Developments in the Long Quest for Economical Civilian Nuclear Power

An icon of a
  nuclear reactor with an atom symbol on a cooling tower and a lightning bolt on
  the reactor.

Presented by:

Slides by whatisnuclear.com

How a

NUCLEAR POWER PLANT

works

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Eta Carinae (NASA/ESA)

Uranium ore (Geomartin)

Yellowcake (IAEA)

Isotopic concentrations (whatisnuclear)

Gas centrifuges (GAO-18-126)

Nuclear fuel pellets (NRC)

Fuel assembly (NRC)

Reactor core refueling (D.C. Cook)

A neutron chain reaction

A Pressurized Water Reactor (TVA)

Spent fuel pool (NRC)

A dry cask (@ParisOrtizWines)

Swedish KBS-3 capsule for nuclear waste

REACTOR DESIGN CHOICES

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Fuel nuclides

  • Uranium consumer
  • Uranium-Plutonium breeder
  • Thorium-Uranium breeder
  • Plutonium consumer

Fuel cycles

  • Once-through
  • Single recycling
  • Full recycling

Fuel forms

  • Oxide
  • Carbide
  • Nitride
  • Metal (solid or molten)
  • Molten salt

Coolants

  • Water
  • Heavy water
  • Liquid metal
    • Sodium/NaK
    • Lead/PbBi
  • Gas
    • Air
    • Nitrogen
    • CO₂
    • Helium
  • Organics (Terphenyl)
  • Molten salt
    • Fluoride
    • Chloride
  • Liquid Hydrogen
  • Heat pipes

Moderators

  • Water
  • Heavy water
  • Graphite
  • Unmoderated (fast reactor)
  • Beryllium
  • Organics
  • Hydrogen/hydride

Power cycles

  • Rankine
  • Brayton
  • Stirling
  • Piston
  • Chemical
  • Thermionic
  • ...

Other design parameters

Size/Power level

  • Micro
  • Small
  • Medium
  • Large
  • Gargantuan

Site

  • Land
  • Sea (surface)
  • Sea (submerged)
  • Air
  • Space
  • Ice base

Construction method

  • Stick-built
  • Factory-built modules
  • Factory-built reactor
  • Hybrid

The whatisnuclear random reactor generator

EARLY REACTORS

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The Starting Point

Chicago Pile-1 (https://doi.org/10.2172/1832360)

Graphite-moderated, natural uranium fueled

There was no enrichment at the time...

The ORNL X-10 reactor (CC-SA Ɱ)

Hanford B plutonium-production reactor (LOC)

The New Piles Committee

Some early reactor ideas from MUC-LAO-42. See also the Piles of the Future Review from October, 1944 where a longer discussion of their views of future reactors is recorded. They thought pressurized water would lead to corrosion issues at high temperature and considered liquid metal (specifically lead-bismuth) to be the most promising coolant. Written 5 days after Hanford B came online.

Four Foundational Reactors

Proposed in 1947 to be completed in the early 1950s.

  • Fast reactor — A fast reactor to explore the possibilities of breeding (now known as EBR-1)
  • Navy thermal reactor — a prototype for submarine propulsion (now known as STR or S1W)
  • Materials Testing Reactor (MTR) — A testing facility to investigate potential materials to be used in power reactor construction. The resistance of materials to the environment required for power production was the primary challenge of power reactor development.
  • Knolls intermediate reactor — to explore the possibilities of breeding and to develop usable power

The Experimental Breeder Reactor (EBR-1)

  • In 1946, Walter Zinn designed a proof-of-principle for breeding
  • It was thought that uranium was very scarce, so breeders would be the only option for economical civilian power.
  • EBR-1 was hooked to a generator and made the first significant amount of nuclear electricity
  • It also proved that a conversion ratio >1.0 was possible
    • They didn’t consider it a true breeder because it used U-235

The EBR-I (AEC)

MTR Fuel Fab for Mockup

The MTR fuel

Fuel for the MTR mockup (AEC)

The Materials Testing Reactor (MTR)

Data source for all future reactors

The LITR reactor top

The LITR, the 1st water-cooled/moderated reactor (CC-BY-2.0 ORNL)

The MTR (AEC)

