computational fluid dynamics for reactor design and...
TRANSCRIPT
Massachusetts Institute of Technology
NSENuclear Science & Engineering at MIT
science : systems : society
Computational Fluid Dynamics for Reactor Design and Safety-related Applications
Emilio [email protected]
web.mit.edu/newsoffice/2012/baglietto-better-reactors.html
STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
An Industrial/Research/Academic viewWearing multiple hats:
Massachusetts Institute of Technology
Assistant Professor of Nuclear Science and Engineering, Massachusetts Institute of Technology.
Deputy Lead TH Methods Focus Area, CASL – a US Department of Energy HUB.
Nuclear Industry Sector SpecialistCD-adapco.
Member of NQA-1 Software Subcommittee.
Disclaimer: the following slides are intended for general discussion. They represent the personal view of the author and not that of MIT, CASL or the ASME NQA-1 Software Subcommittee.
STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
Nuclear Industry Competitiveness CFD for Nuclear Reactor Design Leveraging the research/academia efforts
Review - State of the art and current challenges Where and why CFD Multiscale Applications CFD as Multi-physics platform
CFD for Safety Related Applications The US-NRC example Commercial Grade Dedication of Software Experience and Challenges
Contents
Emilio Baglietto - Nuclear Science & Engineering at MIT
Background 2011- present Assistant Professor of Nuclear Science and Engineering, MIT 2006-2011 Director Nuclear Application, CD-adapco 2004-2006 Research Associate, Tokyo Institute of Technology
20122009
PBM
R
2005
Emilio Baglietto - Nuclear Science & Engineering at MIT
Nuclear Industry Competitiveness
(since ICONE13 – 2005)
STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
CASL: The Consortium for Advanced Simulation of Light Water ReactorsA DOE Energy Innovation Hub forModeling & Simulation of Nuclear Reactors
Task 1: Develop computer models that simulate nuclear powerplant operations, forming a “virtual reactor” for the predictivesimulation of light water reactors.Task 2: Use computer models to reduce capitaland operating costs per unit of energy, ……
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STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
Licensing Time / O&M Cost
7
1 Core and core components
2 Upper Internals
3 Steam Generator Internals
4 Steam Lines
5 PRZ components
6 Pumps and seals
7 Flow mixing, fatigue, shedding
8 Stratification, hydrogen accumulation
Emilio Baglietto - Nuclear Science & Engineering at MIT
• Local T&H conditions such as pressure, velocity, cross flow magnitude can be used to address challenge problems: oGTRF oFADoDebris flow and blockage• The design TH questions under normal operating and accident conditions such as:oLower plenum flow anomalyoCore inlet flow mal-distributionoPressure dropoTurbulence mixing coefficients
input to channel codeoLift forceoCross flow between fuel
assembliesoBypass flow
• The local low information can be used as boundary conditions for micro scale models.
Model 1 Model 2
A “Typical” Multi-Scale ProblemFull-core performance is affected by localized phenomena
Emilio Baglietto - Nuclear Science & Engineering at MIT
STAR-CCM+ Platform for MultiphysicsHigh Fidelity T-H / Neutronics / CRUD / Chemistry Modeling
Petrov, V., Kendrick, B., Walter, D., Manera, A., Impact of fluid-dynamic 3D spatial effects on the prediction of crud deposition in a 4x4 PWR sub-assembly - NURETH15, 2013
Emilio Baglietto - Nuclear Science & Engineering at MIT
STAR-CCM+ Platform for MultiphysicsHigh Fidelity T-H / Neutronics / CRUD / Chemistry Modeling
Petrov, V., Kendrick, B., Walter, D., Manera- NURETH15, 2013
STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
Not only Fuel Related Applications 11
Mature Applications Fuel
Pressure Drops Crud (CIPS/CILC) Vibrations (GTRF)
System and BOP Transient Mixing Hot Leg Streaming Thermal Striping SG performance Cooling Towers Interference
Fuel Cycle and Beyond Design Basis Applications Spent fuel transportation and
Storage
Emilio Baglietto - Nuclear Science & Engineering at MIT
Multiphase CFD… better physical understanding
boiling heat transfer DNBvoid fraction
Emilio Baglietto - Nuclear Science & Engineering at MIT
CFD for Safety-Related Design and Analysis
CFD is undoubtedly becoming a fundamental instrument in the Safety Analyst Toolbox.
CFD offers a unique opportunity for improved physical understanding
Leads to more general applicability Reduced need for empirical
calibration, which means “lower costs!”
