ARC-100: A Sustainable, Modular Nuclear Plant for Emerging Markets

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1 ARC-100: A Sustainable, Modular Nuclear Plant for Emerging Markets David C. Wade and Leon Walters Advanced Reactor Concepts, LLC (ARC) Plaza America Drive, Suite 2000 Reston, VA Tel: , dwade@arcnuclear.com, lwalters@arcnuclear.com Abstract The ARC-100 reactor concept and its supporting fuel cycle infrastructure is intended to offer a 21 st century configuration of nuclear energy, -- one tailored to meet the needs of emerging electricity markets in developing countries as well as imminent global need for carbonfree non-electric energy sources. This new configuration relies on the huge energy density of nuclear fuel (>10 6 times that of fossil fuel) to enable a distributed fleet of small, fast reactors of long (20 year) refueling interval, providing local energy services supported by a small number of centralized facilities handling fuel supply and waste management for the entire fleet. This paper describes ARC-100 the small, fast reactor component of the infrastructure. I. INTRODUCTION The ARC-100 reactor concept and its supporting fuel cycle infrastructure is intended to offer a 21 st century configuration of nuclear energy, one tailored to meet the needs of emerging electricity markets in developing countries as well as imminent global need for carbon-free non-electric energy sources. This new configuration relies on the huge energy density of nuclear fuel (>10 6 times that of fossil fuel) to enable a distributed fleet of small fast reactors of long (20 year) refueling interval, providing local energy services supported by a small number of centralized facilities handling fuel supply and waste management for the entire fleet. The reactors are sized for local and/or small grids, and are standardized, modularized and prelicensed for factory fabrication and rapid site assembly. Correspondingly, the centralized fuel cycle infrastructure is sized for economy of scale to support a large fleet of reactors in the region and is operated under international safeguards oversight. The arrangement is designed to meet the tenets of sustainable development. Figure 1 illustrates the nuclear energy infrastructure in its mature stage. This paper describes ARC-100 the small, fast reactor component of the infrastructure. II. REACTOR OVERVIEW ARC-100 is a 100 MW e (260 MW t ), sodium-cooled fast reactor operating on a long (20 year) whole core refueling interval. Its initial fuel load is of enriched Fig. 1. Nuclear Energy Architecture uranium ( 20% enriched) in the form of metal alloy fuel slugs, sodium bonded to ferritic-martinsitic cladding. (An extensive database for such fuel pins exists from EBR-II and FFTF operations.[1]). The reactor exhibits an internal breeding ratio near unity such that its reactivity burnup swing is small and its core is fissile self-sufficient. It attains 80 MW t d/kg fuel average burnup, and upon pyrometallurgical recycle at completion of its 20 year burn cycle, depleted uranium makeup feedstock is all that is required for the reload core. Upon multiple recycles, the core composition gradually shifts to an equilibrium transuranic fuel composition, which is also fissile self sufficient requiring only U238 makeup upon recycle. The forced circulation heat source reactor delivers heat at ~500 C through a sodium intermediate loop that drives a supercritical CO 2 (S-CO 2 ) Brayton Cycle power converter attaining ~40% conversion efficiency and is

2 capable to incorporate bottoming cycles for desalination, district heat, etc. The ARC-100 employs passive decay heat removal; achieves passive safety response to Anticipated Transients Without Scram; and employs passive load follow. The balance of plant has no nuclear safety function. The plant is sized to permit factory fabrication of rail and barge shippable modules for rapid assembly at the site. Its features are targeted to meet the infrastructure and institutional needs of rapidly growing cities in the developing world as well as non-electric industrial and/municipal niche applications in all nations. The ARC-100 is being commercialized by Advanced Reactor Concepts, LLC, (ARC) a startup company incorporated in Delaware in the fall of ( III. TARGETING EMERGING MARKETS Nuclear energy is a well-established industrial business which, over the past 35 years, has attained 13,000 reactor years of operating experience and 16% market share of world electricity supply being deployed primarily in the form of large size ( > ~ 1200 MW e ) plants in industrialized nations. There are currently 436 reactors deployed in 30 countries. Future growth in nuclear deployments is projected to be as much as 66% additional capacity by 2030.