Validation of a Continuous-Energy Monte Carlo Burn-up Code MVP-BURN and Its Application to Analysis of Post Irradiation Experiment

Abstract In the paper, we assess the accuracy of the Monte Carlo continuous energy burnup code (MCB) in predicting final concentrations of major actinides in the spent nuclear fuel from commercial PWR. The Ohi-2 PWR irradiation experiment was chosen for the numerical reconstruction due to the availability of the final concentrations for eleven major actinides including five uranium isotopes (U-232, U-234, U-235, U-236, U-238) and six plutonium isotopes (Pu-236, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242). The main results were presented as a calculated-to-experimental ratio (C/E) for measured and calculated final actinide concentrations. The good agreement in the range of ±5% was obtained for 78% C/E factors (43 out of 55). The MCB modeling shows significant improvement compared with the results of previous studies conducted on the Ohi-2 experiment, which proves the reliability and accuracy of the developed methodology.

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Validation of a New Lattice Physics Code GALAXY for PWRs

18th International Conference on Nuclear Engineering: Volume 2 ◽

10.1115/icone18-29221 ◽

2010 ◽

Author(s):

Kazuya Yamaji ◽

Hiroki Koike ◽

Daisuke Sato ◽

Shinobu Tsubota ◽

Hideki Matsumoto

Keyword(s):

Monte Carlo ◽

Calculation Method ◽

Post Irradiation ◽

Energy Group ◽

Continuous Energy ◽

The Galaxy ◽

Critical Experiment ◽

The Many ◽

Nuclear Constants ◽

Calculation Code

A new lattice physics and assembly calculation code GALAXY with the 172 energy-group ENDF/B-VII.0 library has been developed. GALAXY generates few group nuclear constants used in a new core simulator COSMO-S. The GALAXY code uses the many enhanced calculation method for more explicit treatment of neutronics characteristics. The outline of enhanced methods used in GALAXY and the qualification results are shown in this paper. From the qualifications in the continuous energy Monte Carlo benchmark, critical experiment analyses and post irradiation examination (PIE) analyses, GALAXY with the library was validated and the applicability of GALAXY to PWR nuclear design was confirmed.

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Comparison of Direct and Adjoint k and α-Eigenfunctions

Journal of Nuclear Engineering ◽

10.3390/jne2020014 ◽

2021 ◽

Vol 2 (2) ◽

pp. 132-151

Author(s):

Vito Vitali ◽

Florent Chevallier ◽

Alexis Jinaphanh ◽

Andrea Zoia ◽

Patrick Blaise

Keyword(s):

Monte Carlo ◽

Monte Carlo Methods ◽

Energy Transport ◽

Distinct Point ◽

Point Of View ◽

Critical Systems ◽

Small Deviations ◽

Power Iteration ◽

Continuous Energy ◽

Fission Probability

Modal expansions based on k-eigenvalues and α-eigenvalues are commonly used in order to investigate the reactor behaviour, each with a distinct point of view: the former is related to fission generations, whereas the latter is related to time. Well-known Monte Carlo methods exist to compute the direct k or α fundamental eigenmodes, based on variants of the power iteration. The possibility of computing adjoint eigenfunctions in continuous-energy transport has been recently implemented and tested in the development version of TRIPOLI-4®, using a modified version of the Iterated Fission Probability (IFP) method for the adjoint α calculation. In this work we present a preliminary comparison of direct and adjoint k and α eigenmodes by Monte Carlo methods, for small deviations from criticality. When the reactor is exactly critical, i.e., for k0 = 1 or equivalently α0 = 0, the fundamental modes of both eigenfunction bases coincide, as expected on physical grounds. However, for non-critical systems the fundamental k and α eigenmodes show significant discrepancies.

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