Challenge: Provide a path for application of CFD in
Safety Analysis. Assure that the process will capture all
“critical characteristics” of the application. Make the process “Applicable”.
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Emilio Baglietto - Nuclear Science & Engineering at MIT
Can we apply CFD to Safety-Related Design and Analysis ?
14
Let’s try to reformulate the question: Is there a process that is robust, flexible, and cost effective
allowing application of CFD to Safety-Related Design and Analysis.
Does the process guarantee confidence in the application of CFD.
Corollary: Is the application of CFD completely
different from that of system codes.. Is it more challenging. Is it more costly.
Emilio Baglietto - Nuclear Science & Engineering at MIT
Commercial Off-The-Shelf (COTS)
CFD is apt to rely on COTSGeneral Purpose CFD…
…reasons It has been heavily used by other industries with success. Requires very large investment for development. Inherits “experience” and verification practices. Allows leveraging a very large base of users for testing.
What are the requirements for use of COTS?
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STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
The fear of change … Changes from NQA-1-2008 to NQA-1a-2009 Part II, Subpart 2.7
Section 302 require application of: Part I, Requirement 7, Control of Purchased Items and Services and Part II Subpart 2.14, Quality Assurance Requirements for
Commercial Grade Items and Services
For acquisition of software that has not been previously approved under a program consistent with NQA-1 for use in its intended application.
Is it really that bad? Is it going to make it too costly to adopt COTS? Is adoption of COTS more challenging or more costly?
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STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
A realistic challenge Subpart 2.14 had not really been written for software, therefore
not a straightforward interpretation for an applicant. There was a need to provide a guidance for CGD of software
which would for example include.
NQA-1-2012 Non-Mandatory Appendix (NMA) Focused on dedication of Design and Analysis Computer Programs Aligns with each of the Sections of SP 2.14 and provides information
where the SP cannot be clearly interpreted as it applies to computer programs
Unique Definitions that apply to computer programs Limits application of Like-for-Like Omits Equivalency unless complete evaluation is possible
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Emilio Baglietto - Nuclear Science & Engineering at MIT
The process:Commercial Grade Dedication
U.S. NRC Regulatory Guide 1.28 Rev. 4, June 2010
NQA-1-2008 with NQA-1a-2009 addendum
NQA-1-2012 Non-Mandatory Appendix (NMA)
EPRI 2012 - CGD Guidance for Safety-Related Design and Analysis
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STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
NQA-1-2012 Non-Mandatory Appendix (NMA)CC Description Acceptance Criteria Method of VerificationHost computer operating environment
The manufacture and model number of the host assembly or computer hardware computer program is intended to reside. This critical characteristic is applicable to all computer programs.
Host computer operating environment criteria must match the purchase specification. This should include the manufacturer name and model from a supplier’s catalog. (e.g., Dell PowerEdge T110 Tower Server, IBM AIX & System, and Dell Precision T3500 Workstation, Siemens Simatic S7-400)
Verified through one or more of the following:o Inspection of receipt inspection
documentation (Method 1)o Inspection of test system operating
system identifiers. (Method 1)
Host computer operating system identifier
Vendor name, operating system version, service packs or patch identifiers that are needed for the computer to be executed. This critical characteristic is applicable to all computer programs.
Host computer operating system identifier must match the identifier in the vendor product list (e.g., Microsoft Windows 7, UNIX Operating System Version 5.1, B-5, and Yokogawa Pro-Safe-RS R2.01.00)
Verified through one or more of the following:o Inspection of receipt inspection
documentation (Method 1)o Inspection of test system operating
system identifiers. (Method 1)
Software Name
The full name of the software. It should be the same identifier as used for during the procurement/acquisition process. This critical characteristic is applicable to all computer programs.
Software name must match the product name from vendor catalog. (e.g., CFAST, Wolfram Mathematica 8, Monte Carlo N-Particle Transport Code System (MCNP5), Emerson valve Link, and Organic Concatenater)
Verified through one or more of the following:o Inspection of receipt inspection
documentation (Method 1)o Inspection of test system operating
system identifiers. (Method 1)
Software Version Identifier
The complete version identifier including any patches. This critical characteristic is applicable to all computer programs.
