3
The Generation IV and Nuclear Hydrogen Initiative Programs

BACKGROUND

As of mid-2007, there were 439 operating nuclear power plants totaling 371.7 GWe of capacity in 31 countries and generating nearly 16 percent of the world’s electricity. In addition there are five units in long-term shutdown with a total capacity 2.8 GWe. Thirty reactor units with a total capacity 23.4 GWe are under construction in 12 countries. Nuclear power had improved its performance and achieved an excellent operating record by the end of the twentieth century. In the United States, where no new plants have been ordered since the 1970s, improved operation and power upgrades to 104 nuclear power plants have enabled nuclear energy to maintain a 20 percent share of electricity generation since 1985.

Concerns over energy resource availability, climate change, air quality, and energy security suggest an important role for nuclear power in the future energy supply. Current nuclear power plants (Generation II models in the United States or the more recent Generation III models deployed internationally) supply reliable and economic baseload electricity in many markets. With a total of over 12,000 reactor-years of worldwide experience, the performance of these reactors today is far more satisfactory than it was two decades ago. Also, the NP 2010 program, as noted in Chapter 2, is assisting with the licensing and deployment of some new reactors with improved features (Generation III+) that are ready for the market. However, longer term advances in nuclear energy system design could broaden the desirability and future uses of nuclear energy. The U.S. Department of Energy (DOE) has engaged other governments, the international and domestic industry, and the research community in a wide-ranging effort to develop advanced next-generation nuclear energy systems (Generation IV). The goals are to widen the applications and enhance the economics, safety, and physical protection of the reactors, to improve the management of fuel cycle waste, and to advance proliferation resistance in the coming decades—that is, 2020 and beyond.

OVERALL PROGRAM DESCRIPTION

Six nuclear reactor technology concepts were identified in the DOE-initiated international Generation IV Technology Roadmap (DOE, 2002). Each of these six technologies, as well as several areas of crosscutting research, is now being pursued by a consortium of countries as part of the Generation IV International Forum (GIF), with varying levels of effort being expended by the various members of GIF based on the technology that is of interest to them and its status and potential to meet national goals. Three of the concepts are thermal neutron spectrum systems—very-high-temperature reactors (VHTRs), molten salt reactors (MSRs), and super-critical-water-cooled reactors (SCWRs)—with coolants and temperatures that enable hydrogen or electricity production with high efficiency. The remaining three concepts are fast neutron spectrum systems—gas-cooled fast reactors (GFRs), lead-cooled fast reactors (LFRs), and sodium-cooled fast reactors (SFRs)—that will enable better fuel use and more effective management of actinides by recycling most components in the discharged fuel. DOE has selected the VHTR as the highest priority concept but has given some support for the other concepts (except for the MSR, where DOE has only funded an effort to monitor international activities and university-based programs). The priority ranking of the other concepts has varied over the years, with the SFR recently taking second place. Crosscutting fuel cycle research has been performed under the Advanced Fuel Cycle Initiative (AFCI), which is a national program but could become an international one under the recent Global Nuclear Energy Partnership (GNEP), started in 2006 (see Chapter 4).

There are three major strategic goals on the Generation IV Technology Roadmap:

  • Electricity generation at competitive cost in large and small reactors,

  • Use of process heat to produce alternative energy products (e.g., hydrogen), and



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3 The Generation iV and Nuclear hydrogen initiative Programs BacKGroUNd oVerall ProGram descriPTioN As of mid-2007, there were 439 operating nuclear power Six nuclear reactor technology concepts were identified plants totaling 371.7 GWe of capacity in 31 countries and in the DOE-initiated international Generation IV Technology generating nearly 16 percent of the world’s electricity. In ad- Roadmap (DOE, 2002). Each of these six technologies, as dition there are five units in long-term shutdown with a total well as several areas of crosscutting research, is now being capacity 2.8 GWe. Thirty reactor units with a total capacity pursued by a consortium of countries as part of the Genera- 23.4 GWe are under construction in 12 countries. Nuclear tion IV International Forum (GIF), with varying levels of power had improved its performance and achieved an excel- effort being expended by the various members of GIF based lent operating record by the end of the twentieth century. In on the technology that is of interest to them and its status and the United States, where no new plants have been ordered potential to meet national goals. Three of the concepts are since the 1970s, improved operation and power upgrades to thermal neutron spectrum systems—very-high-temperature 104 nuclear power plants have enabled nuclear energy to reactors (VHTRs), molten salt reactors (MSRs), and super- maintain a 20 percent share of electricity generation since critical-water-cooled reactors (SCWRs)—with coolants and 1985. temperatures that enable hydrogen or electricity production Concerns over energy resource availability, climate with high efficiency. The remaining three concepts are fast change, air quality, and energy security suggest an important neutron spectrum systems—gas-cooled fast reactors (GFRs), role for nuclear power in the future energy supply. Current lead-cooled fast reactors (LFRs), and sodium-cooled fast nuclear power plants (Generation II models in the United reactors (SFRs)—that will enable better fuel use and more States or the more recent Generation III models deployed effective management of actinides by recycling most com- internationally) supply reliable and economic baseload ponents in the discharged fuel. DOE has selected the VHTR electricity in many markets. With a total of over 12,000 as the highest priority concept but has given some support reactor-years of worldwide experience, the performance of for the other concepts (except for the MSR, where DOE has these reactors today is far more satisfactory than it was two only funded an effort to monitor international activities and decades ago. Also, the NP 2010 program, as noted in Chapter university-based programs). The priority ranking of the other 2, is assisting with the licensing and deployment of some concepts has varied over the years, with the SFR recently new reactors with improved features (Generation III+) that taking second place. Crosscutting fuel cycle research has are ready for the market. However, longer term advances in been performed under the Advanced Fuel Cycle Initiative nuclear energy system design could broaden the desirability (AFCI), which is a national program but could become an and future uses of nuclear energy. The U.S. Department of international one under the recent Global Nuclear Energy Energy (DOE) has engaged other governments, the interna- Partnership (GNEP), started in 2006 (see Chapter 4). tional and domestic industry, and the research community in There are three major strategic goals on the Generation a wide-ranging effort to develop advanced next-generation IV Technology Roadmap: nuclear energy systems (Generation IV). The goals are to widen the applications and enhance the economics, safety, • Electricity generation at competitive cost in large and and physical protection of the reactors, to improve the man- small reactors, agement of fuel cycle waste, and to advance proliferation re- • Use of process heat to produce alternative energy prod- sistance in the coming decades—that is, 2020 and beyond. ucts (e.g., hydrogen), and 

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 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM • Used-fuel recycle and actinide burning to reduce waste • SFR: development of actinide transmutation fuels, and and enable the sustainable use of fuel resources. reduction of capital costs through improved design features and power conversion technologies. Other Generation IV goals include enhancing reliability and safety and increasing proliferation resistance and physi- At the end of 2005, DOE shifted the fundamental em- cal security. phasis of the overall AFCI and the Generation IV program, making spent fuel management using a closed fuel cycle the main goal of the NE program by introducing GNEP in early Focus areas of the Generation iV Program 2006 as part of the budget request for FY 2007. This new From 2002 to 2005, since the publication of the Genera- priority had a number of effects on the projected funding for tion IV Technology Roadmap (DOE, 2002), the Generation the other programs starting in FY 2007: IV program was reviewed by the DOE Nuclear Energy Research Advisory Committee (NERAC) on an ongoing • Reduced funding for the NP 2010 and NGNP programs; basis. In those years, the primary goal of the program was • Phasing out of the SCWR, GFR, and LFR R&D the use of high-temperature (850ºC to 1000ºC) process heat programs; and innovative approaches to yield energy products, such as • Refocusing the SFR effort on near-term demonstration hydrogen, that might benefit the transportation and chemi- (Chang et al., 2006; DOE, 2006). cal industries. To that end, DOE published an Expression of Interest (DOE, 2004) in the development of industrial and With these changes, NGNP’s VHTR remains the only international partnerships for the Next-Generation Nuclear major reactor concept that is not integrated into the GNEP Plant (NGNP), with the VHTR reactor concept as its key program. In the sections that follow, the NGNP concept is focus. This initiative resulted in reviews of the VHTR con- reviewed first, and the current status of its program plan cept by the Independent Technology Review Group (ITRG, and its R&D results are assessed. Subsequently, the Nuclear 2004) as well as by NERAC.1 These reviews recommended Hydrogen Initiative (NHI) is addressed. Finally, the progress a faster schedule for the NGNP but a technologically less made on the other Generation IV reactor concepts and their aggressive approach for the VHTR concept—for example, current status are examined. The SFR concept, as applied lower gas outlet temperature, more traditional materials, to near-term demonstration, is discussed in greater detail and proven UO2 particle fuel. These recommendations have in Chapter 4 because responsibility for its development has largely been adopted as the NGNP program reaches perfor- been shifted to the GNEP program. mance-phase R&D. The DOE VHTR effort was reinforced by the passage of the Energy Policy Act of 2005 (EPAct05),2 reactor development evaluation criteria from the which authorized $1.25 billion in funding for the NGNP and Generation iV roadmap identified the VHTR as its lead concept. Since FY 2003, over 90 percent of the line item program funds for the Generation During the development of the Generation IV Technology IV systems were used for NGNP (see Table 1-1). Roadmap (DOE, 2002), three different R&D phases were de- In that same time period (2002 to 2005), the secondary fined, going from conceptual design to commercialization: goals of the Generation IV program were to examine innova- tive reactor concepts for managing spent fuel inventories to • Viability assessment phase R&D. Viability phase R&D minimize waste products as well as improve the power con- examines the feasibility of key technologies. Its objective version efficiency and minimize the cost of advanced reactor is to prove out, on a laboratory scale, the basic concepts, systems. These goals were implemented by much smaller technologies, and processes under relevant conditions and to efforts in the other four reactor nuclear energy systems. Each identify and resolve all potential technical show-stoppers. reactor concept research program was focused on its main • Performance assessment phase R&D. Performance viability issues: phase R&D undertakes the development of performance data and optimization of the system on an engineering scale. • SCWR: advanced materials, chemistry, and heat trans- The objective is to verify and optimize engineering-scale fer (T > 500ºC), processes, phenomena, and materials capabilities under • GFR: alternative fuel types and innovative safety prototypical conditions. concepts, • Demonstration phase R&D. Demonstration phase ac- • LFR: lead corrosion and materials studies, modular tivities undertake the licensing, construction, and operation reactor design, and of a prototype or demonstration system in partnership with industry or, perhaps, other countries. The detailed design and 1 U.S. Department of Energy, Generation IV presentations to the NERAC licensing of the system are performed during this phase. Its Generation IV subcommittee on July 19, 2004; October 25, 2004; May 2, objective is to create a new product that is then selected by 2005; and November 15, 2005. industry for wide-scale commercial deployment. 2 See Subtitle C: Next Generation Nuclear Plant Project.

