Contribution of Human Reliability in Power Probabilistic Safety Assessment Models Versus Shutdown Models

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Marko Čepin
Keyword(s):  
Safety Assessment ◽  
Human Error ◽  
Human Action ◽  
Human Reliability ◽  
Human Reliability Analysis ◽  
Probabilistic Safety Assessment ◽  
Full Power ◽  
Human Failure ◽  
Error Probabilities ◽  
Probabilistic Safety

Abstract Human reliability analysis is a method, which evaluates the human error probabilities of human failure events, which may arise when human actions are required in operation of the considered facility or system. The objective of the work is to show the contribution of human failure events in probabilistic safety assessment with focus on comparison of this contribution over the different plant operating states. The method integrates the diagnosis and action part, which are evaluated for all steps, which are needed for modeling of the human action under investigation considering the parameters, which impact the human failure probability and which are obtained from database. The results show that the risk contribution of human failure events is notably higher in low power and shutdown states than in full power operation. The results show that the human factor in shutdown plant states is the most important risk contributor regarding the contribution to the core damage frequency and regarding the risk reduction worth and risk achievement worth. Only at some plant operating states, some other groups of equipment show larger risk achievement worth than group of human failure events.

scholarly journals Comparison of Methods for Dependency Determination between Human Failure Events within Human Reliability Analysis

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Marko Čepin
Keyword(s):  
Reliability Analysis ◽  
Safety Assessment ◽  
Human Error ◽  
Human Performance ◽  
Subjective Evaluation ◽  
Human Reliability ◽  
Human Reliability Analysis ◽  
Probabilistic Safety Assessment ◽  
Error Probabilities ◽  
Probabilistic Safety

The human reliability analysis (HRA) is a highly subjective evaluation of human performance, which is an input for probabilistic safety assessment, which deals with many parameters of high uncertainty. The objective of this paper is to show that subjectivism can have a large impact on human reliability results and consequently on probabilistic safety assessment results and applications. The objective is to identify the key features, which may decrease subjectivity of human reliability analysis. Human reliability methods are compared with focus on dependency comparison between Institute Jožef Stefan human reliability analysis (IJS-HRA) and standardized plant analysis risk human reliability analysis (SPAR-H). Results show large differences in the calculated human error probabilities for the same events within the same probabilistic safety assessment, which are the consequence of subjectivity. The subjectivity can be reduced by development of more detailed guidelines for human reliability analysis with many practical examples for all steps of the process of evaluation of human performance.

The Application of Probabilistic Safety Assessment in the Preliminary Reactor Design Stage: Challenges and Insights

2014 ◽  
Author(s):  
Ibrahim A. Alrammah
Keyword(s):  
Nuclear Power ◽  
Safety Assessment ◽  
Design Stage ◽  
Human Reliability Analysis ◽  
Probabilistic Safety Assessment ◽  
Technical Issues ◽  
Technical Specifications ◽  
And Control ◽  
Novel Design ◽  
Probabilistic Safety

This paper discusses some technical issues related to applying Probabilistic Safety Assessment (PSA) to a novel Nuclear Power Plant (NPP) design. These aspects include: initiating events, passive systems modeling, reliability and common-cause failure (CCF) data, modeling of novel design features, modeling of preventive maintenance and technical specifications, human reliability analysis (HRA), modeling of instrumentation and control (I&C), external hazards, PSA supporting studies and interpretation of PSA results for new plants.

scholarly journals Human reliability analysis of the Tehran research reactor using the SPAR-H method

2012 ◽  
Vol 27 (3) ◽  
pp. 319-332 ◽  
Author(s):  
Ramin Barati ◽  
Saeed Setayeshi
Keyword(s):  
Reliability Analysis ◽  
Research Reactor ◽  
Safety Analysis ◽  
Human Action ◽  
Human Reliability ◽  
Human Reliability Analysis ◽  
Human Errors ◽  
Performance Shaping Factors ◽  
Tehran Research Reactor ◽  
Probabilistic Safety