[2] The majority of the growth is projected to take place in developing countries where institutional and infrastructure conditions often differ from those that, in the past, favored large scale plants and a once through fuel cycle. Developing nations often have small, local grids of under a few tens of GW unable to accommodate a 1.2 to 1.5 GW e sized plant. The ARC-100 at 100 MW e, is not only compatible with smaller grid size but additionally, the smaller capital outlay required for its installation is compatible with a developing country s necessity for sharing limited financing across multiple development projects during the early decades of its rapid economic growth. Importantly, the ARC-100 twenty year refueling interval with fuel supply, recycle, and waste management services outsourced to a regional center enable a nation to attain unprecedented energy security even absent a need to first emplace a complete indigenous fuel cycle/waste management infrastructure. The energy supply growth rate in industrialized countries is projected to be slower than in developing countries. Nonetheless, new nuclear plants will be needed for replacements of coal and nuclear plants as they are decommissioned at end of life. The large capacity interconnected grids in industrialized nations are compatible with large power rating plants. However, niche markets are expected to rapidly emerge in both developed and developing nations for non-electric and/or cogeneration applications of carbon-emission-free nuclear energy. Among these are water desalination, oil sands/oil shale recovery and upgrading, and coal or bio to liquids synthetic fuel production. The ARC-100 passive safety posture precludes any safety function being assigned to the balance of plant and along with its reduced source term favor it s siting adjacent to industrial and municipal installations. IV. CORE DESIGN IV.A. Goals The 260 MW t core design was done by Argonne National Laboratory, on behalf of ARC, using its validated code suite and databases. 1 The optimization goals were to produce an enriched uranium (UZr alloy) fueled design of <20% enrichment that would minimize burnup control swing over a 20 year (0.90 capacity factor) refueling interval in a core layout comprised of 7-assembly clusters, fitting into a core barrel of no more than 3 meters diameter with as high a discharge burnup as possible. The core barrel constraint is to promote shipability of factory-fabricated modules suitable for rapid assembly at the site. The 7-assembly cluster requirement is such that fuel handling can be done on a 7-assembly cluster basis to minimize the number of handling operations during whole core refueling with a concomitant short reactor downtime on reactors that may be the only power source on a local grid. IV.B. Optimized Core Layout The optimized core layout is shown in Fig. 2. It consists of fourteen 7-assembly clusters comprising 92 fuel assemblies plus 6 primary control rod assemblies. Separate from the 7-assembly clusters are 2 safety rod assemblies and a central core clamping assembly. There is also one row (42 assemblies) of replaceable steel reflectors and an outer row (48 assemblies) of removable shield assemblies. These are grouped into 4-assembly clusters. The fueled height of the core is 1.5 meters. There are three radial enrichment zones of 10.1% enrichment (28 assemblies), 12.1% (28 assemblies) and 17.2% (36 1 Acknowledgement: T.K. Kim, Nuclear Engineering Division at Argonne National Laboratory optimized the core neutronics design given specification of design goals by ARC.

