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3007 3 INERTIAL FUSION ENERGY TECHNOLOGIES
3008
3009 This chapter deals with those technologies, other than the driver technologies covered
3010 in Chapter 2, that are required to produce and utilize the energy from fusion nuclear
3011 reactions in an inertial fusion energy (IFE) system. The first subsections in this
3012 chapter cover the targets, chambers, related materials issues, as well as tritium
3013 production and recovery. Additional subsections cover the crosscutting issues of
3014 environment, health, and safety issues, the balance-of-plant, and economic
3015 considerations.
3016
3017 In addition to target science, there are challenging science issues for inertial fusion
3018 energy (IFE) embedded in what is usually labeled "technology" (e.g., chambers)
3019 involving a broad range of scientific disciplines including nuclear and atomic physics,
3020 materials and surface science, and many aspects of engineering science. In the next
3021 several years, IFE research will not be involved in engineering developments, but
3022 rather in science and engineering research aimed at determining whether feasible
3023 solutions exist to very challenging "technology" problems.
3024
3025 An effort is needed to determine whether there is any IFE concept (where concept
3026 means some combination of target type, driver and chamber) that appears to be
3027 feasible. Only certain combinations of targets, drivers and chambers seem to be
3028 possible. While the emphasis today and in the near future should be on target
3029 performance issues, working exclusively on these problems could easily lead to
3030 solutions that are not compatible with practical driver and chamber options. Such a
3031 serial approach can lead to dead ends and will also extend the time scale to possible
3032 practical applications of IFE. For each technological approach, the committee
3033 identifies a series of critical R&D objectives that must be met for that approach to be
3034 viable. If these objectives cannot be met, then other approaches will need to be
3035 considered.
3036
3037 The approach used in the High Average Power Laser (HAPL) program (see Chapter
3038 1) was one in which all the potential feasibility issues of the entire IFE system were
3039 studied, and then the most important ones were addressed to try to find basic
3040 solutions. This is a good example of how a national IFE program might be
3041 structured.
3042
3043 HIGH-LEVEL CONCLUSIONS AND RECOMMENDATIONS
3044
3045 The main high-level conclusions and recommendations from this chapter are given
3046 below.
3047
3048 Conclusions
3049
3050 Conclusion 3-1: Technology issues—e.g., chamber materials damage, target
3051 fabrication and injection, etc.—can have major impacts on the basic feasibility
3052 and attractiveness of IFE and thus on the direction of IFE development.
3-1
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3053
3054 Conclusion 3-2: At this time, there appear to be no insurmountable IFE fusion
3055 technology barriers to the realization of the components of an IFE system,
3056 although knowledge gaps and large performance uncertainties remain, including
3057 for the performance of the system as a whole.
3058
3059
3060 Conclusion 3-3: Significant IFE technology research and engineering efforts are
3061 required to identify and develop solutions for critical technology issues and
3062 systems, such as: targets and target systems; reaction chambers (first
3063 wall/blanket/shield); materials development; tritium production, recovery and
3064 management systems; environment and safety protection systems; and
3065 economics analysis.
3066
3067 Recommendations
3068
3069 Recommendation 3-1: Fusion technology development should be an important
3070 part of a national IFE program to supplement research in IFE science and
3071 engineering.
3072
3073 Recommendation 3-2: The national inertial fusion energy technology effort
3074 should leverage magnetic fusion energy materials and technology development
3075 in the United States and abroad. Examples include: the ITER test blanket
3076 module R&D program, materials development, plasma-facing components,
3077 tritium fuel cycle, remote handling, and fusion safety analysis tools.
3078
3079
3080 TARGET FABRICATION AND HANDLING FOR INERTIAL FUSION
3081 ENERGY
3082
3083 Fabrication of targets at the rate per day required and that meet the exacting
3084 specifications needed to achieve high gain and an acceptable cost has long been
3085 recognized as a key requirement of practical energy application of inertial fusion.
3086 Each of the prior three National Academy of Sciences Inertial Fusion Energy (IFE)
3087 studies has commented on the importance of target fabrication to the success of
3088 inertial fusion for energy applications, and has noted that the prospects for success
3089 appear favorable, but that much work remains to be done. 1 Most of the many IFE
3090 power plant design studies have given serious consideration to how the target
3091 fabrication requirements could be achieved. 2 The consensus of these studies is that
1
E.E. Boyd, “Summary of the Findings and Recommendations of the 1986, 1990, and 1997
National Research Council's Reviews of the Department of Energy's Inertial Confinement
Fusion Program,” NRC staff document provided to the committee, 24 March 2011.
2
For example, see the following: Goodin, D.T., et. al., “Demonstrating a target supply for
inertial fusion energy”, Fusion Science and Technology, 47 (2005) 1131-1138; Frey, D.T., et
al., “Mass production methods for fabrication of inertial fusion targets”, Fusion Science and
Technology, 51 (2007) 786-790; Forman, L.R., “Hohlraum manufacture for inertial
3-2
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3092 with adoption of a limited number of target designs, the selection of mass fabrication
3093 techniques, and a development program, the required accuracy and cost goals may be
3094 achieved. The R&D needed to make these projections a reality has begun with efforts
3095 at General Atomics, the Lawrence Livermore National Laboratory and the University
3096 of Rochester. This recent work has focused primarily on laser driven targets, both
3097 direct and indirect drive. Earlier work on ion-beam-driven targets indicates that
3098 similar conclusions are expected to hold. Pulsed-power target development is at an
3099 early stage, but the slower rep rate (~0.1 Hz vs. 10 Hz) and the simple target design
3100 should ease the challenges of target fabrication for pulsed power. However, much
3101 remains to be done for IFE target development for all drivers.
3102 The committee concurs with the conclusion that suitable target fabrication is possible
3103 at acceptable cost, so that target fabrication does not represent an obvious
3104 insurmountable obstacle for IFE. However, the committee does not endorse the
3105 projected target cost numbers, any more than it endorses estimates of future costs for
3106 any component of IFE technology in the early development stage. The costs could be
3107 much higher or lower than estimated in the conceptual studies that have been done.
3108 Only a substantial national development effort will provide the validation needed.
3109 When and if ignition is reached, it will be necessary to turn more attention to, and
3110 place greater resources on, target fabrication development. Concepts for producing
3111 targets at a rate 100,000 times the rate at which targets are produced today have been
3112 developed; therefore, if ignition is reached, it would be timely to determine if the
3113 target factory components can be validated with real equipment, and if a small,
3114 complete factory operating at modest production rates can be built and operated
3115 successfully. Such a facility should be accompanied by continued development,
3116 begun under the Inertial Confinement Fusion program, of physics models of the
3117 formation of small hollow spheres, subsequent DT layering, and other fabrication
3118 processes.
