Quantification and mechanism analysis of the kinf uncertainty propagated from nuclear data for the TRISO particle fuel pebble

Hao, Chen; Cheng, Youying; Teng, Qichen

doi:10.1016/j.anucene.2018.12.011

Cited by 4 publications

(2 citation statements)

References 7 publications

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“…The average number of neutrons emitted per fission event of 235 U is the main contributor to the k eff uncertainty and accounts for nearly 17.40% of the total uncertainty of k eff -based nuclear data. This phenomenon is similar to the results of a previously reported uncertainty analysis of HTR-10 [10,22]. However, the main k eff uncertainty contributors from the results of uncertainty analyses of typically pressurized water reactors (PWRs) and boiling water reactors (BWRs) [20,21] are different, which has detailed description in Sect.…”

Section: Su Analysis Of K Eff At Czp Conditionsupporting

confidence: 86%

keff uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

et al. 2021

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To benefit from recent advances in modeling and computational algorithms, as well as the availability of new covariance data, sensitivity and uncertainty analyses are needed to quantify the impact of uncertain sources on the design parameters of small prismatic high-temperature gascooled reactors (HTGRs). In particular, the contribution of nuclear data to the k eff uncertainty is an important part of the uncertainty analysis of small-sized HTGR physical calculations. In this study, a small-sized HTGR designed by China Nuclear Power Engineering Co., Ltd. was selected for k eff uncertainty analysis during full lifetime burnup calculations. Models of the cold zero power (CZP) condition and full lifetime burnup process were constructed using the Reactor Monte Carlo Code RMC for neutron transport calculation, depletion calculation, and sensitivity and uncertainty analysis. For the sensitivity analysis, the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via Track length importance Characterization (CLUTCH) method was applied to obtain sensitive information, and the ''sandwich'' method was used to quantify the k eff uncertainty. We also compared the k eff uncertainties to other typical reactors. Our results show that 235 U is the largest contributor to k eff uncertainty for both the CZP and depletion conditions, while the contribution of 239 Pu is not very significant because of the design of low discharge burnup. It is worth noting that the radioactive capture reaction of 28 Si significantly contributes to the k eff uncertainty owing to its specific fuel design. However, the k eff uncertainty during the full lifetime depletion process was relatively stable, only increasing by 1.12% owing to the low discharge burnup design of small-sized HTGRs. These numerical results are beneficial for neutronics design and core parameters optimization in further uncertainty propagation and quantification study for small-sized HTGR.

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Section: Su Analysis Of K Eff At Czp Conditionsupporting

confidence: 86%

keff uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

et al. 2021

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“…In order to systematically and thoroughly investigate the uncertainties propagation in pebble-bed HTGR, an IAEA Coordinated Research Plan (CRP) [2,3] has been initiated after the start of OECD/NEA UAM-LWR [4]. Recent advances regarding uncertainty propagation analysis in pebble-bed HTGR mainly concern the nuclear cross section uncertainties propagation in reactor neutronic calculations [5][6][7][8][9]. As pebble-bed HTGR allows fuels recirculation during fuel cycles and adopts higher fuel enrichment (8.5 wt.%), fuels usually could achieve larger burnup values, and then fission product yields could be nonnegligible uncertainty sources in reactor burnup and decay heat calculations.…”

Section: Introductionmentioning

confidence: 99%

Lognormal-Based Sampling for Fission Product Yields Uncertainty Propagation in Pebble-Bed HTGR

Wang

Cui

Guo

et al. 2020

Science and Technology of Nuclear Installations

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Uncertainty analyses of fission product yields are indispensable in evaluating reactor burnup and decay heat calculation credibility. Compared with neutron cross section, there are fewer uncertainty analyses conducted and it has been a controversial topic by lack of properly estimated covariance matrix as well as adequate sampling method. Specifically, the conventional normal-based sampling method in sampling large uncertainty independent fission yields could inevitably generate nonphysical negative samples. Cutting off these samples would introduce bias into uncertainty results. Here, we evaluate thermal neutron-induced U-235 independent fission yields covariance matrix by the Bayesian updating method, and then we use lognormal-based sampling method to overcome the negative fission yields samples issue. Fission yields uncertainty contribution to effective multiplication factor and several fission products’ atomic densities at equilibrium core of pebble-bed HTGR are quantified and investigated. The results show that the lognormal-based sampling method could prevent generating negative yields samples and maintain the skewness of fission yields distribution. Compared with the zero cut-off normal-based sampling method, the lognormal-based sampling method evaluates the uncertainty of effective multiplication factor and atomic densities are larger. This implies that zero cut-off effect in the normal-based sampling method would underestimate the fission yields uncertainty contribution. Therefore, adopting the lognormal-based sampling method is crucial for providing reliable uncertainty analysis results in fission product yields uncertainty analysis.

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Uncertainty quantification of fuel pebble model and its effect on the uncertainty propagation of nuclear data in pebble bed HTR

Cheng

Hao

2020

Annals of Nuclear Energy

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Quantification and mechanism analysis of the kinf uncertainty propagated from nuclear data for the TRISO particle fuel pebble

Cited by 4 publications

References 7 publications

keff uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

keff uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

Lognormal-Based Sampling for Fission Product Yields Uncertainty Propagation in Pebble-Bed HTGR

Uncertainty quantification of fuel pebble model and its effect on the uncertainty propagation of nuclear data in pebble bed HTR

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