The reader should note that the capital cost estimates presented in Tables 4.4 and 4.5 are early-stage estimates and that such estimates for future technology facilities often prove to be underestimates.
In addition to target science, there are other deep science issues embedded in what is usually labeled “technology” (e.g., chambers) involving a broad range of scientific disciplines, including nuclear and atomic physics, materials and surface science, and engineering science. In the next several years, the IFE program will probably not be involved in engineering development but rather in science and engineering research aimed at determining if feasible solutions exist to the very challenging problems.
An organized program that encompasses all technology options most effectively determines the roadmap to an IFE DEMO plant. Only such a program will have a broad enough view to ultimately identify the most promising IFE DEMO design(s).
The committee recognizes how challenging and complex the unresolved issues are and how much remains to be accomplished and understood if IFE is to become a practical energy source. Each potential driver and target combination has advantages and disadvantages, technologies are evolving rapidly, and scientific challenges remain. If the nation intends to establish IFE as part of its energy R&D portfolio, it is clear that both science and technology components must be addressed in an integrated and coordinated effort.
The roadmap concept put forward by this committee carries forward all IFE approaches to some point at which off-ramp or continuation decisions are made. Should the NIF achieve ignition with indirect drive and the nation decide to pursue IFE, the R&D required to pursue IFE as a practical energy option would begin to diverge from the R&D that NNSA is likely to support for stockpile stewardship applications. In this case, a nationally coordinated R&D program for IFE would be needed to pursue a broad-based roadmap. Inertial fusion energy is an integrated concept whose overall probability of success depends on the success of several individual items. If one component fails a physics test or fails to be cost-effective, the system fails, regardless of whether reactor-scale ignition and gain are reached.
There has been considerable discussion within the committee about the timing for—and the extent of—a technology development element (chambers, target fabrication, etc.) as described in Chapter 3, as part of the early phase(s) of the IFE program. The committee recognizes that absent ignition within the physics element of the program, technology would be of limited value as part of the early phase(s) of the IFE program. There are, however, several reasons for establishing a technology element even in the earliest phases of the IFE program.