Structural integrity assessment of reactor pressure vessels during pressurized thermal shock

Jhung, Myung Jo; Kim, Seok Hun; Choi, Young Hwan; Jung, Sung Gyu; Kim, Jong Min; Kim, Ji Ho; Kim, Jong Wook; Jang, Changheui; Chang, Yoon‐Suk; Kang, Kyungsu

doi:10.1007/s12206-008-0421-x

Cited by 7 publications

(3 citation statements)

References 8 publications

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“…Hasil akhir dari penelitian ini adalah nilai stress intensity factor untuk mengevaluasi keandalan bejana tekan reaktor PWR. Output dari MSC MARC adalah nilaiJintegral, yang kemudian diubah menjadi stress intensity factor (SIF) untuk mengevaluasi keandalan RPV 3-D [8, [17][18].…”

Section: Pendahuluanunclassified

Analisis Probabilistic Fracture Mechanics Pada Evaluasi Keandalan Bejana Tekan Reaktor Secara 3-D

Hartini

Himawan

Susmikanti

2018

urania

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ABSTRAK ANALISIS PROBABILISTIC FRACTURE MECHANICS PADA EVALUASI KEANDALAN BEJANA TEKAN REAKTOR SECARA 3-D. Analisis integritas material sangat diperlukan padaReactor Pressure Vessel (RPV). Komponen tersebut merupakan pressure boundary yang berfungsi untuk mengungkung material radioaktif. Adanya retak pada dinding dapat mempengaruhi integritas RPV tersebut. Penelitian ini bertujuan melakukan analisis fracture mechanics menggunakan model probabilistik untuk evaluasi keandalan RPV. Model probabilistik digunakan untuk pendekatan karakter random dari kuantitas input seperti sifat mekanik material dan lingkungan fisik. Karakter random dari kuantitas input menggunakan teknik sampling berdasarkan probability density function. Material yang digunakan pada RPV adalah baja feritik (SA 533). Analisis fracture mechanics dilakukan berdasarkan metode elemen hingga (FEM) menggunakan perangkat lunak MSC MARC. Output dari MSC MARC adalah nilai J integral untuk mendapatkan nilai stress intensity factor (SIF) pada evaluasi keandalan bejana tekan reaktor 3D. Hasil perhitungan menunjukan bahwa SIF probabilistik lebih dulu mencapai nilai batas fracture toughness dibanding SIF deterministik. Nilai SIF yang dihasilkan dengan metode probabilistik adalah 95,8 MPa m 0,5 , sedangkan dengan metode deterministik adalah 91,8 MPa m 0,5 , rasio crack (a/c) semakin kecil akan dihasilkan nilai SIF yang semakin besar.Kata kunci:Probabilistic fracture mechanics, bejana tekan, 3-D. ABSTRACT PROBABILISTIC FRACTURE MECHANICS ANALYSIS FOR THE EVALUATION OF REACTOR PRESSURE VESSEL RELIABILITY USING 3-D MODEL. Material integrity analysisis required for the reactor pressure vessel (RPV). The component is the pressure boundary that serves to contain radioactive materials. The presence of cracks on the walls can affect the integrity of the RPV. The objective of this studyis to analyze fracture mechanics using probabilistic models for the evaluation of RPV reliability. Probabilistic models are used as an analysis approach for random character of input quantities such as the mechanical properties of materials and the physical environment. The random character of input quantities was obtained by sampling technique base on probability density function. The material used in this study was ferritic steel (SA 533). Fracture mechanics analysis was performed by Finite Element Method (FEM) with MSC MARC software. The outputs of MSC MARC, which is of J integral values,were converted into stress intensity factor (SIF) for evaluating the reliability of RPV in 3D model. It is found thatthe calculation resulted from the SIF by probabilistic method reaches a limit value of fracture toughness earlier tha nthe SIF by deterministic method. The SIF generated by probabilistic method is 95,8 MPa m 0.5 , while the SIF generated by deterministic method is 91,8 MPa m 0.5 , where lower ratio value of (a/c) will produce greater value of SIF.

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Section: Pendahuluanunclassified

Analisis Probabilistic Fracture Mechanics Pada Evaluasi Keandalan Bejana Tekan Reaktor Secara 3-D

Hartini

Himawan

Susmikanti

2018

urania

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“…Chen et al have performed the structural integrity assessment of the RPV under the PTS loading initiated by a loss of coolant accident (LOCA) [7]. Also, Jhung et al have evaluated the structural integrity of RPV based on pressurized thermal shock caused by SBLOCA [8]. Murtaza and Hyder have investigated the fracture mechanics analysis of the set-in nozzle of a RPV based on SBLOCA and Rancho-Seco transient events [9].…”

Section: Introductionmentioning

confidence: 99%

Integrity Evaluation of a Reactor Pressure Vessel Based on a Sequential Abaqus-FRANC3D Simulation Method

