NUSAFE - Reactor Safety

The assessment and improvement of the safety of nuclear reactors together with the protection of the population against radiation exposure constitute strategic long-term goals of the Helmholtz reactor safety research even after termination of nuclear electricity generation in Germany. The research in this topic concentrates on the one hand on the development of a coupled simulation tool that covers the complete calculation chain from the creation of input data over the conduction of core analyses until the analysis of design basis accidents. On the other hand, the research is dedicated to the further development of the international Severe Accident Management based on an improved plant-specific modeling of the possible radiological source term coupled with specific emergency management measures.

Subtopic 2.1: Design Basis Accidents and Materials Research

B. Chanaron, C. Ahnert, N. Crouzet, V. Sanchez, […], S. Kliem, et al., Advanced multi-physics simulation for reactor safety in the framework of the NURESAFE project, Ann. Nucl. Energy  84, 166 (2015)

A. Das, H.-W. Viehrig, F. Bergner, C. Heintze, E. Altstadt, J. Hoffmann, Effect of microstructural anisotropy on fracture toughness of hot rolled 13Cr ODS steel - the role of primary and secondary cracking, J. Nucl. Mater. 491, 83 (2017) DOI: 10.1016/j.jnucmat.2017.04.059

W. Ding, T. Geißler, E. Krepper, U. Hampel, Critical heat flux as a mass flux dependent local or global phenomenon: Theoretical analysis and experimental confirmation, Int. J.Therm. Sci. 130, 200 (2018) 10.1016/j.ijthermalsci.2018.04.040

C. Heintze, I. Hilger, F. Bergner, T. Weissgärber, B. Kieback, Nanoindentation of single- (Fe) and dual-beam (Fe and He) ion-irradiated ODS Fe-14Cr-based alloys: effect of the initial microstructure on irradiation-induced hardening, J. Nucl. Mater. 518, 1 (2019) 10.1016/j.jnucmat.2019.02.037

T. Höhne, S. Gabriel, Simulation of a counter-current horizontal gas-liquid flow experiment at the WENKA channel using a droplet entrainment model, Ann. Nucl. Energy 121, 414 (2018)

V. Jauregui Chavez, U. Imke, V. Sanchez-Espinoza, TWOPORFLOW: A two-phase flow porous media code, main features and validation with BWR-relevant bundle experiments, Nucl. Eng. Des. 338, 181 (2018)

E. Nikitin, E. Fridman, Extension of the reactor dynamics code DYN3D to SFR applications – Part I: Thermal expansion models, Ann. Nucl. Energy 119, 382 (2018)  10.1016/j.anucene.2018.05.015

M. Knebel, L. Mercatali, V. Sanchez, R. Stieglitz, R. Macian-Juan, Validation of the Serpent 2-DYNSUB code sequence using the Special Power Excursion Reactor Test III (SPERT III) Ann. Nucl. Energy  91, 79 (2016)

E. Krepper, R. Rzehak, D. Lucas, Validation of a closure model framework for turbulent bubbly two-phase flow in different flow situations, Nucl. Eng. Des. 340, 388 (2018) 10.1016/j.nucengdes.2018.09.042

Y. Liao, D. Lucas, Poly-disperse simulation of flash evaporation of water inside a large vertical pipe using class method of population balance, Int. J. Heat Fluid Fl. 77, 299 (2019) 10.1016/j.ijheatfluidflow.2019.05.005

J. Pacio, M. Daubner, F. Fellmoser, K. Litfin, T. Wetzel, Heat transfer experiment in a partially (internally) blocked 19-rod bundle with wire spacers cooled by LBE, Nucl. Eng. Des. 330, 225 (2018)

J. Pacio, T. Wetzel, H. Doolaard, F. Roelofs, K. Van Tichelen, Thermal-hydraulic study of the LBE-cooled fuel assembly in the MYRRHA reactor: Experiments and simulations, Nucl. Eng. Des. 312, 327 (2016)

V. Tsisar, C. Schroer, O. Wedemeyer, A. Skrypnik, J. Konys, Effect of Structural State and Surface Finishing on Corrosion Behavior of 1.4970 Austenitic Steel at 400 and 500 °C in Flowing Pb-Bi Eutectic With Dissolved Oxygen, ASME J. of Nuclear Rad. Sci. 1(4), 047001 (2015)

