Author: Atomic Energy of Canada LimitedPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Deformation and Failure of Zircaloy Fuel Sheaths Under Local Conditions
Author: Atomic Energy of Canada LimitedPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Deformation and Failure of Zircaloy Fuel Sheaths Under LOCA Conditions
Author: S. SagatPublisher:
ISBN:
Category : Alloys
Languages : en
Pages : 25
Book Description
A unified, microstructural creep law which simulates the transient creep deformation of Zircaloy at temperatures above 750 K has been used to follow the interaction of diffusional and dislocation creep with changes in material microstructure (grain size, recrystallization, phase fraction and anisotropy) under loss-of-coolant accident (LOCA) conditions. Comparison of a membrane sheath model using this creep law with a large number of tube tests (>700) in an inert environment has demonstrated good predictive capability.
Deformation and failure of zircaloy fuel sheaths under loca conditions
Author: S. SagatZirconium in the Nuclear Industry
Author: Zirconium in the Nuclear Industry
Author: D. G. FranklinPublisher: ASTM International
ISBN: 9780803102705
Category : Science
Languages : en
Pages : 866
Book Description
Deformation and Fracture Characteristics of Spent Zircaloy Fuel Cladding
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
For a better understanding of Zircaloy fuel-rod failure by the pellet-cladding interaction (PCI) phenomenon, a mechanistic study of deformation and fracture behavior of spent power reactor fuel cladding under simulated PCI conditions was conducted. Zircaloy-2 cladding specimens, obtained from fuel assemblies of operating power reactors, were deformed to fracture at 325°C by internal gas pressurization in the absence of fission product simulants. Fracture characteristics and microstructures were examined via SEM, TEM, and HVEM. Numerous dislocation tangles and cell structures, observed in TEM specimens of cladding tubes that failed in a ductile manner, were consistent with SEM observations of a limited number of dimples characteristic of microvoid coalescence. A number of brittle-type failures were produced without the influence of fission product simulants. The brittle cracks occurred near the areas compressed by the Swagelok fittings of the internally pressurized tube and propagated from the outer to the inner surface. Since the outer surface was isolated and maintained under a flowing stream of pure helium, it is unlikely that the brittle-type failure was influenced by any fission product traces. SEM fractography of the brittle-type failure revealed a large area of transgranular pseudocleavage with limited areas of ductile fluting, which were similar in appearance to the surfaces produced by in-reactor PCI-type failures. A TEM evaluation of the cladding in the vicinity of the through-wall crack revealed numerous locations that contained an extensive amount of second-phase precipitate (Zr3O). We believe that the brittle-type failures of the irradiated spent fuel cladding in the stress rupture experiments are associated with segregation of oxygen, which leads to the formation of the order structure, an immobilization of dislocations, and minimal plastic deformation in the material.
Deformation and Rupture Behavior of Zircaloy Cladding Under Simulated Loss-of-Coolant Accident Conditions
Author: HM. ChungPublisher:
ISBN:
Category : Deformation
Languages : en
Pages : 16
Book Description
Information on the diametral expansion and rupture characteristics of Zircaloy-4 cladding has been obtained in a vacuum environment over a wide range of internal pressures at several heating rates. The effect of axial constraint of the cladding, exerted by a mandrel that simulated the pellets in a fuel rod, on the relationship between the maximum circumferential strain and the burst temperature also was investigated. The circumferential strain for unconstrained cladding was significantly larger than for axially constrained tubes, particularly for burst temperatures below ~850°C, in which cladding remains essentially in the ?-phase. Three superplastic strain peaks have been identified, namely, at rupture temperatures of ~850, ~1050, and ~1220°C. In the case of complete axial restraint, the failure strains were not dependent on heating rate for burst temperatures above ~920°C; however the low-temperature (~850°C) strain peak increases and moves to lower temperatures as the heating rate decreases. The deformation data in this investigation also have been used to evaluate instability criteria proposed for thin-wall tubes under a biaxial stress state. The onset of plastic instability or local ballooning in the cladding has been defined in terms of the effective stress and strain during transient-heating conditions.
Fracture Behavior of Zircaloy Spent-fuel Cladding
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The Zircaloy cladding of water reactor fuel rods is susceptible to local breach-type failure, commonly known as pellet-cladding interaction (PCI) failure, during operational and off-normal power transients after the fuel has achieved a sufficiently high burnup. An optimization of power ramp procedures or fuel rod fabrication to minimize the cladding failure would result in a significant decrease in radiation exposure of plant personnel due to background and airborne radioactivity as well as an extension of core life in terms of allowable off-gas radioactivity. As part of a program to provide a better understanding of the fuel rod faiure phenomenon and to facilitate the formulation of a better failure criterion, a mechanistic study of the deformation and fracture behavior of high-burnup spent-fuel cladding is in progress under simulated PCI conditions.
Energy Research Abstracts
Author: Ceramic Materials for Energy Applications III, Volume 34, Issue 9
Author: Hua-Tay LinPublisher: John Wiley & Sons
ISBN: 1118807855
Category : Technology & Engineering
Languages : en
Pages : 204
Book Description
Ceramic Engineering and Science Proceedings Volume 34, Issue 9 - Ceramic Materials for Energy Applications III A collection of 15 papers from The American Ceramic Society's 37th International Conference on Advanced Ceramics and Composites, held in Daytona Beach, Florida, January 27-February 1, 2013. This issue includes papers presented in Symposia 6 - Advanced Materials and Technologies for Rechargeable Energy Storage; Symposium 13 - Advanced Ceramics and Composites for Sustainable Nuclear Energy and Fusion Energy; Focused Session 4 - Advanced Processing for Photonics and Energy; and the Engineering Summit of the Americas session.