Annor-Nyarko

Xia

2021

Science and Technology of Nuclear Installations

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The safety-risk pressurized thermal shock (PTS) have on a reactor pressure vessel (RPV) is one of the most important studies for the lifetime ageing management of a reactor. Several studies have investigated PTS induced by postulated accidents and other anticipated transients. However, there is no study that analyzes the effect of PTS induced by one of the most frequent anticipated operational occurrences—inadvertent operation of the safety injection system. In this paper, a sequential Abaqus-FRANC3D simulation method is proposed to study the integrity status of an ageing pressurized water reactor subjected to PTS induced by inadvertent actuation of the safety injection system. A sequential thermal-mechanical coupling analysis is first performed using a three-dimensional reactor pressure vessel finite element model (3D-FEM). A linear elastic fracture mechanics submodel with a postulated semielliptical surface crack is then created from the 3D-FEM. Subsequently, the submodel is used to evaluate the stress intensity factors based on the M-integral approach coupled within the proposed simulation method. Finally, the stress intensity factors (SIFs) obtained using the proposed method are compared with the conventional extended finite element method approach, and the result shows a good agreement. The maximal thermomechanical stress concentration was observed at the inlet nozzle-inner wall intersection. In addition, The ASME fracture toughness of the reactor vessel’s steel compared with SIFs show that the PTS event and crack configuration analysed may not pose a risk to the integrity of the RPV. This work serves as a critical reference for the ageing management and fatigue life prediction of reactor pressure vessels.

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“…The RPVs are large forgings and with wall thickness of more than 200 mm 11 . Generally, the forged RPVs are quenched and tempered, as result, the through-thickness microstructure vary significantly because of the differential cooling rates during quenching.…”

Section: Introductionmentioning

confidence: 99%

Effect of microstructure on the impact toughness and temper embrittlement of SA508Gr.4N steel for advanced pressure vessel materials

Yang

Liu

et al. 2018

Sci Rep

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The effect of microstructure on the impact toughness and the temper embrittlement of a SA508Gr.4N steel was investigated. Martensitic and bainitic structures formed in this material were examined via scanning electron microscopy, electron backscatter diffraction, transmission electron microscopy, and Auger electron spectroscopy (AES) analysis. The martensitic structure had a positive effect on both the strength and toughness. Compared with the bainitic structure, this structure consisted of smaller blocks and more high-angle grain boundaries (HAGBs). Changes in the ultimate tensile strength and toughness of the martensitic structure were attributed to an increase in the crack propagation path. This increase resulted from an increased number of HAGBs and refinement of the sub-structure (block). The AES results revealed that sulfur segregation is higher in the martensitic structure than in the bainitic structure. Therefore, the martensitic structure is more susceptible to temper embrittlement than the bainitic structure.Reactor pressure vessels (RPV) are generally considered to be the most critical components in the nuclear plant beside the reactor core 1,2 . The RPV should serve for 40 years under high-temperature, high-pressure, and neutron-irradiation conditions. Therefore, to ensure safe operation of the reactor, the RPV should be fabricated from material with high strength, high fracture toughness, and high resistance to irradiation embrittlement 3-5 .The RPV is typically fabricated from ASME SA508 Class 3 steel [6][7][8] . With the development of generation IV reactors, larger and higher-power nuclear power plants (compared with those housing generation III reactors) are being built. However, the low strength (620 MPa) of the SA508 Class 3 steel renders this material unsuitable for generation IV reactors and, hence, new materials must be developed. Many countries have considered SA508Gr.4N steel as a candidate material 9,10 .The RPVs are large forgings and with wall thickness of more than 200 mm 11 . Generally, the forged RPVs are quenched and tempered, as result, the through-thickness microstructure vary significantly because of the differential cooling rates during quenching. These differing microstructures will lead to heterogeneous mechanical properties along the thickness direction of the RPV. Therefore, an understanding of the microstructure and mechanical properties of RPV steels with different quenched microstructures is essential.The microstructure of the initial quenched martensite is a key factor in determining the performance of RPVs. Park et al. 12 reported that the strength of a quenched Ni-Cr-Mo low alloy steel with a fully martensitic microstructure is significantly higher than that of the quenched microstructure composed of bainite. Similarly, compared with bainite, tempered martensite is more susceptible to temper embrittlement. Raoul et al. 13 found that, in high-P (0.017%) A533 steel, P segregation in martensite is considerably higher than that in bainite. Furthermore, Lee et al. 14 dete...

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Structural integrity assessment of reactor pressure vessels during pressurized thermal shock

Cited by 7 publications

References 8 publications

Analisis Probabilistic Fracture Mechanics Pada Evaluasi Keandalan Bejana Tekan Reaktor Secara 3-D

Analisis Probabilistic Fracture Mechanics Pada Evaluasi Keandalan Bejana Tekan Reaktor Secara 3-D

Integrity Evaluation of a Reactor Pressure Vessel Based on a Sequential Abaqus-FRANC3D Simulation Method

Effect of microstructure on the impact toughness and temper embrittlement of SA508Gr.4N steel for advanced pressure vessel materials

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