key elements of the documentation for the ie definition

Basic Level 1. PSA course for analystsBasic Level 1. PSA course for analysts

Key elements of the documentation for the IE Key elements of the documentation for the IE definition, success criteria determination and definition, success criteria determination and

event sequence modellingevent sequence modelling

IAEA Training in level 1 PSA and PSA applications

Key elements of the documentation for the IE definition, success criteria determination and event sequence modelling

Slide 2.

ContentContent

Introduction: Why? Key elements of the task procedure(s)Key elements of the task analysis file(s)

Introduction: Why? Introduction: Why? Key elements of the task procedure(s)Key elements of the task procedure(s)Key elements of the task analysis file(s)Key elements of the task analysis file(s)


Slide 3.

Introduction: Why?Introduction: Why?

BECAUSE THE ANALYSIS NEEDS TO BE:

TRACEABLEREPRODUCIBLEVERIFIABLE

BECAUSE THE ANALYSIS NEEDS TO BE:BECAUSE THE ANALYSIS NEEDS TO BE:

TRACEABLETRACEABLEREPRODUCIBLEREPRODUCIBLEVERIFIABLEVERIFIABLE


Slide 4.

Key Elements of the Task Procedure(s)Key Elements of the Task Procedure(s)Key Elements of the Task Procedure(s)Key Elements of the Task Procedure(s)

Interface between this(these) task(s) and the human reliability, system modelling and data analysis tasks. Definition of the information to be exchanged

Guidance for preparation of the Task Analysis File(s)

Interface between this(these) task(s) and the Interface between this(these) task(s) and the human reliability, system modelling and data human reliability, system modelling and data analysis tasks. Definition of the information to be analysis tasks. Definition of the information to be exchangedexchanged

Guidance for preparation of the Task Analysis Guidance for preparation of the Task Analysis File(s)File(s)


Slide 5.

Key Elements of the Task Procedure(s)Key Elements of the Task Procedure(s)IE DefinitionIE Definition

Processes to be used in the identification and definition of initiating events

Source documents to be used

Way in which consequential initiating events are to be developed

Process for grouping initiating events

Processes to be used in the identification and Processes to be used in the identification and definition of initiating eventsdefinition of initiating events

Source documents to be usedSource documents to be used

Way in which consequential initiating events Way in which consequential initiating events are to be developedare to be developed

Process for grouping initiating eventsProcess for grouping initiating events


Slide 6.

Key Elements of the Task Procedure(s)Key Elements of the Task Procedure(s)Success Criteria DeterminationSuccess Criteria Determination

Sources to be used for the derivation of success criteria

Thermal hydraulic codes to be used for derivation of plant specific criteria

Definition of the sequence end states for success/failure (cladding temperature, containment temperature and pressure, etc..)Specific acceptance criteria for the performance of equipment during the course of an accident

sequence

Sources to be used for the derivation of success Sources to be used for the derivation of success criteriacriteria

Thermal hydraulic codes to be used for derivation of Thermal hydraulic codes to be used for derivation of plant specific criteriaplant specific criteria

Definition of the sequence end states for Definition of the sequence end states for success/failure (cladding temperature, containment success/failure (cladding temperature, containment temperature and pressure, etc..)temperature and pressure, etc..)Specific acceptance criteria for the performance of Specific acceptance criteria for the performance of equipment during the course of an accident equipment during the course of an accident

sequencesequence


Slide 7.

Key Elements of the Task Procedure(s)Key Elements of the Task Procedure(s)Event Sequence ModellingEvent Sequence Modelling

General assumptions relating to all event tree development

Sequence end statesLevel at which the event tree headings are to be defined (function, system, train)

Requirements for the development of Event Sequence Diagrams

Interface between Level 1 and Level 2

General assumptions relating to all event tree General assumptions relating to all event tree developmentdevelopment

Sequence end statesSequence end statesLevel at which the event tree headings are to be Level at which the event tree headings are to be defined (function, system, train)defined (function, system, train)

Requirements for the development of Event Requirements for the development of Event Sequence DiagramsSequence Diagrams

Interface between Level 1 and Level 2Interface between Level 1 and Level 2


Slide 8.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)GeneralGeneral

Information exchanged between this(these) task(s) and other PSA tasks

List of all the references used, including version number and date

Information exchanged between this(these) Information exchanged between this(these) task(s) and other PSA taskstask(s) and other PSA tasks

