5
Strategy and Roadmap for a Pilot Plant
In response to the statement of task, the committee took the feedback from the utilities into account, which framed the timeline requirements for the pilot plant. As noted above, the electrical utilities in the United States are working toward the transition to low-carbon emission electricity production by 2050. This motivates exploring a schedule to bring a pilot plant into operation between 2035 and 2040: this is aggressive relative to recent construction of large fusion facilities and other countries’ fusion program plans, with the exception of China’s CFETR program and the United Kingdom’s recently announced STEP program. Both programs seek to be the first to put electricity from fusion on the grid. Unlike the program plans developed by the Community Planning Process (CPP),1 which considered a comprehensive bottom-up approach that is appropriate to developing a program and includes many elements beyond those associated with a pilot plant, the committee took a more targeted approach to explore what would be needed to bring a pilot plant into operation as soon as possible for fusion to be considered as a viable generation alternative during the investment window. This schedule-driven approach will require the execution of many parallel activities and engagement of a broad group of participants in the private and public sectors as discussed in Chapter 4. In parallel with the development of this report, Fusion Energy Sciences Advisory Committee (FESAC) is addressing the schedule implications and priorities of the CPP report. Ultimately, it will be necessary to reconcile the upcoming FESAC report and its priorities with the top-down schedule-driven approach described herein.
In the 2019 report Final Report of the Committee on a Strategic Plan for U.S. Burning Plasma Research (hereafter the “Burning Plasma report”),2 the tokamak
concept was identified as the primary track to a fusion pilot plant and the stellarator as the leading alternative. The statement of task for this report does not presume which fusion concept to pursue for a pilot plant, and this committee did not evaluate different concepts. Since both technical performance and economic attractiveness are major considerations for a pilot plant, a parallel approach in the development of more than one fusion concept, at least to the preliminary design level, is appropriate. A key element in the successful Commercial Orbital Transportation Services (COTS) program was the competition between companies. That spirit of competition to develop the most viable pilot plant is appropriate. While specifying the precise number of pilot plant teams is premature, two to four design teams can be envisioned to encourage competition.
Conclusion: To meet the challenge of operating a pilot plant between 2035 and 2040, the development of fusion concepts, technology, and pilot plant designs will need to be performed in parallel.
Parallel development of fusion concepts enables the schedule acceleration required for fusion to be ready as a possible generation alternative as the U.S. transitions to low-carbon emission electricity. Such an approach, however, enables schedule acceleration and is needed for fusion to be ready as a possible generation alternative as the mix in the U.S. transition to low-carbon emission. Parallel development, however, includes inherent risk where some lines of research may not be successful and additional resources will be needed to accomplish multiple lines of activity at the same time as compared to completing activities sequentially. Using the 2019 Burning Plasma report as an example, additional resources will be required for the pilot plant and to complete the necessary research and development identified in that report.
Six phases have been identified in the development and operation of a fusion pilot plant: (1) conceptual and preliminary design, (2) final design and construction, (3) start of operation, (4) first phase of operation, (5) second phase of operation, and (6) third phase of operation to take advantage of this unique facility. The scope of these phases is described below. The accompanying timeline illustrates when the various phases need to be implemented to commission a pilot plant into operation sometime between 2035-2040. Detailed planning and resource allocation would be required to develop a more accurate timeline. A timeline with the major elements is shown in Figure 5.1.
PRIOR TO START OF CONSTRUCTION: CONCEPTUAL AND PRELIMINARY DESIGN (2021-2028)
The highly integrated nature of a pilot plant requires that both scientific and technical issues are comprehensively addressed. The goal of a lower cost pilot plant relies on innovations in science and technology. These must be performed and extensively evaluated prior to finalizing the design and initiating construction.
While substantial progress has occurred in achieving plasma parameters that may extrapolate to that needed for a pilot plant, outstanding technical issues remain for even the most mature fusion concepts. As discussed in the CPP report, the remaining gaps, which are significant, must be addressed to have confidence in the performance of a pilot plant.
Conclusion: Each successful pilot plant fusion concept must demonstrate that the requisite Lawson parameter to extrapolate fusion plasma gain, particle and energy confinement time, heat exhaust, stability, energetic particle confinement and sustainment, can be achieved with small extrapolation to the parameters needed for a pilot plant to provide confidence in the performance of the pilot plant.
