SMR Design #2 (IMSR) Flashcards by Missy Balachorek

IMSR stands for

itegral molten salt reactor

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MSRs are _____ fueled reactors

liquid fueled

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Flows between ___ and ____ to transfer heat to transfer _____ to a _______

a critical core
primary heat exchanger
heat
secondary “clean” salt

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___ temperature (__celsius) couples well to ___/____ with ____ efficiency (up to ___%)

high (700C)
to steam / gas brayton
high
(up to 50%)

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What is used to moderate

typically graphite
but fast spectrum concepts as well as using chlorides

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can be configured as ________ or _____ using ____ _____ Uranium

thorium breeders (MSR-Breeder)
simplified burners (MSR-Burner)
Low Enriched Uranium

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Related concept is ______

MSR-Cooled (FHR)

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Solid Fuels (TRISO) cooled with ___ which replaces ___ _____ ____

FLiNe salt
high pressure helium

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Advantages of Fluoride Salts
list all 8

-wide range of uranium and thorium solubility

-stable thermodynamically do not undergo decomposition

-have very low vapor pressure at operating temp

-with redox control, low corrosion for stainless or nickel based alloys used for circulating salt plumbing

-no adverse reactions with air/water

-excellent thermal properties

-transparent

-very high boiling points

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advantages of MSR - main 4

safety
reduced capital cost
long lived waste issues
resource sustainability and low fuel cycle

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advantages of MSR - safety
list 4

enhanced ability for passive decay heat removal

inherent stability from strong negative reactivity coefficients

low pressure and no chemical driving force

cesium and iodine relativity stable within fuel slat

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advantages of MSR -reduced capital cost
list 4

inherent safety simplified entire facility low pressure,

high thermal efficiency,

superior coolants (smaller pumps, heat exchangers),

no complex refuelling mechanisms

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advantages of MSR - long lived waste issue

ideal system for consuming existent transuranic wastes even msr-burner designs can see almost no transuranics going to waste

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advantages of MSR - resource sustainability and low fuel cycle cost

thorium breeders obvious but msr burners also very efficient on uranium use

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Liquid Fuel Affords Inherent Stability: Negative Temperature Reactivity Coefficients

___ feedback to a power and temp ___
values range up to -___pcm/C (pcm=10^-5 K)

negative
increase
-15

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Liquid Fuel Affords Inherent Stability: Very Low Reactivity control Requirements

online fuel makeup mean ____ with time

___ effects quite small as it bubbles out of salt
typical total shim requirements perhaps__% dk?K (5mk =500 pcm)

little reactivity change

xenon 135
0.5

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Liquid Fuel Affords Inherent Stability:Control Rods in many cases viewed as ___

-reactor power can be controlled by ___

core average temp stays _____, _____temp varies

-steam island can effectively ____

optional

amount of heat removed

const
input - output

drive reactor

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US Historic Timeline
first envisaged in _____

in ____ became leading candidate in well funded _________ (Successful test reactor operates at up to ____celsius)

in _____ to ____ MSBR/ _______.
-thought ___ were needed due to ___. thus ____ and ___ dominate US efforts

in ___ the falling of the political axe
program _____

1940s

1950s
aircraft reactor program
860C

1960-1970s
“Thorium Breeder”
breeders
uranium shortage
sodium fast breeder

1970s
cancelled

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aircraft nuclear propulsion program: initiated work on molten salt tech
from ______ to _____
$____ investment pioneering work including ________
________
_________
_________
__________
successful ___MWth aircraft reactor experiment in ____

1946-1961
$1B
- molten salt fuels
-liquid metal heat transfer
-light weight metals
-advanced I&C
-high temp corrosion resistant materials

2.5MWth
1954

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operating experience: MSRE successful demonstration
operated _____ to ____ at _____

design features
_MW ____ output
___fluid, simple ____ core design

fuels:
____
_____

_____ moderated

______ vessel and piping

achievements
first use of ______fuel
first use of ______fuel
____ refueling
____ full power hours

