Ductile Tearing Simulations to Support Design of Large Scale Tests on Ferritic Pipes to Be Performed in the European Project ATLAS+

2019 ◽  
Author(s):  
Tomas Nicak
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Fracture Behavior ◽  
Large Scale ◽  
High Stress ◽  
Stress Triaxiality ◽  
Local Approach ◽  
Integrity Assessment ◽  
European Project

Abstract The safety and reliability of all systems has to be maintained throughout the lifetime of a nuclear power plant (NPP). This requires a systematic ageing management procedure for justifying their safe long term operation. One fundamental part in this process is to demonstrate the integrity of the nuclear power plant components. The European project ATLAS+ aims to develop and validate advanced methods of structural integrity assessment applicable in the ageing and lifetime management of primary and secondary circuit components. To support development and validation of those methods, a large scale test program was developed with the aim to investigate fracture behavior of relevant piping material at the component level. Three of planned large scale experiments focus on the fracture behavior of ferritic piping made of material WB 36 (15 NiCuMoNb 5), that is representative of secondary feedwater lines installed in German NPPs. In order to verify design calculations conducted by means of the classical fracture mechanics approach based on J-Integral [1], detailed local approach analyses are performed for three mock-ups with different initial defects. The local approach analyses presented in this paper are based on the local micromechanical model proposed by Gurson and further modified by Tvergaard. Calibration of required material parameters and prediction of the mock-up behavior during the test is discussed. In order to support constraint investigations stress triaxiality ahead of the crack front during crack propagation in the mock-ups is evaluated and compared to the stress triaxiality in CT20 and SENT specimens. As high stress triaxiality generally limits plastic deformation and increases the crack tip constraint, it is a good parameter to look at if constraint effects are considered.

A High Effective Parallel Method for the Coupling Between Neutronics and Thermal-Hydraulic

2016 ◽  
Author(s):  
Xiaomeng Dong ◽  
Zhijian Zhang ◽  
Zhaofei Tian ◽  
Lei Li ◽  
Guangliang Chen
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Large Scale ◽  
Nuclear Reactor ◽  
Reactor Core ◽  
Decisive Role ◽  
Reactor Power ◽  
Coupling Method ◽  
Outlet Temperature

Multi-physics coupling analysis is one of the most important fields among the analysis of nuclear power plant. The basis of multi-physics coupling is the coupling between neutronics and thermal-hydraulic because it plays a decisive role in the computation of reactor power, outlet temperature of the reactor core and pressure of vessel, which determines the economy and security of the nuclear power plant. This paper develops a coupling method which uses OPENFOAM and the REMARK code. OPENFOAM is a 3-dimension CFD open-source code for thermal-hydraulic, and the REMARK code (produced by GSE Systems) is a real-time simulation multi-group core model for neutronics while it solves diffusion equations. Additionally, a coupled computation using these two codes is new and has not been done. The method is tested and verified using data of the QINSHAN Phase II typical nuclear reactor which will have 16 × 121 elements. The coupled code has been modified to adapt unlimited CPUs after parallelization. With the further development and additional testing, this coupling method has the potential to extend to a more large-scale and accurate computation.

Design Concept of Composite Module for Nuclear Power Plant Construction

2004 ◽  
Author(s):  
Taihei Yotsuya ◽  
Kouichi Murayama ◽  
Jun Miura ◽  
Akira Nakajima ◽  
Junichi Kawahata
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Large Scale ◽  
Construction Method ◽  
Nuclear Plant ◽  
Small Scale ◽  
Modular Construction ◽  
Plant Construction ◽  
Composite Module

A composite module construction method is to be examined reflecting one of the elements of construction rationalization of a future nuclear plant planned by Hitachi. This concept is based on accomplishments and many successes achieved by Hitachi through application of the modular construction method to nuclear power plant construction over 20 years. The feature of the composite module typically includes a planned civil structure, such as a wall, a floor, and a post, representing modular components. In this way, an increased level of rationalization is expected in the conventional large-scale nuclear plants. Furthermore, the concept aiming at the modularization of all the building parts comprising medium- or small-scale reactors is also to be examined. Additional aims include improved reductions in the construction duration and rationalization through use of the composite module. On the other hand, present circumstances in nuclear plant construction are very pressing because of economic pressures. With this in mind, Hitachi is pursuing additional research into the introduction of drastic construction rationalization, such as the composite module. This concept is one of the keys to successful future plant construction, faced with such a severe situation.

