Transcript Working Group on Fuel Safety RIA fuel codes benchmark

FRAPCON/FRAPTRAN Users Group
Meeting:
Recent Code Updates and Future
Plans
Ken Geelhood
Walter Luscher
Carl Beyer
Pacific Northwest National Laboratory
September 19, 2013
1
Outline
Current code versions
Changes made so far
FRAPCON-3.5
FRAPTRAN 1.5
FRAPCON-ARM
Recent code benchmarks
Upcoming Changes
FRAPCON-3.5
FRAPTRAN 1.5
Changes beyond these versions
Next Code Release
2
Current Code Versions
FRAPCON-3.4a
Code Description: NUREG/CR-7022 Vol.1
Integral Assessment: NUREG/CR-7022 Vol.2
FRAPTRAN 1.4
Code Description: NUREG/CR-7023 Vol.1
Integral Assessment: NUREG/CR-7023 Vol.2
Consistent material properties in both codes
Material Property Correlations: NUREG/CR-7024
Documentation available on: http://frapcon.labworks.org/
The ongoing development of FRAPCON-3 and
FRAPTRAN is sponsored by the U.S. NRC
3
Changes Made to Date:
FRAPCON-3.5
Model improvements
Model for gaseous swelling added to better predict cladding
hoop strain during high burnup ramp tests
Improved primary creep model
Improved beginning of life temperature predictions
New Capabilities
Ability to model pellets with chamfers was added
Ability to input variable axial node lengths was added
More output was added for stochastic analysis
Axial variation of enrichment, gadolinia, and central hole
More time steps, nodes, and axial shapes allowed
Gadolinia assumption evaluated
New model for swelling
User guidance developed
4
Changes Made to Date:
FRAPCON-3.5
Error correction
Better error messages were added to help debug input file
Default values in manual and code were matched
5
FRAPCON-3.5 model Improvements:
Gaseous Swelling
Gaseous swelling observed between 960˚C and 1832˚C
8.0
7.0
6.0
Swelling, DV/V (%)
5.0
4.0
3.0
2.0
1.0
0.0
0
500
1000
1500
2000
2500
Temperature (°C)
Mogensen Data at 39 GWd/MTU
Mogensen Data at 33 GWd/MTU
Gaseous Swelling Model
Model is linearly phased in between 40 and 50 GWd/MTU
and fully applied above 50 GWd/MTU
6
FRAPCON-3.5 model Improvements:
Gaseous Swelling
New model improves predictions of ramp hoop strain at
high burnup
Predicted minus Measured Plastic Strain Incrament, %
1.5
7
1
0.5
0
-0.5
-1
-1.5
-2
15
25
35
45
55
65
75
Rod Average Burnup, GWd/MTU
Original Assessment Cases
SCIP Long Hold Times
SCIP Short Hold Times
B&W Stud Long Hold Time
Original Assessment Mod
SCIP Long Mod
SCIP Short Mod
B&W Mod
85
FRAPCON-3.5 model Improvements:
Improved Primary Creep
New model improves prediction of primary creep following
stress reversals and stress changes
3.E-03
-50MPa
-75MPa
+110MPa
+30MPa
3.E-03
2.E-03
Creep strain, m/m
2.E-03
1.E-03
5.E-04
0.E+00
-5.E-04
-1.E-03
-2.E-03
0
1000
2000
3000
4000
Time, hours
Data
8
New Methodology
Old Methodology
5000
6000
FRAPCON-3.5 model Improvements:
Axial Variations
User may input custom axial node lengths
For each axial node, the user may input a different value of
Enrichment
Gadolinia concentration
Presence or absence of central hole
Size of central hole
Old input of equal length axial nodes and constant values
for all nodes still work
9
Changes Made to Date:
FRAPTRAN 1.5
Model improvements
Changes made to how the code does ballooning calculations
Double sided oxidation changed
New Capabilities
Number of input coolant zones changed from 10 to 20
Interpolate between input coolant zones for axial nodes
Ability to specify an external plenum volume
Maximum number of axial nodes changed from 25 to 150
Different values of gadolinia for each node
Ability to model chamfers
10
Changes Made to Date:
FRAPTRAN 1.5
Error correction
Lower bound for Cathcart/Pawel model changed from 1000K
to 1073K
Errors in heat transfer correlations corrected
Better error messages were added to help debug input file
Default values in manual and code were matched
Error in fill gas composition after rupture
Review of FLECHT reflood correlation performed
11
FRAPTRAN 1.5 model Improvements:
Ballooning Model
More strain values are output to FRAPTRAN
Thinned cladding used to calculation ECR
Increased diameter used to calculation metal water
reaction energy
12
FRAPTRAN 1.5 model Improvements:
ID Oxidation
New options added
FRAPTRAN 1.4
ID oxidation only calculated in burst area after burst
FRAPTRAN 1.5
Option to calculate ID oxidation one of two ways
FRAPTRAN 1.4 method
-orCalculate for all nodes regardless of burst if nodal burnup
exceeds value set by user
13
Changes made to Date:
Uncertainty Analysis with FRAPCON-ARM
Stochastic framework capable of running many realizations
of FRAPCON-3.4 varying:
Manufacturing uncertainties
Model uncertainties
Power uncertainties
Package reads data from each realization and compiles
distributions for each output of interest.
Allows staff to validate vendor predictions of nominal and
upper tolerance limit for various code outputs.
Methodology does not rely on assumptions of normality for
input or output distributions as the RMS methods typically
used in industry do.
14
Uncertainty Analysis with FRAPCON-ARM
Input
15
Uncertainty Analysis with FRAPCON-ARM
Input
16
Uncertainty Analysis with FRAPCON-ARM
Output
Output distributions
Inputs and outputs for each realization
Calculated Upper Tolerance Limits
17
Uncertainty Analysis with FRAPCON-ARM
Output
Output vs. Input
18
Test for Normality
Recent Code Benchmarks
IFA-699
Subject: Creep
Presented at: 2011 EHPG Meeting and 2013 TopFuel
SCIP, TRANS RAMP IV
Subject: FGR during short hold time ramps
Presented at: Not publically presented
Hydrogen pickup models
Presented at: 2011 Water Reactor Fuel Performance
Meeting
IRSN RIA Benchmarks
High burnup RIA tests
FUMEX-III
Participated with TRACTEBEL and NRI
19
Upcoming Changes:
FRAPCON-3.5
New Capabilities
Improved ability to model refabricated rodlets
Model base irradiation and create restart file
Model test on refabricated rod using selected axial nodes from
restart
Excel input generator updates and improvements to match
FRAPCON-3.5 change
Possible support of SNAP within 1-2 years
20
Upcoming Changes:
FRAPTRAN 1.5
Excel input generator updates and improvements to match
FRAPTRAN 1.5 changes
Possible support of SNAP within 1-2 years
21
Changes beyond FRAPCON-3.5 and
FRAPTRAN 1.5
FORTRAN Updates
Use all Modern F95
Reduce need for compiler options
Improve variable declaration and use dynamic dimensioning
Improvement in reliability
Reduce crashes
Retune FRAPFGR model
Fix FRAPTRAN problems with coolant boundary conditions
Address peer review items
Couple FRAPCON and DATING for spent fuel creep
analysis
Develop stochastic capability for FRAPTRAN
Include new ANS5.4 model in FRAPCON
Update decay heat model
22
New Code Release
Plans to release FRAPCON-3.5 and FRAPTRAN 1.5 early
2014
Documentation
NUREG/CR
23