3 assemblies). parameters. Table I summarizes the top level design TABLE I Design Parameters and Optimized Core Loading Parameters Unit Value Thermal power MW t 260 Number of driver assemblies 92 Number of control assemblies Primary Safety Core barrel inner diameter m 3.0 Active fuel height, cm cm Initial heavy metal loading tonnes 20.7 Specific power density MW/tonne 12.5 Average Power Density kw t /l The total fuel mass is 20.7 tonnes HM and the average enrichment is 13.5%. 2 Average specific power is 12.5 kw t /kg HM and average power density is 69.6 kw t /l. These are quite low compared to traditional fast reactor designs which have specific powers of 50 to >100 kw t /kg HM. By derating specific power and power density values as compared to traditional fast reactor values, the fuel discharge burnup remains within the proven range of the metal alloy fuel irradiation database even with a 20 year burn cycle. The peak discharge burnup is MW t days/kg HM. Derating fuel specific power also reduces decay heat levels per unit fuel mass and thereby permits reload fuel handling to be conducted on a 7-assembly cluster basis and with minimal cooling time after reactor shutdown. IV. C. Assembly and Pin Designs Inner core (28) Middle core (28) Outer core (36) P Primary control (6) S Secondary control (3) Reflector (42) Shield (48) Total (191) Fig. 2. Refueling Cluster Layout and Core Radial Enrichment Zoning of ARC-100 Table II summarizes the mass loadings by enrichment zone. Table II Heavy Metal Loading and Required Natural Uranium Assemblies LEU mass, t Enrich., % Nat. U mass, t * SWU, t * Inner core Middle core Outer core Total (ave) * 0.3% tails assay The hexagonal fuel assemblies of 17 cm flat-to-flat distance comprise 127 pins per assembly of fat pins of 1.3 cm (0.51 inches) diameter. The fuel, sodium bond, structure and coolant volume fractions are 42.9, 14.3, 17.7 and 25.6% respectively. The average pin linear heat rate is 13.9 kw t /m. IV. D. Burnup Performance A remarkably small (positive) burnup swing of only 1.2% k/k has been achieved through extensive internal breeding in driver pins. The average discharge burnup is 80.6 MW t d/kg HM and the peak is MW t d/kg HM lying within the extensive database from EBR-II and FFTF testing of metal alloy fuels. Peak discharge fast fluence is fast nvt. This fluence slightly exceeds the historical guideline for HT-9 for which no swelling was indicated in experiments run to fast nvt. (The irradiation campaign was terminated before further fluence could be delivered.) The core is designed to be fissile self-sufficient (i.e., new fissionable mass that is bred during the core refueling interval is sufficient to fuel the reload core). The breeding ratio, defined here as mass of fissionable material at core discharge BR= initial mass of fissile material 2 For comparison, an LWR operating for 20 years and producing the same electrical energy as ARC-100 (at a plant efficiency of 0.32) with 4.3% enriched fuel of 40 MW td/kg discharge burnup requires 51.2 tonnes of fuel, tonnes of Nat U and tonnes SWU. The benefit of the fissile self regeneration of ARC-100 vs an LWR appears because only depleted uranium makeup is needed for the ARC-100 s second, third and all succeeding 20 year energy delivery campaigns.

4 has a value of All transuranics are treated as fissionable in this definition. The value is less than one owing to the fact that the bred-in transuranic mass has a higher reactivity/unit mass than does the burned out U235 (η value is higher). IV.E. Power Profiles Assembly powers (axially integrated) at BOL and EOL are shown in Fig. 3. Axially-integrated radial assembly peak to average power peaking factors are 1.21, 1.22, and 1.33 at BOL, MOL, and EOL respectively. The overall core peak to average power density profiles are 1.84, 1.69, and 1.76 at BOL, MOL and EOL respectively Fig. 3. Assembly Powers (Axially Integrated) at BOL and EOL IV.F. Core Thermal/Hydraulics Performance Core inlet temperature is 355 C; core ave outlet temperature is 510 C. It has been possible to design the high fuel volume fraction needed to minimize burnup control swing by going to a fat pin diameter. At the same time fat pins maximize hydraulic diameter to