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Investigation into the Viability of a Passively Active Decay Heat Removal System In ALLEGRO
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Investigation into the Investigation into the Viability of a Passively Active Viability of a Passively Active Decay Heat Removal System In Decay Heat Removal System In ALLEGRO ALLEGRO Laura Carroll, Graduate Physicist Physics & Licensing Team, AMEC MSc Physics & Technology of Nuclear Reactors University of Birmingham
description
Investigation into the Viability of a Passively Active Decay Heat Removal System In ALLEGRO. Laura Carroll, Graduate Physicist Physics & Licensing Team, AMEC MSc Physics & Technology of Nuclear Reactors University of Birmingham. Introduction: My Project at a Glance. - PowerPoint PPT Presentation
Transcript of Investigation into the Viability of a Passively Active Decay Heat Removal System In ALLEGRO
Investigation into the Viability of a Investigation into the Viability of a Passively Active Decay Heat Removal Passively Active Decay Heat Removal
System In System In ALLEGROALLEGRO
Laura Carroll, Graduate PhysicistPhysics & Licensing Team, AMEC
MSc Physics & Technology of Nuclear Reactors University of Birmingham
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Countries we work in
Introduction: My Project at a GlanceIntroduction: My Project at a Glance
To assess a proposed modification of a safety feature of a new type of reactor
Use of RELAP5/MOD3
Steady State (normal operation)
Loss Of Forced Cooling (LOFC) transient (accident scenario)
ALLEGRO: experimental demonstration reactor for the Gas Cooled Fast Reactor
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1 0f 6 designs chosen by Generation IV International Forum (GIF)
Fast spectrum
Helium coolant
High outlet temperature
High power density
The Gas Cooled Fast ReactorThe Gas Cooled Fast Reactor
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ALLEGROALLEGRO
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Residual Heat; the need for constant Residual Heat; the need for constant cooling post shutdowncooling post shutdown
Once a reactor is shut down, its power will fall to approximately 7% of full power and then reduces exponentially thereafter.
The Decay Heat Removal (DHR) system exists to remove this residual heat from the reactor core.
It is currently activated after a reactor trip by a valve sequence
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Loss of Forced Cooling Transient: Existing Loss of Forced Cooling Transient: Existing DesignDesign
After 10s Blower begins to run down The reactor is shut down When mass flow rate reaches 3% of
its original flow, main loop valve closes
Simultaneously, DHR loop valves open
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Modification: Direct connection and Modification: Direct connection and Stratification of Upper PlenumStratification of Upper Plenum
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Stratification of the Upper PlenumStratification of the Upper Plenum
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Stratification of the Upper Plenum: LOFCStratification of the Upper Plenum: LOFC
Core outlet temperature as a function of time
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Maximum clad temperature in hot channel as a function of time
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ConclusionsConclusions
Results are not ideal
Clad temperatures not as terrible as initially feared
Stratification of Upper Plenum showed great improvement on previous modifications
Substantial Potential for future Research and Development in this area
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Further InvestigationsFurther Investigations
Develop a removable Decay Heat Removal system heat sink
Add a fluidic diode
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For more information…For more information…
A Technology Roadmap for Generation IV Nuclear Energy Systems Dec 2002 U.S DOE Nuclear Energy Research Advisory
Committee
http://www.world-nuclear.org/info/inf77.html
Vortex Diode Pumps: No Moving Part Pumping Systems, NuVision Engineering
http://www.nuvisioneng.com/uploads/VortexDiodeProfile.pdf
Thank you…Thank you…
Any Questions?Any Questions?
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Parameter Original Stratificationcore power (MW) 50.00 50
Total mass system (Kg) 11126.67 11055.25pressure lower plenum (Pa) 7090038.00 7090040.00pressure upper plenum (Pa) 7029872.00 7025060.00
core inlet temp (K) 535.76 494.80core outlet temp (K) 835.39 769.83
Mass flow out of average channel (Kg/s) 27.52 29.95Max clad temperature hot channel (K) 893.16 823.94Max fuel temperature hot channel (K) 1320.55 1255.54
DHR hot leg mass flow rate (Kg/s) 0.07 7.38DHR hot leg temperature (K) 835.38 769.82DHR cold leg temperature (K) 363.78 622.93
Mass flow rate main heat exchanger (Kg/s) 32.00 34.84Total main heat exchanger flux -50365542.00 -33683116.00Total DHR heat exchanger flux 0.13 -4668545.40
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Mass Flow rate through DHR hot leg and main heat exchanger (hx) as a function of time
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Mass Flow rate through core as a function of time
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Maximum fuel temperature in hot channel as a function of time
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1. Region of Blower run down
2. Establishment of Natural Convection
3. Natural Convection
LOFCLOFC resultsresults
