Human Reliability Analysis - International Atomic …

1 Human Reliability AnalysisHuman Reliability AnalysisIAEA Training Course on Safety Assessment of NPPs to Assist Decision MakingWorkshop InformationWorkshop InformationIAEA WorkshopIAEA WorkshopCity , CountryXX - XX Month, YearCity , CountryXX - XX Month, YearLecturerLesson IV IV Training Course on Safety Assessment of NPPs to Assist Decision Making1 Human ReliabilityHuman ReliabilityHUMAN RELIABILITYThe probability of successful performance of only those Human activities necessary to make a system reliable or ERRORH uman Error is simply some Human output which is outside the tolerances established by the system requirements in which the person Training Course on Safety Assessment of NPPs to Assist Decision Making2 Human Reliability AnalysisHuman Reliability Analysis What can happen, , what can go wrong?

2 How likely is it that this will happen?. If it does happen, which are the consequenses?. iaea Training Course on Safety Assessment of NPPs to Assist Decision Making3 Goal of Modeling the Human Goal of Modeling the Human Performance for PSAP erformance for PSA To develop descriptive models to predict how well people will perform what they are supposed to do in normal and abnormal situations. It is not to understand Human behavior and all the motivations behind it. A model of a system is an abstraction which reproduces (simulates) symbolically the way in which the system Training Course on Safety Assessment of NPPs to Assist Decision Making4 Human HRA ModelHuman HRA ModelIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making5 Human Error Human Error CategorisationCategorisation4 Too Much.

3 ERRORS OF COMMISSION Selection error Errors of Sequence Timing Errors Qualitative Errors ERRORS OF OMISSION Omits entite task. Omits a step in a wrong of wrong command on Training Course on Safety Assessment of NPPs to Assist Decision Making6 Human Action CategoriesHuman Action CategoriesRUTINEH uman actions explicitly included in documents (Procedures, Specification, ).COGNOSCITIVEH uman actuations that require a cognitive process of understanding and decision making, previous to do an Training Course on Safety Assessment of NPPs to Assist Decision Making7 Performance Shaping Factors (PSF)Performance Shaping Factors (PSF)Categories of PSF s External.

4 Stressor. Internal. Any factor that shapes (Influences) Human performance. Less than adequate PSF - Higher Human error Training Course on Safety Assessment of NPPs to Assist Decision Making8 Some PSFSome PSF s in Mans in Man--Machine SystemMachine SystemIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making9 BehaviourBehaviourTypesTypes Skillbased behaviour. Rulebased behaviour. Knowledgebased Training Course on Safety Assessment of NPPs to Assist Decision Making10 DefinitionsDefinitionsofofSkillSkill--Ba sedBased, , RuleRule--BasedBased, , andandKnowledgeKnowledge--BasedBasedBeha viourBehaviour# Rasmussen, J.

5 , Human Errors. A Taxonomy for DescribingHuman Malfunction in Industrial Installations, Riso-M-2304, Riso National laboratory, Roskilde, Denmark, August Training Course on Safety Assessment of NPPs to Assist Decision Making11 LogicLogicTreeTreetotoAidAidin in SelectionSelectionofofExpectedExpectedBe haviourBehaviourTypesTypesIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making12 Human Human ActionActionClassificationClassification TYPE 1 Before an initiating event, plant personnelcan affect availability and safety either by inadvertantly disabling equipment, during testing or maintenance.

6 Or they can improve theavailability of systems by restoring failed equipment through testing and 2By committing some error, plant personnel can initiate an 3By following procedures during the course of an accident, plant personnel can operate standbyequipment that will terminate the 4 Plant personnel, attempting to follow procedures, can make a mistake that aggravates thesituation or fails to terminate the 5By improvising, plant personnel can restore and operate initial unavailable equipment toterminate an Training Course on Safety Assessment of NPPs to Assist Decision Making13 Procedures Procedures SHARP(SYSTEMATIC Human ACTION Reliability PROCEDURE).

7 EPRI-NP-3583 The SHARP methodology can be employed by the analyst as guidance to make assessments of Human Reliability , suitable for use in a PSA, Different techniques can be used within the SHARP framework, Innovation can be employed when current techniques are deemed insufficient for adequately addressing the case under Training Course on Safety Assessment of NPPs to Assist Decision Making14 SHARP Steps (1/2)SHARP Steps (1/2)1. DefinitionTo ensure that all Human interactions are adequately considered in the identify the Human interactions that are significant to the operation and safety of the develop a detailed description of important Human interactions by defining the key influence factors necessary to complete the modelling.

8 The Human interaction modelling consists of a representation ( , qualitative model), impact assessments and Training Course on Safety Assessment of NPPs to Assist Decision Making15 SHARP Steps (2/2)SHARP Steps (2/2)4. RepresentationTo select and apply techniques for modelling important Human interactions in logic structures. Such methods help to identify additional significant Human actions that might impact the system logic AssessmentTo explore the impact of significant Human actions identified in the preceding Step on the system logic apply appropriate data or other quantification methods to assign probabilities for the various interactions examined, determine sensitivities and establish uncertainty include all necessary information for getting a traceable, understandable.

9 And reproducible Training Course on Safety Assessment of NPPs to Assist Decision Making16 SHARP Flow DiagramSHARP Flow DiagramIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making17 Pathways for Quantification of Human Errror Pathways for Quantification of Human Errror ProbabilitiesProbabilitiesREPRESENTATION MODEL/DATAIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making18 HRA Event Tree. Operator Action Tree, OAT. Expanded Operator Action Tree, EXOAT. Confusion Human Action Representation is a Logic Structure Used to Explain the Different Activities (Decision and/orActuation) that the Operators Could do when they have to Respond to a Concret Situation.

10 Human Action RepresentationHuman Action RepresentationIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making19 HRA Event TreeHRA Event TreeIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making20 Operator Action TreeOperator Action TreeIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making21 Expanded Operator Action Tree RepresentationExpanded Operator Action Tree RepresentationIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making22 Example of Confusion Matrix for Example of Confusion Matrix for Misdiagnosis of an EventMisdiagnosis of an EventIAEA Training Course on Safety Assessment of NPPs to Assist Decision Making23 Human Quantification TechniquesHuman Quantification Techniques Handbook of Human Reliability Analysis (THERP) NUREG/CR-1278.