S1W Submarine Thermal Reactor

The S1W prototype

Prototype submarine in Idaho

Launch of USS Nautilus (1955)

Intermediate Power Breeder Prototype

  • Intended to be 1st industrial/commercial power reactor
  • Sodium-cooled, beryllium-moderated: intermediate-speed neutrons
  • Supposed to breed and make commercial power
  • On April 15, 1950, was repurposed as a submarine prototype because:
    • Technical challenges
    • Darkening relationships with the USSR
  • Ended up as the S1G, the prototype for the USS Seawolf
  • Large dome in NY remains
The Knolls Intermediate Power Breeder

The Knolls Intermediate Power Breeder (AEC)

Aircraft Nuclear Power Program

The HTRE-2 nuclear-heated jet engine

An actual test of a nuclear-powered jet engine in Idaho, called HTRE-2 (photo by me)

ARE

Aircraft Reactor Experiment

The Army Nuclear Power Program

  • Intended to power remote areas
  • PM-1 in Wyoming
  • PM-2A in Camp Century ice base (Greenland)
  • ML-1 Truck-mounted mobile
  • SL-1 in Idaho
  • SM-1A Fort Greely, Alaska
  • MH-1A floating barge in Panama
  • PM-3A in Antarctica
Map of Army nuclear reactors

The Army had true shippable microreactors

ML-1

ML-1 field test in Idaho

PM-1 being loaded onto a C-130

PM-1 being sent to Wyoming

CRITICAL ASSEMBLIES

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What is a critical assembly?

  • Minimal assemblage of fuel/coolant/moderator/control
  • Used to check basic nuclear characteristics against theory
  • Room temperature
  • Very low power (<10 W)
  • Often reconfigurable
  • Often used to support final design (e.g. rod worth curves)
  • Diminished need due to robust nuclear data and radiation transport codes

REACTOR EXPERIMENTS

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What is a reactor experiment?

  • Small scale nuclear-powered test
  • Cutting edge of technology
  • More complex than a zero-power critical assembly
  • Appreciable, but not high, power (< 10 MW)
  • Smaller/simpler than full system prototype
  • Sometimes has power conversion, but usually not
  • Cheapest way to show that a certain combination of core materials can work at power

Homogeneous Reactor Experiments (HRE) 1 and 2

  • Fluid fuel: uranium sulfate
  • Ran at ORNL in 1952
  • Expected to be simple and compact
  • Kept burning holes in containment
  • Holes were repaired, but concept was abandoned

BOiling water ReActor eXperiment (BORAX) 1-5

  • Is it possible to operate a core with boiling water?
  • Experiments ran at National Reactor Testing Station, starting in 1953
  • BORAX-I exploded at end of life (to test limits)
  • After small success with BORAX-1 larger BORAX-2 was built.
  • Re-designated BORAX-III with the addition of a turbine
  • Powered town of Arco, ID
  • Formed basis for BWRs

Aircraft Reactor Experiment (ARE)

  • Molten salt fluid fuel
  • Ran at ORNL in 1954
  • Expected to be compact and very high power density
  • Intended for nuclear-powered bomber
  • Ran for 4 days
  • Got leak, they blew fission products into the forest to the south

Heat Transfer Reactor Experiments (HTRE) 1-3

  • High temperature reactors coupled to jet engines in 1956
  • Developing nuclear-powered flight for long-range bomber
  • Ran in Idaho
  • Never flew
  • Can be seen in parking lot of EBR-1 museum

Sodium Reactor Experiment (SRE)

  • Sodium metal coolant, graphite moderator
  • Started in 1957
  • Expected to make economical power
  • Low pressure, high temperature, LEU fuel
  • Near LA
  • Prototype for Hallam reactor
  • Suffered core melt

Organic Moderated Reactor Experiment (OMRE)

  • Terphenyl coolant/moderator
  • Low pressure, high temperature, low corrosion, chemically inert
  • Ran at the NRTS in 1957
  • Expected to lead to low-cost commercial power

Ultra-High Temperature Reactor Experiment (UHTREX)

