TY - GEN
T1 - Nuclear data uncertainty propagation in a lattice physics code using stochastic sampling
AU - Wieselquist, W.
AU - Vasiliev, A.
AU - Ferroukhi, H.
PY - 2012
Y1 - 2012
N2 - A methodology is presented for "black box" nuclear data uncertainty propagation in a lattice physics code using stochastic sampling. The methodology has 4 components: i) processing nuclear data variance/covariance matrices including converting the native group structure to a group structure "compatible" with the lattice physics code, ii) generating (relative) random samples of nuclear data, iii) perturbing the lattice physics code nuclear data according to the random samples, and iv) analyzing the distribution of outputs to estimate the uncertainty. The scheme is described as implemented at PSI, in a modified version of the lattice physics code CASMO-5M, including all relevant practical details. Uncertainty results are presented for a BWR pincell at hot zero power conditions and a PWR assembly at hot full power conditions with depletion. Results are presented for uncertainties in eigenvalue, 1-group microscopic cross sections, 2-group macroscopic cross sections, and isotopics. Interesting behavior is observed with burnup, including a minimum uncertainty due to the presence of fertile U-238 and a global effect described as "synergy", observed when comparing the uncertainty resulting from simultaneous and one-at-a-time variations of nuclear data.
AB - A methodology is presented for "black box" nuclear data uncertainty propagation in a lattice physics code using stochastic sampling. The methodology has 4 components: i) processing nuclear data variance/covariance matrices including converting the native group structure to a group structure "compatible" with the lattice physics code, ii) generating (relative) random samples of nuclear data, iii) perturbing the lattice physics code nuclear data according to the random samples, and iv) analyzing the distribution of outputs to estimate the uncertainty. The scheme is described as implemented at PSI, in a modified version of the lattice physics code CASMO-5M, including all relevant practical details. Uncertainty results are presented for a BWR pincell at hot zero power conditions and a PWR assembly at hot full power conditions with depletion. Results are presented for uncertainties in eigenvalue, 1-group microscopic cross sections, 2-group macroscopic cross sections, and isotopics. Interesting behavior is observed with burnup, including a minimum uncertainty due to the presence of fertile U-238 and a global effect described as "synergy", observed when comparing the uncertainty resulting from simultaneous and one-at-a-time variations of nuclear data.
KW - Depletion
KW - Lattice physics
KW - Nuclear data
KW - Uncertainty quantification
UR - http://www.scopus.com/inward/record.url?scp=84870329659&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84870329659
SN - 9781622763894
T3 - International Conference on the Physics of Reactors 2012, PHYSOR 2012: Advances in Reactor Physics
SP - 3000
EP - 3015
BT - International Conference on the Physics of Reactors 2012, PHYSOR 2012
T2 - International Conference on the Physics of Reactors 2012: Advances in Reactor Physics, PHYSOR 2012
Y2 - 15 April 2012 through 20 April 2012
ER -