3119 Background and Status 3
3120 For direct drive, an inertial fusion target consists of a spherical capsule that contains a
3121 smooth layer of deuterium-tritium (DT) fuel. For indirect drive, the capsule is
3122 contained within a metal “hohlraum” that converts the driver energy into X-rays to
3123 drive the capsule. These concepts are shown schematically in Fig. 3.1. For pulsed-
confinement fusion”, Fusion Technology, 26 (1994) 696-701; Monsler, M.J., et al.,
“Automated target production for inertial fusion energy”, Fusion Technology, 26 (1994) 873-
880; Wise, K.D., et al, “A method for the mass production of ICF targets”, J. of Nuclear
Materials, 85 and 86 (1979) 103-106; Vermillion, B.A., et. al, “Development of a new
horizontal rotary GDP coater enabling increased production”, Fusion Science and
Technology, 51 (2007) 791-794; Bousquet, J.T., et al, “Advancements in glow discharge
polymer coatings for mass production”, Fusion Science and Technology, 55 (2009) 446-449;
Rickman, W.S., et. al, “Cost Modeling for fabrication of direct drive inertial fusion energy
targets”, Fusion Science and Technology, 43 (2003) 353-358; Schultz, K.R., “Cost effective
steps to fusion power: IFE target fabrication, injection and tracking”, J. of Fusion Energy, 17
(1998) 237-247.
3
Portions of this discussion are taken from Appendix C of the 1999 FESAC report
“Summary of Opportunities in the Fusion Energy Sciences Program.”
3-3
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3124 power, target designs vary from those similar to indirect drive, to cylindrical metal
3125 shells containing DT. Several examples of IFE targets are shown in Fig. 3.2.
3126
3127
3128
3129 FIGURE 3.1: Indirect-drive and direct-drive IFE target concepts. SOURCE:
3130 Lawrence Livermore National Laboratory.
3131
3132
3133 FIGURE 3.2: Examples of IFE targets used with various driver schemes. SOURCE:
3134 General Atomics.
3135
3-4
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3136 Fusion fuel targets must be delivered in a form that meets the stringent requirements
3137 of the particular inertial fusion energy scheme, in sufficient quantity and with low
3138 enough cost to supply affordable electricity to the grid. A fusion power plant will
3139 consume as many as one million targets per day. The allowable target cost will
3140 depend on the maximum marketable cost of electricity and the target yield, with
3141 estimates for laser and heavy ion beam systems of 20−40 cents each, based on
3142 conceptual modeling studies. For higher-yield, pulsed-power systems, the cost could
3143 be proportionately higher. The cost of raw materials is at the few-cents-per-target
3144 level. Mass manufacturing experience in other industries suggests that these
3145 production cost goals are possible, but a development program is required to validate
3146 the conceptual modeling studies. Current target production costs and rates are not
3147 useful for estimating the costs of mass-produced targets, although the gap between
3148 what can be done today and what is needed indicates that target fabrication for IFE
3149 plants is a challenge.
3150 The fabrication techniques currently used for inertial confinement fusion (ICF)
3151 research targets must meet exacting specifications, have maximum flexibility to
3152 accommodate changes in target designs, and provide thorough characterization for
3153 each target. Current ICF target fabrication techniques for research targets may not be
3154 well suited to economical mass production of inertial fusion energy targets. Because
3155 of the large number of designs and the thorough characterization required for each
3156 target, an ICF research target can currently cost thousands of dollars apiece.
3157 However, IFE target mass-fabrication studies are encouraging. Fabrication techniques
3158 are proposed that are well suited for economic mass production and promise the
3159 precision, reliability, and economy needed. However, work has just begun to actually
3160 develop these techniques.
3161 • Fuel capsules. The capsules must meet stringent specifications including out-
3162 of-round (dmax – dmin < 1 µm), wall thickness uniformity (∆w < 0.5 µm), and
3163 surface smoothness (<200 Å RMS). 4 The micro-encapsulation process, by
3164 which tiny particles or droplets are surrounded by a coating, appears well-
3165 suited to IFE target production if sphericity and uniformity can be maintained
3166 as the capsules size is increased from current 0.5- to 2-mm capsules to the ~5-
3167 mm-diam capsule needed for IFE. Microencapsulation also appears to be
3168 suited to production of foam shells, which are needed for several IFE target
3169 designs. Capsule designs for OMEGA experiments and direct drive IFE
3170 power plants are shown in Fig. 3.3.
3171
4
D. Goodin, General Atomics, presentation to the Committee on April 26, 2011.
3-5
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3172
3173 FIGURE 3.3 Direct-drive target capsules. SOURCE: The University of Rochester.
3174
3175 • Hohlraums. Inertial Confinement Fusion (ICF) hohlraums are currently made
3176 by electroplating the hohlraum material, generally gold, onto a mandrel that is
3177 then dissolved, leaving the empty hohlraum shell. This technique does not
3178 extrapolate to mass production. Stamping, die-casting, and injection molding,
3179 however, do hold promise for IFE hohlraum production. 5
3180 • Target assembly. ICF research targets are currently assembled manually
3181 using micromanipulators under a microscope. Placement of the capsule at the
3182 center of the hohlraum must be accurate to within 25 µm. For IFE, this
3183 process must be fully automated, which appears possible. Initial efforts with
3184 robotic target assembly and “snap-together” alignment techniques have shown
3185 promising results. 6
3186 • Target characterization. Precise target characterization of every research
3187 target is needed to prepare the complete “pedigree” required by the ICF
3188 experimentalists. Characterization for current research targets is largely done
3189 manually and is laborious. For IFE the target production processes must be
3190 sufficiently repeatable and accurate that characterization can be fully
3191 automated and used only with statistical sampling of key parameters for
3192 process control.
3193 • D-T filling and layering. Targets for ICF experiments are filled by
3194 permeation, and a uniform D-T ice layer is formed by “beta layering.” Using
3195 very precise temperature control, excellent layer thickness uniformity and
3196 surface smoothness of about 1-µm RMS can be achieved. 7 These processes
3197 are suited to IFE although the long fill and layering times needed may result in
3198 large (up to ~10 kg) tritium inventories. Advanced techniques, such as liquid
3199 wicking into a foam shell, could greatly reduce this amount. These processes
5
A. Nikroo, General Atomics, in a presentation to the committee on July 7, 2011.
6
A. Nikroo, in a site visit to General Atomics on Feb. 22, 2012.
7
D.T. Goodin, op. cit.
