction treatment standards. The MOU also lists a number of recent EPA regulations that are likely to affect DOE’s plans and technical needs for managing MLLW (see Sidebar 2.3). USNRC regulations that affect the management of MLLW include the Low-Level Waste Disposal Regulations (10 CFR 61) and Radiation Protection Standards (10 CFR 20). The USNRC regulates the radioactive characteristics of low-level waste materials acceptable for near-surface land disposal through a combination of prescriptive and performance-based requirements. Performance assessment is required to calculate worker and public exposure risks associated with waste disposal. According to the USNRC, a near-surface disposal facility is one in which radioactive waste is disposed within the upper 30 meters of the land surface. Institutional control of access is required for 100 years, and within 500 years, wastes must decay to a sufficiently low level that the remaining radioactivity will not pose unacceptable hazards to an intruder or the general public. To meet this latter requirement, further prescriptive regulations define three classes of waste that are deemed suitable for near-surface disposal. Classification as Class A (the easiest to dispose), Class B, or Class C depends on which radionuclides are present and their concentrations (see Table 2.4). If the waste qualifies as TRU or is contaminated above certain limits with long-lived radionuclides, it is not suitable for near-surface disposal.14 DOE expects to use Envirocare’s Utah facility to dispose of about 30 percent of its MLLW (DOE, 1997). This is a commercial facility located in Tooele County, Utah, which is permitted for the disposal of several types of waste. This facility also provides some treatment capabilities, including stabilization by converting the waste to a solid material, macroencapsulation, and microencapsulation (see Chapter 3). The State of Utah has permitting authority for low-level waste and hazardous waste using USNRC and EPA rules, respectively. Currently the facility is licensed to receive only USNRC Class A radioactive waste and naturally occurring or accelerator-produced material. Disposal of Class B or C waste requires additional approvals by the Utah Radiation Control Board (already issued), the governor, and the Utah legislature. However, it is not clear at this time if Envirocare will pursue these approvals. 14   Mining industry waste is excluded from this requirement.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes SIDEBAR 2.3 ENVIRONMENTAL PROTECTION AGENCY (EPA) ACTIVITIES AFFECTING DOE MIXED WASTE A number of EPA’s regulatory activities that are under way or have been completed recently will impact mixed waste storage, treatment, and disposal. Research and development are necessary to support the development of emerging rules and to comply in a cost-effective manner with rules that have been finalized. Examples of regulatory activities that likely will drive research and development needs within the next three to five years include the following: Mercury Hazardous Waste Treatment Standards—Notice of Data Availability. The EPA, working with DOE, is evaluating technologies to stabilize mercury-containing wastes that are not suited for mercury recovery and elemental mercury stocks. These studies will describe the conditions under which various treatment process residues may remain stable in a landfill over the long term. The data report is being prepared and will be subjected to peer review. A Notice of Data Availability containing the data and the peer review results is expected in late 2002. Mercury Action Plan. This consists of an assembly of potential regulatory and voluntary actions, enforcement and compliance, research, and outreach to characterize and reduce risks associated with mercury. Its multimedia and cross-discipline focus and its emphasis on pollution prevention will impact mixed wastes containing mercury. Estimated completion is expected in late 2002. Hazardous Waste Combustion Emission Standards. On September 30, 1999, EPA promulgated standards to control emissions of hazardous air pollutants from incinerators, cement kilns, and lightweight aggregate kilns that burn hazardous wastes (referred to as the Phase I rule). A number of parties, representing the interests of both industrial sources and the environmental community, sought judicial review of the rule. On July 24, 2001, the United States Court of Appeals for the District of Columbia Circuit granted the Sierra Club’s petition for review and vacated the challenged portions of the rule. On October 19, 2001, after several months of negotiation, EPA, together with all other petitioners that challenged the hazardous waste combustor emission standards, filed a joint motion asking the court to stay the issuance of its mandate for four months to allow time to develop interim standards. These stopgap interim standards were promulgated on February 13 and 14, 2002. They replace the vacated standards temporarily, until revised replacement standards are promulgated in 2005 through a full Along with using commercial disposal facilities, DOE sites can establish on-site facilities. Both the DOE Hanford Site and the Nevada Test Site are developing RCRA-compliant facilities for their own wastes and might receive waste from other sites in the future (see Figure 2.4).15 In summary, MLLW that contains certain specified materials is pro- 15   Hanford’s MLLW facility is operating under an interim permit. Hanford expects to be fully permitted to accept MLLW in about 2003. The Nevada Test Site expects to have permits in about 2004 (Maio and Reese, 2002).

