Analysis of a gas stratification break-up by a vertical jet using the GOTHIC code

Hydrogen distribution and Passive Autocatalytic Recombiner (PAR) mitigation in a PWR-KWU containment type

“…As a conclusion, the utilisation of GOTHIC shows clear advantages compared to lumped parameter codes in terms of precision, and to CFD codes, mainly in terms of lower calculation costs thanks to the adoption of a relatively coarse mesh. The fair accuracy of GOTHIC coarse mesh models has been demonstrated with a num ber of experimental exercises, as the OECD/NEA PSI CFD bench mark (at the PANDA facility in Switzerland) (Andreani et al, 2015;Fernández Cosials et al, 2015).…”

Analysis and improvement of hydrogen mitigation strategies during a severe accident in nuclear containments

“…OECD-SETH2 project performed research on the erosion and break-up of a stratified atmosphere. The OECD-SETH 2 project was followed by the International Benchmark Exercise 3 (IBE-3) [118] This experiment has been deeply analyzed [89]. In this benchmark, the participants had to adequately simulate the erosion of a helium stratified layer by a vertical helium jet.…”

“…In this section the validation performed by the author to address some specific characteristics of the Thesis will be made. The first validation exercise showed will be the benchmark exercise made at PANDA facilities in PSI [89,136,137] (which later will become part of the GOTHIC 8.2 qualification Report, [138]). This validation had to do with the stratification break-up of a hydrogen cloud inside a large enclosure.…”

“…The following section is an adaptation of the author's publication, "Analysis of a gas stratification break-up by a vertical jet using the GOTHIC code" [89], published in Nuclear Engineering and Design in 2016. It will describe the insights of the benchmark experiment, the different GOTHIC models used for its simulation, the different sensitivities and finally the Parameter Influence Chart (PIC) of the simulation.…”

“…The following paragraphs describe the state of the art in hydrogen distribution in containment analyses. (Extracted from Fernández-Cosials et al[89]) .Three tools are normally used when simulating the hydrogen distribution in a containment building: lumped parameter codes, CFD codes and containment codes with 3D capabilities. The LP codes, such as MAAP or MELCOR, are found appropriate to simulate a large number of severe accident sequences and phenomenology of core degradation and hydrogen production.…”