3-6
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3200 are improving but remain far short of the level of reproducibility that a reactor
3201 would require. If IFE targets need D-T ice smoothness better than ~1 µm to
3202 achieve high gain, new layering techniques will be needed.
3203 • Target handling and injection. IFE targets will be injected into the target
3204 chamber at rates as high as ~10−20 Hz. The targets must have adequate
3205 thermal and mechanical robustness and protection, such as hohlraums or
3206 sabots, to survive the injection and in-chamber flight. This solution must also
3207 be compatible with the chamber protection and energy recovery schemes (see
3208 next section).
3209 In small quantities, ICF research targets that meet all current specifications for both
3210 laser direct and indirect drive have been fabricated and fielded, including the uniform,
3211 smooth DT ice layer. ICF research targets currently cost thousands of dollars apiece
3212 on average but the costs vary widely; simple production targets can cost many times
3213 less and targets requiring significant development effort could cost many times more
3214 than that amount. For a power plant, a significant transition needs to be undertaken
3215 using low-cost, high-throughput manufacturing techniques, along with large batch
3216 sizes for any chemical processes, as well as likely use of statistical characterization.
3217 Many of the processes used for current target fabrication do not scale well to mass
3218 production and will need to be replaced. Examples are die-casting arrays of hohlraum
3219 parts instead of diamond turning a mandrel for gold plating, and the use of large-
3220 batch chemical vapor deposition (CVD) diamond coaters for the ablators and
3221 membranes instead of the small size bounce-pan coaters now used. Both the HAPL
3222 program, led by the Naval Research Laboratory, which went well beyond laser
3223 drivers to consider all aspects of IFE power by laser direct drive, and the Laser
3224 Inertial Fusion Energy (LIFE) program, led by Lawrence Livermore National
3225 Laboratory (LLNL), which focused on IFE by laser indirect drive, have begun
3226 evaluation and selection of mass production methods that can meet IFE requirements.
3227 The demise of the HAPL program has slowed this effort.
3228 There have been successful efforts on the development of several IFE target mass
3229 production techniques. To make thick-walled polymer capsules, a poly-alpha-methyl-
3230 styrene (PAMS) mandrel is made by microencapsulation, then the PAMS mandrel is
3231 coated with glow discharge polymer (GDP). A rotary kiln version of the GDP coater
3232 has been made that is capable of mass production, but it has not be used enough to
3233 demonstrate that it can meet the surface roughness specification. 8 In the HAPL
3234 program, 9 foam shells were made that met the HAPL target specification with
3235 appreciable yield using micro-encapsulation droplet generators. Applying a smooth
3236 gas-tight overcoat to these foam shells was the focus of development at the time that
3237 the HAPL program ended. A cryogenic fluidized bed for layering deuterium in direct-
3238 drive targets was built in the HAPL program. It was successfully operated at
3239 cryogenic temperatures using empty capsules, but has yet to be operated with
8
A. Nikroo, op. cit., July, 2011.
9
J.D. Sethian et al., "The Science and Technologies for Fusion Energy with Lasers and Direct
Drive Targets," IEEE Transactions on Plasma Science, Vol. 38, No. 4, April 2010 pp. 690-
703.
3-7
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3240 deuterium-filled capsules. General Atomics has built a robotic target assembly station
3241 based on commercially available industrial robots. This station has glued together
3242 cone-in-shell targets suitable for fast ignition experiments 10 such that the virtual cone
3243 tip co-insides with the capsule center to within the specification of 10 µm. LLNL is
3244 developing target assembly techniques for the National Ignition Facility (NIF)
3245 National Ignition Campaign (NIC) that facilitate target component self-alignment
3246 (“snap together” assembly), which will be useful for IFE target assembly.
3247 Development of lead-hohlraum part manufacture by cold forging (or stamping) has
3248 recently started. Some development of die-casting hohlraum parts is also expected to
3249 begin soon. 11 Innovative concepts such as the University of Rochester’s use of
3250 electric-field mediated microfluidics (“lab-on-a-chip”), 12 shown in Fig. 3.4, may offer
3251 the possibility to achieve higher quality at lower cost. In summary, progress has been
3252 made on IFE target fabrication, and there are many opportunities for improved
3253 materials and technologies, but much remains to be done.
3254
3255 FIGURE 3.4 Electric-field-mediated microfluidics (“lab-on-a-chip”) wicking of
3256 cryogenic D2 into a foam capsule target. SOURCE: The University of Rochester.
3257 To estimate possible costs, factory models have been constructed utilizing experience
3258 from the chemical batch processing industry combined with in-house expertise at GA
3259 and LLNL. These models considered likely manufacturing and assembly equipment
3260 types, factory build costs, personnel and operational costs, in-process volumes (etc.)
3261 and amortized the integrated costs over the volume of targets produced. Predictions
10
A. Nikroo, op. cit., Feb. 22, 2012.
11
A. Nikroo, op. cit., July 7, 2011.
12
D.R. Harding, T.B. Jones, Z.Bei, W.Wang, S.H. Chen, R.Q. Gram, M. Moynihan, and G.
Randall, “Microfluidic Methods for Producing Millimeter-Size Fuel Capsules for Inertial
Fusion,” Materials Research Society Fall Meeting, Boston, MA, 2010.
3-8
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3262 ranged from 17 to 35 cents per target. 13 A breakout of projected target costs based on
3263 a target factory economics model is shown in Figure 3.5.
3264
3265
3266 FIGURE 3.5 Cost breakout for target mass manufacture, based on a representative
3267 factory model (example shown for LIFE targets). SOURCE: R. Miles et al., Lawrence
3268 Livermore National Laboratory, LLNL-TR-408722.
3269
3270 Conclusion 3-4: Target fabrication at the quality and production rate needed
3271 appears possible with continued development.
3272
3273 Scientific and Engineering Challenges and R&D Priorities
3274
3275 Target Fabrication
3276
3277 The scientific challenges to IFE target fabrication lie primarily in understanding the
3278 physics behind the specifications for inertial fusion target requirements: sphericity,
3279 uniformity and smoothness (How good is good enough?), and understanding the
3280 physics and chemistry behind the ability to achieve those requirements (What
3281 physical processes control sphericity, uniformity and smoothness?) Experiments with
13
See, for example: D.T. Goodin et al., “Addressing The Issues of Target Fabrication and
Injection of Inertial Fusion Energy,” Fusion Engineering and Design, Vol. 69, 2003, pp. 803-
806; R. Miles et. al., ”LIFE Target Fabrication Costs,” LLNL-TR-416932; and R. Miles et
al., “LIFE Target Fabrication Research Plan Sept. 2008,” LLNL-TR-408722.
