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EMSP Research Portfolio: Technological Risk and Desired Attributes This chapter provides programmatic recommendations for building an effective research portfolio. The recommendations address the issue of technological risk and desired attributes for the EMSP portfolio. These recommendations are based on the technical recommendations provid- ed in Chapters 3 through 6 in this report, the committee's interim report (Appendix A), as well as the reports of previous committees on the EMSP (NRC, 1997a, 2000a). Managing Technological Risk In selecting long-term research topics for HEW management, the EMSP should take into account technological risk. A technological risk in HEW management is the risk that existing technologies will fail to accomplish goals and performance requirements set by environmental remediation policies or regulations. Neglecting to consider technologi- cal risk may lead to decreased public safety, underperformance, process failure, overruns in cost and schedule, and loss of credibility followed by a negative public perception. Examples of technological risk within the EM-HLW program are the following: failure to produce an acceptable glass product because of diffi- culties in ensuring homogeneity of the feed stock or because of deviations from the expected melter feed composition; premature failure of melter or of other equipment because of corrosion or mechanical problems; and E M S P R e s e a r c h P 0 r t f 0 1 i 0

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failure of radionuclide separation processes because of unex- pected secondary reactions. One example of technological failure is the abandonment of the (large-scale) in-tank precipitation process as it was first proposed at the SRS to separate cesium from HEW (NRC, 2000b). As a consequence, DOE had to rapidly identify an alternative to this process. The EMSP, which had already invested resources for research in alternatives to the in-tank precipitation process, for instance, by funding a solvent extrac- tion process using a calixarene to separate cesium from the waste, played an important role in the screening of processes to replace the original one. Another example of an operational issue is the shutdown of the 2H evaporator and subsequent interruption of waste processing activities at the SRS because of aluminosilicate precipitation in one of the evaporator tanks (see Chapter 5, Sidebar 5.4~. The research program proposed by the committee in Chapters 3 through 6 could help the EMSP in reducing technological risk. Technological risk can be reduced by improving process effectiveness and by providing contingency approaches to baseline technologies before interferences or disruptions to current HLW management pro- grams occur. Improving process effectiveness can lead to more robust approaches requiring fewer steps to achieve the desired result; there- fore, a simple and robust process presents less technological risk com- pared to a multi-step process. This is because there is a finite probabili- ty of encountering a problem causing process failure in any one of the individual steps. For instance, separation techniques removing more than one targeted species in a single step pose fewer technological risks than a series of steps to achieve the same result. Of course, the single- step process might still fail, but the probability for this event is compa- rable to the probability of failure for each of the individual steps. Consequently, it is important that the sites and DOE-EM collaborate to build research roadmaps identifying technological risk and including contingency approaches.2 A fundamental part of technological risk management consists of evaluating the progress of the research and nurturing those studies yielding promising results. To this end, the com- mittee recognizes that renewals of EMSP proposals must undergo the The DOE is expected to select the preferred cesium separation process during the summer of 2001. An NRC committee is providing DOE with advice for the final choice; its final report is forthcoming. 2This was also one of the recommendations to the EMSP by the Environmental Management Advisory Board (EMAB, 2001). H ~ G H - L E V E E W A S T E 78

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same evaluation process as new proposals so that only highly potential studies are renewed.3 To provide contingency approaches, it is also necessary to allocate funding for exploratory research relevant to HEW cleanup. The need for exploratory research to identify contingency approaches within the EM was also supported by previous N RC reports (N RC, 1 995, 1 996b, 1 996c, 1 997a, 1 999c, 2000a). The committee recognizes that exploratory research efforts do not immediately bear fruit and that many of the alternative concepts may never be deployed in the field. However, the success of a basic research program should not be mea- sured only by the proportion of projects that become field-applicable. Rather, it is necessary to investigate a number of possibilities before identifying a successful approach; it is accordingly impossible to pre- dict the pathway between innovative investigations and full-scale appli- cation. Desired Attributes of the EMSP Research Portfolio In the selection process for proposed EMSP research topics, atten- tion should be paid to the set of attributes listed below. Maintain long-term vision. As noted in the interim report, the research projects that are funded should be focused not only on DOE's short-term issues but also on significant long-term prob- lems to advance the state of knowledge well beyond the next decade. This recommendation is based on the concept of retain- ing a long-term vision, preserving the EMSP mission, and miti- gating the technological risk of any interruption in the EM-HLW program. Such interruptions, arising from unforeseen technologi- cal problems, can be avoided by considering innovative approaches to materials, processes, and products. a. Maintain relevance. Because of its mission, the EMSP should support research on the basic science underlying processes and phenomena relevant to HEW management in concert with other EM programs. EMSP basic research projects can then spark the applied research and development that will be needed for imple- 3in the year 2000, only 42 EMSP projects, out of the 202 coming to conclu- sion, have been renewed (Gilbertson, 2001 ). E M S P R e s e a r c h P 0 r t f 0 1 i 0