give minimum core pressure drop. Average coolant velocity through the lattice is 4.6 m/sec and core pressure drop is 35.7 psi. The core average pin linear heat rate is 13.9 and the maximum is 25.5 kw t /m. This leads to an average fuel meat temperature rise of: ( ) T = 104 C T(fuelcenterline) T (cladinner surface) fuel BOL EOL which is only about 2/3 of traditional values for metal alloy pins. Table III summarizes Core Thermal/Hydraulics Performance. Table III also shows margin to design limits for 3-sigma design parameters. (Peak temperatures include 3-sigma hot channel factors that were used for the CRBRP design.) The ARC-100 thermal conditions are mild and the margins to thermal limits are large. TABLE III Core Steady-State Thermal/Hydraulic Performance Parameters Unit Value Coolant temperature (inlet/outlet) ºC 355 / 510 Coolant pressure drop psi 35.7 Coolant flow rate per pin (ave./hot channel) kg/s / Average coolant velocity in lattice m/s 4.6 Linear heat rate (ave./peak) kw/m 13.9 / 25.5 Cladding outer surface temperature (ave./peak) ºC 435 / 553 Cladding inner surface temperature (ave./peak) ºC 442 / 556 Fuel centerline temperature (ave./peak) ºC 546 / 686 Average fuel surface to centerline temp. rise ºC Sigma Design Values vs Limit - Fuel centerline temperature (limit/margin) - Fuel/cladding eutectic temperature (.limit/margin) - Linear heat rate ºC ºC kw/w 1081/ /94 37/11 II.G. Kinetics Parameters and Reactivity Feedback Coefficients Delayed neutron fraction and reactivity coefficients are shown in Table IV versus time in life. The reduction of delayed neutron fraction with burnup is due to replacement of U235 fission fraction with plutonium fission fraction, which attains 20% by EOL. Even at end of life, β eff is characteristic of a U235 fueled core. A strongly negative radial expansion coefficient dominates the Doppler coefficient indicating that reactivity vested in coolant temperature rise will dominate that which is vested in fuel temperature rise above coolant temperature (a favorable attribute for passive safety).

5 TABLE IV Kinetics Parameters and Reactivity Feedback Coefficients Unit BOC MOC EOC Effective delayed neutron fraction Prompt lifetime µs Radial expansion coefficient /C Axial expansion coefficient /C Sodium void worth $ Sodium density coefficient /C Doppler coefficient /C Sodium voided Doppler coeff /C Fuel density coefficient /C Structure density coefficient /C Control rod driveline expansion coefficient /cm IV.H. Control Rod Performance As shown in Fig. 2, the core contains six primary control rods and two secondary (safety) rods. Table V shows that the 6-rod primary rod bank and the 2-rod safety rod bank each can meet shutdown requirements throughout life using only natural boron content in the absorber rods. TABLE V Shutdown Margin (in $) Upon unintended single primary rod runout from its maximum insertion position (at MOL) the most severe accidental single-rod runout will introduce much less than one dollar of reactivity thus assuring safe passive response to the Transient Overpower Without Scram accident initiator. Primary Secondary BOC MOC EOC BOC MOC EOC Number of control assemblies Reactivity worth of system Maximum worth of one stuck assembly Reactivity worth available Reactivity control requirement Shutdown margin IV.I. Detailed Mass Flows and Fuel Cycle Table VI displays the isotopic mass flows integrated over each of the enrichment zones and over the core as a whole. During the 20 year burn cycle, 1642 kg of fission products are generated, 1360 kg or 48.6% of U235 mass is consumed (fissioned or converted to U236) while 1613 kg or 8.99% of U238 is consumed (converted to plutonium or fissioned). Meanwhile a (reactivity equivalent) amount of transuranics (primarily plutonium) is bred and partly consumed in situ. The net production of transuranic mass is 962 kg which when added to the remaining U235, sums to 2396 of fissionable material for the reload core. Nonetheless, because of its higher reactivity per neutron absorbed in fuel, the fissile mass required for the reload core is sufficient, and only U238 makeup is needed subsequent to fission product removal during recycle in order to fuel refabrication of a replacement core.

