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Science and Technology for DOE Site Cleanup: Workshop Summary 3 Workshop Summary This chapter provides the rapporteur’s summary of the presentations and discussions that took place at the March 13, 2007 workshop entitled “Development and Implementation of a Cleanup Technology Roadmap for DOE’s Office of Environmental Management.” As noted in the Preface, this workshop was organized by the National Research Council (NRC) to bring together regulators and other interested parties to discuss current site conditions and science and technology needs. The workshop agenda and participants are provided in Appendixes B and C, respectively. OPENING COMMENTS The organizing committee invited two speakers to provide opening remarks to help establish the context for the day’s workshop discussions: Mr. Mark Gilbertson (Deputy Assistant Secretary, Office of Engineering and Technology, Department of Energy Office of Environmental Management [DOE-EM]) provided an overview of DOE’s progress in site cleanup, future challenges, and DOE’s rationale for requesting the workshop and Phase 2 study (the Phase 2 study is described in the Preface). Ms. Terry Tyborowski (Staff Assistant, House Committee on Appropriations, Energy and Water Development Subcommittee) provided a congressional perspective on technology utilization in DOE’s cleanup program. Mr. Gilbertson noted that EM has made good progress in site cleanup, but great challenges remain. With the successful closure of some smaller DOE sites (e.g., Rocky Flats in Colorado and sites in Ohio), the cleanup program is becoming increasingly focused. Most of the future cleanup work will be carried out at the DOE sites that are the focus of this workshop: Hanford, Idaho, Oak Ridge, Savannah River, Paducah, and Portsmouth. It will cost an additional $100 billion and require several decades to complete the currently planned cleanup programs at these sites. There are additional DOE sites (operated by the National Nuclear Security Administration, Office of Nuclear Energy, and Office of Science) that could be added to EM’s cleanup program in the future. At present there is no indication that the cleanup challenges at these sites are markedly different than what EM already faces at its current sites.
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Science and Technology for DOE Site Cleanup: Workshop Summary However, there is a substantial amount of new deactivation and decommissioning (D&D) work, particularly at sites like Y-12 at Oak Ridge. Congress has asked EM to provide its vision for bringing greater technical innovation to bear in its cleanup program. That office is preparing a technology roadmap for Congress that identifies targets of opportunity for the more effective use of cleanup technologies. An abbreviated version of the roadmap is expected to be submitted to Congress at the end of March 2007.1 The roadmap will be routinely updated in the future as new information becomes available. EM has requested this National Academies study to help with its roadmap development efforts. EM hopes that this study can help identify opportunities to make targeted investments in technology and to leverage the resources and capabilities of other organizations, including other DOE offices. The primary focus of this workshop is to assess whether EM is missing any technology development opportunities at its sites, specifically with respect to high-level waste cleanup, soil and groundwater cleanup, D&D of facilities, and waste and contamination containment. The current centralized technology development program within EM for addressing these cleanup challenges is small (about $20 million per year) and focused, unlike the $300 million to $400 million per year investments in the mid-1990s. However, there is a willingness on the part of EM management to expand support if a new vision for technology development can be articulated. This workshop is the first phase of a two-part study. The second phase of the study2 will provide advice to EM on leveraging the resources and capabilities of other organizations, including other offices within DOE, and preserving critical assets at the national laboratories so that they are available to support the long-term cleanup mission. EM does not need to manage the national labs to have access to their capabilities. However, EM does need to provide and manage resources for people, programs, and facilities, and it needs to keep national laboratory staff working on its problems. EM now spends between $150 million and $200 million per year at national laboratories for direct and indirect technical support of its cleanup projects. It is not clear, however, that these investments are being managed in a strategic manner. The transfer of the EM Science Program to the Office of Science is a case in point. When the Office of Science contacted the sites for advice on high-level waste research, site responses focused on short-term needs. The Office of Science interpreted this response as an indication that the sites did 1 A draft version of the roadmap was delivered in mid April 2007. 2 As noted previously, the Phase 2 study is described in the Preface.