  • Helium gas-cooled reactor with UC₂ fuel coated with 3 layers of pyrolitic carbon
  • 2400 °F coolant temperature
  • Elemental carbon structure
  • Run at LANL from 1959-1971
  • Spin-off of Project Rover (nuclear rocket)
  • Rotating core loader
  • Un-clad annular porous carbon extruded fuel elements
  • Remote online refueling

Los Alamos Power Reactor Experiment (LAPRE-1 and 2)

  • High-pressure uranyl phosphate solution fuel
  • Highly-enriched uranium
  • Would have made 10-50 MWe compact reactors
  • Remote power for military bases
  • LAPRE-II started in 1959

Los Alamos Molten Plutonium Reactor Experiment (LAMPRE)

  • Molten Plutonium-Iron alloy fuel in tantalum tubes
  • Developed for fast breeder reactors
  • Ran in 1960
  • In-situ reprocessing

Gas-Cooled Reactor Experiment (GCRE)

  • Nitrogen-cooled
  • Supported the truck-mounted Army reactor
  • 1962

Bare Reactor Experiment, Nevada (BREN)

  • Lifted the ORNL Health Physics Research Reactor
  • Went up 1500-foot tower
  • 1962
  • A small Japanese village was built at the bottom
  • Tower provided information on neutron dose from elevated sources on tissue

NERVA Reactor Experiment (NRX)

  • Nuclear-powered rocket for space propulsion
  • Liquid-hydrogen cooled
  • NRX-A2 ran in 1964 for 6 minutes, and then 20 minutes

Molten Salt Reactor Experiment (MSRE)

  • Follow-up from the ARE
  • Focused on commercial power potential
  • Ran at ORNL in 1965
  • Formed basis for Molten Salt Reactors

The Quest For

ECONOMICAL POWER

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Atoms for Peace

A reactor in Geneva

We flew a reactor to Geneva

Shippingport

  • Congress was concerned about falling behind UK and USSR in power reactors
  • Rickover was put in charge b/c he could get stuff done
  • Dev program tried various fuels, settled on UO₂ with zirconium clad
  • Nuclear design by Bettis: HEU seed with NU driver
  • Fierce opposition b/c LWRs are inefficient with uranium resources
  • Had 2 B&W U-tube SGs and 2 Foster Wheeler straight-pipe SGs
  • Critical on December 2, 1957, cost $72.5M
  • Open design: all details published at Geneva 1958
  • Operated reliably
  • 10x more expensive than an equivalent fossil plant

Construction of a boiler chamber in the Shippingport PWR (from Library of Congress)

The Power Demonstration Reactor Program (PDRP)

  • Major AEC program started in 1955
  • Focus on advanced reactors most likely to achieve economic parity with coal
  • Government benefits:
    • waive fuel usage fees
    • perform pre-construction R&D
    • subsidize post-construction R&D
  • Intended to inspire private investment in nuclear
  • Three main rounds
  • Round 1: applicant would fully fund, construct, and operate nuclear and turbine island
  • Round 2: focusing on rural utilities, applicant built turbine island; AEC built nuclear island and offered option to purchase

The Yankee Rowe PWR

  • Consortium of New England utilities came together to propose
  • AEC selected under round 1 PDRP
  • Constructed by same team as Shippingport
  • On time, on budget
  • Operated beautifully

The Fermi-1 Sodium-cooled Fast Reactor (SFR)

  • Consortium of 23 utilities came together to propose
  • AEC selected under round 1 PDRP
  • More expensive than expected
  • Many operational challenges
  • Core melt and recovery
  • Shut down early due to poor economic performance

The Hallam Sodium-cooled Graphite-moderated Reactor (SGR)

  • Small utility in Nebraska
  • SGR concept appeared highly likely to be economical (low pressure, high temperature, low enriched fuel)
  • Literally shared a turbine with a coal plant
  • Leaking moderator cans caused operational outages
  • Utility declined to purchase
  • Coal plant is still there today
  • Cool historical films online

The Elk River Reactor, a small rural BWR in Minnesota

  • Proposal from Rural Cooperative Power Association with newcomer constructor
  • Many arguments with contracting
  • Municipal reactor in tiny town
  • Natural circulation
  • Entire control system replaced (single channel -> multi)
  • Reactor vessel reworked
  • Plant ran for 4 years, but was leaking primary coolant
  • When shut down to find problem, repairs deemed too expensive
  • Plant was decommissioned, converted to fossil in 1968
  • Building torn down around 2021