Structure Topology Optimization Design and Shock Resistance Study on Nuclear Power Safety DCS Cast Aluminum Cabinet

2020 ◽  
Author(s):  
Wang Dongwei ◽  
Liu Mingxing ◽  
Wu Xiao ◽  
Yan Hao ◽  
Wu Zhiqiang
Keyword(s):  
Topology Optimization ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Optimization Design ◽  
High Stress ◽  
Shock Load ◽  
Normal Operation ◽  
Cast Aluminum ◽  
Structure Topology

Abstract Offshore floating nuclear power plant (FNPP) is characterized by its small and mobility, which is not only able to provide safe and efficient electric energy to remote islands, but to the oil and gas platforms. The safety digital control system (DCS) cabinet, as a carrier for the electronic devices, plays a significant role in ensuring the normal operation of the nuclear power plant. To satisfy the requirements of cabinet used in the sea environment, such as well rigidity, shock load resistance, good seal and corrosion resistance, etc, more and more attention is focused on the cast aluminum cabinet. However, the cast aluminum structure may cause larger weight of cabinet, which inevitability affects the mobility of cabinet, and increases the carried load of ship as well. Therefore, seeking for an effective approach to design a light weight cast aluminum cabinet for the offshore FNPP is definitely necessary. In this work, a frame of cast aluminum cabinet with lightweight is obtained successfully via structure topology optimization design, it is found that the weight of the frame can be reduced to 50% after optimization iterations. Subsequently, the natural frequency of the optimized cast aluminum cabinet is calculated by using ABAQUS, it is seen that the first mode frequency of the frame is beyond 30 Hz, which can meet the basic stiffness requirement. Accordingly, dynamic design analysis method (DDAM) is performed to verify the ability of the optimized cast aluminum cabinet in resisting sudden shock load, and the shock response characteristics of the cabinet are determined. Numerical results support that the optimized frame of cabinet possesses good resistance to high level shock. However, for the assembled cast aluminum cabinet, the vertical shock circumstance turns out to be the most critical condition, high stress and deformation regions occurs at the bracket and column. Reinforcements are proposed to make the bracket stiffer in this shock loading condition.

Grid-Connected Nuclear Power Plant Key Issues Summary

2014 ◽  
Vol 521 ◽  
pp. 530-535
Author(s):  
Meng Wang ◽  
Jian Ding ◽  
Tian Tang ◽  
Zhang Sui Lin ◽  
Zhen Da Hu ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Large Scale ◽  
Power Modeling ◽  
Modeling Simulation ◽  
Load Following ◽  
Key Issues ◽  
The Impact

The current situation of nuclear power plants at home and abroad is described, and the impact of large-scale nuclear power accessing to the grid is analyzed, specifically in the aspects of nuclear power modeling, simulation, load following, reliability, fault diagnosis, etc. Nuclear power accessing to the grid will bring a series of problems, the causes of each problem, the main solutions and future development directions are summarized.

Limit Loads for Circumferential Cracks in the Steam Generator Tube under Combined Pressure and Bending Loads

2007 ◽  
Vol 345-346 ◽  
pp. 1357-1360
Author(s):  
Hyun Su Kim ◽  
Tae Eun Jin ◽  
Hong Deok Kim ◽  
Han Sub Chung ◽  
Yoon Suk Chang ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Steam Generator ◽  
Nuclear Power ◽  
Plastic Material ◽  
Material Behavior ◽  
Limit Loads ◽  
Integrity Assessment ◽  
Bending Loads ◽  
Steam Generator Tubes

Steam generator in a nuclear power plant is huge heat exchanger that transfers heat from reactor to make steam to drive turbine-generator. Failure of the steam generator tubes can result in the release of fission products to the secondary side. Therefore, accurate integrity assessment of the cracked steam generator tubes is of great importance for maintaining the safety of the nuclear power plant. This paper provides limit loads for circumferential through-wall cracks in steam generator tubes under combined internal pressure and bending loads. Such limit loads are developed on the basis of three dimensional finite element analyses assuming elastic-perfectly plastic material behavior. As for the crack location, both the top of the tubesheet and U-bend regions are considered. The analysis results can be directly applied to the practical integrity assessment of cracked steam generator tubes, because the comparison between experimental data and FE results shows a very good agreement.

Recovery and Resilience After a Nuclear Power Plant Disaster: A Medical Decision Model for Managing an Effective, Timely, and Balanced Response

2013 ◽  
Vol 7 (2) ◽  
pp. 136-145 ◽  
Author(s):  
C. Norman Coleman ◽  
Daniel J. Blumenthal ◽  
Charles A. Casto ◽  
Michael Alfant ◽  
Steven L. Simon ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Decision Model ◽  
Large Scale ◽  
Medical Decision ◽  
Incident Management ◽  
Additional Information ◽  
Medical Issues ◽  
High Level

AbstractResilience after a nuclear power plant or other radiation emergency requires response and recovery activities that are appropriately safe, timely, effective, and well organized. Timely informed decisions must be made, and the logic behind them communicated during the evolution of the incident before the final outcome is known. Based on our experiences in Tokyo responding to the Fukushima Daiichi nuclear power plant crisis, we propose a real-time, medical decision model by which to make key health-related decisions that are central drivers to the overall incident management. Using this approach, on-site decision makers empowered to make interim decisions can act without undue delay using readily available and high-level scientific, medical, communication, and policy expertise. Ongoing assessment, consultation, and adaption to the changing conditions and additional information are additional key features. Given the central role of health and medical issues in all disasters, we propose that this medical decision model, which is compatible with the existing US National Response Framework structure, be considered for effective management of complex, large-scale, and large-consequence incidents. (Disaster Med Public Health Preparedness. 2012;0:1-10)

scholarly journals A Dialogic Perspective on Managing Knowledge Differences: Problem-Solving while Building a Nuclear Power Plant Safety System