6 TABLE VI Heavy Metal Mass Flow (kg) Charge Discharge total Inner middle outer total Inner middle outer U U U Pu Pu Pu Pu Pu MA Total Fissile U U235/U TRU V. PLANT LAYOUT OVERVIEW The reactor vessel is positioned in a seismically isolated silo with a heavy concrete cover. The ambient pressure primary system is wholly contained within the reactor vessel and comprises the enriched uranium-fueled core, the sodium pump and the sodium-to-sodium intermediate heat exchangers. Core outlet temperature is 510 C well matched to the S-CO 2 Brayton Cycle working fluid properties and consistent with extensive structural materials experience base for sodium cooled reactors. An ambient pressure sodium intermediate loop carries the heat across the containment boundary to the non-nuclear safety grade balance of plant (BOP) where a sodium to S-CO 2 printed circuit heat exchanger receives the heat at ~500 C to drive the Brayton Cycle. The intermediate loop return temperature to the reactor is ~355 C. The reactor containment is comprised of a guard vessel and a small steel dome over the reactor deck which together enclose the reactor vessel. The silo and its concrete cover comprise a shield structure to protect the containment structures and ancillary systems important to safety from external hazards. The S-CO 2 Brayton Cycle is a closed loop system operating between pressures of 21 MPa and 7 MPa. The rotating machinery is remarkably small per unit power rating. High conversion efficiency (heat to electricity η ~0.4) at a temperature of ~500 C is attained owing to fluid compression just above the CO 2 critical point at 7 MPa and 31 C where the CO 2 has a high density and low compressibility. The cycle is highly recuperated using printed circuit heat exchangers of very high power density. The outlet temperature from recuperation is ~70 to 100 C while Brayton Cycle heat rejection takes the CO 2 to 31 C so as to benefit from critical point properties mentioned above, thus heat in a useful temperature range for bottoming cycles is available. District heating; district chilled water; and multi-effects distillation desalination are possible applications in municipal settings. Cogeneration opportunities in industrial settings are also possible by lessening recuperation so that ~100 C heat is available for raising steam at ambient pressure. These favorable heat rejection temperatures not only allow to convert a larger fraction of the reactor s heat to useful products, they also reduce the thermal footprint of the plant, thereby favoring reduced cooling water withdrawals. VI. PASSIVE SAFETY RESPONSE The ARC-100 reactor incorporates an active scram system and a defense in depth design philosophy. Additionally, extensive passive safety features are employed. The reactor is designed to innately maintain

7 heat production in balance with heat removal. The reactivity adjustment (at unchanging control rod position) relies on thermostructural geometrical changes, which affect neutron leakage, and on fuel temperature changes which act on Doppler coefficient of reactivity. This passive safety response leads to accommodation without damage of the loss of flow without scram and loss of heat sink without scram Anticipated Transients Without Scram (ATWS) events. An internal breeding ratio of about unity makes the burnup reactivity swing nearly zero such that the single rod runout without scram ATWS event is also passively accommodated without damage. The ambient pressure primary system that is contained completely within the reactor vessel with a backup guard vessel eliminates the Loss of Coolant Accident (LOCA) by design. An always operating RVACS passive decay heat removal channel to the ambient atmosphere heat sink, when combined with natural circulation at decay heat levels and the large heat capacity of the sodium pool and internal structures passively prevents reaching damaging temperatures even upon loss of heat sink or loss of pumping power without scram. The fuel and coolant are chemically compatible such that run beyond cladding breach does not lead to flow blockages from low density reaction products. The passive reactivity feedbacks and passive decay heat removal channel operability can be confirmed at all stages of core life by nonintrusive, insitu tests. The extensive passive safety features employed in ARC-100 have all been well established for sodium-cooled, metallic-fueled fast reactors having been demonstrated in tests conducted at EBR-II during the 1980 s and early 1990s.