Small Modular Reactors and the Second Nuclear Era Daniel Ingersoll Oak Ridge National Laboratory ingersolldt@ornl.gov

1. Small Modular Reactorsand the Second Nuclear EraDaniel IngersollOak Ridge National Laboratoryingersolldt@ornl.gov November 17, 2011 ET Section of AIChE

2. Background

3. The U.S. began developing small nuclear reactors for military applications USS Nautilus 1954-80 Nuclear Test Aircraft 1955-57 Camp Century 1960-62

4. Navy’s experience spawned nuclear propulsion for merchant shipping N.S. Savannah 1961-71 N.S. Otto Hahn 1968-79

5. The first commercial power plants were small prototypes Dresden 1 (200 MWe) 1960 Vallicetos (5 MWe) 1957 Shippingport (60 MWe) 1957

6. Commercial nuclear power plants escalated rapidly in size during the 70s 1400 1200 1000 800 Electrical Output (MWe) U.S. plant construction during the first nuclear era 600 400 200 0 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 Date of Initial Operation

7. Weinberg study* (1985) explored merits of smaller, simpler, safer reactors Motivated by the dismal performance of the large plants (at that time) Main findings: • Large light-water reactors pose very low risk to the public but high risk to the investor • Large reactors are difficult to operate: complex and finicky • Small inherently safe (highly forgiving) designs are possible if they can be made economically • Two designs were especially promising: • The Process Inherent Ultimately Safe (PIUS) reactor • The Modular High-Temperature Gas-Cooled Reactor (MHTGR) *A. M. Weinberg, et al, The Second Nuclear Era, Praeger Publishers, 1985

8. Integral LWR designs evolved in the 80s to enhance plant robustness Process Inherent Ultimate Safety (PIUS) Safe Integral Reactor (SIR)

9. Air Inlet (8) RVACS Flow Air Outlet Paths Stack Grade Containment Inlet Plenum Inlet Plenum Overflow Path Collector Cylinder Normal Flow Path CORE Containment Vessel Reactor Vessel Reactor Silo ELEVATION Non-LWR SMR designs also developed during the 80s Modular High-Temperature Gas-cooled Reactor (MHTGR) Power Reactor Inherently Safe Module (PRISM)

10. Current Interests

11. Interest in SMRs is reemerging Enabled by excellent performance of existing fleet of large nuclear plants Motivated by carbon emission goals, energy security concerns and economic challenges • Key Benefits • Enhanced safety and robustness from simplified designs • Enhanced security from below-grade siting • Reduced capital cost—a major barrier for many utilities • Competitive power costs due to factory fabrication and modularization/standardization • Ability to add new electrical capacity incrementally to match power demand and growth rate • Domestic supply chain—no large forging bottlenecks • Adaptable to a broader range of energy needs • More flexible siting (access, water impacts, seismic, etc.)

12. Interest in SMRs is reemerging Enabled by excellent performance of existing fleet of large nuclear plants Motivated by carbon emission goals, energy security concerns and economic challenges • Key Benefits • Enhanced safety and robustness from simplified designs • Enhanced security from below-grade siting • Reduced capital cost—a major barrier for many utilities • Competitive power costs due to factory fabrication and modularization/standardization • Ability to add new electrical capacity incrementally to match power demand and growth rate • Domestic supply chain—no large forging bottlenecks • Adaptable to a broader range of energy needs • More flexible siting (access, water impacts, seismic, etc.)

13. Interest in SMRs is reemerging Enabled by excellent performance of existing fleet of large nuclear plants Motivated by carbon emission goals, energy security concerns and economic challenges • Key Benefits • Enhanced safety and robustness from simplified designs • Enhanced security from below-grade siting • Reduced capital cost—a major barrier for many utilities • Competitive power costs due to factory fabrication and modularization/standardization • Ability to add new electrical capacity incrementally to match power demand and growth rate • Domestic supply chain—no large forging bottlenecks • Adaptable to a broader range of energy needs • More flexible siting (access, water impacts, seismic, etc.)

14. Utility interests in SMRs U.S. Coal Plants Plants >50 yr old have capacities Less than 300 MWe • Affordability • Smaller up-front cost • Better financing options • Load demand • Better match to power needs • Incremental capacity for regionswith low growth rate • Allows shorter range planning • Site selection • Lower land and water usage • Replacement of older coal plants • Potentially more robust designs • Grid stability • Closer match to traditional power generators • Smaller fraction of total grid capacity • Potential to offset non-dispatchable renewables

15. Government interests in SMRs • Carbon Emission • Reduce U.S. greenhouse gas emissions 17% by 2020…83% by 2050 • E.O. 13514: Reduce federal GHG emissions 28% by 2020 • Defense Mission Surety • Studying SMR deployment at DOD domestic facilities • Address grid vulnerabilities and fuel supply needs • Energy and Economic Security • Pursue energy security through a diversified energy portfolio • Improve the economy through innovation and technology leadership 2005 U.S. CO2 Emissions (Tg)

16. Safety Considerations

17. Design features that enhance plant safety for integral LWRs iPWR SMR designs share a common set of design principles to enhance plant safety and robustness • Elimination of ex-vessel primary piping • Smaller decay heat per unit • More effective decay heat removal • Increased water inventory ratio in the primary reactor vessel • Increased pressurizer volume ratio • Vessel and component layouts that facilitate natural convection cooling of the core and vessel • Below-grade construction of the reactor vessel and spent fuel storage pool • Enhanced resistance to seismic events 1200 MWe PWR 125 MWe mPower