2021 ◽  
pp. 017084062110618
Author(s):  
Chia-Yu Kou ◽  
Sarah Harvey
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Large Scale ◽  
Knowledge Integration ◽  
Safety System ◽  
Problem Situation ◽  
Plant Safety ◽  
Nuclear Power Plant Safety ◽  
Large Scale Project

To manage knowledge differences, existing research has documented two sets of practices: traversing and transcending knowledge boundaries. What research has yet to explore, however, is the dynamics through which traversing or transcending practices emerge in response to a particular problem situation. Using a qualitative, inductive study of the problem episodes encountered by groups of experts working on a large-scale project to build the safety system for a nuclear power plant, we observed that the emergence of traversing or transcending depended on how experts interpreted problems and initiated dialogues around specific problems. Our work provides insight into the condition through which knowledge integration trajectories may emerge.

scholarly journals PERHITUNGAN BIAYA OPERASI DAN PERAWATAN PLTN SKALA BESAR DAN KECIL

2015 ◽  
Vol 17 (2) ◽  
pp. 87
Author(s):  
Mochamad Nasrullah ◽  
Wiku Lulus Widodo
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Large Scale ◽  
Secondary Data ◽  
Capacity Factor ◽  
Maintenance Cost ◽  
Small Scale ◽  
Operation And Maintenance ◽  
Operation And Maintenance Cost

ABSTRAK PERHITUNGAN BIAYA OPERASI DAN PERAWATAN PLTN SKALA BESAR DAN KECIL. Biaya pembangkit PLTN terdiri dari tiga komponen, yaitu biaya investasi, bahan bakar dan operasi perawatan (O & M). Besarnya biaya O&M pada PLTN besar dan kecil tidaklah sama. Studi ini bertujuan untuk menghitung biaya O&M PLTN skala besar dan kecil dengan mempertimbangkan parameter teknis dan ekonomis yang diambil dari berbagai data sekunder dan sumber lainnya. Studi dilakukan menggunakan data dari PLTN jenis PWR dengan daya 1343 MWe untuk PLTN ukuran besar dan daya 90 MWe untuk PLTN ukuran kecil. Asumsi digunakan tingkat eskalasi sebesar 5%, faktor kapasitas 90%. Metodologi yang digunakan adalah menghitung dengan spreadsheet yang meliputi skala masing-masing komponen O&M. Hasil perhitungan menunjukkan biaya O & M jika dihitung dengan satuan juta US$/tahun, maka biaya O&M PLTN 1343 MWe sebesar 99,21 juta US$/tahun lebih mahal dari PLTN 90 MWe sebesar 45,13 juta US $/tahun. Namun jika biaya O & M PLTN 1343 MWe dihitung dengan satuan mills $/kWh, maka hasilnya  sebesar 9,37 lebih murah dibandingkan dengan PLTN 90 MWe yaitu sebesar 63,70 mills $/kWh. Hal ini berarti semakin kecil ukuran kapasitas dayanya maka biaya operasi dan perawatannya semakin mahal. Penyebab perbedaan biaya operasi dan perawatan antara PLTN skala besar dan kecil, adalah kapasitas daya, faktor kapasitas, jumlah personal yang bekerja pada biaya administrasi umum pegawai dan manajemen, operasi pembangkit tahunan, biaya tenaga kerja offsite. Kata kunci : Biaya operasi dan perawatan, PLTN, LEGECOST ABSTRACT CALCULATION OF OPERATION AND MAINTENANCE COST FOR LARGE AND SMALL SCALE NPP. The generation cost of nuclear power plant consists of three components:  investment costs, fuel cost operation and maintenance (O&M) cost. O&M costs in the large scale of NPP is different from small scale NPP. The objective of this study are to calculate the O&M cost of large NPP and small NPP by considering technical and economic parameters from secondary data and  other references. This study uses 1343 MWe PWR data for large NPP and 90 MWe PWR for small NPP. The assumptions are 5% escalation level and 90% capacity factor. The methodology for calculation using spreadsheet with scaling methods for each O&M components. The results shows that the O &M cost if calculated in units of million US$/year, the O&M cost of NPP 1343 MWe is US$million 99.21/ year which is more expensive than the O&M cost of NPP 90 Mwe which is only US$million 45.13/ year.  But if the cost of O&M 1343 MWe nuclear power plant unit is calculated in units of mills $/kWh, the result shows that the O&M cost is 9.37 mills $/kWh which is less than the 90 MWe NPP which reaches $ 63.70 mills/kWh. The conclusion is  lower NPP capacity  has higher O&M cost. Different O&M cost is caused by power capacity, capacity factor, the amount of worker on site staff, the annual net generation and the offsite technical support. Keywords: Operation and maintenance cost, NPP, LEGECOST 

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