The Piqua Organic cooled/moderated reactor in Ohio

  • Municipal reactor in tiny town
  • Town initially hyped about it: dubbed itself the Atomic City
  • Another promising concept: low pressure, high temperature
  • Lots of operational and reliability challenges
  • Town declined option to purchase
  • Shut down early

Pathfinder Superheat BWR in Sioux Falls, SD

  • Built near Sioux Falls, SD
  • Consortium of investor-owned utilities
  • Goal was to get practical experience operating a nuclear plant
  • Longest run was 30 minutes
  • Ran for about a year, had accident in 1967, decided to abandon
  • Now a 327 MWe gas plant runs on the site

Carolinas-Virginia Tube Reactor (CVTR) in Parr, SC

  • Third-round PDRP reactor, proposed by group of 4 utilities
  • First US power reactor with heavy water
  • 1.5-2% enriched uranium, 65 MWe
  • Produced saturated steam, which was fed into an oil-fired superheater
  • Operated from 1963-1967 with 78.14% availability
  • Co-located with coal AND hydro plants!
  • AEC paid $11.3M, industry paid $32.1M
  • Power was uprated, but 3 of 4 test assemblies failed

Co-located coal, hydro, and nuclear, thought to be unique worldwide.

BONUS Superheat BWR near Rincón, Puerto Rico

  • Advanced BWR: Increased thermal efficiency
  • Allowed use of off-the-shelf turbine
  • Increased corrosion and fuel failures
  • Costly repairs and modifications
  • Technical difficulties led to shut down in 1968
  • Digitized film on Youtube

Peach Bottom High-Temperature Gas-Cooled Reactor (HTGR) in PA

  • Unsolicited proposal by Philadelphia Electric Co. and other utilities
  • Ran from 1967 - 1974
  • First HTGR in USA
  • 37.2% thermal efficiency
  • 538 °C superheated steam at 10 MPa
  • Capacity factor 74%
  • Uneconomical to operate alongside GW-scale neighboring units because it was too small
  • Major retrofit was required to meet revised safety criteria

Big Rock Point high power density BWR in MI

  • Joint proposal from Consumers Power and GE in 1959
  • Fun promotional film ft. Ronald Reagan
  • World's first direct cycle, forced circulation, high power density BWR
  • Constructed in 29 months for $27M
  • Ran beautifully, shut down in 1997
  • 9 miles from my mom's house

La Crosse 50 MWe BWR in Wisconsin

  • Co-located with coal-fired Genoa Station #3
  • Forced-circulation, direct-cycle BWR
  • Constructor, Allis-Chalmers, struggled to deliver it due to various problems; was initially 4 years late
  • Contracted under 2nd round terms, though far past deadline (1961)
  • Expected to give useful technical info about medium-sized BWRs
  • Ran until 1987, when it was deemed too small to compete economically and decommissioned

San Onofre 375 MWe PWR in California

  • Southern California Edison-Westinghouse joint proposal
  • More than 2x the size of Yankee
  • Forced-circulation, direct-cycle BWR
  • An extra containment was built around the dome later
  • Ran well until 1987, when it was deemed too small to compete economically and decommissioned

STATUS

of nuclear power

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In 2022, nuclear fission made:

  • 4.2% of world energy
  • 10% of world electricity
  • 22% of US electricity
  • 55% of US low-carbon electricity

There are ~437 power reactors in operation (Carbon Brief)

Global capacity changes (Carbon Brief)

France went all-in on nuclear (@whatisnuclear)

We've gotten extremely good at running nuclear plants

Fraction of the time the plant is running at full capacity (whatisnuclear.com)

Nuclear plants can load follow at around 40 MW per minute!

Technical and Economic Aspects of Load Following with Nuclear Power Plants (OECD-NEA)

Nuclear plants can load follow at around 40 MW per minute!