1965-1969 at ORNL

8MW
thermal output
single
bare

Fuels (see slide 8)

graphite
hastelloy N

U-233 Fuel
mixed U/Pu salt fuel
on line
>13000

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end goal of ORNL Program the graphite moderated molten salt breeder reactor (from _____ to _____)

____ to _____ breeder
___MWth for ____MWe
__ fluid with on site _____ to remove _____ and collect ______

Breeding ratio ____ _____ than sodium fast reactor but ______ loading meant comparable ___ year ___ time

___ rapidly removed to ____ losses to _____

____ power density giving __ year graphite lifetime leading to ______ replacement

1968-1976

thorium to U233
2250 MWth for 100MWe

single fluid
chemical processing
fission products
excess U233

1.06 smaller
low fissile
20
doubling time

off gas
lower
xenon

high
4
full core replacement

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Early msr outside US: france

significant program through 1970s similar to ORNL

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Early msr outside US: UK

modest efforts studying fast chloride systems

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Early msr outside US: india

expanding collaborations with ORNL , major PuF3 chemistry facilities built

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Early msr outside US:china

first reactor in china a zero power MSR

Early msr outside US:Russia

major program and only 1 continues well into 1980s (chernobyl led to cut back of most advanced reactor concepts)

generation IV Forum Goals: Sustainability 1

minimize and manage waste, reduce long term stewardship burden

generation IV Forum Goals list 6

sustainability 1 sustainability 2 economics 1 Economics 2 safety and reliability proliferation resistance and physical protection

generation IV Forum Goals: Sustainability 2

resource sustainability

generation IV Forum Goals: Economics 1

compete directly on cost with other energy systems

generation IV Forum Goals: Economics 2

finance risks similar to other energy systems

generation IV Forum Goals: safety and reliability list 3

1. excel in safety 2. core damage frequency 3. avoid offsite emergency response

major challenges of 1970's MSR Breeder Design ______ product removal ___ control _____ temp coefficients ( only weakly ___) use of highly _____ ____ in __/___ cycle ___ -___ management long term ___ or ____ damage ___ replacement operations

online fission tritium reactivity negative enriched uranium Th/U233 cycle off gas corrosion radiation graphite

why breeders? uranium is ____ even large fleet expansion will ____ at least in intermediate term msr burner approach of running of ____ solves many challenges last major work of ORNL in late 1970s was ___

abundant (quoted resources are only what is confirmed by expensive drilling, more exploration equals more resources. not require breeder operations low enriched uranium MSR bURNER THE DENATURED MOLTEN SALT REACTOR (DMSR)

Issues solved by MSR-Burner Approach list 4

fission product removal reactivity coefficients tritium control HEU Use and Proliferation

Issues solved by MSR-Burner Approach: fission product removal no need for _____ ____ ___ used over ____ with ___ ___ additions

salt processing fuel salts long duration periodic fuel

Issues solved by MSR-Burner Approach: reactivity coefficients have ____ ___ ____ of temp

superior reactivity coefficients

Issues solved by MSR-Burner Approach: tritium control tritiums ability to ____ makes it ____ able to avoid ___ or __ use to virtually eliminate ____ __,__,__and__ among low cost salts accomplish goals if ___ employed, blocks ___ access to ____

through hot metal a management challenge Li or Be triitium production NaF, KF, RbF and ZRF4 3rd nitrate salt loop tritium steam cycle

Issues solved by MSR-Burner Approach: HEU Use and Proliferation uranium always ______ (_____) STANDARD assay LEU ____ can be employed for _____ and _____ avoids need to construct new high assay lEU (HALEU) FACILITIES FOR ABOVE ______ needed by most other GEN IV systems __ content builds up to high __ and ____content and never ____ even if fuel eventually recycled can avoid all of ___ and ___issues

