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PSA-Beginner
  • Next Event:  NINE Headquarters, LUCCA (Italy), 17 - 21 March 2025
  • Early Registration Deadline: Jan 25, 2025

NRSHOT - PSA-Beginner

Day 1
•    Brief overview of the Training Curriculum
•    Overview of the Main Terms and Concepts of PSA
      o    Concept of Risk, Typical PSA Scope, Terms and Definitions used in PSA, Introduction to Boolean Algebra, Brief overview of Typical Level-1 PSA Tasks
•    Initiating Events (IE) Analysis
      o    Definition of an Initiating Event in PSA, Initiating Events Selection, Initiating Events Grouping, Initiating Events Frequency Assessment, Typical Lists of IEs for Different Reactor Types, IEs Frequencies Assessment
•    Presentation on the Design of the Facility to be Used for the Case Study on PSA Model Development
      o    Presentation of the Main Design Features of a Simplified Nuclear Installation to be used during training
            -    Main Safety Systems
            -    Main Support Systems
•    Accident Sequence Models Development
      o    Safety Functions and Modelling Functions in the Accident Sequence Models, Successful and Non-Successful End States, Typical definition of End States in Accident Sequence Models, Success Criteria Definition, Supporting Analyses, Mission Time and Cliff-Edge Effects, Typical Formats of Accident Sequence Models, Approach for Construction of  Small Event Tree - Large Fault Tree PSA Models
      o    Example of Event Trees Construction Process
•    Introduction to PSA Software and Construction of Event Trees
      o    Brief description of the PSA Software Used  (SAPHIRE or RISKSPECTRUM)
      o    Work in working groups: each group develops one ET (later to be integrated in one PSA model)  
            -    Each working group construct one ET (Large LOCA, Medium LOCA, Small LOCA, Loss of Off-Site Power)
            -    Experts provides advices at request and reviews the work done

Day 2
•    System Models Development
      o    Typical Methods for System Models Development
      o    Fault Tree (FT) Method
            -    Structure of FT, Typical Elements of FT, Typical Basic Events in FT
            -    Types of Components, Components Failure Modes and Related Probabilistic Models
            -    Components Boundaries and Link with Existing Reliability Data
      o    Methods to Control the Logic of System Models in FTs (house events, boundary condition sets, etc.)
      o    Typical Coding Scheme for Naming Basic Events in the PSA Model
      o    Failure Modes and Effects Analysis (FMEA)
      o    Example of a FT Development Process, Breaking Logic Loops
•    Exercise: Construction of Fault Trees. Development of the Coding Scheme to be used in the PSA Model Development Process.
      Performing and Documenting FMEA
      o    Construction of System Models in the Form of FT (using PSA Software). Defining Reliability Models for Basic Events and Introduction of “Dummy” Values. System Models Quantification. Analyses of Minimal Cutsets (MCSs) obtained.

Day 3
•    PSA Data Analysis
      o    Overview of Data required for PSA. Component Reliability Data Collection and Treatment Process. Initiating Events Data Collection and Treatment.
      o    Methods for Reliability Parameters and IEs Frequencies Estimation (Classical Statistic Methods, Bayesian Updating Process)
      o    Introduction to Human Error Probability (HEP) Evaluation
•    Exercises on data assessment. Assessment of the Data Needed for their part of the PSA Model. Treatment of the Raw Data
      (data to be provided by experts). Estimation of Reliability Parameters for the Components and Failure Modes to be used in the PSA Model Under Development. Entering the Data obtained in the PSA Model. Quantification of MCSs with the Data obtained (replacement of “dummy” values).

Day 4
•    Modelling Dependencies in PSA (including Common Cause Failures [CCF])
      o    Types of Dependencies to be modelled in the PSA
      o    Common Cause Failures (CCF): CCF Models, CCF Parameters and Sources of Data, CCF Groups.
      o    Inclusion of CCF Events in the PSA Model (depending on the software to be used)
•    Exercise: Modelling of the CCF in the PSA model. CCF Analyses for the Equipment Modelled in their part of the Model.
      Defining CCF Groups. Introduction of CCF Groups in the PSA Model. Re-Quantification of the Model with CCF Data.

Day 5
•    PSA Model Quantification and Analysis of the Results
      o    Typical Results from Level-1 PSA
      o    Analysis of MCSs and Dominant Accident Sequences
      o    Importance Measures Quantification and Analysis: Types of Importance Measure, Typical Insights from Importance Measures
      o    Uncertainty Analyses and Types of Uncertainties in PSA: Parametric Uncertainty, Modelling Uncertainty, Incompleteness Uncertainty
      o    Sensitivity Studies: Sensitivity Studies to Address Uncertainties, Sensitivity Studies to Assess the Impact of Modifications,
           Other Sensitivity Studies
•    Exercise: PSA Model Quantification and Analysis of the Results. Quantification of the Model and review MCSs obtained, review of the Results
      of Importance Measures Quantification and Uncertainty of the Results, definition of Sensitivity Cases including Model Adjustment and Model.
•    Discussion on the Final Results achieved
•    High-Level overview of Internal and External Hazards Level-1 PSA, Level-2 PSA and use of PSA Results
      o    High-Level overview of Internal and External Hazards Level-1 PSA
      o    High-Level overview of Level-2 PSA Tasks
      o    High-Level overview of Use and Application of PSA
•    Questions, Open Issues and Individual Consultations
•    Closing of the training and release of the Certificate of Attendance