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Science and Technology for DOE Site Cleanup: Workshop Summary not have any longer-term needs that could be addressed by the EM Science Program. Consequently, the Office of Science decided to focus that program on subsurface research instead. EM has reengaged the Office of Science to correct this miscommunication. A member of the audience asked Mr. Gilbertson if EM was providing direct support to the national laboratories. Mr. Gilberston responded that most EM support to the national laboratories is presently being done through cleanup contractors. There might be opportunities to provide funding directly to the labs in the future, but EM wants advice on capabilities and infrastructure that should be supported. He noted that EM also invests about $20 million per year in university research activities. Another audience member asked whether the cleanup technology roadmap addresses buried waste and spent fuel and nuclear materials management. Mr. Gilbertson noted that buried waste is addressed in the roadmap under soil and groundwater cleanup needs. The current draft of the roadmap does not address management of spent fuel or nuclear materials. An audience member suggested that EM will need to provide a continuous source of funding if it wants to maintain capabilities at the national laboratories. Mr. Gilbertson agreed that critical capabilities need to be looked after by EM, but that there were other federal agencies that could provide some of the needed funding. For example, the Department of Homeland Security has picked up some of the research and development (R&D) on sensors that was formerly funded by EM. Ms. Tyborowski began her remarks by noting that the Energy and Water Development Committee is frustrated by the lack of utilization of new technology in EM’s cleanup program. The committee has received complaints from companies about EM’s resistance to the use of company-developed technologies. At the same time, there is a legacy of pauses, stops, and reevaluations of cleanup projects because technology does not get inserted at the right time. The committee does not understand the reasons for the resistance to new technology utilization. The Energy and Water Development Committee agrees that there is a need for more innovative technology in the cleanup program. The committee is also happy to see that EM is rebuilding its technology programs and is ready to support increased technology investments. EM’s cleanup work needs to be done smartly by taking advantage of new technologies, rather than the current focus on “fast” and “cheap.” EM’s use of design-build projects to cut costs and save time is not working. The committee agrees with a Government Accountability
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Science and Technology for DOE Site Cleanup: Workshop Summary Office3 report that there should be a gauge of technology maturity before a cleanup project moves forward. The Energy and Water Development Committee is encouraged that the National Academies are looking at technology development needs. The Academies can speak independently, and its reports cannot be edited by the administration. It would be helpful to Congress if the Academies could identify the barriers for inserting new technologies into the cleanup program. It would also be useful to have advice on technology investment priorities and criteria (e.g., safety and mortgage cost reduction) for prioritization. During the question and answer session following Ms. Tyborowski’s formal remarks, a national laboratory staff member offered comments about barriers to new technology deployment. He noted that cleanup projects are contract driven: contractors get paid to execute the contracts and are penalized if contract obligations are not met. There are few incentives in current contracts for the deployment of new technologies. Also, there is often not enough money to do all of the necessary planning up front, which requires that projects be implemented in stages. It is hard to predict “show-stopper” problems until they are encountered during project execution, and by that time there is pressure to spend additional time and money to solve the problem rather than select another technology. A cleanup contractor listed several obstacles for getting new technologies used in the cleanup program: lack of continuity of site contractors; use of performance-based contracts that lack incentives for contractors to use new technologies; and the cost of paperwork for revisions to agreed-upon work, especially for safety documentation. In short, contractors have zero or negative incentives for using new technologies. Another contractor noted that new technologies such as caustic side solvent extraction, which will be used to process salt waste at Savannah River in place of in-tank precipitation, have taken years to reach maturity. He suggested that EM should look to the nuclear industry for mature technologies to add to its cleanup toolbox. A state regulator expressed support for the development of the cleanup technology roadmap. She noted that the closure of tanks at the Savannah River Site will be carried out from 2010 to 2022, and that not all of the tools necessary to close the tanks are available at present. She commented that there is still time to develop such tools 3 Department of Energy: Major Construction Projects Need a Consistent Approach for Assessing Technology Readiness to Help Avoid Cost Increases and Delays, GAO-07-336, March 27, 2007, available at http://www.gao.gov/cgi-bin/getrpt?GAO-07-336.
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Science and Technology for DOE Site Cleanup: Workshop Summary and that regulatory drivers can provide the necessary pressure and incentives to do so. Another state regulator noted that without continued regulatory pressure, cleanup progress tends to stall. He commented that regulators have the flexibility to allow EM to introduce new technologies into its cleanup projects. CLEANUP CHALLENGES AT FOUR DOE SITES Panel sessions were organized for each of the four large DOE sites: Hanford, Idaho, Oak Ridge, and Savannah River. For each panel session a DOE staff member initiated the discussion by providing comments on site science and technology gaps and/or the underlying site technology needs and cleanup challenges. The panelists were then invited to provide comments on these DOE-identified gaps (or the underlying technology needs and cleanup challenges) and to identify other gaps that require attention. The DOE speakers and panelists were also encouraged to comment on the science and technology gaps identified in the workshop discussion paper—particularly with respect to the current relevance of those identified gaps to their sites. Following panel comments, questions and comments from the audience were invited. Savannah River Site Cleanup challenges and technology needs at the Savannah River Site were reviewed by Panelist Pat Suggs (Chemical Engineer, DOE Savannah River Operations Office, Salt Processing Division). She noted that the primary objective of the cleanup program at the site is to meet federal facility agreement commitments for waste retrieval and tank closure, solidification of high-level waste at the Defense Waste Processing Facility (DWPF), and processing and disposal of low-activity waste at the Salt Processing Facility. While meeting these regulatory commitments, DOE-EM is also trying to preserve working tank space, which is in very short supply, for its current and future waste processing operations (e.g., operation of the H Canyon,4 DWPF, and the Salt Waste Processing facility [SWPF]). EM’s principal high-level waste cleanup challenges include: 4 DOE-EM has proposed to extend the operation of the H Canyon at the Savannah River Site through 2019 to process 26 metric tons of highly enriched uranium and 2 metric tons of plutonium, mostly from aluminum-clad spent fuel that is now being stored at the site.
