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The prediction of moisture and temperature distribution in a concrete reactor containment

Åhs, Magnus LU and Poyet, Stéphane (2015) In TVBM
Abstract
The objective in this research has been to predict the current and future moisture and temperature distribution in a concrete reactor containment, RC. The overall objective in this project was to create a model to be able to predict the moisture and temperature distribution in the concrete wall of the RC of a Pressurized Water Reactor, PWR. In addition, one objective was to design a model to simulate the climate exposure through an operational time of about 60 years. In order to accomplish this, the material properties to be used in a transient moisture and heat transfer model had to be estimated.

A three dimensional finite element model was developed to simulate the moisture and temperature conditions during the first 30 years of... (More)
The objective in this research has been to predict the current and future moisture and temperature distribution in a concrete reactor containment, RC. The overall objective in this project was to create a model to be able to predict the moisture and temperature distribution in the concrete wall of the RC of a Pressurized Water Reactor, PWR. In addition, one objective was to design a model to simulate the climate exposure through an operational time of about 60 years. In order to accomplish this, the material properties to be used in a transient moisture and heat transfer model had to be estimated.

A three dimensional finite element model was developed to simulate the moisture and temperature conditions during the first 30 years of operation and also to predict the coming 30 years of an RC. The model uses the relative humidity as the driving potential. The model also presents methods to take into account the temperature dependency of the moisture properties, such as the moisture fixation i.e. sorption isotherm and the moisture transport properties, i.e. the diffusion coefficient. Thermal properties were considered to be const ant, .i.e. they were assumed not to be affected by the moisture content.

The developed hygro-thermal model was applied in COMSOL Multiphysics, a mathematical software, and used in a number of simulations. The model is developed to predict moisture and temperature distributions in a RC when there is a significant temperature gradient through the concrete structure, which is the case in a PWR. The exterior surface of the RC is exposed to the natural climate.

The results from the simulated moisture distributions of a concrete RC were compared with results from measurement performed on a Swedish concrete RC, Ringhals. The simulated moisture distributions in this project and the moisture distribution determined on the Swedish concrete RC were found to qualitatively correspond to each other. There was no possibility to compare the moisture distribution quantitatively. (Less)
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author
organization
publishing date
type
Book/Report
publication status
published
subject
in
TVBM
issue
7218
pages
72 pages
publisher
Division of Building Materials, LTH, Lund University
ISSN
0348-7911
language
English
LU publication?
yes
id
084292f1-dbad-4589-a825-ba7dfcf6692a
date added to LUP
2018-06-21 13:23:56
date last changed
2018-06-25 09:43:59
@techreport{084292f1-dbad-4589-a825-ba7dfcf6692a,
  abstract     = {The objective in this research has been to predict the current and future moisture and temperature distribution in a concrete reactor containment, RC. The overall objective in this project was to create a model to be able to predict the moisture and temperature distribution in the concrete wall of the RC of a Pressurized Water Reactor, PWR. In addition, one objective was to design a model to simulate the climate exposure through an operational time of about 60 years. In order to accomplish this, the material properties to be used in a transient moisture and heat transfer model had to be estimated.<br/><br/>A three dimensional finite element model was developed to simulate the moisture and temperature conditions during the first 30 years of operation and also to predict the coming 30 years of an RC. The model uses the relative humidity as the driving potential. The model also presents methods to take into account the temperature dependency of the moisture properties, such as the moisture fixation i.e. sorption isotherm and the moisture transport properties, i.e. the diffusion coefficient. Thermal properties were considered to be const ant, .i.e. they were assumed not to be affected by the moisture content.<br/><br/>The developed hygro-thermal model was applied in COMSOL Multiphysics, a mathematical software, and used in a number of simulations. The model is developed to predict moisture and temperature distributions in a RC when there is a significant temperature gradient through the concrete structure, which is the case in a PWR. The exterior surface of the RC is exposed to the natural climate.<br/><br/>The results from the simulated moisture distributions of a concrete RC were compared with results from measurement performed on a Swedish concrete RC, Ringhals. The simulated moisture distributions in this project and the moisture distribution determined on the Swedish concrete RC were found to qualitatively correspond to each other. There was no possibility to compare the moisture distribution quantitatively.  },
  author       = {Åhs, Magnus and Poyet, Stéphane},
  institution  = {Division of Building Materials, LTH, Lund University},
  issn         = {0348-7911},
  language     = {eng},
  number       = {7218},
  pages        = {72},
  series       = {TVBM},
  title        = {The prediction of moisture and temperature distribution in a concrete reactor containment},
  year         = {2015},
}