LEU (denatURED) <5% startup makeup fuel. avoids need to construct new high assay lEU ABOVE 10% enrichment Pu 240-242 separated thorium and thus U233

slide 20 : tritium management

remaining challenges are material related list 2

long term corrosion or radiation damage graphite replacement

long term corrosion or radiation damage ____alloys, ___and ___ perform well if _____control is maintained proving ___+ yr lifetime is challenge for __and ___

high nickel alloys, 316 and 304 chemistry 30+ yr reactor vessel and primary heat exchanger

graphite replacement ___graphite use gives very strong advantages ___ (__% enrichment LEU) makes ____virtually impossible protects vessel wall from __its lifetime however is directly related to___

unclad very low enrichment fuel 2% out of core criticality high neutron flux power density

integral molten salt reactor ISMR by terrestrial eng ____ design,____ %LEU startup and ___% LEU makeup integrates all ____systems into _____ ___yr replaceable core unit lifetime approach to _____ lifetime planned as ___ MWth (___MWe) ___m wide core unit for easy transportation alternate __ for low __ and ___approach ___ heat removal ____ w/out ___ ___ at forefront-cost innovation

msr burning design 2% <5% primary sealed reactor vessel 7yr graphite 442 MWth (195 MWe) 4.1m salt tritium new gas passive decay in situ w/out dump tanks safety

how imsr power plant works - see slide 23

imsr consists of 2 parts for efficient industrial use

ismr heat and power facility (non nuclear parts) ismr nuclear facility (nuclear systems)

ismr heat and power facility (non nuclear parts) supplies ___and ___for industrial end-user as a ____facility engineered to pair with ___ facility initially supplied with ___and ____ flexibility in design as regulated by ____ and ____

heat and power standalone facility nuclear facility natural gas and grid electric power (including wind and solar gen) industry construction codes and standards

ismr nuclear facility (nuclear systems) generates ____ from ____( in op regulates____ supply to back up role for ____ facility) transfers ___ to _____ facility modular and standardized design as regulated by ____and ___

high quality heat nuclear fission natural gas and grid electric supply heat and power facility heat to heat and power facility nuclear codes and standards

transformative power plant economics enables with iMSR list 3

molten salt lower CAPEX Higher revenue (see slide 25)

pragmatic innovation of ISMR __yr core unit replacements allows advantages of ____ __ carrier salt to avoid ____ similar fuel economy to ___ and planned evolution such as eventual use of ___ that can _____ ______ heat removal featuring ____circulation designed with _____coefficients for ____load following (____ not needed) and _____ ___ are used but not _____ soft spectrum allows___% startup and ___% standard assay makeup partial reuse of ______ minimizes ___

7 graphite moderation and simplifies vessel and HX quals inexpensive tritium production of LiF PWR LiF reduce this to small fraction passive decay closed cycle natural circulation strongly negative temp inherent control rods passive shutdown shutdown rods credited for safety 2% 4.95% fuel salt minimizes used salt volume

waste management: common sense is often better than innovation must be _____is proposing a _____(improved by _____) IMSR not picky - ability ____( makeup of ___ plus ___) Can close its ___ with aid of minor additions of ____ ____ from ___ or ___ can be consumed as part of makeup fuel straight forward ____ STILL _____PROCESSING and includes production of ____

clearly stated the IMSR once through fuel cycle direct partial reuse) to self consume own production of Pu in used fuel LEU plus recycled Pu own fuel cycle of LEU Pu from CANDU or LWR dry process NUCLEAR secondary streams

waste management: waste from conditioning on-site storage of _____ during facility lifetime is _____ ____ does have ____ solubility in water - not ideal for ______ ____ possible but specialized methods required _____ preferred option that offers most ____ durability - conversion _____ through ____technique of mineralization developed at ANSTO in Australia

used fluoride fuel not challenge fluorides salt low direct disposal options vitrification fluoride content geological glass-ceramic mix synroc

