1. Recent FRAPCON and FRAPTRAN activity at VTT
Users group meeting V. Tulkki VTT Technical Research Centre of Finland

2. Recent FRAPCON & FRAPTRAN use at VTT
Statistical studies
OECD/NEA benchmark on uncertainty analysis of best estimate modelling of light water reactors
Support to STUK
EPR LBLOCA
Halden LOCA experiment simulations
FRAPTRAN-GENFLO bundle simulations
Changing the date: View – Slide Master – change the date on the slide master uppermost

3. Statistical studies
FRAPCON used for a statistical study on input interactions
Sobol’ variance decomposition used in analysis
Provides information on higher order interactions
Downside: ~106 FRAPCON runs
Traditional first-order ranking methods commonly used in sensitivity analysis not always sufficient due to complex interactions
Discussed in OECD/NEA UAM workshops and Halden uncertainty workshop this fall
”The importance of input interactions in the uncertainty and sensitivity analysis of the nuclear fuel behavior”, T. Ikonen and V. Tulkki, submitted to Nuclear Engineering and Design
Work continues with FRAPTRAN analysis

4. LBLOCA
Comparative analysis for STUK on number of failed rods during EPR LBLOCA
Regulatory requirement <10%
For reference / information to STUK, not part of official process
System code APROS used for 59 global simulations of plant state
59x1000 FRAPTRAN/GENFLO subchannel analysis used with local variations
Results extended to whole core with neural networks
-> fraction of failed rods
Work in progress

5. Use of FRAPTRAN for benchmarking our FINIX fuel module
Study on impact of variation of heating power for future Halden LOCA test
Also, simulation of the effect of spacer grid simulation
Should be implementable in the FEA model
Extension of FRAPTRAN/GENFLO hot channel mode to bundle model with several concurrent FRAPTRAN simulations
Coupling of FRAPCON to Serpent 2 MC reactor physics code via universal multiphysics interface
Use of FRAPTRAN for benchmarking our FINIX fuel module
FINIX initialization from FRAPCON restart
FRAPTRAN to be used in IAEA CRP FUMAC and possibly OECD RIA phase II benchmark

6. VTT creates business from technology
Final slide is optional in VTT’s internal presentations