V. Tsisar, C. Schroer, O. Wedemeyer, A. Skrypnik, J. Konys, Characterization of corrosion phenomena and kinetics on T91 ferritic/martensitic steel exposed at 450 and 550 °C to flowing Pb-Bi eutectic with 10⁻⁷  mass% dissolved oxygen, J. Nucl. Mater. 494, 422 (2017)

F. Röder, C. Heintze, […], F. Bergner, A. Ulbricht, E. Altstadt, Nanoindentation of ion-irradiated reactor pressure vessel steels – model-based interpretation and comparison with neutron irradiation, Philos. Mag. 89, 911 (2018) 10.1080/14786435.2018.1425007


Subtopic 2.2: Beyond Design Basis Accidents and Emergency Management

X. Gaus-Liu, A. Miassoedov, Influence of Boundary Conditions, Vessel Geometry, and Simulant Materials on the Heat Transfer of Volumetrically Heated Melt in a Light Water Reactor Lower Head. ASME J. of Nuclear Rad. Sci. 3(3), 031003 (2017) DOI: 10.1115/1.4035853

I. Gómez-García-Toraño, V. Sánchez-Espinoza, R. Stieglitz, J. Stuckert, L. Laborde, et al., Validation of ASTECV2.1 based on the QUENCH-08 experiment, Nucl. Eng. Des. 314, 29 (2017)

I. Gómez-García-Toraño, V. Sánchez-Espinoza, R. Stieglitz, C. Queral, M. Rebollo, Assessment of primary and secondary bleed and feed procedures during a Station Blackout in a German Konvoi PWR using ASTECV2.0, Ann. Nucl. Energy 113, 476 32.02.11

M. Grosse, S. Pulvermacher, M. Steinbrück, B. Schillinger, In-situ neutron radiography investigations of the reaction of Zircaloy-4 in steam, nitrogen/steam and air/steam atmospheres, Physica B  Condens. Matter. 551, 244 (2018)

S. Kelm, W. Jahn, J. Lehmkuhl, H.-J. Allelein,  A comparative assessment of different experiments on buoyancy driven mixing processes by means of CFD, Ann. Nucl. Energy 93, 50 (2016)

S. Kelm, R. Kapulla, H.-J. Allelein, Erosion of a confined stratified layer by a vertical jet - detailed assessment of a CFD approach against the OECD/NEA PSI Benchmark, Nucl. Eng. Des. 312, 228 (2017)

M. Kurata, M. Barrachin, T. Haste, M. Steinbrück, Phenomenology of BWR fuel assembly degradation, J. Nucl. Mater 500, 119 (2018)

J. Lehmkuhl, S. Kelm, M. Bucci, H.-J. Allelein, Improvement of wall condensation modeling with suction wall functions for containment application, Nucl. Eng. Des. 299, 105 (2016)

S. Moehrle, W. Raskob, Structuring and reusing knowledge from historical events for supporting nuclear emergency and remediation management Eng. Appl. Artif. Intel. 46(Part B) 303 (2015)

H. Nowack, P. Chatelard, L. Chailan, S. Hermsmeyer, V. Sanchez, et al., CESAM – Code for European severe accident management, EURATOM project on ASTEC improvement, Ann. Nucl. Energy 116, 128 (2018)

W. Raskob, T. Almahayni, N. Beresford, Radioecology in CONFIDENCE: Dealing with uncertainties relevant for decision making, J. Environ. Radioact .192, 399 (2018)

E.-A. Reinecke, S. Kelm, P.-M. Steffen, M. Klauck, H.-J. Allelein, Validation and application of the REKO-DIREKT code for the simulation of passive auto-catalytic recombiners (PARs) operational behavior, Nucl. Technol .196(2), 355 (2016)

E.-A. Reinecke, A. Bentaïb, J. Dornseiffer, D. Heidelberg, F. Morfin, P. Zavaleta, H.-J. Allelein, A first orienting investigation of the interaction of cable fire products with passive auto-catalytic recombiners (PARs), Nucl. Technol. 196(2), 367 (2016)

T. Schneider, F. Gering, S. Charron, M. Zhelezniak, […], W. Raskob, Nuclear and Radiological Preparedness: The Achievements of the European Research Project PREPARE, Radiat. Prot. Dosim. 173(1-3), 151(2017)

T. Schneider, S. Lafage, J. Bardelay, T. Duranova, […], W. Raskob, NERIS: European platform on preparedness for nuclear and radiological emergency response and recovery - Activities and perspectives, Radioprotection 51(HS1), S5 (2016)