Jimenez, J.

Sanchez-Espinoza, V.

Vargas, J.

English

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KIT – Universität des Landes Baden-Württemberg undnationales Forschungszentrum in der Helmholtz-GemeinschaftInstitute for Neutron Physics and Reactor Technology (INR)Reactor Physics and Dynamic Group (RPD)www.kit.eduUsing the NEMTAB XS libraries from the Oskarshamn-2 Benchmark with DYN3DJ. Vargas, J. Jiménez, v. Sanchez2Content O2 BWR ABB-Atom Design: Data Neutron Kinetic Core Model: DYN3D Current status• Preliminary Steady State Results obtained with DYN3DOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 20143O2 BWR ABB-Atom Design: DataOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 20144O2 RPV and Core Loading for Cycle 24O2 Core: Radial distribution of the FA-TypesOskarshamn-2 RPVOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 20145Neutron Kinetic Core Model: DYN3DOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 20146XS library specifications    The CASMO code was applied to generate the 2-group macroscopic cross-sections needed for DYN3D calculations. The burnup and the historical parameters are implicitly included in the macroscopic cross-section. 25 axial nodes in the active core are used.  Fifteen branching points for the moderator density are selected. They range from the core inlet density up to the minimum core exit density (in kg/m³): 176.68, 177.44, 177.53, 317.95, 330.85, 341.59, 458.37, 485.01, 505.74, 598.79, 639.18, 669.89, 739.20, 793.35, 834.04.  Eight fuel temperature branching points are selected (in K): 500, 650, 800, 950,1100, 1250, 1400, and 1550.OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 20147XS library specifications    The half core rotational symmetry is used to limit the number of materials therefore leading to a total of different fuel materials of 444/2 * 25 (rodded) + 444/2 *25 (unrodded) + 3 reflector = 11103 XS sets. The XS library is given in 2G NEMTAB format:• Diffusion coefficient• Absorption cross-section• Fission cross-section• Nu-fission cross-section• Scattering cross-section (only from group 1 to group 2)• ADF-West• ADF-South• Macroscopic Xe cross-section (only for group 2)• Microscopic Xe cross-section (only for group 2)OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 20148O2 Core loading according to the XS library In the XS library, 11103 different materials compositions are defined which correspond to 445 (222+1+222) sets of fuel assemblies, they are classified as follow:• Fuel Assemblies from 1 to 222 → unrodded, material from 1 to 5550• Fuel Assembly 223→ radial reflector, materials 5551, 5552 and 5553• Fuel Assemblies from 224 to 445 → rodded, materials from 5554 to 11103OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 20149O2 Core loading according to the XS libraryComposition # Axial Layer unrodded Composition # Axial Layer roddedBottom ReflectorTop ReflectorOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201410Geometry definition The radial node width is assumed to be 15.275 cm.  The active core height is 371.2 cm and is uniformly divided into 25 segments of 14.848 cm each.  As far as the homogenization is concerned:• The active core starts from node 2 end ends in node 26• Node 1 is the bottom reflector• Node 27 is the top reflector Bottom reflector has 23.91 cm and a top reflector 38.15 cmOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201411CR Bank definition In the Oskarshamn-2 power plant the control rods are grouped in 19 banksOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201412CR Bank definition The material composition of the fuel unrodded assemblies OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201413Control rod position For modeling CR entering from the bottom of the core with DYN3DOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201414Preliminary Steady State Results obtained with DYN3DOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201415Considered Cases Objective: Checking the XS library by inserting the CR Banks at 5 different elevations, considering 5 different cases. DYN3D is coupled with FLOCAL  Oskarshamn-2 input deck with XS library given by Benchmark organizers.  Elevation Keff HZP Keff HFP0.0 (ARO) 1.014586 NaN71.2 1.14575 NaN171.2 1.014196 NaN271.2 1.004227 NaN371.2 (ARI) 0.796669 NaNCalc. FailedCase 1OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201416Case 1 Power is very much displaced to the top of the coreBottom of the core Top of the coreElevation Keff HZP0.0 (ARO) 1.01458671.2 1.14575171.2 1.014196271.2 1.004227371.2 (ARI) 0.796669OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201417Case 2 Oskarshamn-2 input deck with XS library given by Benchmark organizers, but inverting axially the materials in the FA (Slide 9).  Bottom of the core Top of the coreElevation Keff HZP0.0 (ARO) 1.01409971.2 0.997035171.2 0.988555271.2 0.969849371.2 (ARI) 0.795158HFPCalc. Failed OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201418Case 3 Peach Bottom Benchmark (Previously validated) DYN3D results coupled with FLOCAL Analysis of the axial power profileElevation Keff HZP Keff HFP0.0 (ARO) 1.082898 1.01799960.96 1.082893 1.021462106.68 1.082869 1.022193167.64 1.082507 1.020976335.28 0.973378 0.842685371,2 (ARI) 0.899009 0.758581OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201419Case 3OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201420 DYN3D executed for this case successfully. The behaviour of axial power distribution as we expected.Case 3OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201421Case 4 Input deck for Oskarshamn-2 but considering the XS library of Peach Bottom Benchmark and repeating one fuel assembly in the whole core.Elevation Keff HZP Keff HFP0.0 (ARO) 1.172246 1.0845271.2 1.171262 1.080034171.2 1.163719 1.066463271.2 1.113755 NaN371.2 (ARI) 0.937954 0.752765OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201422Case 4OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201423 The behaviour of axial power distribution as we expected. Case 4OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201424Case 5 Input deck for Oskarshamn-2 but considering the Oskarshamn XS library and one fuel assembly loaded in the all the core.Bottom of the core Top of the coreElevation Keff HZP0.0 (ARO) 0.90697071.2 0.906969171.2 0.906968271.2 0.905266371.2 (ARI) 0.713506HFPCalc. Failed OECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 201425Conclusions and Outlook Objective: test the DYN3D input deck for Oskarshamn-2 and the XS The HZP calculations show a big accumulation of the power distribution in the top of the core. Some calculations at HFP Failed. • The same tendency in the axial power profile• Too high values of the power which produce unphysical temperatures in FLOCAL and extrapolation of the XS conduce to code crash. The values of Keff seem to be OK at first sight.FUTURE WORK Further testing of the XS libraries• Could be an error in the geometry definition of DYN3D• Could be a problem in XS libraries or in the material type definition Once fixed those issues:• NURESAFE work can continue within WP1.3• Next will follow coupled neutronics computations to this modelOECD/NEA Oskarshamn-2 Third Workshop, GRS, April 12-13, 2014

Using the NEMTAB XS libraries from the Oskarshamn-2 benchmark with DYN3D

https://publikationen.bibliothek.kit.edu/230096105/3816555

Using the NEMTAB XS libraries from the Oskarshamn-2 benchmark with DYN3D

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