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Science and Technology for DOE Site Cleanup: Workshop Summary Removal of residual high-level waste from tanks and waste transfer lines: Removal of sludge “heels” (i.e., the sludge remaining after bulk waste retrieval is completed) from tanks, especially tanks with internal obstructions such as cooling coils. Removal of waste from the spaces (annuli) between the inner and outer tank containments in tanks that have leaked. Removal of residual waste from transfer lines between tanks and other facilities. Reduction of sludge mass to be sent to the DWPF for immobilization in glass. Improvements in waste processing to preserve working tank space to support future site operations. Savannah River is examining a number of technologies for meeting these cleanup challenges. For residual waste removal, the site will employ an oxalic acid cleaning technology in two tanks. However, the use of oxalic acid can cause hydrogen generation and can have downstream processing impacts. The site hopes to develop an alternate technology that does not have these impacts for future tank cleaning operations. The site also hopes to employ new mechanical cleaning technologies in tanks with cleaning coils, especially technologies that use little or no added water. Recent analytical projections indicate that there is more mass such as aluminum, iron, and nickel in the sludge waste in the tanks than initially anticipated. These projections are based on samples of sludge waste sent to the DWPF for vitrification. Under worst-case projections, it could take 12 years to process the additional sludge mass, and this processing could produce an additional 2000 canisters of vitrified (glass) waste. EM currently spends about $500 million per year on its high-level waste operations at the site, so the incentive for reducing excess sludge mass is very high. EM has not yet identified clear final technologies for sludge mass reduction. The site has some historical experience with tank farm aluminum dissolution by sodium hydroxide that could be used to reduce sludge mass. The site plans to involve industry and other national labs/DOE sites to identify alternative technologies. For waste processing improvements, the site hopes to implement technologies to improve waste throughput in the DWPF, possibly through a combination of higher waste loadings in glass (current waste loadings are 37 to 38 percent), new melter technologies, and relaxing current compositional standards for glass products. The site will also examine approaches for speeding up the preparation of
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Science and Technology for DOE Site Cleanup: Workshop Summary sludge batches to be fed to the DWPF and for minimizing the addition of water during sludge processing. Panelist David Wilson (Bureau Chief, South Carolina Department of Health and Environmental Control) commented that high-level waste cleanup was the highest priority for the state of South Carolina; getting the tanks closed is “paramount” to the state. Cleaning tanks with cooling coils, tanks with waste in the annuli, and waste transfer lines are significant technical challenges. The state is also interested in the disposition of surplus plutonium, which is being consolidated at the site. Some of this surplus plutonium could be used in mixed oxide fuel, but some may have to be processed through the DWPF. Disposition of this material is a significant concern to the state. Panelist Shelly Sherritt (Federal Facilities Liaison, South Carolina Department of Health and Environmental Control) reiterated the state’s interest in tank closure and also noted the state’s interest in minimizing the quantity of radionuclides left onsite from high-level waste cleanup. The state is relying on the SWPF to remove radionuclides from the tank waste, but the state does not want Savannah River to “put all of its eggs” in the SWPF basket. An important lesson from the site’s transuranic waste cleanup program is that targeted technologies can be used in innovative ways to meet cleanup goals. This approach is now beginning to be extended to the high-level waste cleanup program, for example, through the use of new technologies to treat the waste in Tank 48 (from the unsuccessful in-tank precipitation process) to remove about 800,000 curies of radioactivity. Other technology needs at the site include advanced technologies for characterizing and stabilizing residual waste in the tanks; technologies to improve waste storage in tanks to minimize risks and chip away at the conservatism that limits operational flexibility; advanced soil and groundwater remediation technologies; and low-worker-risk technologies for characterizing retrievable transuranic waste that is now being stored in soil-covered drums on pads. Panelist John Marra (Associate Laboratory Director, Savannah River National Laboratory) noted that the high-level waste at Savannah River is relatively uniform in composition and that there are established disposition pathways for this waste. The site has encountered surprises in processing some of this waste (e.g., the recent analytical projection of a larger-than-anticipated sludge mass in the tanks), and the limited working space in the tanks continues to hinder operational flexibility. The current operating environment is conservative from a safety standpoint, which further limits operational flexibility. The carbon steel construction of the tanks limits options for in-tank processing of waste as well as waste retrieval.
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Science and Technology for DOE Site Cleanup: Workshop Summary The site has been very successful in maintaining the high-level waste tanks in a safe condition, which tends to promote a status quo operating mentality that can prevent progress from being made. In particular, there is a tendency to wait for “best” cleanup solutions that are more complex and time consuming to implement. The Savannah River National Laboratory receives $60 million to $70 million per year for EM-related work; much of this funding is project directed. In the past the lab received direct funding to work on EM problems, but direct funding was eliminated when the cleanup work was “projectized.” It is difficult to sustain R&D programs in the absence of direct funding. Questions and Discussion Questions from the audience covered a wide range of cleanup and closure challenges, some of which were not mentioned by the panel is its initial round of comments. Ms. Suggs was asked whether current EM investments in tank cleanout technology development were sufficient to meet site needs. She responded that current investments were project directed and were being made in real time. This work is also being carried out in real tanks because the site does not have a cold test facility (a realistic mock-up of an actual tank). Additional funding can always be used, but such funding is hard to find. Dr. Marra commented that cleanup schedules and budgets require that technology development be done in parallel with actual cleanup. The panel was questioned about the level of technology development for cleanout of tanks with cooling coils. Ms. Suggs noted that tank cleanout is the site’s first priority to meet regulatory milestones. She reiterated that oxalic acid and other methods are being tried. Dr. Marra commented that there is debris in many tanks (e.g., measuring tapes, spent zeolite from ion exchange columns), which also makes cleanout difficult. Ms. Sherritt commented that the state of South Carolina will not approve closures of tanks that contain too much residual waste. She also noted that the schedules for cleanout of Tanks 18 and 19 are being adjusted so that EM can try new retrieval technologies. Ms. Suggs was asked whether the lack of knowledge about tank waste composition was hindering progress in the program. She responded that characterization is carried out on an as-needed basis. The contractor samples the waste that is removed from tanks to obtain characterization information. Ms. Suggs was also asked to elaborate on needs for post closure monitoring. She noted that DOE plans to monitor the tanks after closure but has not yet developed detailed plans to do so. She