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 THE GENERATION IV AND NUCLEAR HYDROGEN INITIATIVE PROGRAMS Each of these three R&D phases involves increasingly ex- helium coolant with an exit temperature of ~850ºC to 950ºC pensive efforts and facilities. For this reason, the Generation to produce electricity and/or hydrogen. (While concep- IV Technology Roadmap identified nine criteria that a tech- tual design studies totaling $2.9 million were performed nology would be required to meet before it would be allowed in FY 2005 and FY 2006 on a liquid-salt-cooled variant to advance to the next R&D phase. These nine criteria, listed operating at higher power with the same high-temperature in Table 3-1, set expectations for nuclear energy R&D that fuel design, that design is no longer being considered for the had national and international agreement. Each of the six re- NGNP. However, concept evaluation of salt-cooled reactors actor concepts identified on the roadmap had several viability continues at universities.) The NGNP will be designed to topics that needed resolution through viability R&D before meet as many as possible of the Generation IV objectives of the concept could transition to the performance assessment high reliability, enhanced safety, proliferation resistance, sus- phase. When these criteria were finalized (mid-2002), it was tainability (low waste generation), and improved economics assumed that there would be a viability downselect in 2007 compared to existing commercial nuclear power plants. to choose among the six technologies. There are two basic candidates for the reactor core: one Because these Generation IV R&D end points establish based on pebble fuel and the other based on prismatic/block reasonable criteria for evaluating nuclear technologies, fuel. The fundamental element of both fuel types is tristruc- the committee has used them as a basis for evaluating the tural isotropic (TRISO)-coated particles that have high fuel technology readiness of the NGNP. Further, the committee integrity characteristics even at high fuel burn-up and excel- finds these R&D end points useful as criteria to evaluate the lent fission product retention under steady state and postu- major GNEP technologies (UREX+ and pyro-reprocessing, lated adverse transient and accident conditions. The program transmutation fuel fabrication, and the SFR). benefits from significant past experience with helium cooled reactors in the United States and Germany, but it couples the reactor to a gas-turbine power cycle instead of a steam tur- NeXT-GeNeraTioN NUclear PlaNT bine cycle for power conversion. The program also benefits from the experience in operating small (10- to 30-MWth) Program description test reactors in China and Japan and the design studies for a The NGNP program represents DOE’s focused effort 400-MWth power plant that is planned to enter construction under the Generation IV program on the VHTR. NGNP is in 2008 in South Africa. The Generation IV Technology envisioned to be a commercial-scale modular gas-cooled Roadmap identified six R&D areas for the VHTR, which was thermal reactor with a power output of ~600 megawatts of assumed to have a coolant outlet temperature above 1000ºC thermal energy (MWth). The NGNP will use high-temperature (DOE, 2002, p. 81): TABLE 3-1 End Points for Viability Phase and Performance Phase R&D, as Defined in the Generation IV Technology Roadmap Viability Phase End Points Performance Phase End Points 1. Preconceptual design of the entire system, with nominal interface 1. Conceptual design of the entire system, sufficient for procurement requirements between subsystems, and established pathways for specifications for construction of a demonstration plant and with disposal of all waste streams validated acceptability of disposal of all waste streams 2. Basic fuel cycle and energy conversion (if applicable) process 2. Processes validated at scale sufficient for demonstration plant flowsheets established through testing at appropriate scale 3. Cost analysis based on preconceptual design 3. Detailed cost evaluation for the system 4. Simplified probabilistic risk assessment for the system 4. Probabilistic risk assessment for the system 5. Definition of analytical tools 5. Validation of analytical tools 6. Preconceptual design and analysis of safety features 6. Demonstration of safety features through testing, analysis, or relevant experience 7. Simplified preliminary environmental impact statement for the 7. Environmental impact statement for the system system 8. Preliminary safeguards and physical protection strategy 8. Safeguards and physical protection strategy for system, including cost estimate for extrinsic features 9. Consultation(s) with regulatory agency on safety approach and 9. Preapplication meeting(s) with regulatory agency framework issues SOURCE: DOE, 2002, p. 80.

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 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM plications for high-temperature process heat; some of them • High-temperature helium turbine, will also need economic bulk hydrogen in the future. This • Reactor/hydrogen production process coupling partnership is being formed to show Congress that there is approach, genuine interest in this technology for the intended purposes • Identification of targeted operating temperature, and to attract the needed cost-share funding to accomplish • Fuel coating material and design concept, the goals of the program without asking for more public • Adequacy of fuel performance potential, and sector funding, which might be difficult to obtain. This ap- • Reactor structural material selection. proach is consistent with the R&D model recommended by Electric Power Research Institute (EPRI) and INL, which Subsequently, the desirable maximum temperature of the proposed substantial industry contributions for nearer-term coolant was reduced to 900ºC, with a longer-term target of R&D, with the government maintaining primary but not 950ºC, which reduced the challenge to materials and fuel sole responsibility for funding longer-term R&D (Modeen, integrity in the construction of NGNP. 2006). The NGNP program is authorized under EPAct05 at This NGNP public/private partnership initiative has for- total funding of $1.25 billion for Phase I, which extends to mulated a four-phase program that starts with a currently 2011. During this phase, fundamental R&D would be car- contracted 1-year NGNP preconceptual engineering effort, ried out for the associated technologies and components. scheduled for completion in August 2007, and ends in FY This includes the reactor and its fuel, the energy conversion 2017 with full commissioning and start-up of a plant at the system, materials, and hydrogen generation technologies. INL site. This is a more aggressive schedule than that of In addition, certain fundamental decisions are to be made, EPAct05, which called for 2020. The earlier target date was including selection of the mission of the NGNP (efficient motivated by congressional supporters, INL management, electricity production, process heat, hydrogen generation, or and the engaged industrial participants as a way to drive the a combination of these) and the specific hydrogen generation technology to commercialization during a period of strong technology. EPAct05 also discusses Phase II, which extends interest in a nuclear energy renaissance and growing indus- from 2012 to 2021 and wherein a detailed design should be trial demand for the capabilities of the NGNP. competitively developed, a license should be obtained from the U.S. Nuclear Regulatory Commission (USNRC), and the a Brief history of high-Temperature plant should be constructed and commissioned. reactor development According to EPAct05, the program will be based on the R&D activities of the Generation IV program, the Idaho The United Kingdom embraced high-temperature reactor National Laboratory (INL) will be the lead national labora- (HTR) technology in the early 1950s with the start of a large tory, and the NGNP demonstration will be sited at INL. INL fleet of graphite-moderated, metal fueled, and CO2-cooled is charged to organize a consortium of industrial partners to MAGNOX reactors for electricity generation and weapons cost-share the project. The NGNP project is to maximize plutonium production. In total, 28 reactors of this type were technical exchange and transfer from other relevant sources, built, with outputs ranging from 50 to 490 MWe and a total including other industries and international Generation IV capacity of 4,200 MWe. In 2006, eight of these MAGNOX partners. reactors remained operational, but all will be shut down The overall program has been estimated to cost ap- by 2011. The 20-MWth helium-cooled Dragon reactor, a proximately $2.3 billion, which means that significant cost cooperative project of the Organisation for Economic Co- share (roughly 50 percent) will be needed from collabora- operation and Development (OECD) and Euratom, dem- tive private sector partners, in the form of actual funding or onstrated the use of thorium/uranium fuel starting in 1964, work in kind and transfer of already developed intellectual with operations continuing to 1975. Also in 1964, while the property. MAGNOX build program was in full swing, the U.K. govern- INL has formed program plans for the basic NGNP ment decided to start the next phase of CO2-cooled reactor program, and a complementary private sector initiative has development with advanced gas-cooled reactors (AGRs). been started to form a public/private partnership for bringing Eventually, 14 AGRs would be built, with outputs ranging end users, industrial suppliers, technology developers, and from 550 to 625 MWe and a total capacity of 8,600 MWe. national laboratories together with DOE for the develop- These reactors had coolant, at 4 MPa, traveling downward in ment and demonstration of NGNP on a commercial scale. the core and exiting at 645°C, coupled to a steam cycle power Potential end users might include the petroleum industry, conversion system, through a steam generator. The steam, at industrial gas producers, the transportation industry, the coal 17 MPa, entered the turbines at 540°C, which provided over industry and their associates who are interested in gasifica- 40 percent thermal conversion efficiency. tion and liquefaction applications, and traditional electric The performance of the AGR reactors was poor in the power companies. early days because of materials problems and lack of stan- The potential end users represent the broad range of ap- dardization of the design. The principal technical issues