3-9
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3282 IFE targets on the National Ignition Facility can help provide the physics
3283 understanding. The engineering challenges lie in selecting and developing materials
3284 that can achieve these requirements and in developing the processes and equipment
3285 needed to do so reliably and repeatedly with very high yield at reasonable cost.
3286
3287 The specific requirements appear at present to include:
3288
3289 • The ability to fabricate IFE targets that meet specifications such as:
3290 Indirect drive:
3291 o Capsules with 4-mm diameter, <1 µm sphericity, ~100 µm wall with
3292 <0.5 µm Δw, and <200 Å RMS surface smoothness, and a surface
3293 power spectrum below the NIF capsule profile.
3294 o Hohlraums fabricated to ≤10 µm accuracy. Targets assembled to ≤10
3295 µm accuracy.
3296 Direct drive:
3297 o Foam shell capsules with thickness ~150 µm with < 0.5 µm Δw, and
3298 ~4-mm diameter with <1 µm sphericity. Foam density ≤100mg/cc
3299 with cell size <1 µm. A seal coat 14 on top of the capsule with a 1-5 µm
3300 wall with <0.5 µm Δw, <200 Å RMS surface smoothness, and surface
3301 power spectrum meeting the NIF-NIC required profile.
3302 • A projected cost of IFE target mass production for a power plant of ≤ $0.50
3303 each.
3304 The objectives of IFE target fabrication R&D must be to understand the
3305 physics behind the specifications for inertial fusion target requirements and
3306 understand the physics behind the ability to achieve those requirements to such a
3307 depth that target materials can be selected and/or developed that can meet target
3308 specifications, and processes and equipment can be developed to do so reliably and
3309 repeatedly with very high yield at reasonable cost.
3310
3311 Target Injection at High Repetition Rates
3312
3313 After the targets have been fabricated they must be injected into the chamber. For
3314 laser drivers and accelerators, several methods of ballistic injection have been
3315 suggested, including gas guns and electromagnetic accelerators. For present pulsed-
3316 power fusion system designs, the targets are attached directly to the end of a
3317 transmission line. In this case, the targets and a replaceable transmission line are
3318 inserted into the chamber mechanically. In this section we consider only ballistic
3319 injection.
3320
3321 Gas guns have been built at Lawrence Berkeley National Laboratory and at General
3322 Atomics (shown in Fig. 3.6). These have been used to accelerate surrogate targets to
3323 high velocity (>100 m/s). In the case of direct drive, the targets must be carried by
14
The seal coat surface for the direct drive capsule both seals the capsule and facilitates its
injection into the target chamber without going out of specifications by the time it reaches the
center.
3-10
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3324 some kind of sabot to protect the target as it is accelerated in the gun barrel and
3325 injected into the chamber. The sabot is removed either mechanically (with a spring)
3326 or magnetically. The gas-gun experiments have demonstrated high-repetition-rate
3327 injection, including separation of the sabots from the targets, in a burst mode. 15 In
3328 these experiments, the placement accuracy at a distance of 20 m was about 10 mm.
3329 This 10 mm includes the contributions from the accuracy of the gun and from the
3330 separation of the target from the sabot. Estimates of the placement accuracy for
3331 indirectly driven targets (no sabots required) are much better than 10 mm. This is
3332 adequate for subsequent target tracking and beam steering, as discussed in the next
3333 section.
3334
3335
3336 FIGURE 3.6 Inertial fusion energy target gas-gun injection experiment. SOURCE:
3337 General Atomics.
3338
3339 In summary, one can unquestionably build devices to inject the targets at adequate
3340 velocities and repetition rates. The remaining challenges are associated with wear
3341 and long-term reliability and durability—particularly in a fusion environment.
3342
3343 Conclusion 3-5: Target injection techniques have been developed in the
3344 laboratory that are adequate for subsequent target tracking and steering and
3345 that appear to be scalable to meet the inertial fusion energy requirements for
3346 speed and accuracy.
3347
3348 Target Tracking and Driver Pointing
3349
15
D.T. Goodin, op. cit.
3-11
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4463 development, and would likely be in place before deployment of the first commercial
4464 fusion plant.
4465
4466 Conclusion 3-19: Design studies of IFE power plants indicate that, with the use
4467 of low-activation materials, it will be possible to meet the goal of minimizing
4468 high-level waste. However, the amount of waste that requires disposal, albeit
4469 near-surface, may be very large. Low-level waste disposal in the United States is
4470 becoming increasingly difficult.
4471
4472 Recommendation 3-8: There have been studies that examine the potential for
4473 recycling and reuse of radioactive materials within the fusion system to reduce
4474 the amount of material that must be disposed; the committee encourages the
4475 continuation of these studies.
4476
4477 Licensing and Regulatory Considerations
4478
4479 The United States Nuclear Regulatory Commission (NRC) is a conservative body.
4480 This is appropriate given its role in the oversight of U.S. commercial nuclear
4481 facilities. The vast majority of the NRC’s licensing experience has been with Light
4482 Water Reactors (LWRs), and their regulations, for the most part, have grown out of
4483 their LWR experience. Licensing a fusion power plant will require blazing new
4484 trails, and it will be important for the fusion community to work with the NRC to help
4485 them to understand the hazards (which are much different from the hazards in an
4486 LWR) and the mitigation of hazards in a fusion power plant. Communication early in
4487 the process is important to a successful outcome. 64
4488
4489 Some licensing/regulatory-related work has been done for the ITER program, and
4490 much of that work provides insights into IFE licensing processes and issues. The
4491 LIFE program has considered licensing issues more than any other IFE program;
4492 however, much more effort would be needed if IFE were to seriously pursue an NRC
4493 license. The Next Generation Nuclear Plant (NGNP) fission reactor project plans to
4494 license and build a high-temperature gas fission reactor. Gas reactors have been built
4495 and operated previously in the United States and Europe, although at lower operating
4496 temperatures than are envisioned for the NGNP. The licensing strategy developed for
4497 the NGNP provides a good picture of the challenges associated with licensing a
4498 relatively standard technology. 65
4499
4500 Licensing fission power plants is moving towards a risk-informed approach, where in
4501 the past it has been primarily a deterministic approach. The LIFE program is
4502 developing a similar approach. 66 The favorable safety characteristics of the IFE and
64
R. Meserve, “Licensing a Commercial Inertial Confinement Fusion Energy Facility,”
Presentation to the Committee, October 31, 2011, Washington, D.C.
65
Next Generation Nuclear Plant Licensing Strategy – A Report to Congress,
www.ne.doe.gov/pdfFiles/NGNP_report toCongress.pdf, August 2008.
