TRACE: TRAC/RELAP Advanced Computational Engine NRC Reactor Transient and LOCA Analysis

TRACE: TRAC/RELAP Advanced Computational Engine
TRACE Tall.pdf
1/19/06
NRC Reactor Transient and LOCA Analysis
4:21:49 PM
U. S. Nuclear Regulatory Commission, Washington D.C.
Vision and
Visionand
Long
Long Term
Direction
TRACE Support for 50.46 Break Size Redefinition
Modeling Features
Term Direction
Modeling Features
Able
to
Model
All
Reactor
Designs
“To have the capability
to
perform
T/H
safety
analysis
in
“To have the capability to perform T/H safety analysis in the
Automatic sorting of control blocks, signal
Additional Component Types
future that
allows
for solutions to theto
full spectrum
the future that allows
for
solutions
the offull spectrum
variables and trips
Jet Pump (JETP)
important nuclear safety problems in an efficient and effective
of important nuclear
safety
problems
in an efficient and Steam Separator
manner,
taking complete
advantage of state-of-the-art
Enhanced
input checking
(SEPD)BWR Channel Features
n
Modern
v
Automatic
sorting
of
control
blocks,
modeling, hardware,
and softwareadvantage
capabilities.”
effective manner, taking
complete
of state-of- Turbine (TURB)
v
Partial
length
fuel
rods
signal
variables
and
trips
RELAP5, TRAC-P, and TRAC-B Input Deck
We must be able toand
do more
with less resources:
the-art modeling, hardware,
software
capabilities.” Feedwater Heater (HEATR)
Containment
(CONTAN)
v
Square, cross, and round water
v
Enhanced input checking
Conversion
LESS: We must be able to reduce and consolidate
Fuel Channel (CHAN)
n
RELAP5,
TRAC-P,
and
TRAC-BInput
rod
geometries
personnel resources needed for solving any given
Co-located Heat Structure (HTSTR)
TRACE Project Goals problem and for maintaining code capability by
Additional
Working
Fluids
(H
O,
D
O,
Air,
N
,
2
2
2
v
Ray-traced
Deck Conversion
Radiation Enclosure
(RADENC)radiation view factors
developing and/or improving:
He, Na, PbBi)
Power
(POWER)
Ease-of-use
We must be able to reduce and consolidate personnel resources needed for solving any
n
Extended Component Features
n
Additional Working Fluids (H2O, D2O,
Speed
Fluid Power (FLPOWER)
given problem and for maintaining code capability
by developing and/or improving:
Robustness
v
Additional valve and pump types
He, Na, PbBi)
Air, N2, Support
Single Junction
(SJC)
Generalized
for Coarse-Grained
Flexibility
Exterior Code
Coupling
vEase-of-use
and Coupled-Code
v
Active pressure boundary condition Parallel
n
Generalized
Support forComputations
Coarse-Grained
Maintainability/upgradability
Component
(EXTERIOR)
vSpeed
v
Spherical heat structure geometry
Parallel and Coupled-Code Computations
MORE: We must be able to accommodate the new
SETS & Semi-Implicit Numerical Schemes
vRobustness
challenges and demands for best-estimate T/H
v
New
signal
variable,
control
block,
n
SETS
&
Semi-Implicit
Numerical
Schemes
Advanced
BWR
Channel
Features
analysis coupled to other related capabilities:
vFlexibility
Partial length
rodstrip types
Accuracy
n
User-Defined
Matrix
Solvers
fueland
User-Defined
Matrix
Solvers
Square, cross, and round water rod geometries
Flexibility
vMaintainability/upgradeability
n
1D&3D Kinetics (through PARCS
Maintainability/upgradability
Ray-traced radiation view factors
Simplicity
1D & 3D Kinetics (through PARCS coupling)
coupling)
We must be able to accommodate the newExpanded
challenges
and
demands for best-estimate
scope of
capabilities
Extended
Component
Features
Quality assurance
n
Usability
Enhancements
n
Advanced
1D
&
3D
Level
Tracking
T/H analysis coupled to other related capabilities:
Advanced
1D
&
3D
Level
Tracking
Additional valve and pump types
vAccuracy
v
Command
line argument support
n
ASME Steam Tables
Active pressure
boundary
condition
Trace
Species
Tracking
Additional heat
structure
boundary
conditions
vFlexibility
v
Extended
TRAC-B-style
output
n
New
Reflood
Model
Spherical heat structure geometry
vMaintainability/upgradeability
Improved
n
Improved
Choked Flow Model
New signal v
variable,
controlcode
block,robustness
and trip
ASME
Steam
Tables
Historical Perspective
vSimplicity
types
v
Platform-independent graphics and
n
Enhanced User-Defined Material Tables
on 4 T/H codes
vExpanded scopeNRC
ofrelied
capabilities
New Reflood Model
dump
files
PWR
Usability
Enhancements
vQuality assurance RELAP5
SBLOCA and transients
argument support
Command line
TRAC-P
LBLOCA
Improved Choked Flow Model
BWR
RAMONA
TRAC-B
3D Kinetics and stability
LOCA’s and transients
Historical Perspective
Over time the differences eroded but coding and input
varied substantially
Extended TRAC-B-style output
Improved code robustness
Platform-independent graphics and dump files
Modern Architecture
n
NRC relied on 4 T/Hcodes
Old coding language and procedural style
Large container array
vPWR
Archaic memory saving schemes (bit-packing)
w
RELAP5 ‹ SBLOCA and transients
Identified modeling deficiencies for the same phenomena
w
TRAC-P ‹
LBLOCA
Architectural and modeling improvements required to
vBWR
ameliorate the limitations
NRC would have to expend 4 times the resources to
w
RAMONA ‹
3D Kinetics and stability
continue making improvements to 4 separate tools
w
TRAC-B ‹
LOCA’s and transients
Continue to support old technology or invest in new
Evolve from existing code base or “develop from
scratch”?
n
Decouple Computational Engine
from Input Processor
‹
Decouple Computational
Engine
SNAP System
Model Database
n
The suite was developed in the 70’s
and 80’s and does not take advantage
Evolve!
