1 / 36

Total Monte Carlo and related applications of the TALYS code system

Total Monte Carlo and related applications of the TALYS code system. Arjan Koning NRG Petten, the Netherlands Technical Meeting on Neutron Cross-Section Covariances September 27-30 2010, IAEA, Vienna. Contents. Introduction: TALYS code system Implications and possibilities:

melba
Download Presentation

Total Monte Carlo and related applications of the TALYS code system

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Total Monte Carlo and related applications of the TALYS code system Arjan Koning NRG Petten, the Netherlands Technical Meeting on Neutron Cross-Section Covariances September 27-30 2010, IAEA, Vienna

  2. Contents • Introduction: TALYS code system • Implications and possibilities: • Large scale nuclear data library production (TENDL) • “Total” Monte Carlo uncertainty propagation • Random search for the best data library • Conclusions

  3. TALYS code system • A loop over nuclear physics, data libraries, processing and applications: • Resonance parameters + uncertainties • An EXFOR database with more uncertainties than errors • The TALYS code • The Reference Input Parameter Library (RIPL) • Software for remaining reaction types (nubar, fns + unc.) • For many nuclides: A set of adjusted model parameters + uncertainties + “non-physical evaluation actions” • All major world libraries • The ENDF-6 formatting code TEFAL • NJOY, MCNP(X) + other codes • A script that drives everything • The secret: Insist on absolute reproducibility

  4. Nuclear data scheme + covariances +Uncertainties Determ. code Resonance Parameters . TARES +Covariances +Covariances Output ENDF Gen. purpose file NJOY MCNP • K-eff • Neutron flux • Etc. TEFAL +Covariances Experimental data (EXFOR) Output ENDF/EAF Activ. file PROC. CODE FIS- PACT -activation - transmutation +(Co)variances +Covariances +Covariances Nucl. model parameters TALYS Other (ORIGEN) +Uncertainties Monte Carlo: 1000 TALYS runs TASMAN

  5. Uncertainties for Cu isotopes

  6. Application 1: TENDL • TALYS Evaluated Nuclear Data Library, www.talys.eu/tendl2009 • n, p, d, t ,h, a and g libraries in ENDF-6 format • 2400 nuclides (all with lifetime > 1 sec.) up to 200 MeV • Neutrons: complete covariance data (MF31-MF35) • MCNP-libraries (n,p and d) and multi-group covariances (n only) • Production time: 2 months (40 processors) • Strategy: • Always ensure completeness, global improvement in 2010, 2011.. • Extra effort for important nuclides, especially when high precision is required (e.g. actinides): adjusted parameters (data fitting). These input files per nuclide are stored for future use. • All libraries are always reproducible from scratch • The ENDF-6 libraries are created, not manually touched • Zeroing in on the truth for the whole nuclide chart at once

  7. TENDL: Complete ENDF-6 data libraries • MF1: description and average fission quantities • MF2: resonance data • MF3: cross sections • MF4: angular distributions • MF5: energy spectra • MF6: double-differential spectra, particle yields and residual products • MF8-10: isomeric cross sections and ratios • MF12-15: gamma yields, spectra and angular distributions • MF31: covariances of average fission quantities(TENDL-2010) • MF32: covariances of resonance parameters • MF33: covariances of cross sections • MF34: covariances of angular distributions • MF35: covariances of fission neutron spectra(TENDL-2010) and particle spectra (TENDL-2011) • MF40: covariances of isomeric data (TENDL-2011)

  8. IAEA covariance visualisation system (V. Zerkin)

  9. Application 2: “Total” Monte Carlo • Propagating covariance data is an approximation of true uncertainty propagation (especially regarding ENDF-6 format limitations) • Covariance data requires extra processing and “satellite software” for application codes • Alternative: Create an ENDF-6 file for each random sample and finish the entire physics-to-application loop. (Koning and Rochman, Ann Nuc En 35, 2024 (2008)

  10. Nuclear data scheme + covariances +Uncertainties Determ. code Resonance Parameters . TARES +Covariances +Covariances Output ENDF Gen. purpose file NJOY MCNP • K-eff • Neutron flux • Etc. TEFAL +Covariances Experimental data (EXFOR) Output ENDF/EAF Activ. file PROC. CODE FIS- PACT -activation - transmutation +(Co)variances +Covariances +Covariances Nucl. model parameters TALYS Other (ORIGEN) +Uncertainties Monte Carlo: 1000 TALYS runs TASMAN

  11. Nuclear data scheme: Total Monte Carlo +Uncertainties Determ. code Resonance Parameters . TARES Output ENDF Gen. purpose file NJOY MCNP • K-eff • Neutron flux • Etc. TEFAL +Covariances Experimental data (EXFOR) Output ENDF/EAF Activ. file PROC. CODE FIS- PACT - activation - transmutation +Covariances Nucl. model parameters TALYS Other codes +Uncertainties TASMAN Monte Carlo: 1000 runs of all codes

  12. Application: criticality benchmarks Total of 60000 random ENDF-6 files Sometimes deviation from Gaussian shape Rochman, Koning, van der Marck Ann Nuc En 36, 810 (2009) Yields uncertainties on benchmarks

  13. Covariance versus Total Monte Carlo • Advantages: Advantages: • - Relatively quick - Exact • - Use in sensitivity study - Requires only “main” software • - Easier release (TENDL) • Disadvantages: Disadvantages: • - Approximative (cross-correlations) - (Computer) time consuming • - No covariance for gamma production, - Backward (sensitivity) route • DDX (MF36), etc. not obvious • - Requires special processing • - Requires covariance software for application codes

  14. Application: SFR void coefficient • KALIMER-600 Sodium Fast Reactor (Korea) • Total Monte Carlo with MCNP and FISPACT • Uncertainties due to transport libraries only, but for all materials • Sensitivity profiles with MCNP • K-eff, void coefficient, burn-up and radiotoxicity using TMC

  15. The total uncertainty is underestimated. Uncertainties for: • Activation cross sections • Fission yield data • Decay data • Are not (yet) taken into account.

  16. TMC: Other possibilities • Random thermal scattering data libraries (?) • Random decay data libraries • Random fission yield libraries • Normalization to experimental data or other nuclear data libraries at the basic input level (TENDL-2010) • Optimization to integral benchmarks using e.g. simulated annealing (“search for the best random file”)

  17. Optimization of Pu-239 • Select 120 ICSBEP benchmarks • Create 630 random Pu-239 libraries, all within, or closely around, the uncertainty bands • Do a total of 120 x 630 =75600 MCNP criticality calculations • Do another 120 x 4 calculations:

  18. Optimization of Pu-239

  19. Optimization of Pu-239 • 6% of libraries have lower chi-2 than JEFF-3.1 • Library #307 has the lowest

  20. Conclusions • To improve evaluated libraries, TMC is an easier tool than covariances + perturbation + sensitivity • However, the world wants covariances, and they get covariances (TENDL) • With a reproducible automated system, almost anything is possible. After some years of serious software development we can now fork into various branches: • TALYS Evaluated Nuclear Data Library (TENDL) including complete covariance data (MF31-35) • Total Monte Carlo uncertainty propagation • Nuclear data library optimization • Other applications (not discussed here) • The results of all improvements in uncertainly handling (UMC, model uncertainties, etc.) will be directly visible

More Related