Three-Dimensional Leak before Break Analysis of Nuclear Pipes Containing Cracks

2015 ◽  
Vol 750 ◽  
pp. 376-381
Author(s):  
Wen Fu Liang ◽  
Tong Liu ◽  
Min Shan Liu
Keyword(s):  
High Temperature ◽  
Fast Reactor ◽  
Waste Heat ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Structural Safety ◽  
Piping System ◽  
Pipe Material ◽  
Crack Behavior ◽  
Leak Before Break

Three-dimensional crack behavior simulation analysis and anti-fracture design have been a main subject in fracture theory and engineering application. Piping system is a key part of nuclear power engineering. Utilizing the three-dimensional finite element analysis software ANSYS and the specialized crack analysis programs Franc3D, three-dimensional crack behavior and leak before break (LBB) case were simulated and evaluated of a pipe with a crack in waste heat exhaust system of China Experimental Fast Reactor ( CEFR ). In fast reactor, the piping is working under a high temperature. Therefore, the code RCC-MR.A16 was adopted that is suitable for materials and structural safety design at high temperature. Material used in this article is modified 9Cr1Mo-T91/P91. The analysis model of pipe section was built in three-dimensional entity structure containing a cracks and the high temperature and creep effects were considered. The simulation results show that creep contributes more effect on crack growth than fatigue. The evaluation results on LBB of studied T91 steel pipe with a crack-like defect can satisfy the need of LBB design guidelines. The research results can be referenced in pipe material choose, safety assessment and structural integrity evaluation of a pipe containing defects at high temperature in a fast reactor design.

Research on the Stainless Steel Tubes and Pipes Material Standards of Demonstration Fast Reactor Power Plant

2013 ◽  
Author(s):  
Yaping Li ◽  
Guangdong Song
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Power Plant ◽  
Fast Reactor ◽  
Reactor Power ◽  
Steel Pipe ◽  
Thick Wall ◽  
Pipe Material ◽  
Stainless Steel Pipe ◽  
Reactor Power Plant

The main characteristics of the sodium pipe system in Demonstration Fast Reactor Power Plant (DFRPP) are high-temperature, thin-wall and big-caliber, which is different from high-pressure and thick-wall of the pressurized water reactor system, and the system is long-term operate in the environment of liquid metal sodium. How to guarantee the reliability of materials in high temperature are most important in material option. Engineering design depend on the criterion. Material standards are different in different countries, and corresponding construction codes are different too. Comparing the stainless steel pipe material standers at home and abroad and analyzing the material standards’ difference according to different construction codes, a stainless steel pipe material criterion system is put forward in this paper which is applicable for the DFRPP.

Development of LBB Assessment Method for Japanese Sodium Cooled Fast Reactor (JSFR) Pipes: 3—Fracture Assessment Methods Considering Compliance at a Crack Part

2010 ◽  
Author(s):  
Takashi Wakai ◽  
Hideo Machida ◽  
Shinji Yoshida ◽  
Yasuhiro Enuma ◽  
Tai Asayama
Keyword(s):  
Thermal Expansion ◽  
Internal Pressure ◽  
Fast Reactor ◽  
Load Balance ◽  
Assessment Method ◽  
Assessment Methods ◽  
Piping System ◽  
Thin Wall ◽  
Fracture Assessment ◽  
Leak Before Break

This paper presents a fracture assessment methods used in leak before break (LBB) assessment of sodium piping system in the Japanese sodium cooled fast reactor (JSFR). Use of thin wall pipes and compact layout of piping system are features of the design in JSFR. Since the internal pressure of piping of JSFR is low, the critical load is thermal expansion. Supposing a through wall crack (TWC) in such piping, the stiffness of the crack part will decrease, the load balance of the piping system will change from the condition without crack. The fracture assessment methods paying attention to this stiffness change at the crack part were proposed and these methods enabled rational LBB assessment. The proposed methods are much effective to loosen LBB conditions for the piping system of which the compliance is low. These methods applied to the LBB assessment of the piping system of JSFR which has the compact layout, and it was checked that the validity of these methods to loosen the LBB conditions.

High temperature compressive behavior of three-dimensional five-directional braided composites

2018 ◽  
Vol 60 (7-8) ◽  
pp. 772-776 ◽  
Author(s):  
Jiayi Liu ◽  
Junmeng Zhou ◽  
Yu Wang ◽  
Jie Mei ◽  
Jialin Liu
Keyword(s):  
High Temperature ◽  
Three Dimensional ◽  
Compressive Behavior ◽  
Braided Composites

Three-Dimensional Atomic Structure of Supported Au Nanoparticles at High Temperature

Nanoscale ◽  
2021 ◽  
Author(s):  
Pei Liu ◽  
Ece Arslan Imran ◽  
Annick De Backer ◽  
Annelies de Wael ◽  
Ivan Lobato ◽  
...  
Keyword(s):  
High Temperature ◽  
Atomic Structure ◽  
Au Nanoparticles ◽  
Elevated Temperatures ◽  
Three Dimensional

Au nanoparticles (NPs) deposited on CeO2 are extensively used as thermal catalysts since the morphology of the NPs is expected to be stable at elevated temperatures. Although it is well...