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes notice-and-comment rule making that complies with the court’s mandate. Also, EPA is developing Maximum Achievable Control Technology (MACT) standards for hazardous waste burning boilers and hydrochloric acid production furnaces as a second phase (Phase II) of the hazardous waste combustor (HWC) National Emission Standards for Hazardous Air Pollutants (NESHAP). DOE facility compliance date for the interim standards is September 30, 2003. PCB “Mega-Rule”. On June 29, 1998, EPA promulgated amendments to the regulations in 40 CFR 761 that significantly affect the use, manufacture, processing, distribution in commerce, and disposal of PCBs. This Mega-Rule affects mixed wastes containing PCBs. Among other things, the amendments provide new alternatives for the cleanup and disposal of PCBs, establish standards and procedures for decontaminating materials contaminated with PCBs, and create a mechanism for recognizing, under the Toxic Substances Control Act, other Federal or State waste management permits or approvals for PCBs. The rule became effective in August 1998. LDR Phase IV and Progeny. On May 26, 1998, EPA promulgated treatment standards for characteristic metal-bearing wastes, including mixed wastes, under the RCRA Land Disposal Restrictions (LDR) program. The regulations also adopted alternative treatment standards for soil contaminated with hazardous waste. On May 11, 1999, this rule was corrected and clarified, particularly with respect to treatment residuals and point of generation—both of which directly affect DOE mixed waste facilities. DOE facility compliance date was August 1998 for metal standards; authorized state programs control the effective date of soil treatment standards. Hazardous Waste Identification Rule. On May 16, 2001, EPA published a final rule, known as the Hazardous Waste Identification Rule (HWIR) that retained, with revisions, the mixture rule and the “derived-from” rule in the RCRA regulations (66 FR 27266). The revisions to the mixture and derived-from rules exempt mixtures and/or derivatives of wastes listed solely for their ignitability, corrosivity, and/or reactivity characteristics and also conditionally exempt certain mixed waste from the mixture and derived-from rules. Effective date of final rule was August 14, 2001. SOURCES: EPA Office of Solid Waste and DOE Office of Science and Technology. hibited from near-surface disposal under current EPA and USNRC regulations. These include the following: liquids, reactive or explosive materials, flammable material, untreated biological material, materials that may emit toxic gases or fumes, other materials subject to EPA’s LDR, as listed in 40 CFR 268,

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes TABLE 2.4 Allowable Concentrations of Short-Lived Radionuclides for Near-Surface Disposal   Class A Waste Class B Waste Class C Waste Radionuclide (Ci/m3) (Ci/m3) (Ci/m3) Total of all nuclides with less than 5-year half-life 700 a a H-3 40 a a Co-60 700 a a Ni-63 3.5 70 700 Ni-63 in activated metal 35 700 700 Sr-90 0.04 150 7,000 Cs-137 1 44 4,600 a: There are no limits for these radionuclides in Class B or C wastes. Practical considerations such as the effects of external radiation and internal heat generation on transportation, handling, and disposal limit the concentrations for these wastes. SOURCE: Code of Federal Regulations, Title 10, Part 61.55. FIGURE 2.4 RCRA requirements for disposal of MLLW include use of an impermeable liner and leachate collection system to provide total containment of hazardous chemicals for at least 30 years. Here, a large box of macroencapsulated waste is being placed in a RCRA-compliant disposal facility at Hanford. Source: DOE Richland Operations Office. and radioactive isotopes in amounts that exceed USNRC Class C. In order to be disposed, these wastes require treatments that may be technically difficult and expensive, as described in Chapter 3.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes Evolving Regulations In establishing criteria for accepting waste at the Waste Isolation Pilot Plant, DOE attempted to combine complex regulatory programs with what were expected to be the performance characteristics of the WIPP system, even as WIPP was being designed and built. In hindsight, as actual operation experience is gained, some of the self-imposed and rather restrictive requirements are proving impractical and perhaps even irrelevant from a health and safety perspective, such as the PCB limitations and the lengthy characterization protocols. A previous NRC report (2001d) concluded that the requirements should be reviewed and updated so that the criteria (referred to as waste acceptance criteria, WAC) are kept relevant to long-term performance of the repository and to safety, technical, and legal considerations. DOE has focused its efforts on simplifying the regulatory requirements for wastes that might be prohibited from disposal at WIPP or that might be sidelined due to failure to meet the WAC, particularly because of characterization difficulties. For example, DOE has prepared a draft request for authorization to allow the disposal at WIPP of TRU wastes containing PCBs. Approval of this request would allow DOE to dispose of approximately 88,000 cubic feet (2,500 cubic meters) of TRU wastes containing PCBs subject to regulation under the Toxic Substance Control Act (TSCA). In addition, DOE is also drafting requests for options for waste characterization being conducted at its sites that send waste to WIPP for management and disposal. DOE is particularly interested in simplifying the requirements for characterizing its RH-TRU waste (NRC, 2002b). EPA requirements that will affect DOE’s management of MLLW for the next three to five years are identified in the MOU (see Sidebar 2.3). Given EPA’s broad responsibility to regulate hazardous waste, additional future regulations affecting MLLW are inevitable. Public Concerns The views and concerns of members of the public will play an important role in establishing needs for improved technologies or changing agreed-upon plans for managing TM wastes. The statement of task for this report included evaluating treatment technologies for categories of TM waste for which current treatment technologies are not adequate, “in particular due to new or tightened regulatory requirements or other non-technical considerations such as nascent public opposition to incineration” (see Sidebar 2.4 and Appendix C).