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 THE GENERATION IV AND NUCLEAR HYDROGEN INITIATIVE PROGRAMS from the U.K. gas reactor experience are related to graphite the improved gas-turbine technology to increase thermal ef- corrosion and aging under radiation, as well as carbon de- ficiency and improve economics. These changes resulted in position on the fuel rods. Graphite corrosion can occur for designs that had plant capacities of about 300 MWe or less, thermal and radiolytic reasons. With experience, a coolant which is a significant challenge economically compared to composition was found to inhibit those tendencies with the large LWRs for electricity generation. On the other hand, right levels of CO, CH4 and H2O (Hall and Chaffey, 1982). the small thermal power enables the reactor to transfer de- The CO inhibits corrosion due to radiolysis of CO2, and CH4 cay heat to the surrounding environment without requiring inhibits corrosion as it forms a deposit on graphite pores. emergency coolant or reaching intolerable temperatures. The oxidation of structural steel materials in the presence HTR development has undergone a resurgence outside the of CO2 was also a source of some problems. Subsequently, United States over the past decade. Key national programs the United Kingdom turned to light water reactors (LWRs), are being conducted in China, Japan, and South Africa. importing the technology from the United States but building only one large plant, Sizewell B. China France also experimented with CO2-cooled, graphite- moderated reactors. The initial reactors suffered from unsat- In China, the Institute of Nuclear Energy Technology isfactory fuel performance and graphite corrosion problems. (INET), operated by Tsinghua University, has taken the France turned to LWRs based on the U.S. experience in lead for development of HTR technology. It spearheaded 1974. the design and construction of a small HTR-10 test reactor. The United States and Germany each explored HTR tech- Construction of the HTR-10 started in 1995, and it achieved nology about the same time with two small developmental criticality in 2000. It is a 10-MWth pebble bed reactor that graphite-moderated, helium-cooled reactors, Peach Bottom 1 utilizes UO2 pebble fuel and a steam generator for heat (operated from 1967 to 1974) and AVR (operated from 1966 rejection. Numerous tests have been completed confirming to 1988), respectively. These small reactors demonstrated the the inherent safety features of the design, including reactor prismatic and pebble bed fuel/moderator arrangements and shutdown due to fuel heating when power increases fol- technologies and encouraged their promoters to proceed to lowing the withdrawal of control rods. The intention is to the commercial demonstration stage. The United States com- couple this test reactor directly to a gas turbine, thereby also missioned the Fort St. Vrain reactor in 1979 and Germany demonstrating the Brayton cycle. commissioned a thorium high-temperature reactor in 1985, A commercial project (HTR-PM) has already been both with outputs in the 300-MWe range. With a coolant established as a collaborative effort between INET, China maximum temperature of 700°C, all these plants operated Nuclear Engineering and Construction Company, and the using indirect steam Rankine cycles to generate electricity. China Huaneng Group, a large Chinese electric utility The Fort St. Vrain plant was beset by technical problems. company. The plant design was initially sized at 450 MWth These problems were mainly in the auxiliary systems, such with a 750ºC coolant outlet temperature and a helical steam as the cooling and oil systems. However, there was also a generator providing steam to a Rankine cycle. Recently, the significant problem with flow-induced vibration of the re- thermal output has been reduced to 250 MWth to facilitate flector and fuel graphite blocks. This was partially corrected early deployment. Construction was planned to start about by pinning the blocks together, but the overall coolant flow 2008 and criticality to be achieved around 2013, but delays rate still had to be limited, which prevented the reactor from have been experienced that could push the project back by operating at full power. Technical issues also arose in the several years. German program due to the approach of inserting control rods into the pebbles of the core, introducing the problem Japan of broken pebbles in the fuel handling and storage systems. Furthermore, the German HTR program was caught up in Under the direction and sponsorship of the Japan Atomic the political aftermath of the Chernobyl (water-cooled but Energy Agency, an industry collaborative program on HTRs graphite-moderated) reactor accident. Both the Fort St. Vrain has been in place for nearly two decades. The centerpiece of reactor in the United States and the HTR reactors in Germany this program is the high-temperature test reactor (HTTR), were permanently shut down in 1989, ending the early era of which is a 30-MWth reactor using prismatic fuel/modera- gas reactor demonstration in those two countries. tor arrangement and a coolant outlet temperature of up to Subsequent to the shutdown of these commercial dem- 850ºC, although 950ºC was reached for short operating onstration reactors, system design and evaluation studies periods. Construction on the HTTR started in 1991, and continued and focused on modular, passively safe concepts, criticality was achieved in 2000. The purpose of the project including the German MODUL and the U.S. modular high- is to establish an HTR technology basis, to develop process temperature gas reactor designs. These design studies shifted heat application technology, and to provide a heat source for from an indirect Rankine steam cycle for power conversion a hydrogen production plant based on the thermochemical to a direct recuperative Brayton cycle, taking advantage of sulfur-iodine water splitting process. Although no commer-

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 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM cial demonstration project has been defined, a conceptual market segments and, in the longer term, support the transi- design for a commercial cogeneration plant, called the GTH- tion to a hydrogen economy. TR300C, has been developed. Environmental benefits of HTRs arise from their ef- ficiency at producing carbon-free electricity, carbon-free hydrogen, and/or carbon-free process heat. A 1,000-MW South Africa combined cycle natural gas plant produces about 3 million Pebble Bed Modular Reactor Pty. Ltd. is developing the tonnes of CO2 per year. In the United States, natural gas pebble bed modular reactor (PBMR) design as a national power plants emit a billion tonnes of CO2 per year. Replac- strategic project in South Africa. The design of the demon- ing combined cycle gas turbine capacity with gas turbine stration power plant is for a 400-MWth reactor connected HTRs could significantly reduce carbon emissions. Also, a to a direct cycle helium turbine, with pebble fuel/moderator commercial-scale 3 million cubic meters per day (100 mil- and a coolant outlet temperature of 900ºC. The project has lion standard cubic feet) steam methane reforming (SMR) been defined, all major components ordered and construction plant producing pipeline hydrogen produces at least 1 million will start in 2009 with initial criticality planned for 2013. tonnes of CO2 per year. SMR capacity in the United States The plant will be built at ESKOM’s Koeberg site, where was 56.4 million cubic meters per day in 2004, producing 18 two large LWRs already exist. As part of this overall project, million tonnes of CO2 per year. Hydrogen demand has been extensive testing facilities are planned and several are already growing at 5 percent per year since 2000. HTR technology being commissioned. A pilot fuel plant has been designed could significantly reduce carbon emissions in the hydrogen and should start construction in 2008. Advanced fuel will be production industry. manufactured in a full-size production line facility (already Economic and security benefits follow from reducing constructed) starting in late 2007 for irradiation testing in dependence of the United States on fuel imports. While a Russia beginning in early 2008. small portion (15 percent) of the U.S. needs for natural gas With successful demonstration of the technology, it is is currently imported, there is a growing demand but limited planned that 24-30 PBMRs will be added to the ESKOM supply of it from our major supplier, Canada. Thus liquefied grid starting in about 2015 to distribute power along the natural gas, probably from the Middle East or Russia, will be coast of South Africa and at certain remote inland sites increasingly important to meet U.S. needs. (Western Europe (Rosenberg, 2007; Bloomberg, 2007). A letter of intent has depends heavily on supplies from Russia and North Africa already been issued by ESKOM for these units. In addition, even today.) Natural gas is used for electricity production, process heat plant development is ongoing to evaluate the home heating, and as a feedstock for chemicals and plastics. best applications for this HTR technology and to assess the It is the main source of energy for the U.S. production of economic competitiveness against the competing fuel, natu- process heat and hydrogen for use in the preparation of ral gas. Finally, preapplication review for design certifica- liquid transport fuels from crude oil. In the future, even tion of the basic technology has already started in the United larger quantities of natural gas may be required to produce States, and the USNRC activity is timed to be consistent liquid fuels from unconventional sources that are abundant with the development of information, including the licensing in North America, including tar sands, shale oils, coal, and documentation, on the South African Demonstration Power biomass. Liquid fuels can be expected to continue to play a Plant. large role in the transportation sector, supplemented in the longer term by hydrogen fuel cells or chargeable batteries for ground transportation. HTRs may play a role in displacing Benefits of high-Temperature reactor deployment natural gas consumption in all of these market segments. Economic benefits of early commercialization of HTRs and VHTRs based on NGNP technology could be realized Base-Load Electricity in four market segments where HTRs could make products at a lower cost than competing technologies: base-load elec- For base-load electricity generation, HTRs may initially tricity, combined heat and power, high-temperature process be competitive with mature LWR technology in niche mar- heat, and hydrogen. A long-term goal for the NGNP is to ket segments where HTR’s technical characteristics provide support the production of hydrogen as an energy carrier in a specific advantages. For small grids, as exist in developing hydrogen economy. However, in each of those four market countries, modular HTRs have a direct advantage due to their segments listed above, there are specific applications where smaller unit power outputs and slower transients compared to HTRs will have near-term advantages. By directing NGNP market ready, large-capacity LWRs. Also, in regions where and NHI R&D toward these specific applications, stronger water is scarce, as in the U.S. Southwest, HTRs that use di- near-term industry interest and investment is more likely, rect Brayton cycle power conversion hold an advantage over which in turn will support continued R&D investments for LWRs because they can operate with greater efficiency while subsequent expansion of HTR technology into additional rejecting to the surroundings reduced quantities of waste heat at higher temperatures. This enables economical dry cooling