66
M. Dunne, et al, “Timely Delivery Of Laser Inertial Fusion Energy (LIFE)”; accepted for
publication in Fusion Science and Technology.
3-44
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4503 MFE fusion plant should simplify the licensing process; however, the burden of proof
4504 for IFE plants will be no different than for fission plants. One of the safety-related
4505 goals for fusion is to demonstrate that there is no need for public evacuation under
4506 any event. This is a clear example of the favorable safety characteristics of a fusion
4507 plant.
4508
4509 Conclusion 3-20: Some licensing/regulatory-related research has been carried
4510 out for the ITER (magnetic fusion energy) program, and much of that work
4511 provides insights into the licensing process and issues for inertial fusion energy.
4512 The Laser Inertial Fusion Energy (LIFE) program at Lawrence Livermore
4513 National Laboratory has considered licensing issues more than any other IFE
4514 approach; however, much more effort would be required when a Nuclear
4515 Regulatory Commission license is pursued for inertial fusion energy.
4516
4517 Safety analysis has been an important part of the IFE design studies cited earlier.
4518 Early analyses were relatively simple, often looking at total inventories of radioactive
4519 material and determining how much material could be released based on total system
4520 energy. These analyses have given way to more sophisticated analyses, sometimes
4521 employing tools originally developed for the fission industry and adapted to fusion.67
4522 Tritium inventory and release mitigation is an important part of the fusion safety case.
4523 Tritium can be highly mobile under certain conditions, so minimizing tritium
4524 inventory in fusion facilities is a first step (see the section on tritium management
4525 above). Other radioactive material present in the IFE plant must also be considered,
4526 together with possible release scenarios. Overall, the IFE source term is significantly
4527 smaller than its fission counterpart, which should benefit the licensing process.
4528 Analysis done for systems studies shows acceptable safety performance; however, in
4529 the absence of experimental results to validate models, the actual performance
4530 remains highly uncertain. Validation and verification of models is extremely
4531 important to the Nuclear Regulatory Commission, and will be an important factor in
4532 the licensing process.
4533
4534 Recommendation 3-9: Validation and verification of models is extremely
4535 important to the Nuclear Regulatory Commission (NRC), and will be an
4536 important factor in the licensing process. Development of models, including
4537 validation and verification, should be pursued early. Working with the NRC
4538 early and often will be important, as well as looking to other programs (e.g.,
4539 ITER and fission) for successful licensing strategies.
4540
4541
4542 Scientific and Engineering Challenges and Future R&D Objectives
4543
4544 The environmental, safety and health aspects of the IFE facilities should continue to
4545 be an important point of discussion in any program. The IFE community should
4546 continue to analyze and bring attention to the favorable characteristics of these plants.
67
B.J. Merrill, “A Lithium-Air Reaction Model for the MELCOR Code for Analyzing
Lithium Fires in Fusion Reactors,” Fusion Engineering and Design, Vol. 54, pages 485-493.
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4547 Continued development of sophisticated models, together with data for validation of
4548 the models, are important for preparation for licensing an IFE plant. The IFE program
4549 should continue to keep abreast of NRC licensing activities, and keep the lines of
4550 communication with the NRC open.
4551
4552 Path Forward
4553 Near Term (<5 years)
4554
4555 Needed R&D activities include systems studies with a focus on realistic assumptions
4556 and schedules. Radioactive waste management should be an area of particular focus
4557 given recent activities by the Blue Ribbon Commission on America’s Nuclear Future.
4558 Safety model development (with an eye towards future licensing) and development of
4559 experiments to validate models will be critical.
4560
4561 Medium Term (5-15 years)
4562
4563 Experimental studies of IFE target and chamber materials recycling concepts
4564 (possibly using only non-radioactive elements) need to be done. Experiments would
4565 be done to benchmark accident analysis codes with materials and configurations
4566 typical of fusion power plant designs. Success would be experimental validation of
4567 safety models.
4568
4569 Long Term (>15 years)
4570
4571 The long-term objective would be to begin development of the licensing case for an
4572 IFE demonstration plant.
4573
4574 BALANCE-OF-PLANT CONSIDERATIONS
4575
4576 The purpose of an inertial fusion energy power plant is to produce useful energy in
4577 the form of electricity, or high-temperature process heat, or stored chemical energy in
4578 the form of hydrogen. To do this, the power plant must convert the energetic
4579 products of fusion reactions—high-energy neutrons and charged particles—into the
4580 desired useful forms. To become a practical source of energy, IFE must produce and
4581 convert the fusion energy in a manner that is technically feasible, environmentally
4582 acceptable, and economically attractive compared to other long-term, sustainable
4583 sources of energy.
4584
4585 The high-energy neutrons and charged particles from the fusion reactions deposit
4586 their energy on the walls of the reaction chamber and in the tritium-breeding blanket
4587 surrounding the chamber in the form of thermal energy. Everything outside the
4588 chamber and blanket, excluding the laser or particle beam drivers or the pulsed power
4589 system, is considered the “balance of plant” (BOP). The BOP includes the systems
4590 for conversion of thermal energy to electricity, the buildings and structures for the
4591 power plant and all the conventional services. While schemes have been proposed to
4592 convert some of the charged-particle energy directly into electricity by electrostatic or
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4593 magnetohydrodynamic processes, first-generation IFE power plants will most likely
4594 utilize fairly conventional thermal power conversion systems to convert the energy
4595 contained in the hot coolant from the chamber wall and blanket into electricity.
4596 Similar “heat engine” thermal power conversion systems are widely used on nuclear
4597 fission power plants and on fossil-fired power plants around the world. The Rankine
4598 Cycle, or steam cycle, and the Brayton cycle, or gas-turbine cycle, are widely used
4599 heat engines that appear well suited for application to the conversion of thermal
4600 energy from fusion into electricity. There appears to be little need for power
4601 conversion system development that would be unique to fusion or IFE, although IFE-
4602 specific BOP designs will need to be developed, and opportunities for innovation
4603 should always be welcome.
4604
4605 Conclusion 3-21: Existing balance-of-plant technologies should be suitable for
4606 IFE power plants.
4607
4608 The thermal conditions—inlet and outlet coolant temperatures—proposed for IFE
4609 power plants are similar to those used by fission and fossil power plants today. As a
4610 consequence, the BOP for an IFE power plant should be very similar to those used
4611 today. An area of concern is that of system interfaces and the possibility of hazardous
4612 material transport across those interfaces. The IFE reaction chamber will contain
4613 quantities of radioactive tritium, radioactive target debris, and some radioactive
4614 material sputtered from the first wall. In addition, it will operate at elevated
4615 temperatures. Tritium may migrate through the chamber walls and into the primary
4616 coolant stream. The coolant will pass through heat exchangers and tritium may
4617 migrate through the heat exchangers into the secondary coolant and eventually into
4618 the rest of the power plant and even into the environment. These issues are part of the
4619 larger tritium control issue discussed in the tritium management section above. These
4620 interface concerns may require R&D to develop tritium permeation-resistant coatings
4621 for BOP components and heat exchangers, and tritium removal systems for the
4622 various chamber, blanket and power conversion system coolants.