18. Integral Design: Simple and Robust Loop-type Primary System Integral Primary System Steam Generator Pressurizer Control Control Rod Pressurizer Rod Pump Drive Steam Drive Generator Pump Core Core

19. Features of advanced SMRs may further enhance safety Advanced designs such as gas, metal and molten salt-cooled technologies may offer features that provide additional safety margin, including: • Low pressure coolants to reduce steamenergetics during loss of forced circulation accidents • More robust fuel forms that survive extreme temperatures • Higher burnup fuels that reduce the volume of discharged fuel stored on-site • Advanced cladding and structural materials that survive extreme temperature conditions • Strong negative reactivity coefficients toassure safe shutdown TRISO fuel particle

20. Fukushima will influence SMR R&D priorities • While SMRs offer the potential for enhanced safety and resilience against upset, this must be proven • Fukushima experience emphasizes the need to fully understand the safety features • Common-cause upset modes in multi-module plants • Seismic response of below-grade construction • Reliability of passive safety systems • Quantification and demonstration of plant resilience Fukushima Dai-ichi Unit 4

21. Economic Issues

22. SMR economics are promising but unproven • Total project cost • Lower sticker price • Improved financing options and cost • Is a go/no-go decision for some customers • Cost of electricity • Economy-of-scale works against smaller plants but can be mitigated by other economic factors • Accelerated learning, shared infrastructure, design simplification, factory replication • Investment risk • Maximum cash outlay is lower and more predictable • Maximum cash outlay can be lower even for the same total generating capacity

23. Simplified SMR construction should reduce cost and schedule Stick-built large reactor Factory fabricated small reactor

24. Designs and Challenges

25. U.S. LWR-based SMR designs for electricity generation HI-SMUR (Holtec) NuScale (NuScale) SMR (Westinghouse) mPower (B&W) 225 MWe 125 MWe 140 MWe 45 MWe

26. Demonstrating the “M” in “SMR” is a key to economic viability 4-Module (500 MWe) mPower Plant 12-Module (540 MWe) NuScale Plant

27. Gas-cooled reactor designs can provide high-temperature process heat MHR (General Atomics) PBMR (Westinghouse) ANTARES (Areva) 280 MWe 250 MWe 275 MWe

28. Fast spectrum reactor designs can provide improved fuel cycles PRISM (General Electric) HPM (Hyperion) EM2 (General Atomics) 300 MWe 25 MWe 100 MWe

29. SMR Deployment Challenges • Technical challenges: • All designs have some degree of innovation in components, systems, and engineering • Longer-term systems propose new materials and fuels • New sensors, instrumentation and controls development are critical to reducing capital and operational costs • Institutional challenges: • Too many competing designs • Mindset for large, centralized plants • Traditional focus of regulator on large LWR plants • Fear of first-of-a-kind • “Slash and burn” political environment

30. Prospects for local SMR

31. Today: ORNL’s carbon footprint is driven by purchased electricity DOE GHG emissions, 2008: 4,600,000 metric tons

32. ORNL’s mission-critical research facilities drive GHG emissions

33. Oak Ridge SMR projects enables ORNL to meet GHG goals Scope 3reduction Scope 1 reduction Scope 2 demandreduction SMR Even aggressive efficiencyimprovements and emissionreductions are not sufficient 2020 goal: 247,000

34. DOE’s Oak Ridge Reservationis an attractive demonstration site • TVA site adjacent to DOE facilities • Support to both ORNL and Y-12 • Wealth of technical expertise • Supportive community Clinch River Site Jo Will replace

35. TVA is pursuing the mPower SMR Generation mPower • 125-150 MWe integral PWR • Utilizes standard UO2 LWR fuel • 4-5 year refueling interval • Reactor vessel: 3.6 m diameter and 22 m tall • TVA signed Letter of Intent on June 16, 2011 to build up to 6 mPower modules at the Clinch River Site in Oak Ridge, TN • TVA expects to submit Construction Permit application in 2012 • B&W will follow with a Design Certification application in 2013 Pressurizer Steam Generator Control Rod Drive Mechanisms Reactor Coolant Pumps Core

36. Notional implementation schedule Clinch River Project – 10CFR50 Process Prepare CPA Submit CPA PSAR ER NRC CPA Review CP Issuance CP FSER LWA Prepare Operating License Application 1st Unit Submit OL Application Start-up Testing NRC Review Operating License Applic. Pre-Op Testing OL Issuance Fuel Load FSER Issued mPower DCD and COLA – 10CFR52 Process Prepare Design Certification Application DCA Scope Freeze PSAR and Complete DCA Submit DCA NRC DCA Review ASER Issued DC Rule Final DC Rulemaking Construction/ITAAC 10CFR52 COLA Preparation NRC COLA Review COL Issuance COLA Submittal

37. Bottom Line • SMRs can extend clean and abundant nuclear power to a wider range of energy demands • Several technical and institutional challenges must be solved and demonstrated • Oak Ridge may again be a pioneer in nuclear energy “If commercially successful, SMRs would significantly expand the options for nuclear power and its applications.” - Steven Chu, Wall Street Journal, 3/23/10