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 THE GENERATION IV AND NUCLEAR HYDROGEN INITIATIVE PROGRAMS for inland locations. By breaking the linkage between cool- hydrogen include distributed low-temperature electrolysis ing water availability and electricity production, HTRs can with off-peak base-load nuclear electricity and centralized remove a significant constraint on reactor siting. hydrogen production using high-temperature electrolysis or If a portion of the heat supplied to the gas entering the tur- thermochemical water-splitting cycles (Yildiz et al., 2005; bines in gas-fired plants is derived from HTRs, it will reduce NRC/NAE, 2004). Currently, NHI supports R&D for all the natural gas consumed, which would reduce carbon emis- three of these technologies. sions associated with gas plants. At high natural gas prices LWR-based electrolysis can be applied for hydrogen (about $8 per million Btu [MMBtu]), the nuclear heat addition production with an energy efficiency of about 26-30 percent, is also more economical (Joeng and Kazimi, 2005). while sulfur-iodine (S-I) high-temperature steam electrolysis has the potential to reach an energy efficiency of 45-50 per- cent. The use of HTR for hydrogen production is motivat- Combined Heat and Power ed by its enabling thermochemical schemes that are possible Currently, combined heat and power applications are only at high temperatures. However, the improvement in ef- fueled dominantly by natural gas. In many cases combined ficiency to about 60-80 percent will increase the chances that heat and power facilities run steadily because they are HTR-produced hydrogen could be more economic than hy- coupled to facilities that create a steady demand for heat. drogen produced by LWR-based water electrolysis. Second, In these situations where combined heat and power systems while the reactor side costs of an MHR are likely to be higher run with high availability, HTRs with direct Brayton power than those of an LWR, owing to the lower energy density, its cycles and bottoming steam production can directly displace associated gas turbine power cycle cost is likely to be lower the carbon-emitting natural gas usage. Current large-scale than the cost of the steam power cycle. Third, the financial applications for low- and intermediate-temperature steam terms of a large pressurized water reactor plant may be more include enhanced oil recovery, oil production from tar sands, demanding than those of the smaller capacity, modular HTR and process heat for large petrochemical facilities. unit. Finally, the HTR technology has far more potential for improvement than the more mature LWR technology (for example, moving to liquid salt cooling could increase the High-Temperature Process Heat power density and significantly reduce capital costs). Natural gas is also used to supply high-temperature pro- cess heat. HTRs can also provide high-temperature process hTr/NGNP Technology challenges and heat between 600°C and 950°C and can directly displace development Needs natural gas in these applications, as discussed earlier. Because several gas-cooled reactors have already been built and operated, significant insight into the reliable opera- Nuclear Hydrogen tion of such reactors has been gathered. In addition, better Hydrogen is being used to upgrade heavier crude oils. economy and process heat applications call for operating the Also, as more biomass (e.g., corn) is grown to produce NGNP and future HTRs at even higher temperatures than biofuels, more ammonia-based fertilizer will be required, those attained in past reactors, which implies a need for R&D increasing the demand for hydrogen. Natural gas is currently on materials and other technology needs. Such needs were the dominant feedstock for production of hydrogen through reviewed by the Independent Technology Review Group (ITRG, 2004) and by NERAC.3 These reviews involved steam methane reforming (SMR). Unfortunately, each kilo- gram of hydrogen produced through SMR releases over 9 kg discussions with members of the industrial team building of CO2. EPRI studies (EPRI, 2003) have shown that nuclear a demonstration plant in South Africa that had assessed the heat could be an economic application that partly displaces need for technology development. Six areas were identified high-priced natural gas in steam reforming. The use of hy- as needing the most R&D. drogen is extensive in the petrochemical industry, including large-scale usage in the production of transportation fuels Materials Development and Improvements and fertilizers, and it would increase further if lower cost sources became available. Currently, all major refineries in The unique material challenges for the VHTR are based Texas and Louisiana are connected by a hydrogen pipeline on the need for adequate strength and dimensional stability at that runs within 100 m of Entergy’s Waterford nuclear power high temperatures and for the transport of corrosion products plant. Thus a nuclear plant can be said to have coexisted from metals and graphite in the presence of a potentially in close proximity to hydrogen equipment for a long time, impure helium coolant. Although a number of materials and obviating the need to widely separate a nuclear plant and alloys for high-temperature applications are in use in the a hydrogen plant. In the future, hydrogen may be used di- rectly as a fuel for ground transport. Options for displacing 3 U.S. Department of Energy Generation IV, Presentations to NERAC on the production of hydrogen from natural gas with nuclear July 19, 2004, October 25, 2004, May 2, 2005, and November 15, 2005.

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 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM petrochemical, metals processing, and aerospace industries, adequate. The heat transport fluid should (1) be chemically a very limited number of these materials have been tested or compatible with the surrounding structural materials, (2) qualified for use in nuclear-reactor-related systems. Some have superior fluid-mechanical and heat-transfer properties primary system components of the VHTR will require use of for an economical design of the process heat exchangers materials at temperatures above 800°C; at present, there are and the heat transport loop, and (3) have acceptable safety no such ASME-code-qualified materials. Significant R&D is characteristics under normal and off-normal conditions. The needed in a number of areas: fluid could be a high-pressure inert gas such as helium or a high-temperature molten salt. A molten salt, if it is properly 1. Understanding of the high-temperature- and irra- compatible with the heat exchanger and piping materials, diation-induced dimensional and material property chang- can minimize the temperature drop in the intermediate heat- es of nuclear graphite and carbon fiber/carbon matrix transport loop and the required pumping power, thereby composites. minimizing the cost of the delivered process heat. 2. Development of a basis for professional codes and An immediate problem with using molten salts is their standards for very high-temperature design methodology. corrosive nature at the high temperatures of use. In terms of 3. Improved understanding of environmental effects on corrosion mechanisms in materials, the molten fluoride salt metallic alloys and thermal aging of the alloys, as well as environment is quite different from other high-temperature better models for studying them and mitigating them. environments. The normally accepted paradigm of develop- 4. Understanding of thermal radiation and emissivity of ing a protective oxide layer to provide corrosion resistance large pressure vessels and core barrel surfaces in order to does not fully apply to this environment, owing to thermo- optimize passive core cooling. dynamically driven dissolution effects. Although the heat transfer characteristics of molten salt are superior to those of inert gas, optimizing heat exchanger design at high tem- Fuels Development and Requirements perature and high stresses (due to the pressure differential) The basic fuel element in a gas-cooled reactor is the TRISO is an important area of research. particle, consisting initially of a UO2 fuel kernel covered in layers of porous graphite, dense pyrolytic graphite, silicon car- Plant Operations bide, and pyrolytic graphite. A number of challenges must be overcome before these fuel forms can be optimized for higher The potential need to couple two diverse processes (elec- temperature and higher dose operation and before sufficiently tric power generation and hydrogen production) complicates high reliability and acceptably low fuel failures can be assured. the mission of the NGNP. Differing dynamic responses of These challenges include anisotropic shrinkage and swelling the reactor to the hydrogen production plant or an electricity- of the pyrolytic carbon; adequate mechanical stability at high generating plant must be carefully assessed for NGNP’s gas pressure due to fission gas or carbon dioxide; kernel migra- single mission project. Design and analytical studies are tion due to temperature gradients in the fuel particle; palladium needed to investigate possible configurations and control attack on the silicon carbide layer; and selective diffusion and schemes. The results of these studies will provide insights transport of certain fission products, such as silver, through the into the reactor design conditions, including provision of di- silicon carbide. Some key research activities for mitigating the rect versus indirect process heat cycles and relying on steam current limitations of TRISO particles include using a smaller power cycles instead of helium gas turbines at the outset. fuel kernel, using alternative fuel kernels such as UCO, or replacing the silicon carbide with an alternative such as zirco- Safety and Licensing nium carbide. Additionally, optimizing the microstructure as a function of the processing conditions under which the particles There needs to be a discussion with the USNRC on the are produced may improve performance. key aspects of safety and licensing that should be addressed if the NGNP is deployed in the 2017 to 2021 time frame. It is known that USNRC staff has already begun to develop a Primary to Secondary Heat Transfer technology-neutral licensing framework that the NGNP proj- The extraction of process heat from the NGNP requires ect can use as initial guidance (SECY-05-0130). However, an intermediate heat transport loop. The two key technol- this staff document has not yet been adopted by the USNRC ogy decisions needed are the design of the intermediate heat but is still being reviewed by the staff and the Advisory Com- exchanger (IHX) and the form and composition of the heat mittee on Reactor Safeguards. EPAct05 requires that DOE transport fluid. The high temperatures and potential induced and USNRC develop a joint approach to licensing NGNP stresses in the IHX (e.g., as a result of loss of electrical by August 2008. This activity is currently under way with load or shutdown of the process heat plant) place extreme inputs from the Phase 1 NGNP program. The DOE-USNRC demands on the design. Normal heat exchanger design ap- discussions related to NGNP licensing are focused on defin- proaches using conventional materials will most likely not be ing the approach that will be used. It is possible the technol-

