Measuring the fracture properties of irradiated reactor core graphite

Tzelepi, Athanasia; Ramsay, Paul; Steer, Alan; Dinsdale-Potter, John H.

doi:10.1016/j.jnucmat.2018.07.024

Cited by 18 publications

(10 citation statements)

References 23 publications

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“…In accordance with the model of Deng et al [57], crack tip blunting in the irradiated Gilsocarbon (pore sizes = ~200-400 µm in diameter) should yield reductions in KI at the crack tip of ~5-10%. This is in the range of expected changes in fracture toughness with irradiation alone [23,27,28]. The existence of crack tip blunting in the irradiated Gilsocarbon sample is relatable to the increased open pore structure following radiolytic oxidation, the higher density of larger macro-pores throughout the microstructure in Fig.…”

Section: Crack Propagation and Arrestmentioning

confidence: 58%

“…an adequate coverage of pores along the crack front), also provide an alternative, resistance-free route for crack growth. This likely explains why, despite exclusive exposure to fast neutron irradiation having a toughening effect on graphite as a function of irradiation dose [23,26,27], its combination with radiolytic oxidation reverses this trend to produce a net reduction in fracture toughness that is only magnified with increasing irradiation dose and weight loss [28].…”

Section: Crack Propagation and Arrestmentioning

confidence: 99%

“…Simultaneous to this, radiolytic oxidation internally corrodes the graphite, expanding and opening porosity networks and reducing the graphite's overall density [20,21]. These processes correlate with significant changes in the strength and fracture properties of nuclear graphite [22][23][24][25][26][27][28]. However, to date, there is a limited understanding of how the irradiation and radiolytic oxidation-induced evolution of the graphite 3 microstructure influences the microstructural mechanisms that govern the material's strength performance and fracture behaviour.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

4D synchrotron X-ray microtomography of fracture in nuclear graphite after neutron irradiation and radiolytic oxidation

Wade-Zhu

Krishna

Bodey

et al. 2020

Carbon

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Herein, the first study is presented using 4D synchrotron X-ray microtomography to capture all stages of crack development in neutron irradiated and radiolytically oxidised nuclear graphite.Employing a novel loading setup, specimens of Gilsocarbon graphite, both unirradiated and irradiated at 301 °C to 19.7 x 1020 neutrons/cm2 (~2.6 displacements/atom (dpa)), were loaded to generate a crack.All stages of the fracture process were then captured using synchrotron X-ray imaging. Reconstructed tomographic images and 3D segmented crack volumes have been used to observe and analyse the irradiation-induced evolution of the graphite microstructure as well as corresponding changes in the crack initiation, propagation, and arrest behaviour of graphite after neutron irradiation. Close examination of the applied stress-strain curves highlights the suppression of micro-crack-based damage accumulation in irradiated graphite. Moreover, as well as the crack-bridging and deflection mechanisms characteristic of unirradiated graphite, crack arrest in the irradiated graphite is shown to be significantly influenced by crack tip blunting. This change is associated with the growth of the open pore structure of graphite, specifically the enlargement and increased frequency of macro-pores, resulting from the simultaneous radiolytic oxidation of the graphite microstructure during neutron irradiation.

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Section: Crack Propagation and Arrestmentioning

confidence: 58%

Section: Crack Propagation and Arrestmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

4D synchrotron X-ray microtomography of fracture in nuclear graphite after neutron irradiation and radiolytic oxidation

Wade-Zhu

Krishna

Bodey

et al. 2020

Carbon

View full text Add to dashboard Cite

show abstract

“…Isotropic characteristics of this graphite material can be obtained in the manufacturing process using isopressure method. Figure 4 shows the calculation results of modulus of elasticity based on the propagation time measurements results using ultrasonic method as shown in Table 2 using equations (1) and (2). The notation X, Y and Z indicate the value of the modulus of elasticity in direction of the coordinate axes X, Y, and Z.…”

Section: Resultsmentioning

confidence: 99%

“…As a structural material, graphite reactor core will receive high neutron exposure, high temperatures and loads. Therefore, the fracture behavior of the graphite material has a strong impact to the safety of the reactor as a whole [2]. Neutron exposure is a main trigger for material aging which is not occurred in non-nuclear power plants.…”

mentioning

confidence: 99%

Mechanical Properties Prediction of Ig-110 Graphite by Non Destructive Inspection Using Ultrasonic Method

Himawan

Haryanto

Setiawan

2019

jsmi

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MECHANICAL PROPERTIES PREDICTION OF IG-110 GRAPHITE BY NON DESTRUCTIVE INSPECTION USING ULTRASONIC METHOD. The core structure of high temperature gas cooled reactor is the most important part of the reactor which its integrity must be ensured during operation stage. The structure of reactor core must ensure the position of fuel to be kept in its position, to ensure the control rods can get into the guiding canal, and to ensure the flow of the gas coolant. One of the stressor of the graphite material degradation is neutron exposure. The impact of neutron exposure is the change in mechanical properties such as modulus of elasticity. In order to ensure the integrity of the materials, an in-service non-destructive inspection is implemented. The aim of this study is to develop non-destructive inspection method in order to predict mechanical properties of graphite materials. Inspections were done using Ultrasonic Flaw Detector with 35×35×55 [mm] block-shaped specimens made of graphite IG-110. Two types of transducer were used to generate longitudinal and transversal waves with the same frequency of 5 MHz. Two mechanical properties were predicted, that are isotropic characteristic and the modulus of elasticity. The predicted value of the modulus of elasticity was verified by conducting compressive tests using 10×10×10 [mm] cube specimens. According to the ultrasonic propagation velocities resulted from ultrasonic inspection results showed that the graphite IG-110 is an isotropic material. From the calculation of the modulus of elasticity based on measurement results of transversal and longitudinal waves propagation, IG-110 graphite has a value of modulus of elasticity of 9.1 GPa. Compared to the modulus of elasticity measured from compressive test, this value was 10% lower. It can be concluded that the ultrasonic non-destructive inspection can be used to predict mechanical properties of the IG-110 graphite.

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An Uncertainty Evaluation on the ΔKth and ΔKIC of Fine-grained Isotropic Graphite

Zhang,

Zhu,

Yan

et al. 2024

Acta Mech. Solida Sin.

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Measuring the fracture properties of irradiated reactor core graphite

Cited by 18 publications

References 23 publications

4D synchrotron X-ray microtomography of fracture in nuclear graphite after neutron irradiation and radiolytic oxidation

4D synchrotron X-ray microtomography of fracture in nuclear graphite after neutron irradiation and radiolytic oxidation

Mechanical Properties Prediction of Ig-110 Graphite by Non Destructive Inspection Using Ultrasonic Method

An Uncertainty Evaluation on the ΔKth and ΔKIC of Fine-grained Isotropic Graphite

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