CSNI Workshop

Working Group on Risk Assessment (WGRISK)

Workshop on Fire Probabilistic Safety Assessment

Puerto Vallarta, Mexico 23-26 May 2005

Hosted by the Comisión Nacional de Seguridad Nuclear y Salvaguardias (CNSNS)

The main purpose of this workshop was to provide a forum to discuss recent developments in the state of the art in Fire Probabilistic Safety Assessment (PSA). The information gathered will be used to produce either a new state-of-the-art-report or an addendum to the 1997 WGRISK report Fire Risk Analysis, Fire Simulation, Fire Spreading and Impact of Smoke and Heat on Instrumentation Electronics.


Workshop background

The main mission of the Working Group on Risk Assessment (WGRISK) was to advance the understanding and utilisation of Probabilistic Safety Assessment (PSA) in ensuring continued safety of nuclear installations and in improving the effectiveness of regulatory practices in member countries.

CSNI lists external events, fire, seismic, flooding, etc., as one of its "High-Level Safety Issues/Topics". The purpose of the list is to define topical areas and issues relevant to safety where useful CSNI work remains to be done, and provided, in accordance with the CSNI Strategic Plan.

Numerous Fire PSAs have shown that fire, depending on the design and operational characteristics of a given nuclear power plant, can be a significant or even dominant contributor to the overall risk for that plant. From an analytical standpoint, a significant number of fire probabilistic safety assessment studies have resulted in estimates of mean fire-induced core damage frequencies (CDF) of 10-4/yr or greater, and predicted contributions to the total CDF (i.e., CDF from all contributors) of 20% or greater, or both. From an empirical standpoint, many fire events have been of some safety significance.

WGRISK produced a State-of-the-art report on Fire Risk Analysis, Fire Simulation, Fire Spreading and Impact of Smoke and Heat on Instrumentation (NEA/CSNI/R(99)27) in 1997 and held an International Workshop on Fire Risk Assessment in 1999 in Helsinki, Finland. A technical opinion paper was issued in 2002. At the fourth WGRISK annual meeting in September 2003, taking into account that further developments and applications of Fire PSA are still in progress in member countries, it was agreed to organise a workshop with the aim of reviewing and discussing efforts to upgrade the fire risk assessment methodologies and other recent developments .

This is further enhanced by the initiative of the CSNI to encourage multilateral co-operation in the collection and analysis of data relating to fire events, the OECD Fire Incidents Records Exchange Project (OECD-FIRE). The main objectives of the project are to collect and analyse fire events data to better understand such events, their causes, and their prevention, as well as to generate qualitative insights into the root causes of fire events which can then be used to derive approaches or mechanisms for their prevention and mitigation of their consequences.

Scope, content and outline of the workshop

The workshop addressed the following main topics:

  • Fire PSA methodology and applications;
  • Fire simulation codes applied or available;
  • Ignition and damageability data;
  • Modelling of fire spread on cables or other equipment;
  • Modelling of smoke production and spread;
  • Impact of smoke and heat on instrumentation, electronics, and other electrical equipment;
  • Impact of cable fires on safety systems;
  • Explosive faults of switchgear.

The workshop consisted of an opening presentation, papers from invited speakers, technical sessions, panel discussions and summary closing sessions.

Related links

Committee on the Safety of Nuclear Installations (CSNI)

Working Group on Risk Assessment (WGRISK)

OECD Fire Incidents Records Exchange Project (FIRE)

Fire Risk Analysis, Fire Simulation, Fire Spreading and Impact of Smoke and Heat on Instrumentation Electronics (NEA/CSNI/R(99)27)



© 2004 Organisation for Economic Co-operation and Development
Last updated: April 28, 2016