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 THE GENERATION IV AND NUCLEAR HYDROGEN INITIATIVE PROGRAMS ogy-neutral approach will be used, but it is not clear if that other methods for hydrogen production, the wide oscillations approach would be ready in time for the engineering phase in the price of natural gas, the main source of hydrogen today, of the NGNP. In addition, the PBMR is currently in pre-ap- and the possibility of taxing carbon fuels in the future open plication review for design certification by the USNRC. The the way for nuclear energy to provide hydrogen and/or heat issues being addressed are generic to HTR licensing, and needed in a wide sector of the chemical processing business. this effort will provide a tangible forum in which to make To the extent the HTR is also applied for electricity alone, this progress on a licensing strategy for NGNP. would enlarge the technology base and improve the econom- ics of other HTR energy products, such as process heat and hydrogen. Fuel Cycle and Waste Technology As articulated in EPAct05, the NGNP program did not The disposition of spent fuel from the proposed NGNP explicitly address the broader use of high-temperature process reactor has not yet been addressed. HTR fuel is inherently heat, but the complementary public/private partnership initia- stable in storage because it remains at low temperatures and tive clearly hopes to extend the HTR to industrial process heat because of the graphite matrix’s good thermal conductivity applications that now primarily use expensive natural gas. The and low density of decay heat. However, the fuel volume is generation of bulk hydrogen for a hydrogen economy is an relatively large due to the low thermal power density and the ambitious endeavor that is likely to be decades away because fuel being imbedded in the graphite moderator. It has been of the requirement to develop a hydrogen infrastructure, as suggested that the fuel might be consolidated by removing well as the need to overcome many obstacles posed by a the matrix graphite, leaving only the coated particles, which fuel-cell-based transportation industry. However, nearer-term in pebble bed reactors, reduces volume by more than an applications could use process heat to displace natural gas, order of magnitude. A similar but smaller volume reduction including the combined production of electricity and process (because of the higher packing density of the fuel particles) steam, the direct application of high-temperature process heat is possible with prismatic fuel. After volume reduction, the in technologies such as steam-methane reforming, and the principal fission barrier is still retained by the TRISO coat- generation of hydrogen for existing markets. (Existing hy- ings around the fuel kernels. However, the engineering-scale drogen markets include refineries and ammonia plants, which recovery of actinides from TRISO particles in an economic together use about 7 percent of the natural gas consumed in way has never been demonstrated, so that it is uncertain the United States.) whether the HTR reactor can support a closed fuel cycle. The treatment of the NGNP as a DOE reactor will allow Does the Program Address a Specific and interim storage of its fuels at DOE sites. However, should this Existing Problem? reactor be a demonstration plant for a whole fleet of future reactors, then a broader program to address the disposition of The program is designed to develop an advanced new the fuel from a whole fleet of HTRs is needed. In particular, reactor that can provide process heat and/or electricity. The if a closed-fuel cycle is desired for waste management or cogeneration function appears to be a complication since enhancing the fuel resources in the future, it is important to electricity might be generated more economically by ad- consider the processing that would be required to achieve a vanced LWRs. However, no other nuclear technology can closed cycle for this fuel. This will be a significant challenge generate the high temperatures needed for the broad range since, as already noted, the TRISO coatings that are key to of process heat applications discussed. It has been recom- fission product retention could also seriously complicate the mended by NERAC that this dual mission be reconsidered reprocessing technologies. and not be accepted without further analysis. It was felt that the dual mission would drive the design, increase the cost of the program, and extend the schedule. It is important to NGNP evaluation maintain flexibility in the sizing of the NGNP reactor to facilitate obtaining the needed international collaboration or Is the Program Purpose Clear? co-funding by end users. Furthermore, while a dual-purpose The purpose of the NGNP program is to develop a com- mission would not be necessary for future commercial plants, mercial-scale VHTR that can satisfy the Generation IV VHTR it could serve as an engineering-scale heat exchanger for the goals, which include the generation of electricity and/or hy- NGNP plant to demonstrate the viability of coupling of a drogen, but within somewhat less ambitious parameters—for nuclear plant with a hydrogen production plant. example, lower-temperature helium coolant outlet. This nuclear system, if successful, would provide a method for pro- Is the Program Design Free of Major Flaws That Would ducing the bulk hydrogen necessary to move the country away Limit Its Effectiveness or Efficiency? from a carbon-based energy economy and could thereby help provide long-term energy security for the United States. There is not a single articulated program schedule that is While nuclear hydrogen will have to be competitive with coordinated with all the required elements to successfully

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0 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM Is the Program Effectively Targeted So That Resources Will commission the NGNP. The current disconnect between the Address the Program’s Purpose Directly? base NGNP program plan and the complementary public/pri- vate partnership initiative must be resolved so that all parties The budget for NGNP currently requested by DOE is not are working to achieve a consistent set of milestones. These adequate to meet the preferred schedule: To remedy this state elements include the reactor design; the heat transport system of affairs, a significant ramp-up of roughly $100 million per design, including the IHX; the fuel design and supply; and year would be required within 1 or 2 years. The budget for the hydrogen generation process design. There currently FY 2008 should be at least $60 million if the program is to exist both a schedule gap and a funding gap that prevent the be launched on a trajectory that will meet the 2017 operations hydrogen process plant design and the NGNP reactor design date. DOE’s notional budget projection for the next 6 years is from being available by the time of plant operation (at the only about 20 percent of what is required to meet the stated end of FY 2017). schedule. The budgets for NHI are also probably not ad- Little planning has been done on how the fuel for the equate if this preferred schedule is to be maintained. Finally, NGNP would be supplied. There is a particle fuel R&D it is imperative that private sector funding be brought into the program that is focusing on UCO fuel; however, it will take program to supplement the required research, development, up to two decades to complete the development and testing and demonstration. The technology partners must be selected of this new fuel form before it can be loaded into the NGNP. and end users must be convinced to join the public/private Further, the source of the fuel for the NGNP has largely been partnership at significant levels. ignored. There is very limited capacity available today for TRISO-coated particle fuel—it exists in Japan, China, and Does the Program Have a Limited Number of Long-Term South Africa, but only for UO2 kernels. There is no industrial Performance Measures That Focus on Outcomes and UCO fuel fabrication capacity, nor has the manufacturing Meaningfully Reflect the Purpose of the Program? process been proven. The reactor design is probably the least problematic Program milestones have been established, although there is aspect, although it must soon be decided whether to base no consistent set of milestones that is used by all the relevant it on pebble or prismatic (sometimes called “block”) fuel. stakeholders. The Generation IV program has developed The technology area with the most uncertainty and risk is evaluation methods and measures for assessing nuclear the heat transport system. The intermediate heat exchanger system design options. However, no specific performance (IHX) is a very demanding component and is critical for metrics that clearly define the real commercial targets—for most process heat applications, including the generation of example, the cost of energy on a MWth or a MWe basis or the hydrogen. University- and industry-based R&D is ongoing cost per kilogram of hydrogen generated—have been estab- for both metallic and ceramic designs, but it is not clear that lished for NGNP. On the other hand, once process heat end an acceptable solution will be obtained consistent with the users are engaged, it should be possible to develop specific NGNP program schedule given current funding levels. performance metrics for each fundamental application—for example, the cost of petroleum generated from coal. Are Key Decision Points and Alternative Courses of Action Identified? Has the Program Demonstrated Adequate Progress in Achieving Its Long-Term Performance Goals? The decision points and technical alternatives are well known. The key technical alternatives are the fuel type, the Since the long-term performance goals are not fully heat transport working fluid and the IHX, and the hydrogen established—for example, the final temperature design for generation process. It is important to evaluate the status of the VHTR is not defined—it is not possible to judge the the technology using the Generation IV evaluation criteria NGNP’s program on this criterion yet. The actual NGNP given in Table 3-1 to ensure that the demonstration phase program remains in an early formative stage. This criterion begins at the appropriate time. should be held in abeyance until more progress is made on Another significant decision point is the nuclear licensing the program. approach. The alternatives are the old 10 CFR Part 50 mul- tistep process, the new 10 CFR Part 52 one-step process, or NUclear hYdroGeN iNiTiaTiVe the yet-to-be-developed 10 CFR Part 53 technology-neutral process. To meet the apparently preferred date of FY 2017 Nuclear hydrogen Production for plant operations will require that some of these decisions be made quickly, so that the detailed design, component and NHI is the DOE’s research program for technologies to system testing, and licensing can be initiated to support this produce hydrogen and oxygen from water feedstock using schedule. The approach to licensing the NGNP is critical and nuclear energy. The program includes a small effort support- should be decided on early. ing advanced low-temperature electrolysis, but the primary