scholarly journals A Holistic Strategy for Successful Photovoltaic (PV) Implementation into Singapore’s Built Environment

2021 ◽  
Vol 13 (11) ◽  
pp. 6452
Author(s):  
Vesna Kosorić ◽  
Siu-Kit Lau ◽  
Abel Tablada ◽  
Monika Bieri ◽  
André M. Nobre
Keyword(s):  
Built Environment ◽  
Information Exchange ◽  
Cultural Context ◽  
Wide Spectrum ◽  
Design Principles ◽  
Design Guidelines ◽  
Structural Safety ◽  
Local Context ◽  
Design Framework ◽  
Holistic Strategy

Based on the findings from a recent study by the authors which examined factors affecting diffusion of photovoltaics (PV), while comprehensively considering the local PV and construction industry as well as characteristics of the built environment, this paper proposes a holistic strategy for PV implementation into Singapore’s built environment. It consists of (1) a multilevel mechanism framework, encompassing eleven mechanism categories of instruments and activities and (2) a general design framework including design principles, general project instructions and the main design guidelines. Relying on a survey conducted among PV experts on established mechanisms, the present study suggests that building codes (e.g., fire safety, structural safety, etc.) and initiatives and incentives related to PV/building-integrated photovoltaics (BIPV) should be the highest priority for authorities, followed by assessment of BIPV/PV properties, working toward social acceptance, conducting research projects and information exchange, and education and training activities. Considering all three pillars of sustainability, the design framework is based on the following interrelated design principles: (1) compatibility and coherence with the local context, (2) technical soundness, (3) economic viability, (4) user-centered design, (5) connecting with community and socio-cultural context, and (6) adaptability and flexibility. Despite Singapore’s scarcity of land, the established design guidelines cover a wide spectrum of solutions, including PV integration into both buildings and non-building structures. The synthesis of the two interconnected and inseparable frameworks aims to create an environment conducive to long-term widespread PV integration and stimulate the deployment of BIPV, which should help Singapore and other cities reduce their dependency on imported fossil fuels, while also making them more livable and enjoyable.

Investigation Into Thermal Stress Characteristics of Pipe-in-Pipe Under High Temperature Condition

2018 ◽  
Author(s):  
Si-Hwa Jeong ◽  
Min-Gu Won ◽  
Nam-Su Huh ◽  
Yun-Jae Kim ◽  
Young-Jin Oh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
High Temperature ◽  
Temperature Distribution ◽  
Heat Transfer Analysis ◽  
Piping System ◽  
Curved Pipe ◽  
High Temperature Condition ◽  
Single Pipe ◽  
Radiation Conditions

In this paper, the thermal stress characteristics of the pipe-in-pipe (PIP) system under high temperature condition are analyzed. The PIP is a type of pipe applied in sodium-cooled faster reactor (SFR) and has a different geometry from a single pipe. In particular, under the high temperature condition of the SFR, the high thermal stress is generated due to the temperature gradient occurring between the inner pipe and outer pipe. To investigate the thermal stress characteristics, three cases are considered according to geometry of the support. The fully constrained support and intermediate support are considered for case 1 and 2, respectively. For case 3, both supports are applied to the actual curved pipe. The finite element (FE) analyses are performed in two steps for each case. Firstly, the heat transfer analysis is carried out considering the thermal conduction, convection and radiation conditions. From the heat transfer analysis, the temperature distribution results in the piping system are obtained. Secondly, the structural analysis is performed considering the temperature distribution results and boundary conditions. Finally, the effects of the geometric characteristics on the thermal stress in the PIP system are analyzed.

Simplified LBB Guidance: Stage 1 — Development of a New Software Tool and Initial Scoping Calculations

2018 ◽  
Author(s):  
Peter Gill ◽  
John Sharples ◽  
Chris Aird
Keyword(s):  
Fracture Toughness ◽  
Material Properties ◽  
Software Tool ◽  
Pipe Material ◽  
Loading Conditions ◽  
Design Rules ◽  
Inner Radius ◽  
Inner Diameter ◽  
Stage 1 ◽  
Leak Before Break

This study is focussed on establishing more simplified Leak-before-Break (LbB) guidance for inclusion into Section III.11 of the R6 procedure. The approach adopted has involved the development of a universal software tool for LbB simplified assessments which can be used to perform initial scoping calculations to demonstrate typical LbB cases. It is envisaged that this simplified methodology will enable plant assessment engineers to be more informed on which sites on plant are likely to have LbB successfully applied and to be able to undertake LbB assessments in a more simplistic way than is currently available. Using the developed software tool, a range of LbB calculations for different cracks and loading conditions have been performed to provide guidance on where LbB is more likely to be applied on plant. Loading conditions include primary and secondary stresses, where through-wall changes have been accounted for. The pipe geometries included in this study have been defined by the inner radius and the wall thickness, calculated by minimum pipe thickness required according to meet the design rules of ASME III. The pipe inner radius varies from 40mm to 200mm (80mm to 400mm inner diameter (ID)). All pipe outer diameters are less than 0.5m. All cracks considered in this study are through-wall and circumferential. Pipe material properties are chosen to be broadly representative of an Austenitic Stainless Steel, where the fracture toughness varies from 100 to 180MPa√m and the yield stress is 150MPa.

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