Abstract
The nuclear research and development community has a history of using both integral and differential experiments to support accurate lattice-reactor, nuclear reactor criticality and shielding simulations, as well as verification and validation efforts of cross sections and emitted particle spectra. An important aspect to this type of analysis is the proper consideration of the contribution of the neutron spectrum in its entirety, with correct propagation of uncertainties and standard deviations derived from Monte Carlo simulations, to the local and total uncertainty in the simulated reactions rates (RRs), which usually only apply to one application at a time. This paper identifies deficiencies in the traditional treatment, and discusses correct handling of the RR uncertainty quantification and propagation, including details of the cross section components in the RR uncertainty estimates, which are verified for relevant applications. The methodology that rigorously captures the spectral shift and cross section contributions to the uncertainty in the RR are discussed with quantified examples that demonstrate the importance of the proper treatment of the spectrum profile and cross section contributions to the uncertainty in the RR and subsequent response functions. The recently developed inventory code FISPACT-II, when connected to the processed nuclear data libraries TENDL-2015, ENDF/B-VII.1, JENDL-4.0u or JEFF-3.2, forms an enhanced multi-physics platform providing a wide variety of advanced simulation methods for modelling activation, transmutation, burnup protocols and simulating radiation damage sources terms. The system has extended cutting-edge nuclear data forms, uncertainty quantification and propagation methods, which have been the subject of recent integral and differential, fission, fusion and accelerators validation efforts. The simulation system is used to accurately and predictively probe, understand and underpin a modern and sustainable understanding of the nuclear physics that is so important for many areas of science and technology; advanced fission and fuel systems, magnetic and inertial confinement fusion, high energy, accelerator physics, medical application, isotope production, earth exploration, astrophysics and homeland security.
Highlights
Noticeable in the partials for kerma, dpa and PKA generated by the latest TALYS and the more complete use made of the variance and covariance information contained in this truly general purpose library
This too often forgotten aspect, that the reaction rates is a collapse of the cross section and the flux, that sometimes emphasis strongly the 1/E, or giant resonance region may lead to significant overestimation of the reaction rates when and if
At the core of the main code is a modern rate equation solver that exploits the most advanced physics provided in modern nuclear data forms. This has primarily been driven by the development of the technological TENDL nuclear data libraries that, when coupled with FISPACT-II, allow truly general-purpose simulations for neutron-induced inventory calculations, as well as a charged-particle simulations for proton, deuteron, alpha and gamma-ray irradiation
Summary
The simulation of neutron spectra at any spatial position is carried out by the transport code. Modellers have a choice between using a deterministic or Monte Carlo solver, this choice is not without impact on the “accuracy” of the solution This is mainly due to the fact that both methods have to rely on processed, through different methods, basis nuclear data forms. Deterministic method are groupwise from the start but the energy bins of the group structure they rely upon to simulate the neutron map has been carefully selected with regard to operational criteria that are not general purpose. The legacy PWR spectra (EDF Paluel) show an earlier specificity: the simulation had a cut-off at 10 MeV. This has no influence on the reactor operations, but could be detrimental to any subsequent fuel inventory simulation for wet or dry storage
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
