PRISME Program

The PRISME Programme (Propagation d'un incendie pour des scénarios multilocaux élémentaires – Propagation of fire for elementary multi-room scenarios) is an international research programme carried out by the IRSN under the aegis of the OECD. It studies experimentally the propagation of smoke from a fire in a nuclear installation through openings between rooms and ventilation systems as well as the behaviour of actual fires (electrical cabinets and cables) under oxygen-starved conditions (confined and ventilated rooms). PRISME 1, the first phase of the programme, took place from 2006 to June 2011. PRISME 2 took place from July 2011 to November 2016 while PRISME 3 started in January 2017 for 5 years.

The data collected is used to validate the physical models built into the calculation software that simulates fires, such as SYLVIA and ISIS.

The PRISME 3 programme consists of three areas of research. The first concerns the stratification and propagation of smoke (S3 campaign for “Smoke Stratification and Spread”) during a fire in a multi-compartment installation equipped with a mechanical ventilation system. The second avenue will look at the spread of an electrical cabinet fire to neighbouring cabinets (ECFS campaign for Electrical Cabinet Fire Spread). Lastly the third area will study the propagation of cable tray fire (CFP campaign for Cable Fire Propagation) in a confined and ventilated room.

Area 1: Stratification of smoke in a room and propagation of smoke through openings (S3 Campaign - Smoke Stratification and Spread).

The five new tests which will be performed in the DIVA experimental facility will complement those performed during the PRISME 1 and 2 programmes in the area of propagation of smoke from one room to others via vertical openings (open doors) and horizontal openings. This is important to assess the consequences of smoke on the operation of electrical or electronic equipment. The test campaign will also study the combustion of fires located at height to check the validity of fire codes used for analyses carried out to support expert assessments. It is also planned to perform tests with two fires at the same time in different rooms to evaluate the effect of smoke propagation on combustion conditions for the two fires and to also validate simulation codes in this complex configuration.

Area 2: Propagation of an electrical cabinet fire to neighbouring cabinets (ECFS campaign - Electrical Cabinet Fire Spread).

The tests carried out in this area aim to assess the relevance of the criteria used in the probabilistic safety studies which are used to predict whether a fire will propagate from one electrical cabinet to another or not. These criteria are determining for evaluating the consequences of a fire in electrical rooms.

4 tests  will be performed in the experimental SATURNE facility in free air and 4 in the DIVA facility in a confined and ventilated area, with various propagation scenarios such as: open doors cabinet  and adjacent cabinet with closed doors, opposite cabinet connected by cable trays and so forth.

Area 3: Propagation of cable tray fires (CFP campaign for Cable Fire Propagation).

This campaign will complete the CFS campaign from PRISME 2 which looked at the effect of oxygen starvation on the propagation of an electrical cable fire. The particular configuration of a tunnel containing cabletrays along its entire length will also be studied for the first time in the DIVA facility. The results will be used to enhance the experimental database used to validate fire simulation codes.

8 tests will be performed, 2 in the SATURNE facility in free air and 6 in the DIVA facility in confined and ventilated rooms.