Institute for Energy

December, 2008

JRC Aging PSA Network Task Group 6 : Reliability and data analysis for passive components.

Experts meeting 4-5December 2008, Rez, Czech Republic

Meeting minutes

Participants:Task leader:

Alzbutas,Robertas – LEI, Lithuania.


Getman,Alexander – VNIIES, Russia,

Holy,Jaroslav – UJV Rez, Czech Republic,

Hulsmans,Mark– JRC IE, Netherlands,

Kelly,Dana L. – Idaho NL, USA,

Trifanov,Alexander – CNSC, Canada.

Objectives:to discuss the issues related to the Task 6: Reliability and data analysis for passive components

-Terms of references for the Task activities,

-Schedule and deliverables related to different Subtasks,

-Future planning for scope and content of references/deliverables.

Meeting discussions and conclusions:

The current status and meeting objectives were presented by Task leader. Up to now, the following institutions (in alphabetical order) expressed interest to participate in the Task activities: JRC, CNE, CNSC, INL, INPE, KKG, LEI, UJV, VNIIES.The Task activities are divided in two subtasks. A plan to arrange/support work of Task in such way, that both subtasks activities would be in parallel, was presented and agreed.

The slides on Task work specification and Terms of references for the Task activities were presented by Task leader(see Attachments). The hard copies were kindly prepared and distributed by host of the meeting (UJV Rez).

Considering the objective of Task, it was pointed out that Task activities can focus on assessment of opportunitiesand limitations instead of only limitations of passive component modelling in PSA, as well as assessment oftheir importance for risk-informed decision making.

Regarding the methods applicable for the Task related activities theparticipants expressed/discussed idea that it is reasonable to distinguish two types of models:

  1. Time-dependant models of defects/conditions initiation (relatively long term scale),
  2. Time-dependant models of physical phenomena to assess how defects grow up to the failure (relatively short term scale).

Methods for the first type of the models development can be similar to the statistical methods, which wereconsidered for the analysis of active components failure data. In addition, there is a need to separate specific cases when phenomena under investigation are know (failures are seen) and when phenomena are not known and uncertainty for future predictions is very high.

The grouping of methods and case studies are going to be related tothe definitions and reference survey. All experts/observers as contribution for deliverables agreed to provide at least the references relevant for the Task activities.

During the discussions, a roadmap was established for the practical elaboration of the contents of foreseen deliverable/s.

The first subtask will address an overview of methods and models. INL could provide some general considerations regarding statistical approaches versus modelling approaches to assess/predict phenomena. The approach of CNSC is considered as a valuable starting point (list of components, phenomena and models).

In general, the investigation is directed towards ageing phenomena (e.g. an essential parameter and associated failure criterion)in passive components for which failure probabilities in function of time can be found, and towards the data that are required and available for these models in order to be useable for PSA modelling (e.g. related to the timescale of the phenomena to act).

A preliminary list of references was considered (IAEA docs, NUREGs, CNSC, OPDE database, VNIIAES, material from the previous Moscow meeting, and etc.) and will be further assembled by email.

The intended scope of this subtask should preferably include aging phenomena of mechanical components and in extended scope electrical cables, structures and etc. In general, there is a need to specify phenomena, component, failure criteria, time scale, models and data needed.

It was recognized that at this stage it is also important to document present gaps of areas for research, if any.

For the second subtask, case studies are expected from KKG (1), LEI (1) and VNIIAES (2). It was suggested to adopt a highly interactive approach for the efficient involvement of all Task 6 contributors.

The possible need for a further expert meeting can be considered later.

For first deliverables the agreed time frame: 01/10/2008 - 15/05/2009.

The preliminary work schedule and subjects are as follows:

2008-11-30: Initial draft of report contents and subjects (EOI to contribute, description of applicability);

2009-01-30: Updated draft of report including ideas from partners responses (progress status);

2009-03-30: Final draft of report prepared for partners review/agreement to publish.

2009-05-01: Final deadline for reporting.

2008-12-15: Initial request to contribute presenting case studies (express of interest);

2009-03-15: Initial draft of report contents for case studies (progress status);

2009-04-15: Final draft of report summarizing case studies.

2009-05-01: Final deadline for reporting.

Attachments :

-Slides on Task work specification and Terms of references for the Task 6 activities.