[3] VII. PASSIVE LOAD FOLLOW AND NON- NUCLEAR SAFETY GRADE BALANCE OF PLANT The S-CO 2 Brayton Cycle is actively controlled such that its electrical output meets dispatch requests, but the reactor itself will load follow the BOP over a wide range by passive means. The innate reactivity feedbacks that keep reactor heat production in balance with heat removal to the BOP through the intermediate heat transport loop can be relied on for load follow absent any active control of rod position. All physically attainable combinations of intermediate flow rate and return temperature from the BOP lead passively to reactor power adjustment within the nodamage temperature range. Hence the reactor safely protects itself from any and all BOP equipment failures, maintenance lapses, or operator mistakes. Nor is the BOP essential for decay heat removal. As a result, the BOP carries no nuclear safety function and can be designed, built, maintained and operated to conventional industrial standards. Plant licensing might be confined to reactor island licensing of the heat source reactor per se independent of BOP configuration allowing for a diversity of BOP missions and configurations to mesh with a standardized pre-licensed heat source reactor requiring only minimal additional licensing evaluation for the overall plant configuration. VIII. CLOSED FUEL CYCLE & RESOLUTION OF THE ENERGY SECURITY/NONPROLIFERATION AND THE NUCLEAR WASTE DILEMMAS The reactor includes no refueling equipment nor onsite spent fuel storage capability. The once per 20 year refueling will be conducted by factory personnel who bring refueling equipment to the site with the fresh core, and who take the refueling equipment away with the used core. The derated specific heat of the fuel necessitated by long life enables short cooling period prior to fuel handling. The initial core loading is of Uranium/10 weight % Zirconium metal alloy of <20% enrichment. This both precludes a reliance on LWR used fuel reprocessing and facilitates a delay of 20 years to perfect pyrometallurgical recycle technology. With an internal breeding ratio near unity, there is as much fissionable mass in the core upon its discharge as there was at the beginning. 3 The core will be changed out for a new core and the used core will be recycled using pyrometallurgical recycle technology. The pyrometallurgical recycle technology returns all transuranics, including minor actinides, back to the reactor where they are self-consumed as fuel. Therefore, only fission products go to the waste stream and only U238 is required as makeup. Incomplete fission product removal and carryover of minor actinides in refabricated fuel will keep the fuel radioactive at all stages of the cycle (including new core shipping). The recycle and refabrication will be done in shielded cells with remote handled equipment. The recycle/refabrication facility is envisioned as a regional fuel cycle facility operated under international safeguards oversight and providing both the fuel supply and waste management needs of dozens to hundreds or limit. 3 The core must be discharged upon reaching the fuel assembly

8 even thousands of ARC-100s deployed throughout the region. All bulk handling of fissile material is done at the regional facility where manpower-intensive safeguards measures can benefit from economy of scale. All distributed fuel handling can rely on less manpower intensive item accountancy measures and benefits from innate non-attractiveness of material composition and from its physical inaccessibility and innate radiation field. All nations who choose to avail themselves of outsourced fuel cycle and nuclear waste management services for ARC-100 deployments will be spared the expense and institutional challenges of emplacing indigenous facilities for enrichment, fabrication, recycle, and waste management as a prerequisite to include nuclear in their energy mix. At the same time, the 20 years worth of energy stored in an ARC-100 and securely sited on sovereign territory provides an unprecedented degree of energy security and stability in cost of fuel. IX. AFFORDABILITY AT SMALLER SCALE The ARC-100 design and the ARC business model employ a range of strategies to attain economic competitiveness that surpasses traditional returns to scale used in the familiar LWR strategy. By going to a different technology that is governed by different phenomenology, ARC can move off the LWR scaling curve of LCOE vs power rating to a new curve lying below the LWR curve at small power rating. First, an ambient pressure primary system removes the LOCA accident hazard by design and passive safety response to all anticipated transients without scram (ATWS) takes the reactor to an undamaged, safe state, cooled by passive means. This safety approach simplifies and even eliminates several active safety systems. More importantly it also shrinks the required size and concomitant cost of the containment to that comprised of a guard vessel with a small removable dome over the vessel head all situated in a below grade, seismically isolated concrete silo. Second, the reactor drives a S-CO 2 Brayton Cycle whose >40% conversion efficiency shrinks