Synroc Basis (See slide 29)

review of world MSR Activities argued imsr leader in ___ space and all advanced reactors- clear leader in ______ euratom (france) decade long work on _______MSFR on _____ russia major program for ____(MOSART) specialized for _____ of minor actinides (AM, Np) to be co-located with an existing _____ to combine with ____ use for overall ______ france (CEA) looking at ___on ___cycle with similar goals of russia - focus on ___ destruction us - first new msr in western world likely very _____ at ACU china largest program begun in 2011 with____. already started operations

msr space raising or private financing fluoride salt fast thorium to U233 cycle fluoride fast system deconstruction PUREX facility MOX transuranic consumption chloride fast system U-Pu cycle plutonium small experimental reactor 2 small MWth experimental reactor

gen IV goals self assessment for IMSR : SUSTAINABILITY 1 ____sustainability - good ___ usage with future ability to evolve to ___or ___ needs no___bottleneck (there is one for ___needed for almost all other advanced reactors)

resource uranium fraction LWR or CANDU uranium resource or SWU high assay LEU

gen iV goals self assessment for IMSR : ECONOMICS 1 compete directly with other ___ - projections for nth of kind IMSR at __$/MWh highly competitive

energy systems 54

gen iV goals self assessment for IMSR : ECONOMICS 2 __ risk similar to other energy systems -projected facility costs are ___ current fleet relies on ___

finance ordinarily financeable. sovereign funding

gen iV goals self assessment for IMSR : SUSTAINABILITY 2 __and ___ waste and improve long term ____ -___,___ and ___ on par with___ per unit energy and superior to ___ -___ reuse minimizes____, ___ choice minimizes ___ - major player in __or___ consumption by ___has much attractiveness work towards conditioning ___to highly durable form for ____ work towards __ solutions for__alloys and ___

minimize and manage stewardship burden - fuel waste volume, mass and activity LWR CANDU -partial fuel salt reuse volume, carrier salt tritium production Pu or TRU consumption once through used fuel long term stewardship OPEX graphite alloys OFF GLASSES

gen iV goals self assessment for IMSR : safety 123 excel in __, ___, avoid of ____

saftey, core damage frequency, site emergency response

gen iV goals self assessment for IMSR : proliferation resistance and physical protection arguably the most ___ resistance and best ___of any reactor __require different approach but clear path and ___ of processing facilities

proliferation physical protection safeguards OPEX

liquid fuel affords inherent stability - 3 main

negative temp reactivity coefficients very low reactivity control requirements control rods in many cases viewed as optional

early msr programs outside us: countires

france uk india china russia

____uranium price means ____grade ores opened up as resource

higher lower

in full operation ISMR plant supplies ___ and __ energy from ___ with back up from ___ and ___

thermal and electric nuclear fission electric grid and natural gas

molten salt ____ very stable operates at ___ temp operates at ____ pressure ___ heat capacity ___binds and retains____ substantial ____ ___ coefficient of _____

thermally high atmospheric extremely high chemically fission products negative temp reactivity

LOWER CAPEX no ___ ___ systems, structures or components eliminates all active ___ ___ ___ for cooling allows substantial plant ____- allows ___ plant, supports extensive ____, ___ build time ___ finaceable

high pressure engineered safety systems simplification smaller modularity shorter more

Higher Revenue operetes at ___ temp __% greater ___ efficiency vis-a-vis all gen 3+ systems generates __% more kWh(e) refuelled once every __ years reduced ___ demands ___ maintenance demands

high 50 thermal 50 7 staffing lower

thermally stable molten salt IMSR design leads to ___ CAPEC and ___ power plant revenue

Lower HIgher

Synroc Basics capable of stabilizing____or ____ starting operation for OPAL reactor Moly 99 production _____ DOE Record of Decision made in favour for several wastes including _______but not approved by congress steps mechanically straightforward and engineered for _____ - waste mixed with ____to from minerals advantages in in superior leech rates and waste loading for ____ reduction

liquid or solid wastes liquid wastes weapons grade Pu full post contamination proprietary additives volume

april 2023 CNSC concluded "no fundamental barriers to licensing" the IMSR plant for commercial applications identified in VDR provides 1st step in licensing the IMSR plant for commercial sue

Milestone progress slide 31

gen ___ smr type

4 motlen salt

___megawatts-thermal molten salt fueled reactor

400

* It features a ____ sealed reactor vessel with ___, ___ and ____ all mounted inside a single vessel; replaced ____ at the end of its useful service life (__years)

completely integrated pumps heat exchangers shutdown rods completely 7

no dependence on _____intervention, __ components, ___ injection or their support systems such as electricity supply or instrument air in dealing with upset conditions

operator powered mechanical coolant