Courses

**Preparation and Review of Licensing Documentation (FSAR)**

**Practical and Theoretical Training on Level-1 PSA for Internal Initiating Events**

**Thermal-Hydraulics Core Analysis – COBRA Genesis Codes**

**Fuel Behavior Analysis by TRANSURANUS**

**Severe Accident Analysis: Phenomenology and Computational Tools**

**Important Elements of Risk Quantification and PSA**

Practical and Theoretical Training on Level-1 PSA for
Internal Initiating Events

Minimum number of Participants: 7

**Lecturers and Code Instructors:**
A. Lyubarskiy (AEP), S.
Pogosyan (IAEA)

**Day 1**

- Brief overview of the Training Curriculum
- Overview of the Main Terms and Concepts of the Probabilistic
Safety Assessment
- 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
- 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
- Presentation of the Main Design Features of a Simplified
Nuclear Installation to be used during training
- Main Safety Systems
- Main Support Systems

- All needed Material will distributed in paper copies and electronic form

- Presentation of the Main Design Features of a Simplified
Nuclear Installation to be used during training
- Accident Sequence Models Development
- 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
- Example of Event Trees Construction Process

- Introduction to PSA Software and Construction of Event Trees
- Brief description of the PSA Software Used (SAPHIRE or RISKSPECTRUM)
- 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)
- Expert(s) provides advices at request and reviews the work done

**Day 2**

- System Models Development
- Typical Methods for System Models Development
- 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

- Methods to Control the Logic of System Models in FTs (house events, boundary condition sets, etc.)
- Typical Coding Scheme for Naming Basic Events in the PSA Model
- Failure Modes and Effects Analysis (FMEA)
- Example of a FT Development Process, Breaking Logic Loops

- Exercise: Construction of Fault Trees. Work in working
groups:
- Each group constructs one or two systems models - FTs (depending on the system complexity)
- Development of the Coding Scheme to be used in the PSA Model Development Process
- Performing and Documenting FMEA
- 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**

- Discussion on the Intermediate Results Achieved
- PSA Data Analysis
- Overview of Data required for PSA
- Component Reliability Data Collection and Treatment Process
- Initiating Events Data Collection and Treatment
- Methods for Reliability Parameters and IEs Frequencies
Estimation
- Classical Statistic Methods
- Bayesian Updating Process

- Demonstration of the EXCEL Programme for Reliability Parameters and IEs Frequencies Estimation
- Introduction to Human Error Probability (HEP) Evaluation

- Exercises on data assessment. Work in working groups:
- Each Group Performs 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**

- Discussion on the Intermediate Result Achieved
- Modelling Dependencies in PSA (including Common Cause
Failures [CCF])
- Types of Dependencies to be modelled in the PSA
- Common Cause Failures (CCF)
- CCF Models
- CCF Parameters and Sources of Data
- CCF Groups

- Inclusion of CCF Events in the PSA Model (depending on the software to be used)

- Exercise: Modelling of the CCF in the PSA model. Work in
working groups:
- Each Group perform 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

- Discussion on the Intermediate Result Achieved

**Day 5**

- PSA Model Quantification and Analysis of the Results
- Typical Results from Level-1 PSA
- Analysis of MCSs and Dominant Accident Sequences
- Importance Measures Quantification and Analysis:
- Types of Importance Measure
- Typical Insights from Importance Measures

- Uncertainty Analyses and Types of Uncertainties in PSA:
- Parametric Uncertainty
- Modelling Uncertainty
- Incompleteness Uncertainty

- 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. All working groups are working with the same model
- Each group performs Quantification of the Model and Review MCSs obtained
- Each group reviews the Results of Importance Measures Quantification and Uncertainty of the Results
- Each group defines one Sensitivity Case and performs:
- Model Adjustment for the case
- Model Quantification for the case

- 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
- High-Level overview of Internal and External Hazards Level-1 PSA, Level-2 PSA and use of PSA Results
- High-Level overview of Level-2 PSA Tasks
- High-Level overview of Use and Application of PSA

- Evaluation of the Training Course