The physics parameters required for evaluating a fusion concept for a pilot plant are broadly discussed in Chapters 3 and 4. The parameters depend in detail on the fusion concept under consideration. These will need to be defined early in this phase to ensure that the experimental and theoretical program supports the timely evalua-
tion of the concept, and selection of these parameters must be made prior to making the decision to start construction.
As noted in the CPP report and discussed further in Chapter 4, many technological issues are at a low technology readiness level (TRL) level, and the maturity of many of the technologies required for the pilot plant needs to increase. Furthermore, to improve the economic attractiveness, there is also a need for technological innovations. This was also highlighted in the FESAC Report on Transformative Enabling Capabilities for Efficient Advance Toward Fusion Energy,3 which identified opportunities for technological innovation. Some of these are already being pursued by the fusion industry as well as by universities and national laboratories.
Conclusion: Critical technologies—such as large-bore, high-temperature superconducting magnets, blanket concepts, functional materials, plasma-facing materials, and tritium processing (including the development of low inventory systems)—have to increase in TRL to 6 or 7 to minimize the scale up to a pilot plant.
While the development of some technologies will facilitate many different fusion concepts, some fusion concepts require specific technologies to meet the goals identified in Chapter 3. It is necessary to increase the maturity of critical technologies that have the largest impact on many different concepts while recognizing that the list of critical technologies may evolve as the design of the pilot plant evolves, for example through the conceptual design phase or as breakthrough developments occur. To illustrate this, most fusion concepts rely on deuterium-tritium (D-T) fuel, and development of blanket concepts to breed tritium and process tritium as described in Chapter 4 is needed. The use of hydrogen and boron, pure deuterium, or deuterium and helium-3 as the fuel would not require tritium breeding; however, a breakthrough in the plasma confinement and temperature is required and other technologies would have to be developed.
The regulatory framework required to obtain a construction and operations license is very important to develop an understanding of the cost and schedule for the pilot plant and eventually a first-of-a-kind (FOAK) power plant. This is discussed in more detail in Chapter 3.
Conclusion: The regulatory framework for fusion should be well defined based on a risk-based approach appropriate to fusion.
The site of a pilot plant has important practical ramifications including public acceptance that can affect the cost and schedule as discussed in Chapter 3.
Conclusion: Site requirements and possible options for site selection will need to be identified.
A fusion pilot plant entails the integration of scientific, engineering, and regulatory issues and requires a broad spectrum of skills.
Finding: Due to the highly integrated aspects of a pilot plant, national well-coordinated teams composed of developers; manufacturers; engineering, procurement and construction (EPC) companies; universities; and national laboratories are needed to develop pilot plant concepts to ensure a robust engineering design and a reliable cost and schedule.
Recommendation: The Department of Energy should move forward now to foster the creation of national teams, including public-private partnerships, that will develop conceptual pilot plant designs and technology roadmaps and lead to an engineering design of a pilot plant that will bring fusion to commercial viability.
Without a design and the resolution of the remaining scientific and technical issues, it is not possible to reliably project the cost of the pilot plant at this time. However, in light of the eventual marketplace for a power plant, the cost of building a pilot plant is an important consideration as well as the projected cost of electricity for a power plant.
Conclusion: If the pilot plant cannot be built for less than the projected cost of the FOAK power plant or the concept does not have the potential for producing electricity at an economically competitive cost, then further innovations will be required to reduce the cost and improve the concept prior to proceeding to construction.
A distinguishing feature of a pilot plant relative to a research project is that it must not only meet scientific and engineering objectives but also provide a cost basis for a FOAK power plant. Thus, the cost of the facility in relation to other projects generating electricity is an important consideration as well as the implications for producing electricity. Delays in meeting this goal would result in decreased opportunities for impacting the U.S. marketplace during the transition to low-carbon emission. On a longer timeline, opportunities to replace the fleet of generating equipment with fusion power plants would exist as well as potentially addressing the needs of the international marketplace due to the expected need for increased low-carbon and non-carbon emission electricity generation as discussed in Chapter 2. This longer timeline was not explored by the committee but would have ramifications for private investors.