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Science and Technology for DOE Site Cleanup: Workshop Summary speculated that monitoring might involve instrumentation in the tank annuli. Dr. Marra suggested that EM might also want to try some new monitoring approaches, for example, placing instrumentation directly into the grouted tanks. He commented that it is hard to find funding for monitoring technology development. An audience member asked Ms. Suggs to elaborate on technology priorities for D&D of site facilities. She responded that the site’s priorities are worker protection and characterization of hot spots. EM needs to determine whether it is better to fix contamination in place or remove it. The audience member asked whether current technologies were sufficient for containing contamination in place. Ms. Suggs commented that EM was testing some technologies (e.g., phosphate cements), but additional technologies might be needed. Dr. Marra commented on the importance of leveraging technology development from other organizations in other parts of the world. An audience member asked whether retrieval of buried waste was an important site cleanup challenge. Ms. Sherritt noted that EM must retrieve transuranic waste stored on pads, but this was not as critical an issue as high-level waste retrieval. A regulatory decision has already been made to leave waste in place in the burial grounds at the site. Finally, an audience member asked whether the time frame for technology development and deployment (“10 years or more”) described in the workshop discussion paper (which is incorporated into Chapter 2 of this report) was realistic. Dr. Marra commented that 10 years is not a bad number for deployment of innovative technologies. He pointed out that the success of such deployments can be enhanced through the use of test facilities. He offered as an example the deployment of new waste processing and vitrification technologies in the DWPF. While that facility was being designed and constructed, the site operated a pilot facility at a cost of about $30 million per year to work on technology issues. Ms. Suggs commented that it takes three to four years to develop simple technology. She commented on the importance of early and sustained technology investments so that contractors have the technology when they need it. Idaho Site Panelist Scott Van Camp (Assistant Manager, DOE Idaho Operations Office) opened the discussion with a short presentation of the Idaho Site’s cleanup challenges and technology needs. The Office of Nuclear Energy is the landlord of the site; EM is responsible for site cleanup. This cleanup is proceeding under several
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Science and Technology for DOE Site Cleanup: Workshop Summary agreements, including a 1995 settlement agreement with the state of Idaho. This settlement dictates cleanup requirements and milestones. EM has initiated the Idaho Cleanup Project to accelerate compliance with some of the agreement milestones. The Idaho Site’s principal cleanup challenges include the following: Waste retrieval and treatment: Calcine retrieval (from bins) and treatment. Sodium-bearing waste treatment. Tank closure. Spent nuclear fuel management, including treatment of sodium- and epoxy-bonded fuels. Soil and groundwater cleanup: Retrieval of targeted waste. Monitoring of installed caps. Monitoring of contamination migrating through fractured basalt 200 to 700 feet (60 to 210 meters) below the surface. Long-term stewardship of groundwater contamination and radioactive waste left in place. D&D of highly radioactive structures. Calcine waste retrieval and treatment is the primary cleanup challenge at the site. About 4400 cubic meters (160,000 cubic feet) of highly radioactive granular calcine waste is being stored in stainless steel bin sets inside reinforced concrete silos. The waste must be remotely retrieved and processed into a waste form that is suitable for eventual disposal in a geological repository. The site is testing a retrieval technology for breaking up clumped waste and vacuuming it out of the bins. The site has not yet selected technologies for processing the waste for storage and disposal. The settlement agreement stipulates that by 2035 the calcine waste must be put into a form that is ready to be transported to a repository. The sodium-bearing waste challenges are more schedule than technology driven. There are about 900,000 gallons (3.4 million liters) of mostly liquid waste being stored in stainless steel tanks at the site. This waste will be retrieved and processed using steam reforming to produce a dry granular waste form. The waste may eventually be disposed of in an underground repository in New Mexico (the Waste Isolation Pilot Plant). The settlement agreement stipulates that the sodium-bearing waste be removed from the tanks by 2012 and transported out of the state by 2018. The tanks at the site are constructed of stainless steel, so the high-level waste did not have to be neutralized for storage.
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Science and Technology for DOE Site Cleanup: Workshop Summary Consequently, the tanks contain only minor amounts of solids. This greatly simplifies the process for retrieving waste and cleaning the tanks. Once the tanks are emptied, they will be filled with grout. The site has already begun to grout some of the smaller tanks. DOE has an agreement with the state of Idaho for the retrieval of targeted waste from the Radioactive Waste Management Complex at the site. Current technologies for carrying out this retrieval are labor intensive. Caps will have to be installed over waste burial sites, and their long-term performance will have to be monitored. Contamination in the vadose zone and groundwater will also have to be monitored over the long term. The site contains many highly contaminated facilities (reactors and chemical processing facilities) that must be deactivated and decommissioned. The primary technical challenge is to characterize and remove contamination in the high background radiation environments in these facilities. Additionally, there are pipelines and other structures under a facility at the site that have high radiation fields (up to 1600 rads/hour). Technologies are needed for remote remediation of this waste, otherwise the facility might have to be demolished to access and remediate the contamination. Spent nuclear fuel is also being stored at the Idaho Site. Some of this fuel contains organic (epoxy-bonded fuel) and reactive (sodium-bonded fuel) components. These components must be removed as part of fuel processing for storage and disposal. Less expensive methods are needed for this processing. Some spent fuel has already been put into canisters (“canned”) for storage and eventual disposal. Technologies are needed for nonintrusive characterization of canned fuel that may have damaged cladding. Panelist Nick Ceto (Program Manager, Office of Environmental Cleanup, Hanford/Idaho National Laboratory Project Office, U.S. Environmental Protection Agency [EPA]) identified the primary technical challenge at the site as characterizing and managing chemical and radioactive contamination in the vadose zone and burial grounds. Additional technologies are needed for characterizing and retrieving buried wastes that do not rely on visual inspection and that do not raise worker safety issues. Additional work on in situ stabilization technologies also is needed. Caps are a favorite DOE technology, but they are not a favorite technology of EPA or the public. Their long-term effectiveness is unknown, and they have limited effectiveness when contamination is located in the deep vadose zone. More work is needed on assessing the effectiveness of capping technologies as well as other technologies to characterize and stabilize waste in the deep vadose zone.