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes SIDEBAR 2.4 PUBLIC CONCERNS ABOUT INCINERATION FOR TREATMENT OF TM WASTE DOE’s recognition that the public might oppose some of its waste treatment technologies arose from a lawsuit over plans to construct an incinerator for TM wastes at the Idaho National Engineering and Environmental Laboratory. To settle the suit, DOE appointed a Blue Ribbon Panel of independent experts to identify technological alternatives to incineration that might become available for use at DOE facilities nationwide (DOE, 2000b).1 Subsequently, DOE formed an Alternatives to Incineration Committee (ATIC) to follow-up the technical and public perception issues involving the proposed alternatives.2 To assist the ATIC, the INEEL Citizens Advisory Board produced a list of some 44 concerns for ATIC to consider in evaluating alternatives to incineration. About half are listed below as examples of the range and detail of citizens’ concerns. Size (mobility) of facility Cost of facility Complexity of operation Temperature Pressure Hazardous reagents Energy efficiency Maturity of technology Availability (ability to implement) in the short term Air emissions Type(s) of waste generated Volume(s) of waste generated Validity of monitoring results Disposition of waste generated Effects on worker and public health and safety Environmental impacts Residual effects or impacts that cannot be mitigated Acceptability to Shoshone-Bannock Tribes Description of catastrophic failure or credible accident scenario Description of off-normal operation Vulnerability to off-normal operation Emissions resulting from off-normal operations 1   Settlement Agreement: Keep Yellowstone Nuclear Free v. Richardson, et al.; No 99 CV1042J (D.WY). 2   The co-chairman of ATIC, Victoria Tschinkel, is a member of the committee that developed this report.

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes During its site visits the committee heard from citizen groups at the Idaho National Engineering and Environmental Laboratory (INEEL), the Oak Ridge Reservation, and the Savannah River Site (see Appendix E). The committee did not hear a consistent opposition to incineration, but it did hear concerns about air emissions, buried waste retrieval, and monitoring. These broader concerns indicated that citizens are generally well informed about potential technology-related problems near their communities. Importantly, they expected DOE to address their concerns. The committee believes that the key is not simply to develop new technologies to replace those that have raised public concern—to try to stay technologically one step ahead of the public—but rather to involve the public in the selection of technologies. The need for public participation is well documented (Chopayk and Levesque, 2002; Cohn, 2002; see also Busenberg, 1999). An earlier NRC study emphasized the importance of involving the public in choosing among technical options (NRC, 2001c, p. 24): The challenge is therefore not just to identify options that are deemed suitable by technical experts. . . . Support for any chosen technology will be difficult to achieve unless options for managing wastes can be presented, together with their consequences, and the public can participate in choosing among those options. The committee agrees with this assessment. Any new technologies or changes in accepted cleanup plans are likely to encounter public concerns or opposition unless convincing scientific evidence for their adoption can be presented and citizens are involved in decision making. Providing a scientific basis for decision making that can be understood in the public forum is as important a role for the EMSP as providing routes to new technology. Summary: Meeting TM Waste Challenges DOE’s efforts are focused on removing TM wastes from its sites as rapidly as possible. Although the focus is on near-term accomplishments, in the broader perspective DOE’s waste inventory is large and diverse and wastes will continue to be produced by both site cleanup and new activities. During the course of DOE’s several-decades-long, multibillion-dollar cleanup program, there are certain to be many changes as technology and regulations evolve and citizens express their concerns through the political process. There are both time and opportunity for EMSP research to produce new technologies to significantly

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Research Opportunities for Managing the Department of Energy’s Transuranic and Mixed Wastes enhance safety and reduce costs and uncertainties in DOE’s management and disposal of its TM wastes.16 TRU waste disposal in the Waste Isolation Pilot Plant will require handling and characterizing hundreds of thousands of drums as well as larger containers during the next 20 or more years. DOE is working with pertinent regulators to reduce or eliminate restrictions that may not be necessary for reducing risk and that interfere with waste shipments or disposal. DOE expects this regulatory relief to help accelerate site cleanup and closure. Conversely, DOE has encountered legal, economic, and public concerns about incineration, a technology that was expected to treat a large fraction of the TM waste inventory. Some buried wastes and contaminated soils, which DOE previously considered disposed, may have to be retrieved and treated as new wastes. Monitoring WIPP and other waste disposal facilities will continue for many years. In view of the changes and challenges that DOE will be facing for decades, there are two clear roles for EMSP-funded research in DOE’s TM waste management efforts: To provide the scientific basis for new technologies that will be necessary for improving management and disposal of TM wastes during at least the next 20 years, especially if the regulatory changes that DOE expects to simplify dealing with problematic wastes are not forthcoming. To enhance the scientific information available for regulatory decision making and public involvement, including evidence that disposal systems are operating as intended. 16   This committee follows previous committees in noting that adequate research funding is a prerequisite for realizing benefits of new technologies (NRC 2000a, 2001a, 2001b, 2001e).