Safety Assessment Knowledge for

Competency and Capacity Building

Two Week Workshop on

Essential Safety Assessment Knowledge:

SAFETY ANALYSIS SERIES: INTRODUCTION TO

LEVEL 1 AND LEVEL 2 PSA

3 – 14 October 2011

The Abdus Salaam International Centre for Theoretical Physics, Trieste, Italy

Safety Assessment Education and Training (SAET)

SAFETY ANALYSIS SERIES OTHER WORKSHOPS 2011-2012

Generic Reactor Safety Review Methodology

Introduction to DSA and PSA

Integrated Risk Informed Decision-Making (IRIDM)

Principles of Defence in Depth

Introduction to Level 1 PSA

Introduction to Level 2 PSA

DSA Methodology (Design Basis)

Severe Accident Analysis_______________________________________________________*Workshop durations are of 3-5 days each. Venues to be

announced.

THE SAFETY ASSESSMENT EDUCATION AND TRAINING PROGRAMME (SAET)

The Safety Assessment Education and Training (SAET) Programme has been designed to support the Member States with development of required safety assessment capacity and competency. The Programme provides for courses and training necessary to achieve knowledge of safety requirements associated with the design and operation of nuclear facilities, and focuses on development of specialized knowledge essential for assessment and evaluation of safety including performance of safety analyses.

SAET takes its roots from the IAEA Safety Standards, especially the Fundamental Safety Principles and the Safety Assessment for Facilities and Activities Requirements. The SAET programme content is based on international best practices and expertise. It sets high educational standards and its elements are compatible with academic course requirements.

The training programme addresses education and training needs for a wide range of personnel, from those with little or no experience in safety assessment to those seeking to gain specialized expertise in certain areas of safety assessments. Incorporating a broad scope of safety assessment training modules, the multi-level programme is organized to accommodate the training of staff from differing professional backgrounds and educational levels. The safety assessment knowledge is organized in a modular way, so that training programmes for safety analysts, for professionals focusing on regulatory reviews, as well as for management and other decision-making personnel can be tailored based on actual needs.

Fundamentals of Safety Assessment

Deterministic Safety Assessment

Probabilistic Safety Assessment

Design Basis Analysis

Beyond Design Basis Analysis

Level 1 PSA

Level 2 PSA

Level 3 PSA

Essential Knowledge

Practical Applications

Integrated Risk-Informed Decision-Making

TOPICS OF THE WORKSHOP

I. Introduction to Level 1 PSA

Introduction to PSA • Basic concepts and techniques • Level-1 PSA organization, management and tasks outline

Level-1 PSA tasks• Analysis of initiating events and accident sequences modelling• System analysis• Exercices (FTs, ETs, MCSs, boolean logic, etc)• Component reliability and initiating event frequency analysis• Analysis of dependencies including common cause failures• Human Reliability Analysis• PSA quantification and analysis of results • PSA software

Probabilistic analysis of internal hazards• Fire PSA• Flood PSA• PSA for other internal hazards

Probabilistic analysis of external hazards• Introduction to Seismic PSA• PSA for other External hazards

PSA for low power and shutdown operation modes

PSA and DSA • Role of deterministic calculations in PSA• Integration of deterministic and probabilistic safety assessment

Use of PSA • Applications of PSA by NPP Operators• Living PSA and Risk Monitors• Applications of PSA by designers • Regulatory uses of PSA

Risk informed decision making

Recent IAEA publications in the area of PSA and IRIDM

Practical Demonstrations on Level 1 PSA model /codes

The workshop is intended for representatives of regulatory authorities, TSOs and plant operators from countries developing new or expanding existing nuclear

power programmes seeking to enhance their knowledge of safety assessment.

TOPICS OF THE WORKSHOP (CONT.)

II. Introduction to Level 2 PSA

Overview of Level 2 PSA• Introduction to Level-2 PSA• Level 2 PSA Process - Major Tasks & InterfacesRole of Level 2 PSA concepts in Risk-Informed RegulationLevel 2 PSA Process Level 2 PSA project arrangementsOverview of Severe Accident Behaviour• Chronology of events and governing phenomena associated with accidents involving

severe physical damage to a nuclear reactor core. • Technical foundation for physical principles of severe accident progression and

containment performance for the purposes of Level 2 PSA.• Melt in vessel retention Sample Calculation of Severe Accident Progression• Chronological progression of, and major phenomena associated with, severe accidents

from a sample calculation for a Boiling Water Reactor (BWR)• References to BWR experimental data sourcesContainment performance • LWR Containment Designs. • Possible containment failure modes and computational models for estimating

performance limits.• Data requirements and analyses necessary for defining realistic containment failure

criteria. Deterministic Analysis of Fission Product Release• Basic principles and phenomena governing fission product release from fuel, transport

through the reactor coolant system and containment, and ultimate release to the environment during severe accidents.

• Evaluation of fission product source terms on a plant-specific basis.• Use of computer simulations of postulated severe accidents to develop the knowledge

necessary for evaluating plant behavior and containment performance.Probabilistic Analysis - Logic Models, Quantification and Uncertainty• Level-1/2 Interface • Containment event trees• Techniques for quantifying basic events within the CET• The principal of a “release category”• Grouping or “binning” pathways through a CET that represent accidents progressions,

which would result in a similar fission product source term• Sensitivity analysis and uncertainty analysis.Format & Content of typical Level 2 PSA Results• Typical metrics for expressing the results of a Level 2 PSA• Documentation and interpretation of Level-2 PSA results

IRIDM and Level-2 PSA Applications• Risk informed decision making approach• Level-2 PSA applicationsExercises on Level-2 PSA Safety Assessment and Verification with Level 2 PSAOverview of Level 3 PSA: Assessment of off-site

consequences

For more information contact : M. Mellinger-Deroy (m.mellinger@iaea.org

I. Fundamentals of Safety Assessment

II. Deterministic Safety Assessment

III. Probabilistic Safety Assessment

II.B - Design Basis Analysis

II.C - Beyond Design Basis Analysis

III.A - Level 1 PSA III.B - Level 2 PSA

III.C - Level 3 PSA

Essential Knowledge

Practical Applications

Present Workshop: SAFETY ANALYSIS III : INTRODUCTION TO

LEVEL 1 AND LEVEL 2 PSA

THE SAFETY ASSESSMENT EDUCATION AND TRAINING PROGRAMME