4623
4624 Path Forward
4625
4626 Near Term (<5 years).
4627
4628 The design and analysis of BOP systems will continue to be included in IFE system
4629 studies and design studies, with emphasis on identification and evaluation of critical
4630 issues.
4631
4632 Medium Term (5 - 15 years)
4633
4634 As favored design concepts begin to emerge, R&D into critical issues that have been
4635 identified—such as tritium permeation and control—will need to be carried out to
4636 resolve these issues.
4637
4638 Long Term (>15 years)
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4639
4640 IFE BOP systems will need to be developed and deployed as part of demonstration
4641 IFE systems.
4642
4643 ECONOMIC CONSIDERATIONS
4644
4645 An essential requirement for any new energy system to compete in future markets is
4646 to offer a product at a competitive price. For an IFE power plant, the main measure is
4647 the cost of electricity (COE). The formula for the COE is typically given by:
4648
4649 COE = (Ccap x FCR + Cfuel + COM)/(Penet x 8760 (hrs) x Fcap) + Decom
4650
4651 where
4652
4653 Ccap = Construction costs including interest charges during construction,
4654 FCR = Fixed charge rate,
4655 Cfuel = Fuel costs including targets,
4656 COM = Operations and maintenance,
4657 Penet = Net electric power,
4658 Fcap = Capacity factor, and
4659 Decom = Annual decommissioning charge in mills/kwh or $/MWh, which can be
4660 calculated as the cost of decommissioning, times the appropriate annual sinking fund
4661 factor to accumulate those funds, divided by the amount of electricity produced per
4662 year (Penet x 8760 (hrs) x Fcap).
4663
4664 Conclusion 3-22: An essential requirement for any new energy system to
4665 compete in future markets is to offer a product at a competitive price. For an
4666 IFE power plant, the main measures are the cost of electricity generation and, in
4667 particular, the capital cost.
4668
4669
4670 The capacity (or sometimes called the availability) factor (Fcap) has a large
4671 influence on the COE. It is the crucial number in converting capital costs to
4672 COE. IFE power systems will be very capital-intensive systems with perhaps
4673 relatively modest fuel costs, provided the goals of low-cost targets can be met
4674 (discussed further below). Such plants will likely operate as base-load power
4675 plants where a premium is placed on operating at the maximum capacity
4676 factor. Most IFE power plant studies assign a value of typically 70 percent to
4677 80 percent to Fcap. These values cannot be achieved today given the early
4678 stages of IFE technology development, so really they represent a goal. By way
4679 of comparison, the current fleet of fission power plants in the United States
4680 routinely achieves an average capacity factor of about 90 percent.
4681
4682 Achieving high capacity factors requires two basic features of the system:
4683 high component reliability (usually measured by the mean-time-to-failure for
4684 each component) and acceptable maintenance or down-times (usually
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4685 measured by the mean-time-to-repair for each component). There is a strong,
4686 relationship between the allowed values of the mean-time-to failure and the
4687 mean-time-to-repair for a given component. The longer mean-time-to-repair,
4688 the longer must be the mean-time-to-failure. In other words, the harder it will
4689 be to replace the component, the higher must be the degree of reliability.
4690 Defining the acceptable values for the mean-time-to-failure and mean-time-to-
4691 repair for all the components in a complex IFE power plant will require a
4692 comprehensive systems engineering approach.
4693
4694 Achieving high levels of component reliability requires substantial testing and
4695 qualification of fusion components, far beyond what is available today. For
4696 example, no fusion reaction chamber has ever been built and certainly none
4697 tested to the extent needed to establish failure modes and a reliability
4698 database. Given the large number of components and systems in an IFE
4699 power plant (and an MFE power plant), a substantial investment in time and
4700 money will be required. The time required to do this will have a major impact
4701 on the overall timescale to develop commercial IFE systems. At some time,
4702 testing in an actual fusion environment will be needed, although much useful
4703 testing can and will be done in simulation facilities. Achieving fusion
4704 conditions for testing requires very large investments with long timescales and
4705 will thus have a profound impact on the roadmap for realizing fusion power
4706 systems. While ITER and a future IFE DEMO plant are very different, it
4707 should be possible to take advantage of some of the experience with ITER—
4708 e.g., the hardware and procedures developed for remote maintenance—to
4709 reduce the implementation time for an IFE DEMO plant.
4710
4711 Achieving the necessary replacement times for an IFE system’s components is
4712 an equally challenging task. Some of these components will require using
4713 remote handling systems. While the technology and experience in other fields
4714 (e.g., fission reactors and space systems) can be adapted to fusion needs, there
4715 exists today very limited experience with remote maintenance in actual fusion
4716 systems. ITER is one very important source of such information. Developing
4717 the maintenance systems for an IFE power plant will be a significant effort.
4718 Unfortunately there is very little work underway today in the United States on
4719 this topic.
4720
4721 For these reasons, the capacity factor probably represents the greatest
4722 uncertainty among all the factors that affect the COE. This applies to all
4723 fusion concepts, both IFE and MFE.
4724
4725 Conclusion 3-23: As presently understood, an inertial fusion energy power plant
4726 would have a high capital cost. Such plants would have to operate with a high
4727 availability. Achieving high availabilities is a major challenge for fusion energy
4728 systems. This would involve substantial testing of IFE plant components and
4729 the development of sophisticated remote maintenance approaches.
4730
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4731 Of special concern for the economics of IFE is the cost of the targets. The feasibility
4732 of developing successful fabrication and injection methodologies at the low cost
4733 required for energy production—about $0.25 to $0.30/target, 68 or about a factor of
4734 10,000 less than current costs, and at a production rate per day that is 100,000 times
4735 greater than current rates—is a critical issue for inertial fusion. The IFE researchers
4736 working on target capsule costs argue that between increased yields and batch-size
4737 increases, two orders-of-magnitude cost reductions are possible with significant
4738 development programs. 69 It appears that the target-cost numbers may be possible,
4739 although challenging, considering the number of assumptions and judgments that are
4740 needed to get to the desired reduction of a factor of 10,000.
