Commissariat à l'Energie Atomique, CEA/Saclay, DEN/DM2S/SERMA, Gif sur Yvette
This paper presents the analysis of the VENUS-3 PWR Pressure Vessel Surveillance Dosimetry Benchmark using the three-dimensional (3D) continuous-energy Monte Carlo code TRIPOLI-4.3. VENUS-3 benchmark specifications are taken from the 2004 release of the International Database for Integral Shielding Experiments (SINBAD) of OECD/NEA. Pointwise nuclear data library for TRIPOLI-4.3 transport calculations were prepared from ENDF/B-VI.4. Detector cross sections for 27 Al(n,φ), 58 Ni(n,p), and 115 n(n,n′) from IRDF-2002, IRDF-90.v2, and ENDF/B-VI.4 have been investigated. Two 235 U fission spectra, continuous Watt spectrum and 581 group ENDF/B-VI.4 spectrum have been compared. To speed up the simulation and to predict the axial (50-cm) and azimuthal (0̊-90̊) variation of the reaction rates for core barrel measurement points, variance reduction techniques using cylindrical surface detector and cylindrical biasing meshes have been applied and demonstrated. C/E values at 160 different locations have been evaluated. Without taking into account the uncertainty of the nuclear data in transport calculation and the uncertainty of the 3D neutron source distribution, a 10 % C/E tolerance margin should be accepted.
Paper ID: JAI100338