PRIOR TO START OF OPERATION OF A PILOT PLANT: FINAL DESIGN AND CONSTRUCTION (2028-2032)
The success of the final design and construction phase will rely on the effectiveness of the integrated national team, which is assumed to continue into this phase. During this phase detailed engineering final design would be completed. It is assumed that technical risks were reduced during the preceding phase through the construction of prototypes if needed and that this would also be used to qualify vendors.
Conclusion: Design and construction of the pilot plant needs to be completed, and integrated systems testing needs to be performed to commission a facility prior to start of operation of a pilot plant.
Conclusion: A construction and operating license will need to be obtained.
In the preceding chapters, the report identified a set of recommendations and conclusions that imply actions that need to be addressed. These are summarized in Table 5.1 by different phases leading up to the completion of construction. After
TABLE 5.1 Various Activities in Support of the Development of a Fusion Pilot Plant
| Recommendation or Innovation Category | Completed by | ||||
|---|---|---|---|---|---|
| Immediate Action | Conceptual Design | Preliminary Design | Final Design | Construction | |
| Organization and design | Create national teams to initiate design from private sector, universities, and national labs | Complete concept Enhance teams | Select and consolidate team(s) Define cost and schedule | Execute Fusion Pilot Plant design and construction | |
| Technology approach | Develop technology roadmaps | Complete conceptual design Refine technology roadmaps | Demonstrate preliminary design and critical technology prototypes | Complete final design | Complete construction |
| Public-private partnerships (PPP) | Develop PPP models for fusion and tech development | Execute PPPs | Refine and expand PPPs | ||
| Data/expertise access | Provide access to private-sector to ITER data Expand industrial access to labs and universities | Continued data and expertise sharing from labs/universities into private sector. Intellectual property agreements. |
|||
| Recommendation or Innovation Category | Completed by | ||||
|---|---|---|---|---|---|
| Immediate Action | Conceptual Design | Preliminary Design | Final Design | Construction | |
| Regulatory | Develop regulatory needs/framework | Finalize regulatory framework | Obtain required licenses | ||
| Site | Develop site requirements and options | Develop site | |||
| Workforce | Define Diversity, Equity, and Inclusion (DEI) plan | Execute DEI improvement | Improve workforce growth consistent with DEI plan | ||
| Plasma performance | Improve plasma performance and predictive capability | Demonstrate equivalent Qp>1 | Evolve and improve projections to Qp > 1, Qe > 1 and required availability | ||
| Actuators | Define actuator needs | Develop actuator technology | Design and deploy actuators | ||
| Heat exhaust | Define heat exhaust challenge | Demonstrate heat exhaust solutions | Implement solutions | ||
| Tritium/fuel cycle | Define tritium/ fuel cycle requirements Design demonstration | Demonstrate tritium/fuel cycle process technology | Demonstrate efficient tritium/ fuel cycle processing | ||
| Blanket | Define blanket and test facility requirements Design blanket test facility | Operate blanket test facility Obtain data | Finalize design and build 1st generation | ||
| Neutron material degradation | Design limited volume neutron source | Operate neutron source, obtain initial results | Acquire further data Confirm material and design | ||
| Structural design requirements | Develop high temperature structural design requirements | Obtain requisite data | Implement requirements | ||
| Plasma-facing components (PFCs) | Define PFC requirements | Design and test PFCs | Fabricate and install PFC | ||
| Blackstart | Evaluate blackstart capability | ||||
NOTE: Summaries of recommendations and conclusions of this report are in red boldface.
the creation of the national teams, design work and technology roadmaps would be developed for each concept to provide a more detailed schedule. Depending on the concept, some elements would receive greater or lesser emphasis. The elements are not organized in priority order.
START OF OPERATION (2032-2035)
Operations would proceed from non-nuclear operations and demonstrate the resolution of scientific and technical issues. For facilities using tritium, the tritium fueling systems would be commissioned.
FIRST PHASE OF PILOT PLANT OPERATION (COMPLETED BY 2035-2040)
Operations would proceed from non-nuclear operations to the use of the fuel mix that will be used in the FOAK fusion power plant and demonstrate fusion power production. For the concepts that will use D-T fuel, the performance of the tritium fuel system would be demonstrated, tritium breeding would be evaluated, and tritium breeding performance would be projected to the Second Phase. A more extensive definition of the goals for the first and second phase of the pilot plant is given in Chapter 3.