Technical and Economic Aspects of Load Following with Nuclear Power Plants (OECD-NEA)

Barakah: 4 APR-1400s in UAE

  • Started with proven design
  • Brought in Korean workforce
  • Went from 0 to APR-1400 in 10 years
  • Now offering world's first green certificates for nuclear-powered aluminum plant

Used with permission from @AngelicaOung

Hualong One

  • "China Dragon 1"
  • Developed by CGN and CNNC
  • 3-loop PWR
  • Approved by European Utility Requirements and UK GDA
  • 5 operational, 11 under construction as of Jan 2024
  • ~5 years to construct

Hualong One CC-BY-4.0 Ji Xing

VVER-1200

  • $1,200/kW overnight construction cost
  • 54 month construction time
  • 34.8% net thermal efficiency
  • Being exported broadly
  • Foreign projects often financed by Russian govt

Manufacturing a VVER-1000 RIA Novosti Archive CC-BY-SA 3.0

Westinghouse AP-1000

  • Up-rated from original AP-600 design for economy of scale
  • Vogtle units 3 & 4 first nuclear plants to start construction in US since 1978
  • Boondoggled
  • Unit 3 entered commercial operation in 2023!
  • Construction started in 2013
  • Related VC Summer project cancelled, riddled in scandal

Vogtle Unit 3 (NRC)

ADVANCED REACTORS

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What advances have occurred?

  • The existing fleet gained operational experience. Next-generation models of the same type incorporated the lessons.
  • World energy context changed enough for previous non-water concepts to gain new interest
  • New technology was developed that can be incorporated into new designs

Advanced reactors today intend to solve contemporary problems

  • Natural safety without backup systems
  • More practical to finance (smaller)
  • Decarbonize hard-to-decarbonize sectors
    • Industry
    • Shipping
  • World-scale million-year+ sustainability (breeding)
  • Waste processing/reduction

But...

  • There are lessons to be learned in initial construction and scaling
  • New reactor development is hard and slow

A small reactor (ANL)

Advanced water-cooled reactors

Based on proven, well-known technology

  • Advanced large LWRs
    • Modular construction
    • Simplified systems
    • 72 hours without backup power
    • Digital instrumentation and control
    • ABWR, AP-600, AP-1000, APR-1400, Hualong 1, VVER
  • Small water-cooled reactors
    • Modular delivery and/or construction
    • Depends on economies of mass production exceeding economies of scale

An AP1000 advanced reactor (Westinghouse)

Fast-neutron reactors

Reactors that don't include a moderator

Pros

  • World-scale sustainability
  • Waste processing/reduction
  • Natural safety
  • High thermal efficiency
  • Industrial heat

Cons

  • Higher fissile concentration
  • Chemically reactive coolants
  • Extra costs from extra coolant loops
  • Plutonium scares people

Fast reactor history (adapted from Walter, Fast Breeder Reactors)

Breeder reactors are necessary in the long run

Breeder reactors are as renewable as anything else (whatisnuclear.com)

Thorium reactors

Breeder reactors that don't need fast neutrons

  • Plentiful in India and China
  • Used in Indian Point initial core
  • Works well with fluid-fuel reactors
  • China about to turn on a new experimental Thorium Molten Salt Reactor called TMSR-LF1
  • Does not completely eliminate proliferation or waste issues

A fluid fueled reactor (ARE)

Fusion Power Plants

  • Much less radioactive waste
  • No afterglow heat to cool
  • Many highly-funded startups catching headlines
  • Extremely challenging physics
  • Unknown power conversion
  • Often necessitates tritium breeding
  • Often a powerful neutron source
  • Worth investigating, but lets not rely on it

NUCLEAR STARTUP COMPANIES

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Nuclear Startups

Characteristics:
  • Speculative private funding
  • Disruptor vibes: started by outsiders without nuclear industrial experience
  • No existing revenue at the start
  • Generally touting a revolutionary idea
  • Mysterious: Lots of hype, secrecy, NDAs, patents
  • Typically (but not always!) seeking government funds
  • TED talks
  • Picture of core with person standing next to it, no shielding
Early examples:
  • Tri-Alpha Energy (1998)
  • General Fusion (2002)
  • NuScale (2007)
  • Hyperion (2007)
  • TerraPower (2008)
  • X-Energy (2009)
  • Helion (2009)
  • Transatomic (2011)
  • Flibe (2011)
  • Terrestrial (2012)
  • Oklo (2013)
  • ThorCon (2015)
  • Kairos (2016)
  • Holosgen (2017)