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mentation at the sites. It is thus incumbent upon both the EMSP and other programs, such as the TEA within EM, to understand the overlap of their goals and missions and yet recognize the very different nature of the projects funded. Synergies between the programs are natural and should be exploited to their fullest extent. Collaborations with foreign countries with relevant HLW research activities should be encouraged. At a minimum, the EMSP should be aware of scientific results and research trends for HLW management in countries with similar problems (see Sidebar 7.1 ). 3. Provide for contingencies. The EMSP should promote underlying science and technology that will support contingency approach- es to address unanticipated difficulties encountered in baseline processes. Some fraction of EMSP projects should support exploratory and innovative research, involving non-conventional technologies, possibly leveraged from other disciplines. This rec- ommendation was also endorsed by three previous NRC reports (NRC, 1995, 1997, 2000~. All projects should represent a bal- anced range of research styles from large-scale teams to single i Investigators. 4. Develop working relationships. As noted in two previous NRC reports (NRC, 1997a, 2000a), the EMSP investigators should interact with the problem holders at the sites on a regular basis to learn about the nature of the problems to be solved. In return! problem holders might gain a better understanding of the scien- tific gaps underlying HLW problems. The committee acknowl- edges the fact that the EMSP workshops organized every two years are a good way to reach out to the scientific community. However, an opportunity to improve this approach would be for EMSP researchers (e.g., principal investigators, graduate students, postdoctoral fellows) to visit DOE sites regularly. Conversely, EMSP could identify liaisons among the problem holders at the sites to communicate with the investigators. As suggested in a previous NRC study, the liaisons "will not only have the greatest knowledge about the sites but will also be able to assist in inte- grating the results of EMSP research into the lon~-term EM effort" (NRC, 1997a). 5. Prioritize objectives. The committee recognizes that the EMSP cannot address all the proposed research areas equally in the next few years, nor can its portfolio acquire all the recommend- ed program attributes immediately. Therefore, the EMSP should prioritize research keeping in sight the two overall motivations, a) providing contingency approaches and b) improving process H ~ G H - L E V E E W A S T E 80

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SIDEBAR 7.1 RESEARCH ACTIVITIES RELEVANT TO HLW MANAGEMENT IN FOREIGN COUNTRIES Many countries with a nuclear defense program have produced HLW from the reprocessing of spent nuclear fuel to recover plutonium. However, the details related to these activities are highly classified. According to the information available, the former Soviet Union and the United States have HLW with similar characteristics (alkaline HLW); therefore, research and development activities in the former Soviet Union are relevant to DOE's HLW management programs. In particular, Russia is advanced in the domain of waste retrieval and chemical cleaning of the tanks. DOE's TEA is already collaborating with Russia on several topics.The Universal Solvent Extraction, or UNEX, process, an acid-side treatment for calcite developed in Russia, is currently under study at INEEL. Russia is also promoting research on mixer pump technologies for tank waste retrieval. A pulsating mixer jet pump (Flygt pump) capable of mixing waste at tank-floor level has already been deployed at the Oak Ridge National Laboratory. Other smaller collaborations between TEA and foreign countries are taking place on the following issues: resin vitrification problems (Argentina), cold crucible melter testing and pipeline unplugging (France and Russia), fluidic samplers, LLW grout formulations, saltcake dissolution and solid formation mechanisms in tanks, and residual waste sampling (United Kingdom). Other topics relevant to HLW cleanup in which significant international experience has been gathered are alternative melting technologies, such as "in-can" or "cold crucible" melting processes in France and in the United Kingdom. Alternative radionuclide separation methods are also researched intensively abroad. For instance, France has developed a method to separate cesium from HLW through continu- ous precipitation and filtration of cesium tetraphenylborate (Poncelet et al., 2001). Most of research and development efforts on HLW in foreign countries is related to the reprocessing of commercial spent nuclear fuel, which generates HLW with characteristics different than defense HLW (commercial HLW is highly acidic and relatively salt-free). However, reprocessing of commercial spent nuclear fuel has been adopted only in a few countries (France, United Kingdom, Germany, Belgium, the former Soviet Union, Japan, and India). A majority of the other countries has not decided between reprocessing and direct disposal. Research in these countries with a nuclear power program is oriented on surface storage of spent fuel, either for interim use or disposal. Research has also been performed on alternative immobilization matrices, including polyphase ceramics, for plutonium immobilization, to address anti-proliferation issues. ~. effectiveness, as follows. The EMSP should strive for a balanced portfolio addressing both problems that are already identified and future potential problems. The portfolio should have a pri- mary focus on identified problems that must be solved either for efficient HLW processing operations or to provide for contingen- cies. Characterization, separation, and immobilization methods and processes are problem areas in which EMSP research could improve operations and provide immediate support in case of interferences or disruptions to current HLW processing programs E M S P R e s e a r c h P 0 r t f 0 1 i 0 81

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At the same time, there should also be a consideration for poten- tial problems that could arise or become exacerbated in the future. Examples of research objectives to address future poten- tial problems are the following: new or better separation tech- niques to remove bulk non-hazardous material from the HEW stream, methods to achieve higher waste loading in immobilized waste forms, and improvements in tank closure and near-field . . . man Storing issues. H ~ G H - L E V E E W A S T E 82