A1 Journal article (refereed), original research

Pool stratification and mixing induced by steam injection through spargers: analysis of the PPOOLEX and PANDA experiments


Open Access publication

Publication Details
Authors: Gallego-Marcos Ignacio, Kudinov Pavel, Villanueva Walter, Kapulla Ralf, Paranjape Sidharth, Paladino Domenico, Laine Jani, Puustinen Markku, Räsänen Antti, Pyy Lauri, Kotro Eetu
Publisher: Elsevier
Publication year: 2018
Language: English
Related Journal or Series Information: Nuclear Engineering and Design
Volume number: 337
Start page: 300
End page: 316
Number of pages: 17
ISSN: 0029-5493
eISSN: 1872-759X
JUFO-Level of this publication: 3
Open Access: Open Access publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe201901283330

Abstract

Spargers
are multi-hole injection pipes used in Boiling Water Reactors (BWR) and
Advanced Pressurized (AP) reactors to condense steam in large water pools. A
steam injection induces heat, momentum and mass sources that depend on the
steam injection conditions and can result in thermal stratification or mixing
of the pool. Thermal stratification reduces the steam condensation capacity of
the pool, increases the pool surface temperature and thus the containment
pressure. Development of models with predictive capabilities requires the understanding
of basic phenomena that govern the behavior of the complex multi-scale system.
The goals of this work are (i) to analyze and interpret the experiments on
steam injection into a pool through spargers performed in the large-scale
facilities of PPOOLEX and PANDA, and (ii) to discuss possible modelling
approaches for the observed phenomena. A scaling approach was developed to
address the most important physical phenomena and regimes relevant to
prototypic plant conditions. The focus of the tests was on the low steam mass
flux and oscillatory bubble condensation regimes, which are expected during a
long-term steam injection transient, e.g. in the case of a Station Black Out
(SBO). Exploratory tests were also done for chugging and stable jet conditions.
The results showed a similar behavior in PPOOLEX and PANDA in terms of jet
induced by steam condensation, pool stratification, and development of hot
layer and erosion of the cold one. A correlation using the Richardson number is
proposed to model the erosion rate of the cold layer as a function of the pool
dimensions and steam injection conditions.


Last updated on 2019-13-03 at 12:00

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