ITER Tritium Fuel Cycle Modeling
Scott Willms and Bill Kubic
Los Alamos National Laboratory
Fusion Nuclear Science and Technology Workshop
UCLA
August 2, 2010
Outline
• Tritium Processing modeling history• TEP modeling• Consideration of next steps
2
Tritium processing modeling history
3
Simplified ITER flow diagram
Example fusion fuel cycle modeling efforts
5
Code Period Code Base Institution(s) Type of code PurposeTBR-related FC model
Mid 1980’s Custom UCLA High-level, first-order differential equations
Estimate required TBR
Supercode Late 1980’s Custom ANL, LANL Scaling laws Cost and overall size
TSTA Model Late 1980’s Custom LANL Algebraic flow and reaction equations
Pressure/flow control
Dynsim 1980’s-1990’s Custom LANL-Japan Rigorous ISS ISS understanding and design
CFTSIM 1990’s Custom CFFTP Rigorous ISS ISS understanding and design
TRUFFLES 1990’s Custom UCLA-LANL High-level, modular fuel cycle
T inventory, FC design
TRIMO 1990’s-2000’s Custom CFFTP-UCLA-ITER-FZK
High-level, modular fuel cycle
T inventory, FC design (ITER)
ITER TEP 2006-2010 Commercial LANL-SRNL Medium-level, modular systems code
TEP design
Uses for tritium processing models
• Component design• System design• Parameter regression• Technology trade-off studies• Hazard characterization and analysis• Requirements determination• Control system development• Experimental development augmentation• Design documentation• Operator training
6
ITER TEP modeling
7
TEP process flow diagram
9
TEP modeling overview
• TEP model used for:– Component regression from experimental data
– Technology selection
– Component sizing
• TEP models include:– Component models
o Detailed understanding of component performance
– System modelso Overall process performance
10
Modeling tools relationship
Aspen Plus
Kinetic model data
Aspen property library
Basic flowsheet
data
User defined model
Aspen Custom Modeler
Steady state model
Aspen Dynamics
library
Custom TEP library
Aspen Dynamics
Dynamic model
11
TEP models completed
• Modules– Permeator (ACM)
– PMR (ACM)
– PERMCAT (stand-alone)
– Vacuum Pumps (ACM)
– Ambient molecular sieve bed (ACM)
– Cryogenic molecular sieve bed (ACM)
– Dynamic feed generator (ACM)
– Molecular and transition flow conductance model (ACM)
• Sub-Systems– Hydrogen-like processing
– Air-like processing
– Water-like processing
12
Examples of module bechmarks
Comparison of permeator model with data of Willms et al. (1993)
Comparison the model with LANL data for a Normetex 15 backed by an MB-601
13
Aspen Model of Permeator / AMSB for HLP
1414
Aspen Model of Combined ALP-WLP
15
Aspen system models used to optimize design
• Can account for system interactions in the design process– Permeator-pump interactions
– PMR-pump interactions
– Multistage permeator pump performance
• Easy to modify PFD to reduce equipment sizes and minimize pumping requirements
• Can base sizing calculations on overall system performance
16
Example - Permeator Optimization
• Vary the number of first stage pumps
– Determine tritium release from third (final) stage peremator
– Determine breakthrough area
• Determine number of pumps and permeator area based on point of dimishing returns
– Six MB-601 pumps for first stage– 3 m3 of membrane area for first
stage
• Evaluate system margin– Margin based on overall system
performance and not individual unitsMost Common
Operations
Permeator Train Breakthrough
Tritium release from third stage as a function of number of first stage pumps
First stage area as a function of number of first stage pumps
Tritium release from third stage as a function of feed rate
Consideration of next steps
17
DT
Major flow paths for ITER Fuel Cycle during DT
18
Next steps
• Past modeling efforts have laid an excellent foundation for the next work that needs to be performed
• The ITER TEP modeling effort has laid an excellent template for future work
• Major development needed includes:– Models of ITER sub-systems (expect for TEP)
– ITER Fuel Cycle model
– ITER TBM modeling
– Fusion Nuclear Science Facility model
– Benchmarking
19
20
Summary
• Computer modeling has been an important component of tritium processing development
• Recent ITER TEP modeling was not only successful in itself, but lays an excellent template for future modeling work
• There are a number of current and future projects which would benefit greatly from further modeling work