Methodology and Principle for Emergency Operation Computerization in Loviisa NPP Automation Renewal Project

2008 ◽  
Author(s):  
Claude Kernei¨s ◽  
Jarmo Korhonen ◽  
Mikko Martinsuo
Keyword(s):  
User Interfaces ◽  
Nuclear Power ◽  
Emergency Operation ◽  
Operational Conditions ◽  
Control Functions ◽  
Water Reactors ◽  
Chinese Plant ◽  
Management Functions ◽  
Renewal Project ◽  
Functional Concept

Loviisa NPP has two VVER 440-type pressurised-water reactors. The automation renewal project started in the beginning of 2005 when Fortum signed a contract with a consortium of AREVA-NP and Siemens AG. The functional concept of the new I&C is defined in terms of task categories. In normal operational conditions the nuclear power unit is controlled by normal process control functions. Also safety-related preventive protection functions may be activated. Reactor protection functions are activated in operational transients and in accidents. Also diverse manual and automatic backup of the Reactor Protection System is foreseen. After an operational transient or an accident the operators steer the plant to a safe state using plant shutdown or accident management functions. The new control systems and Man Machine Interface (MMI) will be implemented using safety and non-safety digital control platforms and user interfaces. In addition to these conventional non-digital platform with dedicated MMI will be provided to control selected critical functions. Loviisa NPP is using Emergency Operating Procedures (EOP) designed together with AREVA-NP, EdF and Fortum consisting of event and state oriented procedures. This set of procedures is being adapted to a functional concept of the new I&C together with AREVA-NP and Fortum. The rules for organisation of operation with different EOPs and MMIs and the principles and methods of computerization of the EOPs are defined. The rules for organisation of operation with different EOPs and MMIs are designed taking into account requirements set for different task categories and criticality of the actions to be performed by the operator. Priority to the safety MMI is given in case of critical actions. Conventional MMI is used if fast operator response is required. The principles and methods of computerization of the EOPs are consistent with the concept developed for the French EPR and also for the new Chinese plant. This concept takes into account the N4 plant feedback. One of the main targets of the EOP computerizations is to keep the design of operation and support screens close to the present ones.

scholarly journals An Approach to Analyze Diagnosis Errors in Advanced Main Control Room Operations Using the Cause-Based Decision Tree Method

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3832
Author(s):  
Awwal Mohammed Arigi ◽  
Gayoung Park ◽  
Jonghyun Kim
Keyword(s):  
Decision Tree ◽  
Nuclear Power ◽  
Power Plants ◽  
Human Error ◽  
Cognitive Activity ◽  
Emergency Operation ◽  
Nuclear Industry ◽  
Working Environment ◽  
Control Rooms ◽  
Diagnosis Errors

Advancements in the nuclear industry have led to the development of fully digitized main control rooms (MCRs)—often termed advanced MCRs—for newly built nuclear power plants (NPPs). Diagnosis is a major part of the cognitive activity in NPP MCRs. Advanced MCRs are expected to improve the working environment and reduce human error, especially during the diagnosis of unexpected scenarios. However, with the introduction of new types of tasks and errors by digital MCRs, a new method to analyze the diagnosis errors in these new types of MCRs is required. Task analysis for operator diagnosis in an advanced MCR based on emergency operation was performed to determine the error modes. The cause-based decision tree (CBDT) method—originally developed for analog control rooms—was then revised to a modified CBDT (MCBDT) based on the error mode categorizations. This work examines the possible adoption of the MCBDT method for the evaluation of diagnosis errors in advanced MCRs. We have also provided examples of the application of the proposed method to some common human failure events in emergency operations. The results show that with some modifications of the CBDT method, the human reliability in advanced MCRs can be reasonably estimated.

Recirculation Pump Speed Control System Upgrades in Nuclear Boiling Water Reactors

2008 ◽  
Author(s):  
James W. Morgan
Keyword(s):  
Control System ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Flow Control ◽  
Nuclear Power ◽  
Boiling Water ◽  
Boiling Water Reactors ◽  
Pump Speed ◽  
Water Reactors ◽  
Generator Sets

The nuclear power industry is faced with determining what to do with equipment and instrumentation reaching obsolescence and selecting the appropriate approach for upgrading the affected equipment. One of the systems in a nuclear power plant that has been a source of poor reliability in terms of replacement parts and control performance is the reactor recirculation pump speed/ flow control system for boiling water reactors (BWR). All of the operating BWR-3 and BWR-4’s use motor-generator sets, with a fluid coupled speed changer, to control the speed of the recirculation water pumps over the entire speed range of the pumps. These systems historically have had high maintenance costs, relative low efficiency, and relatively inaccurate speed control creating unwanted unit de-rates. BWR-5 and BWR-6 recirculation flow control schemes, which use flow control valves in conjunction with two-speed pumps, are also subject to upgrades for improved performance and reliability. These systems can be improved by installing solid-state adjustable speed drives (ASD), also known as variable frequency drives (VFD), in place of the motor-generator sets and the flow control valves. Several system configurations and ASD designs have been considered for optimal reliability and return on investment. This paper will discuss a highly reliable system and ASD design that is being developed for nuclear power plant reactor recirculation water pump controls. Design considerations discussed include ASD topology, controls architecture, accident, transient and hydraulic analyses, potential reactor internals modifications, installation, demolition and economic benefits.

