... a given cross section. pressure tube hot extrusion simulation FEM Zr-2.5 wt. %Nb ZIRCONIUM IN THE NUCLEAR INDUSTRY: 17TH INTERNATIONAL SYMPOSIUM 282 STP 1543, 2015 / available online at www.astm.org / doi: 10.1520/STP154320130023 N. Saibaba,1 N. Keskar,2 K. V. Mani Krishna,2 V. Raizada,3 K...

... Early generation of Indian pressurised heavy water reactor (PHWR) units—MAPS-1and 2, NAPS-1 and 2, and KAPS-1 had used Zircaloy-2 pressure tubes. Corrosion of the zirconium alloy pressure tube in the high temperature (250°C–300°C) heavy water coolant flowing through it results in formation...

... Creep experiments have been performed on biaxially stressed 10 mm diameter Zr-2.5Nb capsules. As the pressurized capsules were obtained from micro-pressure tubes, which were fabricated by the same process as CANDU power reactor pressure tubes, they have a similar microstructure...

... Pressure tubes for CANada Deuterium Uranium (CANDU) reactors are extruded from billets of Zr-2.5Nb, at a temperature of ∼815C, and then cold drawn to give a final length of ∼6 m. The manufacturing process often results in a variation of properties along the length of a tube including grain...

... In the case of Zr-2.5%Nb pressure tube material, certain tramp elements (Cl, P, and C) have a deleterious effect on the fracture properties. In order to dramatically reduce the amount of these impurities, vacuum arc re-melting is adopted. The effect of the melting practice (double or quadruple...

... To determine the fracture properties of Zr-2.5Nb pressure tubes irradiated until the end of design life, cantilever beam, curved compact toughness, and transverse tensile samples were prepared from a typical pressure tube and irradiated in the high flux reactor OSIRIS at CEA, Saclay, France...

... Specimens of pressure tubes made from Zr-2.5Nb by various fabrication routes were irradiated in research reactors to evaluate the response of their fracture toughness (represented by crack growth resistance, dJ/da) at 250°C to irradiation by fast neutrons (E > 1 MeV). The reference route...

... The primary factors influencing the crack growth resistance of irradiated Zr-2.5Nb pressure tube material at low concentrations of hydrogen/deuterium are reviewed. These factors include the initial characteristics of the material, which have brought about improvements in the toughness...

... components. The fracture toughness values of these components are determined using standard ASTM specimens and testing procedures. For internally-pressurized tubes, the fracture toughness values are used in combination with theoretically-derived crack driving forces to determine the unstable, or critical...

... Some pressure tubes in reactors moderated by heavy water have been made from heat-treated (HT) Zr-2.5Nb. One such tube was removed from the NPD nuclear reactor after 20 years of operation. An extensive program was carried out jointly by AECL and PNC to evaluate the condition and properties...

... The effects of extrusion temperature and pre-heat soak time for billets on the mechanical properties of Zr-2.5Nb pressure tubes for CANDU reactors have been examined. The β-quenched billets from a quadruple-melted ingot containing approximately 1200 ppm of oxygen were extruded at 780, 815...

... The steps required for the development of a Zr-2.5Nb pressure tube with a 30-year service life are outlined. The life-limiting factors of fracture and deformation are described, and progress towards closing the gap between the properties required to meet the target lifetime and the behavior...

... pressure tubes, were utilised. The cladding tubes were from fuel elements of Tarapur Atomic Power Station (TAPS) that had experienced burnup ranging from 6000 to 15000 MWD/T. The pressure tubes had undergone 3.6 Effective Full Power Years of operation in Rajasthan Atomic Power Station (RAPS). Of the two...

... Zircaloy is commonly used for the cladding or pressure tubes in commercial nuclear reactors because of its strength, corrosion resistance, and low absorption of thermal neutrons. Fracture toughness test techniques using small samples fabricated from archival materials from the N Reactor pressure...

... Tests of full-size pressure tubes and compact tension specimens having several widths are carried out with emphasis on the size effect on the fracture toughness of the pressure tube material, which is made of heat-treated Zr-2.5Nb. The hydrogen concentration of the specimens ranges from 10...

... Rupture of a cold-worked Zircaloy-2 pressure tube in Pickering Unit 2 in 1983 occurred when a crack developed from an array of hydride blisters. These had formed on the outside surface of the pressure tube where it contacted the surrounding calandria tube. Fol-lowing this event, a comprehensive...

... oriented, surface crack in the wall of a pressure tube, a quarter of the tube cross section was modeled in plane strain. Three different crack penetrations were examined by specifying crack depth to wall thickness ratios ( a/t ) equal to 0.25, 0.5, and 0.75. The crack-tip stress-strain field was simulated...

... On 1 August 1983, a Zircaloy-2 pressure tube in Ontario Hydro's Pickering-2 reactor failed by the unstable propagation of an axial crack. The reactor was quickly and safely shut down, without the need for any emergency cooling, and an extensive investigation into the event was initiated. One...

... This paper addresses problems involved in measuring fracture toughness of thin pressure tube material which, in the presence of radial-axial hydrides, undergoes a significant brittle to ductile fracture transition. Compact tension specimens (∼5 mm thickness) are machined from flattened tensile...

... A complete flaw evaluation of a longitudinal defect in a CANDU (CANada Deuterium Uranium) reactor pressure tube requires knowledge of the axial fracture toughness of the material. This paper addresses the problem of measuring fracture toughness of thin pressure tube material. Compact tension...