Header menu link for other important links
X
Review of concrete performance at elevated temperature and hot sodium exposure applications in nuclear industry
K. M. Mohammed Haneefa,
Published in
2013
Volume: 258
   
Pages: 76 - 88
Abstract
In the normal operating conditions of fast breeder reactors [FBRs], liquid sodium is used as heat transfer medium at the maximum temperature of 550 °C. Sodium leakage accidents pose various safety issues related to loss in structural integrity and performance characteristics of concrete structures. Thermo-chemical interactions of liquid sodium with concrete at 550 °C and above result in degradation of concrete in several ways. Concrete is a composite material and exhibits instability due to thermal and chemical loading of hot sodium. The increase in concrete temperature leads to a sequence of events-dehydration of cement paste above 100 °C, crack formation in the range of 400-1000 °C, decomposition of hydrated cement products like calcium hydroxide [Ca(OH)2] at 450 °C, mineralogical changes in aggregates above 500 °C, disintegration of calcium silicate hydrates [CSHs] above 600 °C and formation of glassy powder around 1200 °C. Thermo-chemical interaction of concrete with sodium consists of three phases, namely, initiation, propagation and termination. Initiation phase is accompanied with liberation of moisture from the interior of concrete and its subsequent reactions with sodium resulting in the formation of sodium hydroxide [NaOH], hydrogen gas [H2], sodium oxide [Na2O] and sodium hydride [NaH]. Propagation and termination phase are governed by total sodium leaked, temperature at the reaction interface and types of aggregate used. To protect the structural concrete from deterioration, generally a sacrificial layer of cement composite is employed. Damage behavior of this sacrificial layer depends on total amount, exposure time and impact velocity of leaked sodium, along with composition, water to cement ratios and age of sacrificial concrete used in the floor and wall of the reactor building. This paper presents a compilation of various studies conducted by researchers over the years on performance of concrete at elevated temperature and in the presence of sodium. © 2013 Elsevier B.V.
About the journal
JournalNuclear Engineering and Design
ISSN00295493
Open AccessNo
Concepts (21)
  •  related image
    Calcium silicate hydrate
  •  related image
    CONCRETE TEMPERATURES
  •  related image
    FAST BREEDER REACTORS
  •  related image
    MINERALOGICAL CHANGES
  •  related image
    NORMAL OPERATING CONDITIONS
  •  related image
    Performance characteristics
  •  related image
    THERMO-CHEMICAL INTERACTIONS
  •  related image
    WATER TO CEMENT (BINDER) RATIOS
  •  related image
    Aggregates
  •  related image
    Cements
  •  related image
    Composite materials
  •  related image
    CONCRETE AGGREGATES
  •  related image
    CONCRETE PRODUCTS
  •  related image
    Degradation
  •  related image
    Disintegration
  •  related image
    Fast reactors
  •  related image
    Hydration
  •  related image
    Liquid metals
  •  related image
    Nuclear industry
  •  related image
    Sodium compounds
  •  related image
    Sodium