Conclusion: Sufficient fusion plasma energy gain (Qp) will need to be demonstrated to show that net electricity is feasible (Phase 1a).
Conclusion: A peak ≥50 MWe net electricity production for ≥3 hours with Qe > 1 (Phase 1b) should be targeted.
Conclusion: Safe and environmentally acceptable operation consistent with the operating license will need to be demonstrated.
SECOND PHASE OF PILOT PLANT OPERATION (COMPLETED BY 2040-2045)
The purpose of this phase is to resolve the scientific and technical issues and enable the fusion industry developers and power plant owners and operators to evaluate both the cost of a FOAK power plant as well as project the cost of producing electricity. In addition to producing net electricity with high availability, the pilot plant would need to demonstrate ability to maintain and replace in-vessel and blanket components, tritium breeding to be >0.9 for concept using D-T and have sufficient data to project the performance of a FOAK, and test materials to 2-3 MW-year m−2. The availability of the plant during this phase should exceed
50 percent and be sufficient to enable projection of the availability and reliability of a FOAK reactor. During this phase, tritium breeding should be demonstrated to be sufficient for a FOAK reactor.
Conclusion: The second phase of a pilot plant should demonstrate peak 50-100 MWe net electricity production and average net electricity generated for at least one environmental cycle, which includes the outage to perform maintenance and replacement of in-vessel components.
THIRD PHASE OF PILOT PLANT OPERATION
The pilot plant may be a viable test bed for materials testing and exploring new technologies to further improve the concept. While the second phase of operation will enable evaluation of structural materials to 2-3 MW-year m−2, the materials may perform beyond that level and qualification of materials can be performed in the pilot plant. Furthermore, other more advanced materials can be tested. This also can be a test bed for alternative blanket designs or coolant systems. The scope of this operating phase requires careful consideration. There is clearly a unique capability that can be exploited; however, this may entail making the pilot plant design more flexible and incorporating this capability at the front end. In general, this complicates the design, increases capital cost for construction, and results in longer construction duration schedules.
Conclusion: The full scope of the third phase should be evaluated as part of the preliminary design effort.
STRATEGIC RISKS AND OPPORTUNITIES
The schedule noted in this plan has both opportunities and risks associated with it. The opportunities include engagement by a recently emerged and growing private industry. As noted earlier, private industry brings both financial resources and a market focus. If anything, its market focus involves an even more accelerated timeline. The schedule provides an opportunity to contribute to supporting the transition to a low-carbon emission electrical marketplace. Due to the level of technological readiness, there are risks in meeting this schedule. They are addressed by identifying the key technical goals and will require resources to tackle them. This ambitious plan requires the performance of research and development in parallel with design. This encourages synergy between the design and research and development effort; however, it does introduce risk that the design will have to be modified or even discarded. A key element in the plan is that each concept design activity develops a technology roadmap to address the critical development
requirements. While the recent 2020 CPP and FESAC reports have identified the broad issues, these technology roadmaps will provide a greater level of detail and focus on the advances required for each particular conceptual design strategy. There is also a risk that some of the research development effort will identify that the key goals either cannot be met or result in significant schedule delay; this should not be considered a failure but the result of a healthy, diverse approach to a difficult, integrated design. This issue is addressed by a critical decision point prior to proceeding with construction. While the indicated timeline for the design and construction of pilot plant is less than that of constructing JT-60SA, W7-X, and ITER, it is worth noting that it is longer than for JET and TFTR. The design effort including prototypes of key components will be critical to develop the construction and assembly schedule.
The duration of the operating phase prior to fusion power performance is short relative to what JET and TFTR needed to develop new plasma operating scenarios and commission the tritium and remote handling systems. In this plan, the plasma operating scenario will be demonstrated in experiments that operate with equivalent fusion gains greater than unity prior to the decision to construct. This experience will be invaluable to the pilot plant. Of course, new technologies such as the tritium breeding blankets on the pilot plant will have to be tested and developed, but the prior development on test stands will increase the likelihood of their performance. Since a volumetric neutron source may not be available in time to fully qualify neutron degradation in structural and functional materials, phase three pilot plant operation would fulfill this and assess component lifetime. All risks can never be fully mitigated; however, the major technological issues have been identified in this report.
