LOCA evaluation considering critical flow model with uncertainty parameters

Ilsuk Lee, Youngseog Bang, Deogyeon Oh, Yongchan Kim

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The purpose of the present work is to study the sensitivity of uncertainty parameters of critical flow on analysis of LOCA with MARS-KS (Multi-dimensional Analysis for Reactor Safety) used by KINS as independent regulatory assessment. In this paper, the uncertainty of critical flow model is considered by three parameters, thermal non-equilibrium factor, discharge coefficient and length to diameter ratio and it is determined uncertainty ranges by using large-scale Marviken experimental data. Break flow is strongly dependent on thermal non-equilibrium in the ruptured pipe with small L/D ratio, and appropriate thermal non-equilibrium values are provided in this study by analyzing results between Marviken experimental data and MARS-KS code. Additionally, a correlation for the relation between quality at the throat and L/D ratio was developed using the effect of quality with non-equilibrium on the critical mass flow rate. It also evaluated LBLOCA of APR1400 focused on the effect of three uncertainty parameters that affect PCT and the break flow. Results of plant analysis showed that deviation of PCT was 80.5ºC in the uncertainty range owing to super-heated liquid causing from the thermal non-equilibrium.

Original languageEnglish
Title of host publicationPBNC 2018 - Pacific Basin Nuclear Conference
PublisherAmerican Nuclear Society
Number of pages7
ISBN (Electronic)9780894487743
Publication statusPublished - 2019
Event2018 Pacific Basin Nuclear Conference, PBNC 2018 - San Francisco, United States
Duration: 2018 Sept 302018 Oct 4

Publication series

NamePBNC 2018 - Pacific Basin Nuclear Conference


Conference2018 Pacific Basin Nuclear Conference, PBNC 2018
Country/TerritoryUnited States
CitySan Francisco

Bibliographical note

Funding Information:
This work was supported by the Nuclear Safety Research Program through the Korea Foundation of Nuclear Safety (KOFONS) and the Nuclear Safety and Security Commission (NSSC), Republic of Korea (Grant No. 1805004-0118-SB120)

Publisher Copyright:
© 2018 PBNC 2018 - Pacific Basin Nuclear Conference.All Rights Reserved.

ASJC Scopus subject areas

  • Nuclear Energy and Engineering


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