List of all the references used, including List of all the references used, including version number and dateversion number and date


Slide 9.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)IE DefinitionIE Definition

A data base of abnormal events and incidents which could lead or have led (in similar plants) to

disruption of plant normal operation

Events based on previous experience from similar plants

A record of all failure modes and effects analyses (FMEA) to identify initiating events, capturing all significant assumptions

A data base of abnormal events and incidents A data base of abnormal events and incidents which could lead or have led (in similar plants) to which could lead or have led (in similar plants) to

disruption of plant normal operationdisruption of plant normal operation

Events based on previous experience from similar Events based on previous experience from similar plantsplants

A record of all failure modes and effects analyses A record of all failure modes and effects analyses (FMEA) to identify initiating events, capturing all (FMEA) to identify initiating events, capturing all significant assumptionssignificant assumptions


Slide 10.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)IE Definition IE Definition (Cont.)(Cont.)

Fault trees and human reliability analyses used to derive initiating events (interface with system analysis and human reliability task)

Derivation of consequential initiating events or cross reference to the document(s) in which they are developed

An assessment of the applicability of initiating events to each plant operating mode

Fault trees and human reliability analyses used to Fault trees and human reliability analyses used to derive initiating events (interface with system derive initiating events (interface with system analysis and human reliability task)analysis and human reliability task)

Derivation of consequential initiating events or cross Derivation of consequential initiating events or cross reference to the document(s) in which they reference to the document(s) in which they are are developeddeveloped

An assessment of the applicability of initiating events An assessment of the applicability of initiating events to each plant operating modeto each plant operating mode


Slide 11.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)IE Definition IE Definition (Cont.)(Cont.)

Initiating events within the plant which occur as the result of internal or external hazards

Derivation of the grouping criteria and the mapping to derive the final initiating event groups

Provision of clear definitions of the initiating event groups to the data task for the quantification of initiating event frequencies (interface with data analysis task)

Initiating events within the plant which occur as the Initiating events within the plant which occur as the result of internal or external hazardsresult of internal or external hazards

Derivation of the grouping criteria and the mapping Derivation of the grouping criteria and the mapping to derive the final initiating event groupsto derive the final initiating event groups

Provision of clear definitions of the initiating Provision of clear definitions of the initiating event event groups to the data task for the quantification of groups to the data task for the quantification of initiating event frequencies (interface with data initiating event frequencies (interface with data analysis task)analysis task)


Slide 12.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)Success Criteria DeterminationSuccess Criteria Determination

Definition of the safety functions and the systems which can perform each of the functions

Rationale for the use of success criteria for the various initiating event groups from sources other than plant specific analysis

Definition of the safety functions and the systems Definition of the safety functions and the systems which can perform each of the functionswhich can perform each of the functions

Rationale for the use of success criteria for the Rationale for the use of success criteria for the various initiating event groups from sources various initiating event groups from sources other than plant specific analysisother than plant specific analysis


Slide 13.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)Success Criteria Determination Success Criteria Determination (Cont.)(Cont.)

Thermal hydraulic analyses performed to demonstrate that a given system response will

prevent the safety limit being exceeded, and those performed to develop timing for operator actions

Relationship between the defined safety functions and the event tree headings and functions

Thermal hydraulic analyses performed to Thermal hydraulic analyses performed to demonstrate that a given system response will demonstrate that a given system response will

prevent the safety limit being exceeded, and prevent the safety limit being exceeded, and those performed to develop timing for operator those performed to develop timing for operator actionsactions

Relationship between the defined safety functions Relationship between the defined safety functions and the event tree headings and functionsand the event tree headings and functions


Slide 14.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)Event Sequence ModellingEvent Sequence Modelling

Description of the evolution of the sequence of events following the representative initiator from each group

If Event Sequence Diagrams are developed, the trip parameters challenged to cause the scram, the signals/channels challenged to initiate various safety functions, and the operators intervention in the course of the sequence, either as the result of system failures, or in response to changes in plant state

Description of the evolution of the sequence of Description of the evolution of the sequence of events following the representative initiator events following the representative initiator from from each group each group

If Event Sequence Diagrams are developed, the trip If Event Sequence Diagrams are developed, the trip parameters challenged to cause the scram, the parameters challenged to cause the scram, the signals/channels challenged to initiate various safety signals/channels challenged to initiate various safety functions, and the operators intervention in the functions, and the operators intervention in the course of the sequence, either as the result of course of the sequence, either as the result of system failures, or in response to changes in plant system failures, or in response to changes in plant statestate


Slide 15.