Always have a running product
of modern technology
Takes advantage of current knowledge centers
vOld coding language and procedural style
vLarge container array
vArchaic memory saving schemes (bit-packing)
n
Identified modeling deficiencies for the same phenomena
SNAP
TRACE Input
Processing
3D Neutron
Kinetics
TRAC-B
ASCII
Input
Platform Independent
Binary File
Interprocess Message
Passing Service
Component 1
Component 2
Solution Scheme
Component 1
Component 2
Component 3
Developmental Assessment
Selection of physical models that provide the simulation
fidelity of TRAC-B and RELAP5 without degrading that of
TRAC-P for all targeted applications
TRACE_1A.indd 1
Component 3
Component 1
Component 2
Component 3
Component 1
Component 2
Component 3
FricIF
(sets fluid conditions)
TRACE
{component type,
void fraction,
phase velocities,
fluid properties}
Interfacial
Drag
Module
Interfacial Drag
Coefficient
IntFr
(provides interface)
(etc.)
Horizontal
Pipe
n
XML-Based Automated
Generation
of
Source
Code
XML-Based Automated Generation of
Vertical
Pipe
Accumulator
Bubbly/
Slug
Pressurizer
Annular/
Mist
Transition
Slug
Fraction
Profile Factor
Bubble Diameter
table(1)%to = table(1)%from
Fluid Data
alpn
tln
tvn
New TRACE Physical Models
Transfer Table
table(1)%from table(1)%to
table(2)%from table(2)%to
table(3)%from table(3)%to
n
The ESBWR passive safety systems have strong coupling between the reactor
and the containment.
n
ECCS System
v
Relies on depressurization like operating BWRs
v
Gravity driven cooling system (GDCS) to refill reactor system after blowdown.
n
Decay Heat Removal System
v
Large passive tube condensers (PCCS) to remove decay heat in long term cooling.
Data Flow
Film condensation models appropriate for modeling tubes and containment walls have
been added to TRACE.
TRACE Assessment for ESBWR
n
Separate Effects Test Assessment
v
Void fraction and level swell
v
Tube condensation
v
Flat plate condensation
n
Integral Test Assessment
v
FIST BWR full pressure blowdown
v
PUMA late GDCS to long term cooling
v
PANDA long term cooling
www.nrc.gov/reactors ...
Current Status
Slug
Bubble Drag
Source Code
n
Efficient List-Driven Internal Data
Efficient List-Driven
TransferInternal
Mechanism ‹
Bethsy Test 9.1B (ISP-27) TRACE Simulation
n
Increasing containment spray setpoint or relying on operator action is
feasible for LOCA with break sizes up to SI (cold leg) and PSL (hot leg)
v
Containment design specific
ESBWR Accident Phases
Low-Level Object-Based Representation of
Physical Property Evaluation Scheme
RELAP5 functionality
Input deck
processing knowledge centers
w
Takes advantage
of
current
R5-specific topology and modeling features
Component 2
Calculational Flow
Data Flow
Calculational Flow
Component 1
Component 3
Bubbly
n
Evolve from existing code base or “develop from scratch”?
RAMONA functionality
vEvolve!
Recovered with PARCS (coupled to TRACE)
w
Always have a running product
Flow Modified for
Parallel Calculations
Previous TRACE Calculational
and Data Flow
n
Architectural and modeling improvements required to ameliorate the limitations Object-Based Architecture
n
Object-Based Architecture ‹
Modernization
vNRC would have toTRAC-P
expend
4 astimes
the
resources to continue making
selected
basis for
consolidation
modifications
to take advantage of F90
improvements to 4Architectural
separate
tools
features
Input deck processing
BWR-specific topology and modeling features
n
Increasing EDG start up time has small impact on PCT results
v
Results sensitivity to loop seal clearing is a known phenomena
and is independent of delay time.
v
DEG mitigation not considered.
Computational
Engine
TRAC-P
ASCII
Input
Consolidation Stages
TRAC-B functionality
n
Continue to support old technology
or invest in new technology?
ROSA SB-CL-18 (ISP 26) Assessment
Conclusions
ESBWR Passive Safety Systems
Other Support
Applications
RELAP5
ASCII
Input
from Input Processor
n
Parallelizable Flow Logic and
Parallelizable
Flow Logic
and
Solution
Scheme
‹
n
The TRACE code is under development, but significant assessment has been performed with recent code versions.
n
Applicable integral assessment cases include:
v
ROSA SBLOCA IETs (6 tests)
v
BETHSY ISP-27
TRACE Support for ESBWR Design Certification
technology?
n
Over time the differences eroded but coding and input varied substantially
n
Small Breaks
2”, 3”, 4”, 6” breaks
n
Transition breaks
SI, SI + 20%, SI – 20% , PSL
n
Emergency Diesel Generator (EDG) startup
delay times of10 seconds and 60 seconds
TRACE Assessment
Enhanced User-Defined Material Tables
Modern
Architecture
Modern Architecture
The suite was developed in the 70’s and 80’s and does not
take advantage of modern technology
W 412 Standard Plant
Heat Structure Data
alpn
n
New film condensation models have been added and are being assessed.
n
Integral test assessments are in progress.
n
Plant calculations are in progress.
tln
tvn
Data Transfer Mechanism
2/15/06 3:54:13 PM