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Science and Technology for DOE Site Cleanup: Workshop Summary The site has several other cleanup challenges: tank waste retrieval, which has the potential to exacerbate vadose zone and groundwater contamination if not done carefully; cleanout and closure of the K-Basins in the 100 Area; and disposition of transuranic waste. The definition of transuranic waste is not risk based (the definition is based on concentrations and half-lives), and DOE has the option of petitioning EPA if it wishes to change its approach for managing this waste for specific cleanup projects. Panelist Dirk Dunning (Program Coordinator, Oregon Office of Energy, Nuclear Safety Division) highlighted plutonium migration in the vadose zone as a critical problem at the site. Plutonium beneath the Plutonium Finishing Plant on the Central Plateau is moving in ways that are not predicted by current site models. Plutonium beneath the Z Cribs near the plant has migrated to depths between 20 and 100 meters (65 and 330 feet) and is moving toward groundwater. Remediating or stabilizing this material will be difficult because it is so deep. Advances in understanding of plutonium geochemistry in the past seven to eight years suggest that plutonium bonds to some soil components and is slightly soluble in subsurface environments. The geology beneath the Hanford Site is complex, containing permeable horizontal sedimentary layers, less permeable vertical clay dikes that cut across these layers, and other lateral and vertical discontinuities. This complexity affects the movement of subsurface contamination. Contaminants migrate laterally within the sediment layers and then move vertically when they reach the dikes. Current site models are totally inadequate for predicting this behavior and therefore cannot be used for estimating risk. New models populated with field data are needed—and needed quickly. The site also requires new decision tools for high-level waste cleanup. In particular, the site needs tools that can help EM make decisions about double-shell tank maintenance and capacity management so that the tanks will be available when the WTP is operating. Panelist Susan Leckband (Chair, Hanford Advisory Board) focused her comments on sharing information and implementing technology in the cleanup program. Many DOE sites have common problems, but the site personnel do not get together to share concerns. The loss of funding for the Technical Focus Areas that provided cross-site communication is partly to blame for this problem. DOE-EM should be a facilitator of information sharing rather than a gatekeeper. EM also needs to develop a process for continuous implementation and sharing of new technologies. The Hanford Advisory Board has developed a flowsheet for the Central Plateau
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Science and Technology for DOE Site Cleanup: Workshop Summary that identifies the entry points for new technologies during the cleanup process. The board is working on a similar flowsheet for groundwater cleanup. Panelist Terri Stewart (Initiative Lead for Environmental Biomarkers, Battelle Pacific Northwest National Laboratory) focused her comments on soil and groundwater cleanup challenges at the site. Conceptual model development should be at the top of the list of science and technology gaps in the workshop discussion paper. At the Hanford Site, conceptual model development is needed to promote better understanding of contaminant behavior near the Columbia River and beneath cribs and tank farms on the Central Plateau where contamination enters the subsurface flow system. This improved understanding leads to improved remediation, especially cost-effective in situ remediation. Hanford has had some success in understanding contaminant (especially cesium, strontium, uranium, and technetium) behavior beneath the tank farms because of an EM-funded research project at Pacific Northwest National Laboratory that engaged scientists from across the United States. The project was successful for several reasons: It involved good researchers; it combined basic and applied research; it used “translators” who were able to work with the researchers and cleanup contractors to communicate needs and results in meaningful ways; and the researchers had access to site-and field-relevant samples. This project produced 140 publications and provided important insights into key processes that control contaminant movement in the subsurface. The site would benefit from additional research on how natural subsurface systems work and how to take advantage of those systems to stabilize and immobilize contaminants. The site also needs sampling and characterization tools that provide volumetric information to support conceptual model development and postclosure monitoring. Postclosure monitoring is at least three decades away, so there is still time to develop the necessary knowledge and technologies. However, factoring postclosure concepts into current activities is important to ensure that a life-cycle perspective drives today’s decisions. Dr. Stewart concluded her remarks by asking, “What should be the mission of science on a life-cycle basis in the cleanup program?” She observed that to be effective, science and technology development should not be driven by short-term needs alone. Panelist Roy Gephart (Geohydrologist, Battelle Pacific Northwest National Laboratory) focused his comments on high-level waste cleanup challenges at the site. The Hanford Site holds 60 percent by volume and 40 percent by radioactivity of DOE’s nationwide inventory of high-level waste. There are 89 different waste composition
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Science and Technology for DOE Site Cleanup: Workshop Summary “envelopes” that the WTP will eventually need to process. DOE knows what is in the tanks in a broad sense but lacks detailed information. Completion of the WTP has been delayed until 2018—30 years after the Tri-Party Agreement was signed—which provides adequate time for a well-considered science and technology program focused on waste characterization through processing. There are four major factors that will determine schedule and life-cycle costs for EM’s high-level waste program at the Hanford Site: waste volume to be processed, waste form loading, waste form predictability and consistency, and facility operational effectiveness. Controlling life-cycle costs is a key decision driver when carrying out short- and long-term science and technology investments. Examples of specific technical challenges include the following: Predicting non-newtonian fluid dynamics in waste processing, especially when particles are introduced (e.g., settling velocities, slurry mobilization, turbulence, scaling, and filtering). Understanding the chemistry of multiphase, high-salt systems during extended storage and processing