Abstract
To assess the risk of nuclear power plant operation and
to determine the risk impact of digital systems, there is
a need to quantitatively assess the reliability of the
digital systems in a justifiable manner. Due to the many
unique attributes of digital systems, a number of
modelling and data collection challenges exist, and
consensus has not yet been reached. The OECD/NEA CSNI
Working Group on Risk Assessment (WGRisk) has set up a
task group called DIGREL to develop a taxonomy of failure
modes of digital components for the purposes of
probabilistic safety assessment (PSA). An activity
focused on development of a common failure modes taxonomy
is seen as a step towards standardised digital I&C
reliability assessment techniques. Needs from PSA will
guide the work, meaning e.g. that I&C system and its
failures are studied from their functional significance
point of view. The taxonomy will be the basis of
modelling and quantification efforts. It will also help
to define a structure for data collection and to review
PSA. DIGREL will take advantage from R&D activities,
actual PSA applications as well as experience related to
digital systems. The scope of the taxonomy includes both
protection and control systems, though primary focus is
on protection systems. The taxonomy is divided into
hardware and software related failure modes, for which
purpose example taxonomies have been collected from the
member countries. A representative fictive digital
protection system example has been developed to be used
as a reference in the demonstration of the taxonomy. With
regard to the hardware failure modes taxonomy, the main
issue is to define a feasible level of details. Module
level, i.e., subcomponents of processing units, seems to
be the most appropriate from the PSA modelling point of
view. The software failure modes taxonomy is focused on
identifying and defining which common cause failures are
reasonable to postulate
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 11th International Probabilistic Safety Assessment and Management Conference & The Annual European Safety and Reliability Conference |
| Subtitle of host publication | PSAM11 ESREL 2012 |
| Publisher | Curran Associates Inc. |
| Pages | 1887-1894 |
| Volume | 3 |
| ISBN (Print) | 978-1-62276-436-5 |
| Publication status | Published - 2012 |
| MoE publication type | A4 Article in a conference publication |
| Event | 11th International Probabilistic Safety Assessment and Management Conference and The Annual European Safety and Reliability Conference, PSAM11 & ESREL 2012 - Helsinki, Finland Duration: 25 Jun 2012 → 29 Jun 2012 |
Conference
| Conference | 11th International Probabilistic Safety Assessment and Management Conference and The Annual European Safety and Reliability Conference, PSAM11 & ESREL 2012 |
|---|---|
| Country/Territory | Finland |
| City | Helsinki |
| Period | 25/06/12 → 29/06/12 |
Keywords
- PRA
- PSA
- digital I&C
- failure modes taxonomy