Software version identifier must match the product identifier from the vendor catalog that includes software name-major functional version, minor functional version. corrective revision (e.g., CFAST-05.00.01, Hotspot-02.07.01, Emerson valve Link-02.04-13, and Organic Concatenater-3.1b)
Verified through one or more of the following:o Inspection of receipt inspection
documentation (Method 1)o Inspection of test system operating
system identifiers. (Method 1)
STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
How does it apply to CFD4 Categories of Critical Characteristics Identification i.e., version, build date, release name, or part or catalog number
Physical physical media (e.g., CD, tapes, downloads, or remote access)
Performance/Functional required functionality of the computer program to perform its safety
function and the accuracy of its results Dependability (unique to computer programs) Evaluation to develop judgment regarding built-in quality Includes attributes related to the supplier’s software development
process such as review of the computer program’s lifecycle processes and output documentation, review of configuration management activities, testing and V&V activities, and other activities.
Emilio Baglietto - Nuclear Science & Engineering at MIT
Performance/Functional CCs
Item characteristics
Critical Characteristics for Performance/Functional
Item characteristics
Critical Characteristics for Performance/Functional
COTS CFD
Emilio Baglietto - Nuclear Science & Engineering at MIT
Striking a good balance
It is fundamental to balance the application of the Process and the Analysis Methodology.
Failures in applying CFD to Safety-Related Design and Analysis are related to incorrect use of the process.
Method
Failures are not unique to CFD, but it is a “common” failure mode.
Adoption of CFD for Safety-Related Design and Analysis requires the active contribution from CFD experts*.
Let’s look at 2 representative examples of Incorrect CGD of CFD Software for Safety-Related Design and Analysis
Emilio Baglietto - Nuclear Science & Engineering at MIT
“Faith in the box” failure Solving Navier-Stokes is just like solving another problem (e.g.
structural analysis).
Very personal view: the CGD guidelines are a very natural approach to support CFD.
The process will quickly become lighter and faster as the number of CFD applications grows.
V&V Support Routine
STAR Japanese Conference 2013CFD for Reactor Design and Safety-related Applications
A more challenging example…
The Flux Capacitor would most likely be considered a safety grade component.
SAR would need to include predictions of HTCs during all normal and off-normal operational conditions.
CFD provides an excellent method to support Safety-Related Design and Analysis.
Nuclear Powered DeLorean DMC-12
CFD
model of
Flux Capacitor
Emilio Baglietto - Nuclear Science & Engineering at MIT
Example of SAR
Is this sufficient / adequate ?
Validation of CFD applicability based on separate effects analysis: Flow in a Y – junction
2D Cavity Buoyant flow
Air tests for single tube from literature, HTC data available at representative Re.
Literature recommends K-w SST Model for better HTC prediction due to “superior performance in modeling the near wall region”.
Emilio Baglietto - Nuclear Science & Engineering at MIT
Validation example
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0.01 0.1 1 10
Nu
/Nu
0
Bo
Data of Easby (1978)
Data of Parlatan et al (1996)
CFD results are well within the uncertainty bounds. Good prediction of Buoyancy effect. K-w SST results are conservative. Sensitivity shows acceptable influence of turbulence models.
K-e modelK-w SST model
Is this sufficient / adequate ?
Emilio Baglietto - Nuclear Science & Engineering at MIT
0.3
0.5
0.7
0.9
1.1
1.3
1.5
0.01 0.1 1 10
Nu
/Nu
0
Bo
k-omega-SST Model (ACME CFD)
k-omega-SST Model (BCME CFD)
DBA conditions, flow reversal
CFD Model predict 2x higher HTCs at Bo=0.2 Did CFD fail? Was the Process Correct?
This is not looking good
Emilio Baglietto - Nuclear Science & Engineering at MIT
CFD Results – failure mode analysis
Low-Re k-e K-w SST
Velo
city
Turb
ulen
t Kin
etic
Ene
rgy
Emilio Baglietto - Nuclear Science & Engineering at MIT
How did we fail? Performance/Functional required functionality of the computer program to perform its safety
function and the accuracy of its results … Must account for effect of buoyancy on heat transfer. ..
Missing a fundamental critical characteristic.
The model equations do not have a buoyancy term for TKE and dissipation.
CFD – Code Manual
Gb ??
Emilio Baglietto - Nuclear Science & Engineering at MIT
Conclusions
Yes, it can be done and it has been done. The CGD process provides a robust and flexible framework
to adopt CFD for Safety Analysis. The CGD process requires rigorous assessment of the
“functionality of the computer program to perform its safety function and the accuracy of its results”.
For CFD this means understanding of the physical models and VUQ of the models on the intended application.
The CGD formalizes a process that is applied to all Safety-Related Design and Analysis.
Can we apply CFD to Safety-Related Design and Analysis ?