Three-Dimensional (X,Y,Z) Deterministic Analysis of the PCA-Replica Neutron Shielding Benchmark Experiment using the TORT-3.2 Code and Group Cross Section Libraries for LWR Shielding and Pressure Vessel Dosimetry

Abstract

Abstract. The PCA-Replica 12/13 (H 2 O/Fe) neutron shielding benchmark experiment was analysed using the ORNL TORT-3.2 3D S N code. PCA-Replica, specifically conceived to test the accuracy of nuclear data and transport codes employed in LWR shielding and radiation damage calculations, reproduces a PWR ex-core radial geometry with alternate layers of water and steel including a PWR pressure vessel simulator. Three broad-group coupled neutron/photon working cross section libraries in FIDO-ANISN format with the same energy group structure (47 n + 20 ) and based on different nuclear data were alternatively used: the ENEA BUGJEFF311.BOLIB (JEFF-3.1.1) and BUGENDF70.BOLIB (ENDF/B-VII.0) libraries and the ORNL BUGLE-96 (ENDF/B-VI.3) library. Dosimeter cross sections derived from the IAEA IRDF-2002 dosimetry file were employed. The calculated reaction rates for the Rh-103(n,n )Rh-103 m, In-115(n,n )In115m and S-32(n,p)P-32 threshold activation dosimeters and the calculated neutron spectra are compared with the corresponding experimental results.

BUGJEFF311.BOLIB (JEFF-3.1.1) and BUGENDF70.BOLIB (ENDF/B-VII.0) – Generation Methodology and Preliminary Testing of two ENEA-Bologna Group Cross Section Libraries for LWR Shielding and Pressure Vessel Dosimetry

“…Transport calculations in Cartesian (X,Y,Z) geometry and in P 3 -S 8 approximation (being P 3 the order of the expansion in Legendre polynomials of the scattering cross section matrix and S 8 the order of the flux angular discretization) were performed using flat weighting dosimeter cross sections for the Rh-103(n,n )Rh-103 m, In-115(n,n )In-115 m and S-32(n,p)P-32 threshold activation dosimeters used in PCA-Replica. The calculated reaction rates for all the cited dosimeters are within the desired target accuracy of ±10-15% with respect to the experimental data (see [25] for more details).…”