Fracture behavior of thin-walled Zircaloy fuel clad tubes of Indian pressurized heavy water reactor

Abstract

For structural integrity analysis of thin walled tubular components such as fuel claddings used in nuclear reactors, knowledge of valid fracture mechanics parameters are required. As axiallycracked thin tubes possess a non-standard geometry from the point of view of specimen fabrication, there is no direct straight forward way to derive their fracture mechanics parameters with known functions as can be done for standard test methods. In the present work, the J-R curve for an axially cracked fuel pin from Indian 220 MWe pressurized heavy water reactor is derived after experimental and analytical derivation of the required parameters and the results are compared with earlier published data for similar material. List of symbolsa Crack length a 0 Crack length at the start of the test a bi Blunting corrected crack size at the ith data point of the load-normalization method b 0 Initial unbroken ligament length of the PLT specimen A Cracked area of the PLT specimen fracture surface A uc Area of the remaining ligament or un-cracked area A el Elastic part of area under the load-displacement curve A pl Plastic part of area under the load-displacement curve C Compliance of the PLT specimens E Young's modulus f (a/W ) Geometric shape function for evaluation of stress intensity factor as a function of a/W for a finite PLT specimen F L Limit load of the PLT specimens J J -integral J 0.2 J-integral corresponding to 0.2 mm crack growth J el Elastic part of J-integral J pl

A geometry-dependent generalized shape function for calculation of stress intensity factor for axially cracked thin-walled tubes

“…The details of the experimental procedure and the analytic derivation for calculation of f(a/W) are available in Ref. (Samal et al 2010a, b;Sanyal and Samal 2012a) and briefly narrated in Appendix. Considering all the three cases it can be inferred that the relative deviation between the generalized function and experimental result is always \±35 %.…”

“…In principle, any technique that can measure stresses or displacements can be applied for an experimental determination of the SIF. The most widely applied experimental procedure is the compliance measurement, as used by the authors (Samal et al 2010a(Samal et al , b, 2011Sanyal and Samal 2012a, b;Sanyal and Samal 2012a). But the best possible accuracy of compliance measurements can be expected if the points of load application are as close to the crack as possible.…”

“…Using those functions, they also calculated J-R curves for two different cladding tubes used in Indian nuclear reactors with experimental data both by load normalization (Sanyal et al 2011a, b;Samal and Sanyal 2012;Sanyal and Samal 2012a, b) and load separation procedure and compared the results (Samal et al 2011). In recent past, Sanyal and Samal (2012a) also assessed axial cracking of steam generator tubes used in Indian pressurized heavy-water reactor (PHWR) for generation of electricity with the same method.…”

Multiaxial ratcheting-fatigue interaction on acrylonitrile-butadiene-styrene terpolymer

“…Following this recommendation, the maximum tensile load and torsional torque to fracture the specimen are beyond the capability of our test machine. Referring other studies of the transport tube , we used the industrial ABS fluent transport tubes as test specimens. The shape and dimensions of a typical test specimen are shown in Fig.…”