Advanced Nuclear Worldwide

Third Way map

TerraPower

  • Originally focused on Traveling Wave Reactor
  • High-burnup fuel offers a path to breed without reprocessing
  • Fast neutrons, radiation and corrosion resistant high-temperature fuels/materials
  • TWR collaboration in China banned by DOE in 2018
  • TWR capabilities being approached via the Natrium SFR project, which is also coupled to thermal energy storage in WY a few miles from coal plant
  • Natrium is 1 of 2 primary awardee in DOE's Advanced Reactor Demonstration Program
  • Other projects: Fluid fuel molten chloride salt reactor (doing a reactor experiment!), medical isotopes

Site work for Natrium in WY (Bechtel photo)

X-Energy

  • Bringing the HTGR back to the USA
  • Xe-100 is a small modular pebble-bed HTGR with highly robust TRISO fuel
  • Targeting the normal HTGR things: process heat, high thermal efficiency
  • Moved partnership from WA to Dow Chemical in Texas
  • Xe-100 is the 2nd primary awardee in DOE's Advanced Reactor Demonstration Program
  • Failed $2B merger with Ares Acquisition Corporation Oct. 2023
  • Laid off ~20% of staff 2 weeks later

Xe-100 render (X-energy image)

NuScale

  • Small Modular PWR, founded in 2007
  • Started as professor's project at OSU
  • Integral power modules co-located in giant safety-grade swimming pool
  • Awarded a design certification by the US NRC in 2020!
  • Originally up to 12 50 MWe modules in one building, uprated to 70 MWe for 'better economics' (?)
  • Obtained well over $1B in federal funding since 2007
  • Partnered with consortium of small non-nuclear utilities
  • Consortium broke down after cost estimates tripled in 2023
  • Laid off 30% of staff in January, 2024

NuScale Power Module (CC-BY-SA 3.0 NuScale)

Oklo

  • Microreactor based on EBR-2 SFR
  • Own/operate model with PPAs
  • They plan to recycle
  • Used to be heat pipe cooled, now unclear
  • Submitted to NRC, but rejected due to lack of answers to RAIs
  • Funding lead by Sam Altman (of OpenAI fame)
  • Announced going public via Altman's SPAC mid-2023, deal expected early 2024

Oklo co-founders in The New Fire

Transatomic

  • Molten salt reactor with ZrH moderator started in 2011
  • Claimed to run directly on LWR discharge waste
  • Lots of press, keynotes. Co-founder made Time 30 under 30
  • In 2016, a MIT professor made a homework problem showing it's impossible
  • Pivoted, but reputation damage was done
  • Funding dried up
  • They open-sourced their design and closed down in 2018

WHAT ABOUT BOONDOGGLES?

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Historical construction costs (Lovering, 2016)

The UAE just built 4 large LWRs (IAEA, 2021)

Project Delivery is key

  • Difference in good vs. bad project dwarfs design particulars
  • France and S. Korea show us how to do it: standardization
  • Reactor assembly line
  • Shipyard-constructed reactors (see Offshore Power Systems)
  • Suggestions to reduce cost

    • Complete detailed design prior to construction
    • Use proven supply chain and skilled workforce
    • Incorporate manufacturers and builders into design teams early
    • Appoint single primary contract manager with experience
    • Use contract structure that aligns all actors with project success
    • Enable a flexible regulatory environment that can accommodate changes quickly.
    • Do more serial manufacturing of standardized plants
    • Use inherent and passive safety features
    • Incorporate CO₂ into the cost of energy
    • Governments should establish reactor sites where companies can deploy prototypes
    • Governments should fund prototype testing and commercial deployment via licensing cost share, R&D cost share, technology milestone funding, and production credits for successful demonstration of new designs

    The Future of Nuclear in a Carbon-Constrained world (2018)

    Concluding thoughts

    • We have built all kinds of reactors!
    • LWRs out-performed many other types at first
    • Real issues in financing and construction performance exist
    • Changing moderator/fuel/coolant alone is not a good strategy
    • There are many nuclear startups in fission and fusion
    • Quite a few of them are struggling
    • We must improve delivery to survive!
    • Incorporating project delivery lessons into any project is key

    THANK YOU!

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