14C Distribution in Atmospheric and Aquatic Environments Around Qinshan Nuclear Power Plant, China

Radiocarbon ◽  
2014 ◽  
Vol 56 (3) ◽  
pp. 1107-1114 ◽  
Author(s):  
Zhongtang Wang ◽  
Dan Hu ◽  
Hong Xu ◽  
Qiuju Guo
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Water Samples ◽  
Nuclear Power ◽  
Dissolved Inorganic Carbon ◽  
Tap Water ◽  
Surface Seawater ◽  
Pressurized Water ◽  
Specific Activities ◽  
Water Reactors

Atmospheric CO2 and aquatic water samples were analyzed to evaluate the environmental 14C enrichment due to operation of the Qinshan nuclear power plant (NPP), where two heavy-water reactors and five pressurized-water reactors are employed. Elevated 14C-specific activities (2–26.7 Bq/kg C) were observed in the short-term air samples collected within a 5-km radius, while samples over 5 km were close to background levels. The 14C-specific activities of dissolved inorganic carbon (DIC) in the surface seawater samples ranged from 196.8 to 206.5 Bq/kg C (average 203.4 Bq/kg C), which are close to the background value. No elevated 14C level in surface seawater was found after 20 years of operation of Qinshan NPP, indicating that the 14C discharged was well diffused. The results of the freshwater samples show that excess 14C-specific activity (average 17.1 Bq/kg C) was found in surface water and well water samples, while no obvious 14C increase was found in drinking water (groundwater and tap water) compared to the background level.

Finite Element Analyses of Residual Stresses in Typical Welded Joints Used in Nuclear Power Plants and Comparisons With Experiments

2010 ◽  
Author(s):  
Dean Deng ◽  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joints ◽  
Nuclear Power ◽  
Power Plants ◽  
Butt Joint ◽  
Welding Residual Stress ◽  
Dissimilar Metal ◽  
Water Reactors

Recent discoveries of stress corrosion cracking (SCC) at nickel-based metals in pressurized water reactors (PWRs) and boiling water reactors (BWRs) have raised concerns about safety and integrity of plant components. It has been recognized that welding residual stress is an important factor causing the issue of SCC in a weldment. In this study, both numerical simulation technology and experimental method were employed to investigate the characteristics of welding residual stress distribution in several typical welded joints, which are used in nuclear power plants. These joints include a thick plate butt-welded Alloy 600 joint, a dissimilar metal J-groove set-in joint and a dissimilar metal girth-butt joint. First of all, numerical simulation technology was used to predict welding residual stresses in these three joints, and the influence of heat source model on welding residual stress was examined. Meanwhile, the influence of other thermal processes such as cladding, buttering and heat treatment on the final residual stresses in the dissimilar metal girth-butt joint was also clarified. Secondly, we also measured the residual stresses in three corresponding mock-ups. Finally, the comparisons of the simulation results and the measured data have shed light on how to effectively simulate welding residual stress in these typical joints.

scholarly journals 14C Release in Various Chemical Forms With Gaseous Effluents From the Paks Nuclear Power Plant

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 754-761 ◽  
Author(s):  
Ede Hertelendi ◽  
György Uchrin ◽  
Peter Ormai
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Liquid Scintillation ◽  
Mean Value ◽  
Scintillation Counting ◽  
Pressurized Water ◽  
The Mean ◽  
Water Reactors

We present results of airborne 14C emission measurements from the Paks PWR nuclear power plant. Long-term release of 14C in the form of carbon dioxide or carbon monoxide and hydrocarbons were simultaneously measured. The results of internal gas-proportional and liquid scintillation counting agree well with theoretical assessments of 14C releases from pressurized water reactors. The mean value of the 14C concentration in discharged air is 130Bqm-3 and the normalized release is equal to 740GBq/GWe · yr. > 95% of 14C released is in the form of hydrocarbons, ca 4% is apportioned to CO2, and <1% to CO. Tree-ring measurements were also made and indicated a minute increase of 14C content in the vicinity of the nuclear power plant.