and its effects on tank corrosion, gas generation, and transfer line plugging. Understanding the chemistry of the liquid-glass transition to help predict the properties of glass melts. Particular technical challenges are predicting the properties of glass melts made from composition data alone and from the bismuth phosphate waste streams. There is great value for predicting waste formulations, waste loadings, and melter operations by developing a sound scientific understanding of these issues instead of relying solely on empirical knowledge. Mr. Gephart ended his remarks by observing that none of this science will be done without the continuity and retention of an experienced scientific staff. He suggested that DOE needs to demonstrate a sustained commitment to funding research programs so as to maintain a qualified scientific staff to support the growing science and technology needs of DOE’s tank cleanup mission. Questions and Discussion A regulator in the audience asked about the performance requirements for containment monitoring and what strategies were needed to carry out such monitoring. Mr. Ceto commented that monitoring requirements were site specific. Under CERCLA, monitoring performance goals are established up front. Mr. Weigman noted that EM has conducted a performance assessment for in-place
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Science and Technology for DOE Site Cleanup: Workshop Summary disposal of the emptied single-shell tanks. This has helped EM think about how to monitor tank closures. The site is also examining electrical methods to monitor for tank leaks during waste retrieval. If tanks can be cleaned out thoroughly, the long-term risks shift to the vadose zone (from the contaminants discharged from past tank operations or resulting from tank leaks). An audience member commented on several issues raised by the panelists. He observed that there is no pilot facility for the WTP at Hanford, even though the DWPF pilot facility at Savannah River was considered a success. A pilot facility that was able to reduce the required length of WTP operations, even by a small amount, could easily pay for itself. He also suggested that the EM would benefit from having core expertise in fluid dynamics to help deal with subsurface model complexities, hydrothermal processing (e.g., for steam reforming) to widen the range of waste processing and waste form choices, and multidisciplinary optimization under uncertainty to help manage the tank farms and the WTP. He also commented that current subsurface models at the site combine sophisticated hydrodynamics with overly simplistic chemistry. Mr. Dunning responded to the last point, noting that the U.S. Geological Survey is using multiple constructs for system models. Mr. Wiegman noted that model uncertainties increase as one moves from the waste form through the vadose zone and into the groundwater. Consequently, one needs to do a good job in making the waste form. Another audience member asked the DOE panelists to comment on technology needs for spent nuclear fuel and excess nuclear materials, especially cesium and strontium capsules. Mr. Morse noted that technology needs were not significant relative to other site needs. DOE is using standard engineering for sludge cleanup in the K-Basins and is examining possible waste forms for dry storage of the cesium and strontium capsules. Eventually, those capsules and the site’s spent fuel will be disposed of in a geological repository. Mr. Wiegman commented that EM may end up shipping the cesium and strontium capsules directly to the repository. An audience member noted that these discussions ignore the uncertainties for disposal of high-level waste. Mr. Wiegman commented that the site’s high-level waste would eventually need to be disposed of in a repository, and the sooner that happened the better. But regardless of when that occurs, vitrification and some onsite storage will still be required. An audience member asked the panel how to interpret the apparent lack of focus on D&D at Hanford: Are there no needs, or has the site not yet looked at them? He also commented that lessons learned from D&D of the U Plant at Hanford are potentially applicable to Savannah River, which has similar kinds of facilities. Mr. Morse commented that Hanford is now performing facility D&D. There are
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Science and Technology for DOE Site Cleanup: Workshop Summary 3000 buildings at the site that present a range of difficulties. Some innovative technologies have been applied. A regulator in the audience asked whether EM is using risk-based performance approaches for designing remedial actions, and he suggested that there should be multiagency efforts to establish such approaches. He also asked how EM handles knowledge management so that project managers can take advantage of past experience. Mr. Ceto commented that risk is an important consideration in CERCLA cleanups and that removal actions can be used for high-risk problems. An audience member asked if Hanford was confident that it had the necessary barrier technologies it needed for site closures. Mr. Morse responded that the site has an active program on barriers and continues to collect data from field lysimeters and test beds like the Hanford Cap. The site has accumulated 10 to 12 years of data. The site is a year away from emplacing its first barrier, which will be monitored. Mr. Dunning observed that subsurface heterogeneity at the site complicates the use of barriers, especially for contaminants in the deep vadose zone. The ratio of lateral to vertical transport in the subsurface of the Hanford Site is 1000:1 because of the horizontal layering and vertical dikes. This makes it difficult to estimate barrier “shadow zones” in the subsurface. Assuring long-term barrier performance is also a challenge: The Collins Ranch barrier5 was expected to last for 500 years, but it is failing and will need to be replaced in about 20 years. Mr. Gephart observed that 60 percent of solid waste at the site is pre-1970 waste. What to do with that waste is a “sleeping dog issue” because of its mixture of transuranic and nontransuranic waste. Mr. Dunning noted that this pre-1970 waste contains a large amount of plutonium. PROMOTING THE EFFECTIVE USE OF SCIENCE AND TECHNOLOGY For its final session the workshop organizing committee invited presentations on promoting the effective use of science and technology in the DOE-EM cleanup program. David Maloney (Director, Technology—Nuclear Group, CH2M Hill) provided a cleanup contractor’s perspective, and David Kosson (Chair, Department of Civil and Environmental Engineering, Vanderbilt University) and Chuck Powers (Professor, Department of Civil and Environmental Engineering, Vanderbilt University) provided 5 Collins Ranch is a Uranium Mill Tailings Remedial Action Project disposal cell near Lakeview, Oregon.
