Small Modular Reactors and the Second Nuclear Era

Daniel IngersollOak Ridge National Laboratoryingersolldt@ornl.gov

November 17, 2011ET Section of AIChE

2 Managed by UT-Battellefor the U.S. Department of Energy

Background

3 Managed by UT-Battellefor the U.S. Department of Energy

The U.S. began developing small nuclear reactors for military applications

USS Nautilus1954-80

Nuclear Test Aircraft1955-57

Camp Century1960-62

4 Managed by UT-Battellefor the U.S. Department of Energy

Navy’s experience spawned nuclear propulsion for merchant shipping

N.S. Savannah1961-71

N.S. Otto Hahn 1968-79

5 Managed by UT-Battellefor the U.S. Department of Energy

The first commercial power plants were small prototypes

Vallicetos(5 MWe)1957

Dresden 1(200 MWe)

1960

Shippingport(60 MWe)1957

6 Managed by UT-Battellefor the U.S. Department of Energy

Commercial nuclear power plants escalated rapidly in size during the 70s

0

200

400

600

800

1000

1200

1400

1955 1960 1965 1970 1975 1980 1985 1990 1995

Date of Initial Operation

Ele

ctric

al O

utpu

t (M

We)

2000

U.S. plant construction during the first nuclear era

7 Managed by UT-Battellefor the U.S. Department of Energy

Weinberg study* (1985) explored merits of smaller, simpler, safer reactors

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

Motivated by the dismal performance of the large plants (at that time)

8 Managed by UT-Battellefor the U.S. Department of Energy

Process Inherent Ultimate Safety (PIUS) Safe Integral Reactor (SIR)

Integral LWR designs evolved in the 80s to enhance plant robustness

9 Managed by UT-Battellefor the U.S. Department of Energy

Non-LWR SMR designs also developed during the 80s

Containment Vessel

Reactor Vessel

CORE

Grade

ELEVATION

Air Inlet (8)

Air Outlet

Stack

RVACS Flow Paths

Containment

InletPlenum

Normal Flow Path

Overflow Path

Collector Cylinder

Reactor Silo

InletPlenum

Power Reactor Inherently Safe Module (PRISM)

Modular High-Temperature Gas-cooled Reactor (MHTGR)

10 Managed by UT-Battellefor the U.S. Department of Energy

Current Interests

11 Managed by UT-Battellefor the U.S. Department of Energy

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 Managed by UT-Battellefor the U.S. Department of Energy

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 Managed by UT-Battellefor the U.S. Department of Energy

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 Managed by UT-Battellefor the U.S. Department of Energy

Utility interests in SMRs

• Affordability– Smaller up-front cost– Better financing options

• Load demand– Better match to power needs– Incremental capacity for regions

with 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

Plants >50 yr old have capacitiesLess than 300 MWe

U.S. Coal Plants

15 Managed by UT-Battellefor the U.S. Department of Energy

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 Managed by UT-Battellefor the U.S. Department of Energy

Safety Considerations

17 Managed by UT-Battellefor the U.S. Department of Energy

1200 MWePWR

125 MWemPower

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

Design features that enhance plant safety for integral LWRs

18 Managed by UT-Battellefor the U.S. Department of Energy

Integral Design: Simple and Robust

Loop-typePrimary System

Core

Pressurizer

ControlRodDrive

SteamGenerator

Pump

IntegralPrimary System

Core

Pressurizer

Pump

SteamGenerator

ControlRodDrive

19 Managed by UT-Battellefor the U.S. Department of Energy

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 Managed by UT-Battellefor the U.S. Department of Energy

• 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 will influence SMR R&D priorities

Fukushima Dai-ichi Unit 4

21 Managed by UT-Battellefor the U.S. Department of Energy

Economic Issues

22 Managed by UT-Battellefor the U.S. Department of Energy

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 Managed by UT-Battellefor the U.S. Department of Energy