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 THE GENERATION IV AND NUCLEAR HYDROGEN INITIATIVE PROGRAMS focus of the R&D is three methods that use high-temperature in South Africa to satisfy nearly half of the petroleum fuel process heat to achieve higher efficiency: thermochemical demand. Long-term markets involve the direct use of hydro- cycles, hybrid thermochemical cycles, and high-temperature gen as an energy carrier for ground transportation and energy electrolysis. Because the high-temperature methods could storage. The growth of these markets will be driven by the realize 60-80 percent greater efficiency than conventional evolution of the technology and by economics. To support electrolysis, the NHI program is tightly connected to the NHI planning, these markets should be studied with the aid NGNP program to develop a reactor capable of providing of a systems analysis model. Given the escalating prices of high-temperature process heat. The mission of the NHI gasoline and the mounting desire to reduce carbon emissions, program is to operate a nuclear hydrogen plant to produce the need for these products is likely to grow substantially, hydrogen at a price that is cost competitive with other within years rather than decades. transportation fuels by 2019. NHI activities are coordinated with the larger DOE hydrogen program led by the Office of hydrogen Production Technology options and r&d status Energy Efficiency and Renewable Energy, as well as with the NGNP project. Current R&D on high-temperature steam electrolysis fo- Most of the hydrogen production in the United States cuses on solid oxide electrolysis cells, a process that was re- today uses steam reforming of natural gas as the source of cently demonstrated on the laboratory scale at Idaho National both the hydrogen (about 10 million tons per year) and the Laboratory (INL). The electrolyzer cell energy efficiency heat needed to enable the chemical processes in steam reform- of the process was close to 90 percent at a temperature of ing to take place. With the uncertain availability of low-cost 850°C; this is higher than the conventional alkaline electro- natural gas in the future, it is prudent to look for alternative lyzer cell efficiency of 80 percent. A high-temperature co- ways to produce the hydrogen needed for current and future generation reactor—for example, the NGNP reactor—could applications. About 50 percent of current hydrogen produc- provide both the process heat and the electricity needed for tion in the United States is used to make ammonia, which is this higher-efficiency production of hydrogen. mostly used for manufacturing fertilizers. Almost 40 percent The production of hydrogen from water via nuclear en- of it is used at oil refineries for lightening and sweetening the ergy is also possible by means of high-temperature chemical heavy oils to produce liquid fuel products for vehicles and reactions using heat alone (the so-called thermochemical aircraft. The lightening process used in refineries will grow water-splitting approach). Current NHI R&D focuses on two as production continues to shift toward heavier conventional options, both of which rely on the thermal decomposition oils in the United States and in Central and South America. of sulfuric acid into oxygen and SO2 at 800°C to 1000°C as Additionally, even heavier oils are being produced in greater the fundamental reaction, and two different approaches—S-I quantities from tar sands in Canada, and new production of and hybrid processes—to use the SO2 to produce hydrogen, shale oils in the United States is anticipated. Given the size oxygen, and recycled sulfuric acid. of the unconventional oil resources in North America (about The key elements of the S-I process have been tested 10,000 exajoules, as compared to 2,500 exajoules of conven- separately at the laboratory scale and shown to work in the tional oil reserves in the Middle East), it is plausible that these United States and Japan. In Japan, the synthesized process resources may become a major source of U.S. liquid fuels. was demonstrated at low pressure on a small scale (30 L/hr) In fact, Canada already produces over 1 million barrels a day in December 2004. A similar demonstration (100 L/hr) was from tar sands, getting the needed heat and hydrogen from accomplished 20 years earlier by the Westinghouse Electric natural gas. The environmental burden of extracting and pro- Company using the hybrid sulfur (HyS) process. In the cessing of such unconventional fuels is generally very heavy. United States, the construction of the S-I Integrated Labo- If the heat and hydrogen needed to lighten and sweeten the ratory Scale Experiment will be completed in FY 2007 in heavy oils could be produced from water using nuclear or collaboration with the French CEA and will provide the first renewable energy sources, the importation of liquefied natural pilot-scale integrated demonstration at prototypical pressure gas from sources outside North America and the emisson of and process conditions using electrical heating. In addition, carbon to the atmosphere could both be reduced. small-scale university-based research in the United States is Applications for hydrogen can be classified into near, working on alternative thermochemical cycles that do not use intermediate, and long-term markets. The near-term markets sulfuric acid, along with research in catalysts and membranes involve existing industrial applications for hydrogen: oil re- to improve process efficiency. An integrated laboratory-scale fining, ammonia production for fertilizer, methanol produc- experiment using modern electrolyzer technology is still tion, and tar sands processing. Mid-term markets involve the needed for the HyS process and should be included in the expanding production of liquid fuels from unconventional NHI program. resources, including coal, oil shale, and biomass. Some of The current NHI schedule calls for construction of an these mid-term markets have become economic given the engineering-scale process demonstration (several tens of higher price of oil and gas in the last 2 years in comparison megawatts) in 2015, to be coupled to the NGNP reactor. to the prices before 2004. For example, liquefied coal is used The Japanese are also moving ahead with a project producing

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 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM 30 m3/hr, or 1,000 times bigger than the country’s current the production of liquid fuels from unconventional sources laboratory-scale facility. The project will be coupled to such as tar sands, shale oils, coal, and biomass, and could be Japan’s 30-MW high-temperature nuclear reactor, which used directly as an energy carrier for transportation vehicles started up in 2000. equipped with fuel cells. The NHI program is focused on hydrogen production by nuclear heat or electricity. However, other aspects of the Is the Program Design Free of Major Flaws That Would hydrogen technology are being developed by DOE offices Limit Its Effectiveness or Efficiency? other than NE. The research includes technology for the storage, transport, and regeneration of hydrogen, as well as The program is currently exploring several technology op- infrastructure and standards for safe use by the public. The tions for hydrogen production using laboratory-scale experi- NE effort is being coordinated with the efforts of other DOE ments. For thermochemical processes, integrated laboratory- offices. However, because the use of hydrogen in the near scale experiments are scheduled to start in 2007, while for term is likely to be in large chemical plants, much of the high-temperature electrolysis, cell and stack experiments are practice today for handling hydrogen at large plants can be now under way, and module experiments will start in 2008. applied to nuclear hydrogen as well. The only new element This laboratory-scale R&D is intended to inform decisions might be the potential for generating tritium in some reac- in 2011 on technologies and materials for two pilot-scale tors, which then could be of concern if there is a way for it to integrated experiments. One or more of these pilot-scale tech- leak into the hydrogen side of the complex. However, such a nologies would be selected in 2015 for demonstration at the possibility appears to be minimal when the reactor coolant is engineering scale using heat delivered by the NGNP reactor. a nonhydrogenous material. In the longer term, when hydro- The current portfolio of research in the program is appropriate gen might become useful as a distributed energy carrier, new for the current phase of the project, and the program is free technologies for storage and distribution will be needed. of major flaws. The committee has concerns, however, that the resources being devoted to the program are insufficient to meet the proposed schedule, and that the schedule is not Nuclear hydrogen initiative evaluation fully integrated with the NGNP program schedule. Is the Program Purpose Clear? Are Key Decision Points and Alternative Courses of The purpose of the NHI program is to develop technolo- Action Identified? gies that produce hydrogen using nuclear energy. The most efficient methods for producing hydrogen involve the direct Two key decision points have been defined by the pro- use of high-temperature process heat, possibly coupled with gram, the first in 2011 to select two system designs for some electricity input. The NHI program is closely linked pilot-scale experiments and the second to select one or two to the NGNP program, which will develop a reactor capable designs for engineering-scale demonstration in 2015. At each of providing high-temperature process heat. The principal decision point the design options that prove unsuccessful are technology issues for the NHI program involve (1) identify- discarded. ing materials and associated fabrication methods for heat ex- changers, cell stacks, and other equipment that must operate Is the Program Effectively Targeted So That Resources Will at high temperatures with very corrosive candidate process Address the Program’s Purpose Directly? fluids such as sulfuric acid and (2) selecting, optimizing, and demonstrating integrated processes capable of producing hy- Much of the current NHI R&D is university based, which is drogen at the laboratory, pilot plant, and, finally, engineering appropriate for many aspects of the current laboratory-scale demonstration scales. R&D. However, as integrated experiments are started, an increasing fraction of the program support will need to be di- rected to the national laboratories and industrial participants Does the Program Address a Specific and in the program. More attention to industrial-scale implica- Existing Problem? tions of the technology is needed, starting with studying the The successful development of economically efficient implications of operating conditions for cost, reliability, and methods to generate hydrogen using nuclear energy would safety. address a number of important problems. In the near term, hydrogen produced in this way could replace the large Does the Program Have a Limited Number of Long-Term quantities of hydrogen currently produced using natural Performance Measures That Focus on Outcomes and gas, reducing carbon emissions and reducing the quantities Meaningfully Reflect the Purpose of the Program? of liquefied natural gas that the United States would need to import. In the longer term, this hydrogen could be used The NHI program is evaluated using the Generation IV more broadly in other petrochemical applications, including program performance measures. For the NHI program, the

