Adjoint-based sensitivity and uncertainty analysis of lattice physics calculations with CASMO-4

Maria Pusa

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Abstract

The topic of this paper is the development of sensitivity and uncertainty analysis capability to the reactor physics code CASMO-4 in the UAM (Uncertainty Analysis in Best-Estimate Modelling for Design, Operation and Safety Analysis of LWRs) benchmark. The developed calculation system enables the uncertainty analysis of homogenized multi-group cross-sections, diffusion coefficients and pin powers with respect to nuclear data. The uncertainty analysis methodology is deterministic, meaning that the sensitivity profiles of the responses are computed first, after which uncertainty is propagated by combining the sensitivity profiles with the covariance matrices of the uncertain nuclear data. The sensitivity analysis is based on perturbation theory which enables computing the sensitivity profiles efficiently by solving one generalized adjoint system for each response. The mathematical background of this work is reviewed and the main conclusions related to the implementation are summarized. Special emphasis is placed on the sensitivity analysis of two-group homogenized diffusion coefficients which require some modifications to the standard equations of generalized perturbation theory. Numerical results are presented and analyzed for a PWR fuel assembly with control rods out and inserted. The computational efficiency of the calculations is discussed.
Original languageEnglish
Title of host publicationProceedings of the international conference on physics of reactors
Subtitle of host publicationPHYSOR2014
Number of pages12
VolumeJAEA-Conf 2014-003
DOIs
Publication statusPublished - 2015
MoE publication typeA4 Article in a conference publication
EventInternational Conference on the Physics of Reactors, PHYSOR 2014: The Role of Reactor Physics toward Sustainable Future - Kyoto, Japan
Duration: 28 Sep 20143 Oct 2014

Conference

ConferenceInternational Conference on the Physics of Reactors, PHYSOR 2014
Abbreviated titlePHYSOR2014
CountryJapan
CityKyoto
Period28/09/143/10/14

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Pusa, M. (2015). Adjoint-based sensitivity and uncertainty analysis of lattice physics calculations with CASMO-4. In Proceedings of the international conference on physics of reactors: PHYSOR2014 (Vol. JAEA-Conf 2014-003). [1106024] https://doi.org/10.11484/jaea-conf-2014-003