Analysis of core degradation and relocation phenomena and scenarios in a Nordic-type BWR

Galushin, Sergey; Kudinov, Pavel

doi:10.1016/j.nucengdes.2016.09.029

Cited by 6 publications

(4 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More details can be found in [23]. This model was subsequently used to support the analysis of the effectiveness of severe accident management strategy in Nordic BWRs [7,10], conducted in the Royal Institute of Technology (KTH), to generate the input to dedicated vessel failure analysis models [13] using MELCOR 1.8.6 [12,24]. The Nordic BWR MELCOR model was updated to MELCOR 2.1 and lower plenum nodalization was refined, in order to provide better insights regarding invessel phase of accident progression and debris behavior in the lower plenum, as well as to get better spatial resolution of the lower plenum debris properties.…”

Section: Nordic Bwr Melcor Modelmentioning

confidence: 99%

“…Simulations were performed using simulation driver, implemented in MATLAB, which performs automatic generation of input files, execution of the MELCOR code on multiple parallel calculation threads, adaptive refinement of the maximum time step and restarting in case of crashed calculations, and extraction of the data into the database of solutions and postprocessing of the results. pattern analysis performed in [12] and used as a time point for one-way coupling between MELCOR code and DECOSIM [14] and ANSYS/PECM [13,32] codes, used for analysis of invessel debris coolability and vessel failure mode (see [12] for details).…”

Section: Sampling Of Melcor Scenario Parametersmentioning

confidence: 99%

“…Vessel failure and melt release conditions are dependent on the properties and spatial configuration of the relocated debris in the lower plenum. The properties of debris are determined by progression of core degradation scenarios, timing of possible operator actions, recovery of safety systems (time and capacity of depressurization, water injection) [11,12].…”

Section: Introductionmentioning

confidence: 99%

“…This paper is a follow-up of our previous work [12] where we performed the analysis of the effect of severe accident scenario on the propertied of relocated debris in the lower plenum of Nordic BWR with MELCOR 1.86 (rev2911). In this paper we perform a comparison between the previously obtained results and the results generated with new MELCOR code versions and respective best practices guidelines.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Analysis of the Effect of Severe Accident Scenario on Debris Properties in Lower Plenum of Nordic BWR Using Different Versions of MELCOR Code

Galushin

Kudinov

2019

Science and Technology of Nuclear Installations

Self Cite

View full text Add to dashboard Cite

Nordic Boiling Water Reactors (BWRs) employ ex-vessel debris coolability as a severe accident management strategy (SAM). Core melt is released into a deep pool of water where formation of noncoolable debris bed and ex-vessel steam explosion can pose credible threats to containment integrity. Success of the strategy depends on the scenario of melt release from the vessel that determines the melt-coolant interaction phenomena. The melt release conditions are determined by the in-vessel phase of severe accident progression. Specifically, properties of debris relocated into the lower plenum have influence on the vessel failure and melt release mode. In this work we use MELCOR code for prediction of the relocated debris. Over the years, many code modifications have been made to improve prediction of severe accident progression in light-water reactors. The main objective of this work is to evaluate the effect of models and best practices in different versions of MELCOR code on the in-vessel phase of different accident progression scenarios in Nordic BWR. The results of the analysis show that the MELCOR code versions 1.86 and 2.1 generate qualitatively similar results. Significant discrepancy in the timing of the core support failure and relocated debris mass in the MELCOR 2.2 compared to the MELCOR 1.86 and 2.1 has been found for a domain of scenarios with delayed time of depressurization. The discrepancies in the results can be explained by the changes in the modeling of degradation of the core components and changes in the Lipinski dryout model in MELCOR 2.2.

show abstract

Section: Nordic Bwr Melcor Modelmentioning

confidence: 99%