1. Pacific Northwest National Laboratory
FRAPCON/FRAPTRAN Users Group Meeting: Recent Code Updates and Future Plans
Ken Geelhood
Walter Luscher
Carl Beyer
Pacific Northwest National Laboratory
September 7, 2012

2. Outline Current code versions Changes made so far
FRAPCON-3.5
FRAPTRAN 1.5
FRAPCON-ARM
Recent code benchmarks
Upcoming Changes
Upcoming Activities
Next Code Release

3. Current Code Versions FRAPCON-3.4a FRAPTRAN 1.4
4/14/2017
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:
The ongoing development of FRAPCON-3 and FRAPTRAN is sponsored by the U.S. NRC

4. Changes Made to Date: FRAPCON-3.5
4/14/2017
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
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
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
4/14/2017
FRAPCON-3.5 model Improvements: Gaseous Swelling
Gaseous swelling observed between 960˚C and 1832˚C
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
4/14/2017
FRAPCON-3.5 model Improvements: Gaseous Swelling
New model improves predictions of ramp hoop strain at high burnup

7. Changes Made to Date: FRAPTRAN 1.5
4/14/2017
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
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

8. FRAPTRAN 1.5 model Improvements: Ballooning Model
4/14/2017
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

9. FRAPTRAN 1.5 model Improvements: ID Oxidation
4/14/2017
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
-or-
Calculate for all nodes regardless of burst if nodal burnup exceeds value set by user

10. Changes made to Date: Uncertainty Analysis with FRAPCON-ARM
4/14/2017
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.

11. Uncertainty Analysis with FRAPCON-ARM Input
4/14/2017
Uncertainty Analysis with FRAPCON-ARM Input

12. Uncertainty Analysis with FRAPCON-ARM Input
4/14/2017
Uncertainty Analysis with FRAPCON-ARM Input

13. Uncertainty Analysis with FRAPCON-ARM Output
4/14/2017
Uncertainty Analysis with FRAPCON-ARM Output
Output distributions
Inputs and outputs for each realization
Calculated Upper Tolerance Limits

14. Uncertainty Analysis with FRAPCON-ARM Output
4/14/2017
Uncertainty Analysis with FRAPCON-ARM Output
Output vs. Input
Test for Normality

15. Recent Code Benchmarks
4/14/2017
Recent Code Benchmarks
IFA-699
Subject: Creep
Presented at: 2011 EHPG Meeting
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

16. Upcoming Changes: FRAPCON-3.5
4/14/2017
Upcoming Changes: FRAPCON-3.5
Model improvements
Updates to implementation of creep model in FRAPCON
Updates to better predict BOL temperatures
New Capabilities
Axial variation in enrichment
Axial variation in Gd2O3 content
Ability to specify axial regions with and without a central hole
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

17. Upcoming Changes: FRAPTRAN 1.5
4/14/2017
Upcoming Changes: FRAPTRAN 1.5
Review of FLECHT reflood correlations in code and comparison to FLECHT data set
Ability to model pellets with chamfers
Excel input generator updates and improvements to match FRAPTRAN 1.5 changes
Possible support of SNAP within 1-2 years

18. Upcoming Activities Peer Review
4/14/2017
Upcoming Activities
Peer Review
Need at least five members of Users Group
Peer review should identify:
Code deficiencies
Suggestions for code improvements
Peer review will begin shortly following this meeting
Sign up now to participate
Other members will be contacted by

19. 4/14/2017
New Code Release
Plans to release FRAPCON-3.5 and FRAPTRAN 1.5 early 2014
Documentation?
NUREG/CR?
Web documentation?