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 THE GENERATION IV AND NUCLEAR HYDROGEN INITIATIVE PROGRAMS economics and the safety and reliability criteria are the reactors of the same size with the same fuel, offering the most important. However, specific metrics for evaluating potential for improved economics. performance have not been established. The committee SCWR. Like the VHTR, the supercritical-water-cooled recommends that the NHI program select specific economic metrics that can be linked to the cost of hydrogen produced reactor concept is a thermal-spectrum reactor that also by competing technologies, such as natural gas steam re- holds the potential for improved technology. This reactor forming. It is reasonable that until materials and fabrication concept offers significant advances in economics through methods have been identified for all of the major system plant simplification and increased thermal efficiency, with reactor outlet temperatures of 500oC, well above the 300oC components, a great deal of uncertainty will surround these evaluations. The design information will become avail- of today’s reactors. DOE, through GIF partnerships, has po- able once decisions have been made before entering the sitioned itself to leave the leadership of this reactor concept pilot-scale demonstration phase in 2011. These decisions to its international partners Canada and Japan. The GIF has should be based on the potential to meet specific economic identified the critical R&D issues that were examined from criteria. 2002 to 2005: • Corrosion of structural materials and cladding, Has the Program Demonstrated Adequate Progress in • Water chemistry and heat transfer related to the materi- Achieving Its Long-Term Performance Goals? als issues, and The program is making adequate progress, but some ac- • Demonstration for a base SCWR design of adequate celeration is required to meet the milestones proposed for safety and stability during operation and under off-normal the NGNP project. conditions. oTher GeNeraTioN iV reacTor NUclear Fast Spectrum Reactors: the GFR, LFR, and SFR Concepts eNerGY sYsTems Fast spectrum reactors can operate as either burners or breeders of fissile materials. As breeders they can multi- other Generation iV system Program descriptions ply nuclear fuel resources by between 10- and 100-fold, Six reactor concepts were recommended in the Genera- depending on the particular design. As burners of fissile tion IV Roadmap as having the most promise for meeting the material they have the advantage of burning the minor Generation IV goals. Five concepts were selected for further actinides (neptunium and transplutonium) more efficiently development by DOE. The remaining concept, the MSR, than thermal-spectrum reactors. When operating with a fis- has not been included in the scope of effort supported in the sile breeding ratio of unity, they are called self-sustaining United States, but the United States monitors international reactors, although the fuel they breed can be used by thermal progress on this concept. Of the concepts included in the as well as fast reactors. The use of thorium in thermal reac- plans of DOE, two are thermal neutron spectrum systems and tors, which results in reduced production of the actinides three are fast neutron spectrum systems. The total amount that affect repository capacity and in improved fuel use, of annual R&D funding in the United States for the alterna- has also been studied as a route to self-sustaining reactors. tive concepts (excluding NGNP) has been about $3 million Widespread deployment of self-sustaining reactors based per year. Therefore, even with the efforts abroad to address on some combination of these technologies would extend these concepts outside the United States, this level of fund- the fuel resources for nuclear fission for hundreds of years ing allows only basic concept definition and limits focused should that be needed. One of the chief issues in the develop- research to areas of greatest uncertainty. For each technology ment of a self-sustaining reactor for use in the United States a brief discussion of the concepts, the scope of R&D effort is economic competitiveness, given the requirements for high selected for the DOE effort, and the time line identified for reliability and safety. progress is provided as follows. Since the completion of the Generation IV Technology Roadmap, three self-sustaining fast-spectrum reactors con- cepts—the GFR, LFR, and SFR—have been the subject of Thermal Spectrum Reactors R&D efforts. All three systems were to be brought to a state VHTR. As noted above, this concept has been selected as where the best system could be chosen based on economics, the most promising concept for nuclear energy to produce safety, reliability, sustainability, proliferation resistance, and process heat and hydrogen. Known as NGNP, DOE efforts physical protection. (discussed above) for this concept have focused on the adop- Because the SFR was already at a fairly advanced state of tion of a demonstration plant/prototype. DOE has funded basic design, GIF organized a modest effort between 2002 conceptual design efforts for a liquid-salt-cooled VHTR that and 2005 in which the Japanese and the French led the de- would allow large power-up rates compared to gas-cooled velopment of advanced SFR fuels for actinide transmutation

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 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM evaluation of other Generation iV Nuclear energy and more economically competitive designs. In contrast, the system Programs much less developed LFR effort focused on corrosion is- sues and advanced modular designs. The GFR has received In effect, the United States selected two Generation IV the most attention over the last few years in France, where nuclear energy systems in 2006: the VHTR for NGNP and fuels, safety systems, and power conversion were the focus the SFR for GNEP. Furthermore, the priorities of the two of efforts. main strategic goals of the Generation IV program have been DOE worked with its GIF partners to maintain mod- re-ordered, owing to the emergence of GNEP: est R&D programs for all three fast reactor concepts from 2002 to 2005. Originally the performance downselection • First priority. Used-fuel recycle and actinide burning to for these concepts was planned for the same time frame as minimize waste products. NGNP—2011. The R&D goal for the fast reactors (GFR, • Second priority. Process heat to produce alternative LFR, and SFR) has been to obtain enough reliable informa- energy products (e.g., hydrogen). tion on materials issues and fuel behavior in the event of an accident, while developing an economically competitive The committee observes that the Generation IV concept design. For all three reactor concepts, these R&D issues must evaluation criteria (see Table 3-1) for reactor development be sufficiently understood by 2010 to allow a decision to be adopted by the Generation IV Technology Roadmap were made about the best concept for further development and not applied in this selection. The R&D priorities and concept demonstration between 2011 and 2021. evaluation have been shifting, with minimal discussion of Crosscutting R&D can benefit more than one reactor priorities and alternative courses of action. The Generation concept. Important fundamental information is needed in the IV program formerly had well-defined goals and measures following crosscutting areas: against which to gauge its decisions on the development of reactor technology options for sustainable nuclear energy, • Data to validate the models for the effects of irradiation among them competitive cost, minimal waste streams, and on materials characteristics since the expected service time innovative energy products. Since the arrival of GNEP, the for nuclear power plants has effectively become at least 60 new Generation IV program priorities are not well articulated years and could soon be as much as 80 years. for the portfolio of concepts, and the development of tech- • Data on the behavior of UO2 and nonfertile (neutroni- nology elements that are common to different Generation IV cally inert) actinide-bearing fuels operating at high tem- reactor designs are no longer well coordinated. peratures for long times. For example, ceria, magnesia, and The committee observes that there is one focus on process zirconia could be used in the Generation IV reactors to host heat and hydrogen production and another on reducing the the actinide fuel. high-level waste burden, but there has been no evaluation of • Information on advanced energy conversion systems, the possibility of developing crosscutting technology in sup- including equipment that interfaces between the coolant and port of the VHTR or the SFR in a way that can take advantage the turbine working fluids in advanced cycles, such as the of past related work and expand the base technology. For ex- supercritical CO2 power cycle. ample, there are technology elements that may be common to • Information on the application of technology-neu- both missions, such as supercritical fluid power conversion, tral approaches to reactor licensing and advances in the high-temperature materials development, and innovative regulatory system to include performance-based criteria for technologies for process heat. In fact, NGNP and GNEP ap- monitoring. pear to be competing for the chance to be demonstrated and commercialized, with both vying for the same limited DOE Current Status and Priorities for the Alternative Concepts budget and not taking advantage of synergisms. There are established program goals for the NGNP, but As previously noted, a downselect implicitly took place it is not clear under the new DOE program plans if the old at DOE in late 2005 and early 2006, given the redirection performance measures for Generation IV will be applied to at DOE toward support of GNEP. The DOE R&D focus has NGNP. Similarly, it is clear that no performance evaluations recently been shifted to elevate the priority for development were carried out prior to the inclusion of a large demonstra- and demonstration of the SFR as an advanced burner reactor tion plant for the SFR (i.e., the ABR) or for the large fuel (ABR) (Chang et al., 2006). Under the new DOE priorities separation facility. The SFR program structure seems vague for near-term deployment of a closed fuel cycle, the SCWR at this time, appearing to involve selected studies of technol- design work and any associated R&D are being closed out in ogy issues that are principally beneficial for commercial- the United States and only the international efforts will con- ization rather than being explicitly linked to the long-term tinue. The remaining work on the GFR and LFR concepts is technology needs of nuclear energy. gradually being moved to international support within GIF. The use of the Generation IV program metrics to com- pare the high-temperature reactors and fast-reactor systems