4741
4742 Conclusion 3-24: The cost of targets has a major impact on the economics of
4743 inertial fusion energy power plants. Very large extrapolations are required from
4744 the current state-of-the-art for fabricating targets for inertial confinement fusion
4745 research to the ability to mass-produce inexpensive targets for inertial fusion
4746 energy systems.
4747
4748 Construction or capital costs are typically divided into fusion-specific
4749 components (e.g. laser or particle-beam drivers, chambers, and target
4750 fabrication and injection) and the balance of plant (BOP). The BOP was
4751 discussed in the previous section and will likely rely on existing concepts with
4752 cost estimates that are relatively well known. Cost estimates for the fusion
4753 components necessarily have a larger uncertainty because in some instances
4754 (e.g., chambers and high-capacity target fabrication) they are still in the earlier
4755 stages of development. Nevertheless, the construction costs have less
4756 uncertainty than the capacity factor.
4757
4758 Standard project costs (e.g., owner’s cost and engineering during construction) are
4759 typically taken as a percentage of the basic capital cost based on fission electricity
4760 experience. Escalation/inflation factors may also be incorporated.
4761
4762 The IFE COE has been estimated in various studies, giving a range of 5 to 10
4763 cents/kWh in current dollars. 70 These estimated COE costs for IFE power plants are
68
Rickman, W.S., Goodin, D.T. “Cost Modeling for Fabrication of Direct Drive Inertial
Fusion Energy Targets”, Fusion Sci Tech 43(3): 353-358. 2003.
69
Goodin, D.T., Alexander, N.B., Brown, L.C., Frey, D.T., Gallix, R., Gibson, C.R., et al.,
“A cost-effective target supply for inertial fusion energy”. Nucl Fusion 44(12): S254-265.
2004.
70
Meier, W., et al. "OSIRIS and SOMBRERO Inertial Confinement Fusion Power Plant
Designs," Volume 1. Executive Summary and Overview. WJSA-92-01, DOE/ER/54100-1,
1992; Anklam, T., "Life Delivery Plan", Presentation to National Research Council’s review
on “Prospects for Inertial Confinement Fusion Energy Systems”, 2011; Badger, B., et al.,
"LIBRA-SP, A Light Ion Fusion Power Reactor Design Study Utilizing a Self-Pinched Mode
of Ion Propagation" – Report for the Period Ending June 30, 1995. UWFDM-982.University
of Wisconsin Fusion Technology Institute, 1995; Cook J.T., Rochau G.E., Cipiti B.B.,
Morrow C.W., Rodriguez S.B., Farnum C.O., et al. "Z-Inertial Fusion Energy: Power Plant",
SAND2006-7148, Sandia, 2006; Dunne M., "Overview of the LIFE Power Plant",
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4764 in the same general range as other energy options, but because of the relatively early
4765 phase of the development of IFE components and systems, there is much uncertainty
4766 in these cost estimates. It appears that the COE numbers obtained in past studies are
4767 possible, but they contain uncertain components due to the untested assumptions that
4768 must be made when making estimates for new technology.
4769
4770 Financing and business considerations, such as the fixed charge rate (capital charge
4771 rate), will have an important influence of the COE. Usually this is made up of two
4772 parts: a charge rate for the share held by equity investors; and a (lower) charge rate
4773 for the debt-investor share. These terms can vary based on the confidence investors
4774 have in the readiness and cost-effectiveness of the technology and the extent to which
4775 the investment is protected. Investment can be protected in some states by a decision
4776 of the public utility commission. Debt investment can be protected by federal loan
4777 guarantees or by direct federal assumption of the debt. The charge rate for IFE will
4778 be determined by the entire history of the technology. The more complex the
4779 technology, the more prone it is to a history of delays and bumps along the road to
4780 development and the bigger the effect on investor and guarantor psychology.
4781
4782 For example, most past IFE cost of electricity studies did not carry individual
4783 uncertainty ranges. Some of the difficulties in using estimates of electricity costs for
4784 IFE in comparisons with other energy technologies or among IFE options could be
4785 overcome, in part, if uncertainty ranges were a required component of cost estimates.
4786
4787 It is not clear to what extent the COE studies for IFE are “forward” estimates (made
4788 without looking at a cost goal) or “backward” estimates (made with an eye on a cost
4789 goal), or a mixture of the two. Certainly, the BOP estimates can be based on
4790 conventional databases of cost elements and qualify as forward cost estimates. They
4791 can be compared to cost estimates made for other, traditional energy technologies,
4792 with the caveat that future estimates for all technologies may be low when compared
4793 to actual as-built and as-operated facilities. Hence, cost estimates for fusion, even
4794 were they to be based totally on forward calculations, should be compared to
4795 estimates of future COEs for other technologies, not current day market prices.
4796
4797 Cost estimates for the purely fusion components of the COE may have been, to some
4798 degree, backward estimates, starting from values based on views of future prices of
4799 alternatives. Analysts taking this approach would determine if it was possible to
4800 reach such targets for the fusion components of the COE and then use those possible
4801 numbers to compute a total COE. In such cases, the fusion COEs might be better
4802 labeled as possible values rather than COE estimates.
4803
4804 In addition to calculating potential COE values, cost analysis provides a very
4805 useful tool for identifying where R&D dollars should be targeted. The
Presentation to National Research Council’s review on “Prospects for Inertial Confinement
Fusion Energy Systems”, LLNL, 2011; Sviatoslavsky I.N., et al., "SIRIUS-P, An Inertially
Confined Direct Drive Laser Fusion Power Reactor", UWFDM-950. University of Wisconsin
Fusion Technology Institute, 1993.
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4806 sensitivity of total cost-to-cost variations in system components helps to
4807 identify where reduction in cost (via R&D, for example) would have the
4808 greatest impact. The effectiveness of such analyses depends critically on
4809 having a well-developed system engineering capability.
4810
4811 Similarly, the Technology Readiness Level (TRL) process is another useful
4812 tool that can be used. 71 The use of TRLs is also discussed in Chapter 4. In
4813 dealing with uncertainty ranges, the use of TRLs for each component, with
4814 separate uncertainty ranges on the component COE appropriate for different
4815 TRLs, could help planners decide on where to allocate resources to lower
4816 costs. Such a methodology would help to standardize cost and uncertainty
4817 estimates across different fusion technologies and is discussed further in
4818 Chapter 4.
4819
4820 Use of TRLs and other readiness concepts, such as, "integration readiness
4821 levels,” 72 also provide structure useful for keeping costs under control. There
4822 have been problems historically with cost escalation in government/industry
4823 partnerships from which useful lessons for IFE can be drawn. For instance,
4824 there have been a number of large DOE programs/projects that did not
4825 proceed as planned. Although there are many reasons why projects may fail
4826 technically or not meet their cost objectives, two stand out and are worth
4827 special consideration given the charge to this committee: the breakdown of
4828 large, multi-owner projects; and significant cost increases in large, first-of-a-
4829 kind demonstration/prototype plants. The committee believes that the TRL
4830 methodology should be required to be followed for all major components of
4831 the IFE program.