Simplified SMR construction should reduce cost and schedule

Stick-builtlarge reactor

Factory fabricated small reactor

24 Managed by UT-Battellefor the U.S. Department of Energy

Designs and Challenges

25 Managed by UT-Battellefor the U.S. Department of Energy

mPower (B&W)125 MWe

NuScale (NuScale)45 MWe

SMR (Westinghouse)225 MWe

U.S. LWR-based SMR designs for electricity generation

HI-SMUR (Holtec)140 MWe

26 Managed by UT-Battellefor the U.S. Department of Energy

Demonstrating the “M” in “SMR” is a key to economic viability

12-Module (540 MWe)NuScale Plant

4-Module (500 MWe)mPower Plant

27 Managed by UT-Battellefor the U.S. Department of Energy

Gas-cooled reactor designs can provide high-temperature process heat

MHR (General Atomics) PBMR (Westinghouse) ANTARES (Areva)280 MWe 250 MWe 275 MWe

28 Managed by UT-Battellefor the U.S. Department of Energy

Fast spectrum reactor designs can provide improved fuel cycles

PRISM (General Electric) EM2 (General Atomics)300 MWe 100 MWe

HPM (Hyperion)25 MWe

29 Managed by UT-Battellefor the U.S. Department of Energy

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 Managed by UT-Battellefor the U.S. Department of Energy

Prospects for local SMR

31 Managed by UT-Battellefor the U.S. Department of Energy

Today: ORNL’s carbon footprint is driven by purchased electricity

DOE GHG emissions, 2008: 4,600,000 metric tons

ORNL GHG emissions, 2008CO2 equivalent

(metric tons)

Scope 1: Direct emissions 53,200

Scope 2: Indirect emissionsfrom electricity production 226,000

Scope 3: Other indirect emissions 52,300

Total 331,500

Electricity: Conventional facilities, 30%

Electricity: Mission facil-ities, 38%

Scope 1: Di-rect emis-

sions, 16%

Scope 3: Other indirect

emissions, 16%

32 Managed by UT-Battellefor the U.S. Department of Energy

ORNL’s mission-critical research facilities drive GHG emissions

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 20200

100,000

200,000

300,000

400,000

500,000

600,000

700,000

Electricity: Mission-critical facili-tiesElectricity: Conventional facilitiesScope 1 emissionsScope 3 emissions

Me

tric

to

n C

O2

eq

uiv

ale

nt

33 Managed by UT-Battellefor the U.S. Department of Energy

Oak Ridge SMR projects enables ORNL to meet GHG goals

FY08 FY20with no change

in energy mix

FY20 with SMR

331,500

636,500 −7,000 −40,000−26,000

−550,000

GHG

em

issi

ons,

met

ric to

ns C

O2e

2020 goal:

247,000

Scope 3reduction Scope 1

reduction Scope 2 demandreduction

SMREven aggressive efficiency

improvements and emissionreductions are not sufficient

34 Managed by UT-Battellefor the U.S. Department of Energy

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

Jo Willreplace

Clinch River Site

35 Managed by UT-Battellefor the U.S. Department of Energy

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

Reactor Coolant Pumps

Control Rod Drive Mechanisms

Core

36 Managed by UT-Battellefor the U.S. Department of Energy

Notional implementation scheduleCY CY CY CY CY CY CY CY CY CY CY

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021

Prepare Design Certification Application

Clinch River Project – 10CFR50 Process

PSAR and Complete DCA

Submit CPA

NRC CPA Review

CP FSER CP Issuance

PSARER

Prepare Operating License Application

Submit OL Application

NRC Review Operating License Applic.

FSER Issued

Pre-Op Testing

OL IssuanceFuel Load

Start-up Testing

Submit DCA

NRC DCA Review

DCA Scope Freeze

DC Rule

COL Issuance

10CFR52 COLA Preparation NRC COLA Review

Final DC Rulemaking

Construction/ITAAC

ASER Issued

COLA Submittal

LWA

1st Unit

Prepare CPA

mPower DCD and COLA – 10CFR52 Process

37 Managed by UT-Battellefor the U.S. Department of Energy

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