Key Elements of the Task Analysis File(s)Key Elements of the Task Analysis File(s)Event Sequence Modelling Event Sequence Modelling (Cont.)(Cont.)

Description of each heading in the event tree, and its relationship to a system (or systems) fault tree, human failure event, or other event. (This will include a functional fault tree, top logic or other link to the system models as applicable)

The treatment of dependencies explicitly and implicitly included in the accident sequences

Description of each heading in the event tree, and its Description of each heading in the event tree, and its relationship to a system (or systems) fault tree, relationship to a system (or systems) fault tree, human failure event, or other event. (This will human failure event, or other event. (This will include a functional fault tree, top logic or other link include a functional fault tree, top logic or other link to the system models as applicable) to the system models as applicable)

The treatment of dependencies explicitly and The treatment of dependencies explicitly and implicitly included in the accident sequencesimplicitly included in the accident sequences


Slide 16.


Reference to all relevant operational and emergency procedures used in the development of the individual sequences in the event trees. This information will also be used in the evaluation of the operator response modelling and quantification Boundary conditions for each function. These

include such things as the impact of the function failure on other functions, environmental and

other impacts of initiating events, or dependency on the success or failure of preceding functions

Reference to all relevant operational and emergency Reference to all relevant operational and emergency procedures used in the development of the procedures used in the development of the individual sequences in the event trees. This individual sequences in the event trees. This information will also be used in the evaluation of the information will also be used in the evaluation of the operator operator response modelling and quantification response modelling and quantification Boundary conditions for each function. These Boundary conditions for each function. These

include such things as the impact of the function include such things as the impact of the function failure on other functions, environmental and failure on other functions, environmental and

other impacts of initiating events, or dependency on other impacts of initiating events, or dependency on the success or failure of preceding functionsthe success or failure of preceding functions


Slide 17.


The mission time for each function and the justification for each time

Description of the development of any basic events used to replace an integrated time dependent function (such as the failure of diesel generators to run combined with non recovery of off-site power)

The mission time for each function and the The mission time for each function and the justification for each timejustification for each time

Description of the development of any basic events Description of the development of any basic events used to replace an integrated time dependent used to replace an integrated time dependent function (such as the failure of diesel generators to function (such as the failure of diesel generators to run combined with non recovery of offrun combined with non recovery of off--site power)site power)


Slide 18.


All event tree drawings and core damage events (for example vessel rupture), together with an identification of the end state for each sequence. In the case of a level 1 study this may be simply core damage, while in the case of a Level 1+ or Level 2 study this may be the plant damage state which the sequence is grouped into

All the functional fault tree models (models developed to link the event tree headings with

the system fault trees)

All event tree drawings and core damage events (for All event tree drawings and core damage events (for example vessel rupture), together with an example vessel rupture), together with an identification of the end state for each sequence. In identification of the end state for each sequence. In the case of a level 1 study this may be simply core the case of a level 1 study this may be simply core damage, while in the case of a Level 1+ or Level 2 damage, while in the case of a Level 1+ or Level 2 study this may be the plant damage state which the study this may be the plant damage state which the sequence is grouped intosequence is grouped into

All the functional fault tree models (models All the functional fault tree models (models developed to link the event tree headings with developed to link the event tree headings with

the system fault trees)the system fault trees)


Slide 19.


In the case of a Level 1+ or Level 2 study, the analysis file should include the sequence

grouping criteria for the plant damage states

The development of consequential initiators within event trees and transfer of sequences as initiators in other event trees

In the case of a Level 1+ or Level 2 study, the In the case of a Level 1+ or Level 2 study, the analysis file should include the sequence analysis file should include the sequence

grouping criteria for the plant damage statesgrouping criteria for the plant damage states

The development of consequential initiators within The development of consequential initiators within event trees and transfer of sequences as initiators in event trees and transfer of sequences as initiators in other event treesother event trees

key elements of the documentation for the ie definition

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