4832
4833 It is important to note that the COE for IFE may not be the most immediate obstacle
4834 to successful development. At the size currently envisioned in most studies, the total
4835 cost of an IFE plant may be the biggest obstacle to IFE development, when looked at
4836 through the prism of current-day electricity company concerns. Given the rapid
4837 escalation in capital costs in the last decade, projected costs of gigawatt facilities for
4838 all capital-intensive electricity plants have reached the sticker-shock point, where they
4839 represent a significant fraction of company capitalizations, making investments a
4840 “bet-the-company” decision. Efforts are underway to downsize electricity plants to
4841 reduce the sticker shock. A national IFE program should explore a range of plant
4842 sizes given the uncertain market and financial situation in the US in the coming
4843 decades. In particular, it is very important to understand what is the lower bound of
4844 an IFE plant output in terms of key physics constraints (e.g., target energy gain) and
71
DOE, "Technology Readiness Assessment Guide", DOE G 413.3-4.
Washington:Department of Energy. 2009.
72
See Mankins J.C., "Approaches to strategic research and technology (R&T) analysis and
road mapping." Acta Astronautica 51(1-9): 3-21. 2002, and Sauser B., Ramirez-Marquez J.E.,
Magnaye R., Tan W., "A Systems Approach to Expanding the Technology Readiness Level
within Defense Acquisition", Int J of Defense Acquisition Manage 1: 39-58. 2008.
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4845 engineering constraints.
4846 Conclusion 3-25: The financing of large, capital-intensive energy options such as
4847 an IFE power plant is a major challenge.
4848
4849 R&D can attempt to address the two major economic obstacles confronting IFE,
4850 namely skepticism about reaching cost/kWh targets and the high cost-per-plant
4851 numbers. R&D can also attempt to reduce investor risk, whether for government or
4852 private investors, by encouraging innovation in IFE components and designs,
4853 improving technical readiness levels through engineering advances, and by laying the
4854 ground for spinoffs of private companies.
4855
4856 Systems analysis is an important tool in the development of any complex system.73
4857 Systems analysis, as used in this context, is the purely technical quantitative
4858 assessment of the expected performance of various interconnected technologies.
4859 Also, system analyses define the consequences of various implementation scenarios
4860 based on various assumptions. Systems analysis is primarily concerned with the
4861 performance of various technologies and does not address the path and non-technical
4862 constraints in achieving the implementation of those technologies. However, it does
4863 provide a tool for assessing the sensitivity of the system to non-technical constraints
4864 translated into system impacts. Cost assessment is one of the outcomes of a systems
4865 analysis, as discussed earlier.
4866
4867 As already mentioned, the per-plant cost of 1 GW or greater generating stations
4868 represents a considerable percentage of the book value of U.S. companies likely to
4869 build fusion reactors, which represents a barrier to entry. There is another problem
4870 specific to those high-capitalization facilities that might be built in the many states in
4871 the United States in which competitive, short-term electricity markets have been
4872 established. A fusion facility, like a nuclear fission facility, will not pay off its
4873 investors for a long period of time. In the absence of long-term contracts, these
4874 facilities would endure an extended period of vulnerability to market prices dropping,
4875 forcing bankruptcy and massive losses. Possibly, the establishment of long-term
4876 contracts in competitive markets will take place in the years ahead, but until that time,
4877 investments in expensive, capital intense projects are risky in competitive markets,
4878 implying that investors would be looking for a high rate of return before entering the
4879 market, driving up costs/kWh.
4880
4881 As stated earlier, the fission field is working to modularize and down-size electricity
4882 plants to reduce the sticker shock and impact in the grid. Fusion R&D might want to
4883 follow that example. A possible goal of R&D could be to design, or improve existing
4884 designs, of IFE power plants that are naturally smaller in size or radically cheaper.
4885 Designers might explore modular systems in which relatively small fusion engines—
4886 built in sequence as finances allow—share common driver facilities. The assignment
4887 of an “investor readiness level,” to a design, including differentiated levels of
73
McCarthy K.A., Pasamehmetoglu K.O., "Using Systems Analysis to Guide Fuel Cycle
Development" (Paper 9477, INL/CON-09-15764). In: Global 2009. Paris. 2009.
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4888 readiness to venture capitalists, equity investors, and debt investors, could prove a
4889 useful discipline for planning. Even though the COE might be higher, the smaller
4890 plant design might be more viable in the United States, because its total cost falls into
4891 a range that is marketable.
4892
4893 Because it is not possible to anticipate the most viable business model that may exist
4894 decades from now, the development of a long-range technology should have an eye to
4895 supporting multiple business models. These models range from those in which the
4896 U.S. government stands behind the technology and maintains a high percentage of the
4897 ownership of the construction and possibly acting as an operating company, to a
4898 venture capital model in which venture capitalists support small companies and
4899 obtain key patents on IFE components, to government construction of a few facilities
4900 with the idea that private companies will step in afterward to improve and market the
4901 by then proven technology
4902
4903 Government R&D support of innovation, as part of, and in addition to, systematic
4904 engineering approaches, could greatly benefit IFE under all of these business models.
4905 Rewarding innovation as part of engineering could provide a stronger base from
4906 which spinoff companies could arise. Encouraging ideas from a community broader
4907 than currently involved could provide knowledge benefits freely available to all and
4908 could also increase the number of patents likely to be developed, which is a necessary
4909 precursor to the venture capital model.
4910
4911 Based on the information in this section and its conclusions, the committee makes
4912 three recommendations:
4913
4914 Recommendation 3-10: Economic analyses of inertial fusion energy power
4915 systems should be an integral part of national program planning efforts,
4916 particularly as more cost data become available.
4917
4918 Recommendation 3-11 A comprehensive, systems engineering approach should
4919 be used to assess the performance of IFE systems. Such analyses should also
4920 include the use of a Technology Readiness Levels (TRL) methodology to help
4921 guide the allocation of R&D funds.
4922
4923 Recommendation 3-12: Further efforts are needed to explore how best to
4924 minimize the capital cost of IFE power plants even if this means some increase in
4925 the cost of electricity. Innovation will be a critical aspect of this effort. These
4926 options include use of a smaller fusion module even at higher specific capital cost
4927 per MWe, and also use of a fusion module for which capital cost is reduced by
4928 the acceptance of higher operating cost.
4929
4930
4931
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