1. IRSN work and perspectives
FRAPCON 3.4a and FRAPCON 3.5
IRSN work and perspectives 1

2. Outline
1) IRSN developments performed on the FRAPCON 3.4a
2) … and FRAPCON 3.5
3) Conclusions and future work

3. 1) IRSN developments performed on the FRAPCON 3.4a (1/3)
IRSN migrates the FRAPCON code to a LINUX environment. Few subroutines were modified to complete the migration and a LINUX script was performed in order to install the code and run calculations.
Specific developments were performed by IRSN in order to fully analyse FRAPCON results in a LINUX environment : a post-processing tool based on the Gnuplot Free Software. It allows to plot much more output variables with this new tool than with the Excel interface. IRSN added many output variables in the ‘.plot’ file.
New outputs that can now be plotted (in addition to those already existing)
20 Peak Linear Heat Rating
21 Molar Fraction of He
22 Molar Fraction of Pf(Xe+Kr)
23 Molar Fraction of Air
24 Molar Fraction of Ar
25 Free gas in the rod cm3TPN
26 Lower Plenum Temperature
27 Lower Plenum Volume
28 Upper Plenum Temperature
29 Upper Plenum Volume
30 Stoechiometry
31 Fuel Grain size
32 End of life Plenum Pressure
33 Relative Cladding Axial Extension
34 Peak Axial Element Indicator
35 Rod Peak Burnup
36 Peak Pellet Centerline Temperature
37 Peak Pellet Surface Temperature
38 Peak Clad Inside Temperature
39 Peak Clad Outside Temperature
150 Axial Element Elevation
151 Axial Node Elevation
152 Axial Strain due to Irradiation growth
153 Axial Geometrical Gap
154 Axial Hot Thermal Gap
155 Axial Hot Radial Structural Gap
156 Normalized axial node power
180 Initial Axial Elevation
202 Fuel Rod Mesh Radial Nodes
203 Fuel Rod Mesh Burn Up
204 Linear Porosity Fuel Fraction
205 Pu Concentration
206 Radial Power Profile
207 Radial Fuel Density

4. 1) IRSN developments performed on the FRAPCON 3.4a (2/3)
IRSN works on the axial and radial coordinates. It is now possible to plot the cladding hoop stress (for example) as a function of the axial or radial location with FRAPCON 3.4a, rather than the node number as in the delivered version of FRAPCON 3.4a.

5. 1) IRSN developments performed on the FRAPCON 3.4a (3/3)
An automatic tool was developed in order to assess the code. This tool consists in a launcher of the test-cases and an automatic procedure to extract FRAPCON results and integrate them in a pdf report in order to compare with experimental results (when available).
This tool is originally working on a Linux system.
It is based on the Linux version of the FRAPCON 3.4a code (adapted by IRSN), on Gnuplot and LateX.
PDF Released document >>
This tool was then specifically developed for NRC on the Windows 7 environment and it was delivered to NRC (middle of October 2013)

6. 1) IRSN developments performed on the FRAPCON 3.4a (3/3)
Opportunity to perform comparisons of calculations results of different versions.
Comparison between experimental data and calculation results

7. 1) IRSN developments performed on the FRAPCON 3.4a (3/3)
IRSN developments on version 3.4a :
Linux platform
Post-processing based on .plot file
Automatic tool for assessment of the code
All the items were delivered to NRC at the end of 2013.
IRSN believes that some developments could benefit to other partners and should be implemented in the next version of the code. IRSN fully agreed to send most developments for integration in the next version 3.5.
These developments have not yet been integrated in the FRAPCON version 3.5, released in April-May 2014.

8. 2) …and FRAPCON v3.5
IRSN integrates in the new version (3.5) all developments performed in the frame of FRAPCON 3.4
Linux version,
Post-processing based on Gnuplot (interactive mode),
Much more outputs of the FRAPCON calculations that can be plotted,
Automatic tool for integral assessment of the code or for comparison of input data files.
The second stage on FRAPCON 3.5 will then begin :
Study of the modifications of the cladding creep subroutine in order to model thermal-mechanical evolution of the rod for reactor maintained at intermediate power during extended duration.
IRSN will start in the next months a definition of the strategy for a Storage/Transportation version of FRAPCON, including models to be considered for hydriding, oxidation, creep, hydrogen diffusion, hydride reorientation…

9. 3) Conclusions and future work
IRSN decided few years ago to use the FRAPCON code as an irradiation software.
IRSN performs many developments (mainly tools working around the code) for its own use.
IRSN has major project based on the code : development of a storage/transportation version of the code to be able to model the whole life of fuel rods after reactor irradiation, assessment of the ability of the code to model ramps tests conditions…