The TRAB-SMABRE for 3D Plant Transient and Accident Analyses

Jaakko Miettinen, Hanna Räty, Antti Daavittila

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review


    VTT's three-dimensional TRAB-3D core dynamics code and SMABRE thermal hydraulic system code have been coupled together using an internal coupling scheme in order to increase flexibility in the thermal hydraulics modeling of the core calculation. VTT's reactor dynamics codes have performed well in all the situations that they have originally been designed for. The most important limitation of the present code models is their inability to handle coolant flow reversal in the core channel, a phenomenon that can be encountered in e.g. BWR ATWS cases or WER power excursions. The new coupling of the two codes is realized on the level of each node of each channel in the core, with each fuel bundle described with its own channel. TRAB-3D performs only the neutmnics calculation, SMABRE takes care of the hydraulics calculation of the whole cooling circuit including the reactor core, while heat transfer calculation can be carried out optionally by either code. The codes have earlier been coupled using a parallel coupling scheme. Several modifications were necessary in SMABRE, concerning modeling of hydraulics, heat transfer, geometry and the matrix solution. The accuracy of the steady state calculation in the coupled code has been improved to a level suitable for both PWR and BWR calculations, as compared against the SIMULATE and reference TRAB-3D codes. The BWR dynamics calculations are being tested with single disturbances, such as control rod movements, pump coastdown etc. Besides allowing modeling of reversed flow in the core, the internally coupled code will make future modeling of in-core cross-flows or even 3D flow in a PWR (such as EPR) open core geometry possible, e.g. by using the porous medium approach.
    Original languageEnglish
    Title of host publicationProceedings
    Subtitle of host publicationInternational Conference on Advances in Nuclear Power Plants, ICAPP 2008
    PublisherAmerican Nuclear Society (ANS)
    ISBN (Print)978-0-89448-061-4
    Publication statusPublished - 2008
    MoE publication typeA4 Article in a conference publication
    Event2008 International Congress on Advances in Nuclear Power Plants, ICAPP 2008 - Anaheim, United States
    Duration: 8 Jun 200812 Jun 2008


    Conference2008 International Congress on Advances in Nuclear Power Plants, ICAPP 2008
    Abbreviated titleICAPP 2008
    Country/TerritoryUnited States


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