PM-HIP Research for Pressure Retaining Applications Within the Electric Power Industry

2014 ◽  
Author(s):  
David Gandy ◽  
John Siefert ◽  
Lou Lherbier ◽  
David Novotnak
Keyword(s):  
Electric Power ◽  
Nuclear Power ◽  
Hot Isostatic Pressing ◽  
Electric Power Industry ◽  
Power Industry ◽  
Plate Rolling ◽  
Alloy 690 ◽  
Class 1 ◽  
Water Reactors ◽  
Grade 91

For more than 60 years now, the nuclear power industry has relied on structural and pressure retaining materials generated via established manufacturing practices such as casting, plate rolling-and-welding, forging, drawing, and/or extrusion. During the past three years, EPRI has been leading the development and introduction of another established process, powder metallurgy and hot isostatic pressing (PM/HIP), for pressure retaining applications in the electric power industry. The research includes assessment of two primary alloys: 316L stainless steel and Grade 91 creep-strength enhanced ferritic steels, for introduction into the ASME Boiler and Pressure Vessel Code. Continuing DOE and EPRI research on other structural/pressure retaining alloys such as Alloy 690, SA 508 Class 1, Alloy 625, hard-facing materials, and others are also underway. This research will have a tremendous impact as we move forward over the next few decades on the selection of new alloys and components for advanced light water reactors and small modular reactors. Furthermore, fabrication of high alloy materials/components may require the use of new manufacturing processes to achieve acceptable properties for higher temperature applications such as those in Generation IV applications. Current research by EPRI and DOE will be reviewed and emphasis will be targeted at advanced applications where PM/HIP may be applied in the future.

Verification of Plastic Interactive Systems

i-com ◽  
2015 ◽  
Vol 14 (3) ◽  
Author(s):  
Raquel Oliveira ◽  
Sophie Dupuy-Chessa ◽  
Gaëlle Calvary
Keyword(s):  
Power Plant ◽  
User Interfaces ◽  
Nuclear Power ◽  
Interactive Systems ◽  
System Model ◽  
Equivalence Checking ◽  
The Past ◽  
Different Levels ◽  
Formal Techniques

AbstractInteractive systems have largely evolved over the past years. Nowadays, different users can interact with systems on different devices and in different environments. The user interfaces (UIs) are expected to cope with such variety. Plastic UIs have the capacity to adapt to changes in their context of use while preserving usability. Such capability enhances UIs, however, it adds complexity on them. We propose an approach to verifying interactive systems considering this adaptation capability of the UIs. The approach applies two formal techniques: model checking, to the verification of properties over the system model, and equivalence checking, to compare different versions of a UI, thereby identifying different levels of UI equivalence. We apply the approach to a case study in the nuclear power plant domain in which several UI are analyzed, properties are verified, and the level of equivalence between them is demonstrated.

scholarly journals FUNCTIONS OF MANAGEMENT ACCOUNTING

2021 ◽  
Author(s):  
Oksana Butkevich ◽  
Keyword(s):  
Management Accounting ◽  
Scientific Methods ◽  
Planning And Control ◽  
Control Functions ◽  
Management Processes ◽  
Cognitive Motivation ◽  
General Scientific ◽  
Management Functions ◽  
Almost All ◽  
And Control

One of the most important tasks of management accounting is to provide quality and efficient accounting information to users. The effectiveness of management accounting is manifested through the implementation of its functions, so it is relevant and urgent to consider them. The aim of the article is to study the composition, number and content of the functions of management accounting. The research methodology was based on general scientific methods of cognition like historical, logical, systemic methods, induction, deduction, analysis, as well as the methods of classification and grouping. According to the results of the research, it is found that currently there is no unified, generally accepted approach to the composition and number of the functions of management accounting (on average, there are distinguished five functions). Almost all researchers indicate information and control functions; analytical, predictive and communication functions are also present in most of the authors' papers analyzed. In some works, there are not quite appropriate combinations of two separate functions in one, and also there are similar titles of one and the same function of management accounting. There is a separation of rather narrow, specific functions, which are inherent only in certain management processes. We have summarized 32 different functions of management accounting, analyzed their number and composition, covered more than 50 authorial meanings for each of them. It has been found that researchers determine the different composition and essence of the functions depending on the direction of the study, its object and the specifics of the industry. It is quite logical that most of the various interpretations are given to the content of the information function of management accounting. According to the Conceptual Framework for Management Accounting developed by the International Federation of Accountants, the following functions have only one definition: analytical (evaluation), control and analytical, scientific and cognitive, new scientific and cognitive, motivation, organization, organizational and communication, planning and control, prognostic, reputational and the functions of management accounting. Prospects for further research are to consider the relationship between the functions of management accounting and management functions and to establish the quality and features of the manifestation of the functions of management accounting under the influence of industry characteristics of enterprises.

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