There are risks and opportunities associated with changes in the timeline for the transition to a low-carbon emission electrical marketplace. Due to climate change considerations, the transition may accelerate. This will make it more difficult for fusion to contribute. This motivated, in part, the recommendation for the fusion program increasing its engagement with the energy community. Due to other political or technological considerations, the transition may be delayed. This may be an opportunity for fusion to make a greater contribution if the proposed timeline is followed.
The risks associated with the proposed timeline were considered in the context of the risks of extending the timeline to a pilot plant. The following are some ramifications of an extended timeline or even elimination of the timeline. First and foremost, the transition to low-carbon emission electricity generation is under way. The electrical utilities will use whatever combination of technologies are available to make the transition. Without firm low-carbon and non-carbon emission electricity generators, the the price of electricity will increase. Fusion has the potential to contribute to addressing these electricity price concerns. Since power plants typi-
cally operate for 40 years or more, a delayed timeline will diminish opportunities for fusion to enter the marketplace. By entering the marketplace, it will be possible to refine and improve fusion commercial power plants. Without entering the marketplace, that process of innovation will be hampered. Second, a schedule that does not address the needs of the marketplace or is very long term will discourage private investment and retention of expertise in U.S. industry. Third, China and the United Kingdom are embarking on development to be the first to put fusion on the grid. The United States has played a major role in the development of the fundamental science underlying fusion and has the opportunity to build on its past accomplishments or it can let other countries take the lead on this technology.
The committee acknowledges there are risks and opportunities with the proposed timeline, which were considered in the context of an extended timeline. In addition to the scientific risks of generating fusion power for extended durations and the technical risks of advanced materials and engineering systems to close the fuel cycle in a concept that is cost effective, a major risk is whether the timely resources required from the public and private investors to move forward will become available.
SUMMARY
In response to the statement of task, the committee has in Chapter 2 identified the key requirements for fusion to support the transition to a low-carbon emission electrical marketplace by 2050. A pilot plant is a necessary step in the development of fusion energy. This report identifies the technical and economic considerations that need to be addressed for fusion to make an impact on the marketplace.
The key marketplace requirements combined with the previous technical studies provided a basis for identifying the key goals for fusion in Chapter 3. This was a broad perspective ranging from demonstrating scientific and technical feasibility to defining the performance goals for a fusion pilot plant. In support of the key goals in Chapter 3, the scientific and technical innovations required to both demonstrate feasibility and address the cost requirements of the marketplace were presented in Chapter 4. Fusion development will require participation by industry, including companies developing fusion energy, building components and providing EPC services, national laboratories, and universities bringing together a broad range of skills. A key element in Chapter 4 is the role of public-private partnerships to potentially accelerate the development of fusion and to ensure a transition to the marketplace. In this chapter, an accelerated timeline to build and operate a pilot plant to enable fusion to support the transition in the electrical marketplace is presented.
Conclusion: Successful operation of a pilot plant in the 2035-2040 timeframe requires urgent investments by DOE and private industry—both to resolve the
remaining technical and scientific issues and to design, construct, and commission a pilot plant.
NOTES
1. S. Baalrud, N. Ferraro, L. Garrison, N. Howard, C. Kuranz, J. Sarff, and W. Solomon, 2020, “A Community Plan for Fusion Energy and Discovery Science,” https://arxiv.org/abs/2011.04806.
2. National Academies of Sciences, Engineering, and Medicine, 2019, Final Report of the Committee on a Strategic Plan for U.S. Burning Plasma Research, Washington, DC: The National Academies Press, https://doi.org/10.17226/25331.
3. Fusion Energy Sciences Advisory Committee, 2018, “Fusion Energy Sciences Advisory Committee Report: Transformative Enabling Capabilities for Efficient Advance Toward Fusion Energy,” updated February 15, https://science.osti.gov/-/media/fes/fesac/pdf/2018/TEC_Report_15Feb2018.pdf.