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Science and Technology for DOE Site Cleanup: Workshop Summary perspectives from CRESP (Comprehensive Risk Evaluation with Stakeholder Participation). Perspectives from a Site Cleanup Contractor Dr. Maloney described technology program “lessons learned” on the development and use of new technologies in cleanup of the Rocky Flats Site, a 6000-acre (24-square-kilometer) weapons components production facility near Denver, Colorado. About 600 acres (2.4 square kilometers) of the site was industrialized. The site was shut down in 1989, and cleanup was completed in 2006. The site is now a wildlife refuge. The original schedule and costs for closure of the Rock Flats Site were 2060/$37 billion. EM and the cleanup contractor (Kaiser Hill) were able to reduce the closure schedule and costs to 2010/$7 billion and later to 2006/$6 billion through contracting and technology innovations. Even though the site was closed on an accelerated schedule, the cleanup contractor, with EM support, was able to successfully incorporate new technologies into its cleanup activities. In fact, the closure schedule and cost targets could not have been met without the continuous improvements made possible through the development and use of new technologies. Several factors were responsible for promoting the use of new technologies in site cleanup. Most notably, cleanup was carried out under a performance-based (rather than milestone-based) contract. Also, EM provided about $30 million in funding over eight years to address contractor-identified technology development needs and also encouraged the contractor to tap the expertise in EM’s technology development organization. There was an estimated 30:1 return on this investment in terms of cost savings to the cleanup program. Based on the Rocky Flats experiences, Dr. Maloney identified three factors that promote greater technology use and impacts in the cleanup program: risk-based planning, technology integration, and project integration. Risk-based planning must be carried out throughout the cleanup project using PRA (programmatic risk assessment). This is a probabilistic statistical method for estimating technology, schedule, and other risks in the baseline for a cleanup project. It is carried out at a detailed activity level (typically at Work Breakdown Structure levels 7, 8, and 9) and uses Monte Carlo techniques to develop a distribution of risk estimates. It can be used to identify at-risk activities and to help focus resources (and technology planning) on identified technology risks before they become actual problems. Like PRA, technology development must be integrated throughout the entire cleanup project and must be carried out as a partnership
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Science and Technology for DOE Site Cleanup: Workshop Summary between the contractor and DOE. Technology innovation must be built into project baselines (i.e., “prebaselined”), and the expectation of continuous technical improvement should be reflected in project costs and schedules. Proactive planning for off-baseline technology alternatives should be pursued for activities that are identified as “high risk” by PRA; multiple technology pathways (i.e., incremental improvements to current baseline technologies and off-baseline technology development) should be investigated until the identified risks are under control, and on-ramps should be established to bring successful new technologies into the cleanup program. On ramps are especially important for long-duration and multi-component projects. The design and engineering of such projects should be able to accommodate new or improved technologies during their life cycles. This is more costly up front but less costly over a project’s life. Contracts and regulatory standards can promote or inhibit technology innovation. Contracts that promote innovation are performance based (rather than milestone based) and provide schedule and cost targets through project completion, transfer schedule control to contractors, and transfer of responsibility and risks for technology use to contractors. Contractors in turn may transfer some of this risk to subcontractors such as technology vendors. Many technology vendors are risk averse, so such risk transfer can sometimes be difficult. Cost sharing between contractors, vendors and DOE can be a way to overcome this aversion. National laboratories also act as contractors and can be incentivized by DOE to take risks. Technology innovation is also promoted by performance-based (rather than technology-based) regulatory standards. In performance-based regulatory regimes, regulators in many cases are willing to consider the use of alternate technologies if credible performance bases can be established. However, cleanup contractors must take the initiative for requesting consideration of off-baseline approaches. Finally, technology innovation can also be promoted through predictable funding mechanisms. These include “local banking” of funds for technology development at sites that are under the control of the technology program manager working with the line project manager and can be accessed without an extensive proposal process. These funds can be awarded as grants or as part of a cost-sharing arrangement depending on risk. There can also be a “fenced bank” that is reserved for technology development at the site and possibly retained by the contractor for additional technology development activities through project completion.
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Science and Technology for DOE Site Cleanup: Workshop Summary Questions and Discussion In response to a general comment from an audience member, Dr. Maloney observed that under the performance-based completion contracts described previously, technology innovation is enhanced when DOE manages the contract rather than the contractor. Project managers, not DOE, should be responsible for determining the project’s technology needs. Another audience member asked Dr. Maloney to provide examples of innovative technologies that helped make the Rocky Flats cleanup program a success. Dr. Maloney identified three: a new technology to remove plutonium from surface-contaminated objects saved the project at least $105 million; the use of Standard Waste Boxes, which hold 10 times the volume of waste drums, and the use of a high-efficiency neutron counter (Super HENC) to assay the boxes, saved about $146 million; and implementation of passive reactive barriers at the site saved about $155 million in completion and stewardship costs. A regulator in the audience commented on the importance of tying cleanup plans to land end uses and asked whether cost estimates for different end-use scenarios at Rocky Flats had been estimated. Dr. Maloney responded that he never saw comprehensive cost estimates for industrial versus residential versus wildlife refuge scenarios. Another audience member asked Dr. Maloney to compare the contracting approach at Rocky Flats to those at Hanford and Idaho. Dr. Maloney responded that the Hanford contract had performance-based incentives but also contained milestones. It would have to be “opened up” to be fully effective. Idaho has a closure contract, but the necessary culture change in management had not yet been fully realized. An audience member commented that Hanford is currently using a technology-based approach. A performance-based approach would simplify environmental impact statements because only one case would need to be examined. Dr. Maloney commented that the Hanford Site has limited flexibility to consider alternatives because it has committed to making glass waste forms (for its tank wastes). A DOE staff member from Hanford commented that Rocky Flats used hands-on approaches for D&D at the site. Such approaches would not translate to other sites with larger and more extensive facilities. Dr. Maloney noted that Rocky Flats used some remote control equipment, but even the hands-on approaches are difficult. Building 771 at Rocky Flats was characterized as the most dangerous building in the world before it was successfully taken down. It was easy in hindsight, but that was certainly not the case when the work was being planned and executed.