the reactor s heat rating by 30% as compared to a LWR/Rankine steam cycle of the same electricity output. Third, the reactor passively load follows the S-CO 2 heat demand, which (with the passive safety response), makes it possible to remove all nuclear safety functions from the BOP and to build and maintain it to industrial standards. Fourth, the fuel attains a burnup 2 or 3 times that of LWR fuel. Fifth, the smaller plant power rating reduces capital outlay into a range that is feasible for an enlarged customer base and is appropriate for a broader range of missions. Sixth, small sizing permits factory fabrication of standardized, pre-licensed shippable modules for rapid site assembly; the targeted ~ < 2 year site construction schedule of standardized modules dramatically reduces the amount of interest during construction as compared with LWR field construction and reduces risk of schedule overrun. X. COMMERCIALIZATION BASED ON PROVEN TECHNOLOGY The ARC-100 reactor is based on well-established technology, that can be effectively packaged and customized for a number of emerging applications and markets.. Importantly, both the fuel and the coolant benefit from decades of proven experience to validate their application in the ARC-100. The passive safety and passive load follow features have been demonstrated during extensive EBR-II[3] and FFTF tests that were conducted in the 1980 s. The two technologies that have not yet been demonstrated at scale are the S-CO 2 Brayton Cycle and the pyrometallurgical recycle. The S-CO 2 Brayton Cycle has been demonstrated in engineering tests at Sandia National Laboratories and tests on larger systems are being planned. As a backup, the ARC-100 could use a standard superheated Rankine steam cycle, should the development of S-CO 2 Brayton Cycle be delayed. Pyrometallurgical recycling has been developed and refined at Argonne National Laboratory over the past 20 years[4] and demonstrated at engineering scale production in facilities at Idaho National Laboratory. The initial implementation of the ARC-100 will use enriched uranium to avoid reliance on LWR SNF reprocessing for fueling the first deployments, and recycle of the first ARC-100 cores will not be required until 20 years after first deployments leaving ample time for the commercial deployment of the pyrometallurgical recycling technology. XI. CONCLUSIONS The ARC-100 design features and the supporting fuel cycle infrastructure have been chosen with the tenets of sustainable development in mind. The overall architecture of the distributed Power Plant/Regional Fuel Cycle infrastructure provides a configuration for nuclear energy that facilitates interregional equity in global energy supply. The efficient conversion of heat to electricity using modern Brayton Cycle technology and the option for use of remaining waste heat for municipal or industrial missions further increasing societal benefit from the fission heat meets the goal for efficient use of both resource and infrastructure. The 20 year refueling interval fosters a nation s energy security. The closed fuel cycle starting with an enriched uranium core but thereafter

9 requiring only U238 feedstock provides a millennium of global, carbon free energy availability by using the world s uranium resource base at nearly 100% efficiency. Self-consuming nuclear waste management technology wherein only fission products go to waste for year sequestration while all actinides are returned to the reactor as fuel meets the intergenerational equity tenet of sustainable development. Greenhouse gas emissions are nearly eliminated. This ARC-100 business model and enabling technology choices provide an incentivized and practical way to accommodate extensive future deployments of carbon-free nuclear energy for the benefit of all nations energy security without exacerbating proliferation hazards and while using the world s uranium resource efficiently and at the same time, producing the minimally attainable nuclear waste burden that decays to natural background levels within years. ACKNOWLEDGMENTS T.K. Kim, Nuclear Engineering Division at Argonne National Laboratory optimized the core neutronics design given specification of design goals by ARC. REFERENCES 1. G. L. Hofman, L. C. Walters, and T. H. Bauer, Metallic Fast Reactor Fuels, Progress in Nuclear Energy, Volume 31, Number1/2, (1997). 2. Mohamed ElBaradei, Speech Opening the Beijing International Ministerial Conference on Nuclear Energy in the 21 st Century, Beijing, 20 April 2009, (posted at IAEA website, ( 3. EBR-II Division, The Experimental Breeder Reactor-II Inherent Safety Demonstration, Nuclear Engineering and Design, 101, No.1 (1987). 4. J.J. Laidler, J.E. Battles, W.E Miller, J.P. Ackerman and E.L. Carls, Development of Pyroprocessing Technology, Prog. Nucl. Energy, 31 (1/2), 131 (1997).