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 THE GENERATION IV AND NUCLEAR HYDROGEN INITIATIVE PROGRAMS Recommendation 3-2. DOE should decide whether to pur- for dual missions—a process heat mission and a fuel cycle flexibility mission—appears to be absent from the current sue a different demonstration plant (perhaps a smaller one program. For example, there is little attention to how either with less total energy output or a plant with fewer hydrogen the VHTR or the SFR technology will compete with existing production options or a more basic technology approach for LWRs in the electricity market. the VHTR) with a smaller contribution from industry. The program resources are barely adequate for basic stud- Recommendation 3-3. In assessing NGNP conceptual de- ies related to NGNP and the VHTR design (NGNP construc- tion will begin only after an industry alliance matches DOE signs, NE should favor design approaches that can achieve a funds). Thus the program funding level for these programs variety of objectives at an acceptable technical risk—for ex- is inadequate for developing the SFR, investigating the other ample, hydrogen production, other high-temperature process Generation IV reactor concepts, and developing crosscutting heat products, enabling deep-burn actinide management, and nuclear energy technologies. Currently there is little in the improving economics. way of synergies that can come from R&D developments Recommendation 3-4. NE should size the NGNP reactor across reactor concepts. system to facilitate technology demonstration for future com- mercial units, including safety. Consistent with resources FiNdiNGs aNd recommeNdaTioNs available, NE should adopt an appropriate power level to demonstrate components and functionality of practical sig- Next-Generation Nuclear Plant nificance to commercial size. Finding 3-1. The NGNP program has well-established goals, Recommendation 3-5. Because of the very high tem- decision points, and technical alternatives. The key technical alternatives are the fuel type, the heat transport working fluid peratures and severe material performance requirements and the IHX, and the hydrogen generation process. A key for thermochemical water splitting, NE should maintain the decision point is the nuclear licensing approach for NGNP. flexibility to first operate the NGNP using high-temperature To keep to the apparently preferred schedule, which has a FY steam electrolysis. 2017 plant operations date, some of the technical decisions Recommendation 3-6. DOE should focus on the following must be made quickly, so that detailed design, component and system testing, and licensing can be initiated. However, NGNP technologies that require significant development it is unlikely that operation can be achieved by 2017 due to and ensure that sufficient funds are available to advance significant funding gaps that developed in FY 2006 and FY these technologies whether or not industry matching funds 2007. These gaps affected the scope and schedule for the are available: planned testing of fuel and structural materials as well as the heat transport equipment. • Advanced materials for in-reactor operation at tempera- tures above 900ºC. Finding 3-2. Little planning has been done on how the fuel • Fuel particles that can withstand high burn-up and for the NGNP would be supplied. There is a particle fuel adverse transients. R&D program, but it will take up to two decades to complete • The heat transport system for process heat applications, the development and testing of this new fuel. specifically to improve its efficiency and reliability. • Waste management technologies related to commercial Finding 3-3. The main risk associated with NGNP is that deployment. the total funding under the current business plan calls for the Recommendation 3-7. To ensure good performance of private sector to match the government (DOE) funding. So far, however, not a single program has been articulated that NGNP-based hydrogen production, NE should put more coordinates all the elements required to successfully com- emphasis on the following: mission the NGNP. The current disconnect between the base NGNP program plan and the complementary public/private • Conceptual integrated process development and op- partnership initiative must be resolved. timizing plan flow sheets, before moving to engineering designs. With regard to the NGNP program, the committee recom- • Selecting the interface between the reactor and the mends the following: hydrogen plant. • Developing system performance tools to address Recommendation 3-1. A schedule that coordinates the re- unsteady conditions, such as plant start-up, plant trip, and quired elements for public-private partnership, design evolu- maintenance needs. tion, defined regulatory approach, and R&D results should be • Assessment of total system economics. articulated to enhance the potential for program success.

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 REVIEW OF DOE’S NUCLEAR ENERGY RESEARCH AND DEVELOPMENT PROGRAM Nuclear hydrogen initiative systems for dual missions—a process heat mission and a fuel cycle flexibility mission—appears to be absent from the The NHI program is aimed at developing new technolo- current program. gies to produce hydrogen and oxygen with high efficiency using nuclear energy. The focus of the program is the use of With regard to the other Generation IV nuclear energy sys- high-temperature process heat as the main energy input for tem programs, the committee recommends the following: the production of hydrogen, which promises significantly higher efficiency and lower cost than conventional low-tem- Recommendation 3-9. Within the Generation IV program, perature electrolysis. These processes involve challenging NE should modestly and reasonably support long-term base high-temperature materials problems, which are being ad- technology options other than the VHTR and the SFR, par- dressed with laboratory-scale research at this time for three ticularly for actinide management, using thermal and fast primary hydrogen production methods. Major technology reactors and appropriate fuels. downselections to allow testing at the pilot and engineer- ing demonstration scales are scheduled for 2011 and 2015, Recommendation 3-10. Though NE currently focuses on respectively. the VHTR for process heat and the SFR for advanced fuel NHI is well formulated to identify and develop work- cycles, it should assess the cost-benefit of a single reactor able technologies, but the schedules and budgets need to be system design to meet both needs. adjusted to assure appropriate coupling to the larger NGNP program. Recommendation 3-11. Funding for NGNP and NHI should With regard to the NHI program, the committee recom- be increased if the schedule is to be accelerated to attract mends the following: more industrial support. Recommendation 3-8. DOE should expand NHI program reFereNces interactions with industrial and international research orga- nizations experienced in chemical processes and operating Bloomberg Report. 2007. Sasol in talks with PBMR to improve processes. temperatures similar to those in thermochemical water Business Report. February 16, 2007. splitting. NE should also broaden the hydrogen production Chang, Y., P. Finck, and C. Grandy. 2006. Advanced Burner Test Reactor Preconceptual Design Report. ANL-ABR-1, Argonne National Labora- system performance metrics beyond economics—for ex- tory, September. ample, it could use the Generation IV performance metrics Department of Energy (DOE). 2002. A Technology Roadmap for Gen- of economics, safety, and sustainability. eration IV Nuclear Energy Systems. Washington, D.C.: Department of Energy. DOE. 2004. Next Generation Nuclear Plant, Request for Information and other Generation iV Nuclear energy system Programs Expression of Interest. May 28. DOE, Office of Nuclear Energy. 2006. The U.S. Generation IV Fast Reactor Finding 3-4. The second major concept for development in Strategy. DOE/NE-0130. Washington, D.C.: Department of Energy. the Generation IV program, the SFR program, seems vague Electric Power Research Institute (EPRI). 2003. High-temperature gas- at this time and appears to involve selected studies of technol- cooled reactors for the production of hydrogen: An assessment in ogy issues that are principally beneficial for commercializa- support of the hydrogen economy. EPRI Report 1007802. Palo Alto, Calif.: EPRI, April. tion rather than being explicitly linked to long-term nuclear Hall, R.W., and C.A. Chaffey. 1982. Review of the operational experience energy technology needs. of the Hinkley Point B AGR over the past two years. Nuclear Energy 21 (February): 41-50. Finding 3-5. The committee is concerned that the Genera- Independent Technology Review Group (ITRG). 2004. Design Features tion IV concept evaluation criteria for reactor development and Technology Uncertainties for the Next Generation Nuclear Plant. INEEL/EXT-04-01816, September. adopted by the Generation IV Technology Roadmap were not Joeng, Y.H., and M.S. Kazimi. 2005. Attributes of a Nuclear Assisted Gas applied in the selection of the VHTR and SFR. The Genera- Turbine Power Cycle. MIT-NES-TR-003, February. tion IV R&D priorities have been shifting, with minimum Modeen, D. 2006. Testimony to the House Science Committee, April discussion of criteria and alternatives. 2006. Available at http://gop.science.house.gov/hearings/energy06/ April%206/Modeen.pdf. Finding 3-6. The program resources are barely adequate for National Research Council/National Academy of Engineering (NRC/NAE). 2004. The Hydrogen Economy: Opportunities, Costs, Barriers, and basic studies related to NGNP and the VHTR design and R&D Needs. Washington, D.C.: The National Academies Press. entirely inadequate for exploring the SFR at a research level Rosenberg, M. 2007. Architecture of nuclear innovations. Energy Biz (unless the new GNEP program also includes basic research Magazine (January/February): 52-53. components), for investigating other reactor concepts, and Yildiz, B., M. Petri, G. Conzelmann, and C. Forsberg. 2005. Configuration and Technology Implications of Potential Nuclear Hydrogen System for developing crosscutting reactor technology systems. Applications. ANL-05/03, July. Finding 3-7. The use of the Generation IV program metrics to compare the high-temperature reactors and fast-reactor