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Science and Technology for DOE Site Cleanup: Workshop Summary Perspectives from CRESP Drs. Powers and Kosson briefly described three CRESP projects that provide some lessons learned on technology development and use in cleanup programs. The first was a project at Amchitka Island, Alaska, in which CRESP worked with affected groups (e.g., local Aleut populations) and regulators as an “integrating independent organization” to develop consensus on all of the technical factors relevant to site closure and monitoring of a site that had been used for three underground nuclear tests between 1965 and 1972. The second CRESP project was a December 2006 workshop on cemetitious materials at the Savannah River Site in conjunction with Savannah River National Laboratory. The objectives of the workshop were, first, to develop a common understanding among DOE, regulators, site operators, researchers, and other stakeholders concerning the state of the science, current practices, and knowledge gaps, and second, to identify opportunities to improve the use of cementitious materials for waste management and reduce long-term uncertainties associated with their use. The third CRESP project involved a merit review of the C-Tank Farm Closure Performance assessment at the Hanford Site. The objective of the review was to evaluate whether the performance assessment appropriately considered the processes that could result in future health impacts after tank farm closure and recommended improvements to the performance assessment to make it a more effective risk communications vehicle. Several lessons learned from these projects were identified: process is as important as technology, and public involvement is essential to a credible process; cleanup project success requires an accepting public and persuaded regulators and DOE decision makers; and all of these require a carefully constructed, ongoing, iterative process of engagement. Developing an enduring trust with affected parties should be a central element of technology development and deployment programs. CLOSING COMMENTS Workshop organizing committee members Allen Croff and Carolyn Huntoon identified some key messages from the workshop discussions: There was generally good agreement among the workshop panelists on site cleanup challenges and R&D needs. These include the following needs, listed generally in order of decreasing importance:
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Science and Technology for DOE Site Cleanup: Workshop Summary High-level waste and tank cleanup was a prominently identified cleanup challenge at Hanford, Idaho, and Savannah River; little or no relevant headquarters-directed R&D is being sponsored at national laboratories. Both soil and groundwater contamination are substantial problems at all four sites. Vadose zone contamination is an especially difficult problem at the western sites. There does not appear to be much vadose zone or groundwater R&D within EM. Deactivation and decommissioning: Specific needs include early planning for stabilization and R&D on remote handling, paying special attention to worker safety. Also, end-state identification continues to be a challenge. Buried waste: Specific R&D needs include balancing the extent of contaminant removal with the cost and the ecological impacts and also waste retrieval and stabilization. Spent nuclear fuel and excess nuclear materials stabilization and packaging. R&D is also needed to better understand the long-term performance of engineered barriers such as caps and grout. Improving long-term monitoring effectiveness is another important R&D need, especially to support the transition of sites from the EM cleanup program to the Office of Legacy Management. Several other general observations were offered: Congress has expressed support of technology development but wants prioritization and removal of impediments to new technology deployment from the private sector. Such impediments include aversion to, and penalties for, technology risk taking by cleanup contractors, as well as the long lead times required for technology deployment. EM senior management is also supportive of increased R&D investments. The possible future transfer of additional sites and facilities to the EM cleanup program will likely lead to new R&D needs, although it is presently unclear what these might be. The panelists identified examples of the successful application of new technologies in the cleanup program. Some also identified the continuing need for developing technology alternatives for high-risk cleanup problems and the need for cooperation across DOE sites.
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Science and Technology for DOE Site Cleanup: Workshop Summary There is a need to balance cleanup speed with completeness (i.e., “fast” cleanup versus “good” cleanup). Methods to help strike this balance are needed. Workshop organizing committee Chair Ed Przybylowicz commented on EM’s R&D management challenges. He observed that these challenges are not that different from large industrial organizations that have centrally funded and business-unit-funded technology development programs. The challenges include (1) creating a governance process to effectively manage technology development and sharing; (2) communicating technology needs, both internally (across sites) and externally (with Congress and the public); and (3) managing the development of high-risk technologies, including knowing when to cut off funding for technology development when a technology is no longer viable or needed. Deputy Assistant Secretary Mark Gilberston was invited to offer closing comments. He noted that the future success of EM’s technology development programs depended on the following factors: Improving knowledge management. Better sharing of ideas, concepts, and information on technology development. The EM program is more focused than previously. Cross-site activities and public communication need to be encouraged. Balancing basic and applied research and technology development. There is still an important role for new science within the EM cleanup program. How to rebuild the science program, either through expanded investments in the Office of Science or by other means, is an important challenge. Assuring continuity of funding for technology development. Tying technology development to cleanup baselines, especially to develop additional alternative technologies for high-risk baselines. FUTURE PLANS This workshop summary will be used by DOE to inform the development of its technology roadmap for Congress. It will also be used by the EM Roadmap Committee (Appendix D) to carry out Phase 2 of this study. The committee’s final report, which will address the study task outlined in the Preface, is expected in the fall of 2008.