The purpose of this paper is to cover human reliability analysis of the Tehran research reactor using an appropriate method for the representation of human failure probabilities. In the present work, the technique for human error rate prediction and standardized plant analysis risk-human reliability methods have been utilized to quantify different categories of human errors, applied extensively to nuclear power plants. Human reliability analysis is, indeed, an integral and significant part of probabilistic safety analysis studies, without it probabilistic safety analysis would not be a systematic and complete representation of actual plant risks. In addition, possible human errors in research reactors constitute a significant part of the associated risk of such installations and including them in a probabilistic safety analysis for such facilities is a complicated issue. Standardized plant analysis risk-human can be used to address these concerns; it is a well-documented and systematic human reliability analysis system with tables for human performance choices prepared in consultation with experts in the domain. In this method, performance shaping factors are selected via tables, human action dependencies are accounted for, and the method is well designed for the intended use. In this study, in consultations with reactor operators, human errors are identified and adequate performance shaping factors are assigned to produce proper human failure probabilities. Our importance analysis has revealed that human action contained in the possibility of an external object falling on the reactor core are the most significant human errors concerning the Tehran research reactor to be considered in reactor emergency operating procedures and operator training programs aimed at improving reactor safety.

The extended living probabilistic safety assessment

2019 ◽  
Vol 234 (1) ◽  
pp. 183-192
Author(s):  
Marko Čepin
Keyword(s):  
Low Power ◽  
Nuclear Power ◽  
Safety Assessment ◽  
Risk Level ◽  
Probabilistic Safety Assessment ◽  
Core Damage ◽  
Full Power ◽  
Power Operation ◽  
Plant Shutdown ◽  
Probabilistic Safety

The term living probabilistic safety assessment was defined soon after the initial probabilistic safety assessments were implemented. The objective of this article is to present the extended living probabilistic safety assessment and its applications considering realistic nuclear power plant models, including the low power and shutdown plant operating states. One of the key objectives is to compare the suitability of conventional and additional risk measures, core damage frequency and conditional core damage frequency, respectively. The methods are presented considering all states of the plant from the full power operation to the low power and shutdown states. The example models of the nuclear power plants and the results of the living probabilistic safety assessment of the plant operating states are discussed. The results show that the risk of low power and shutdown states is generally smaller than the risk of full power operation, but the low power and shutdown plant operating states differ significantly among each other regarding the risk level. The deficiency of living probabilistic safety assessment applied to the plant shutdown states is connected with significantly increased human effort for the analyses, with a significantly greater amount of results and with increased uncertainty of some parameters due to the larger dynamics of actions in the plant shutdown versus the full power operation states. The benefit of the living probabilistic safety assessment applied to the plant low power and shutdown states lays in consideration of all states and potential identification of risk significant states and directions for possible safety improvements.

scholarly journals Classification and Quantification of Human Error in Manufacturing: A Case Study in Complex Manual Assembly

2021 ◽  
Vol 11 (2) ◽  
pp. 749
Author(s):  
Yaniel Torres ◽  
Sylvie Nadeau ◽  
Kurt Landau
Keyword(s):  
Human Error ◽  
Human Reliability ◽  
Human Reliability Analysis ◽  
Manual Assembly ◽  
Human Errors ◽  
Assembly Instructions ◽  
Inspection Process ◽  
And Performance ◽  
Error Probabilities ◽  
Assembly Guidance

Manual assembly operations are sensitive to human errors that can diminish the quality of final products. The paper shows an application of human reliability analysis in a realistic manufacturing context to identify where and why manual assembly errors occur. The techniques SHERPA and HEART were used to perform the analysis of human reliability. Three critical tasks were selected for analysis based on quality records: (1) installation of three types of brackets using fasteners, (2) fixation of a data cable to the assembly structure using cushioned loop clamps and (3) installation of cap covers to protect inlets. The identified error modes with SHERPA were: 36 action errors, nine selection errors, eight information retrieval errors and six checking errors. According to HEART, the highest human error probabilities were associated with assembly parts sensitive to geometry-related errors (brackets and cushioned loop clamps). The study showed that perceptually engaging assembly instructions seem to offer the highest potential for error reduction and performance improvement. Other identified areas of action were the improvement of the inspection process and workers’ provision with better tracking and better feedback. Implementation of assembly guidance systems could potentially benefit worker’s performance and decrease assembly errors.

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