Under the auspices of the OECD, a second international PRISME program was launched in July 2011 to study fire-related topics that could not be treated during the first experiment program, such as the propagation of smoke between stacked rooms, propagation of a fire between cableways and the performance of spray systems.
The PRISME 2 program will include four test campaigns to be conducted at the DIVA facility.
Objectives and procedure
Test campaign 1: Vertical smoke propagation (VSP)
This campaign will study vertical smoke propagation using a horizontal opening between two stacked, mechanically ventilated rooms. It involves analysing and understanding the role and relative importance of natural convection caused by temperature differences in the gaseous environment and forced convection caused by ventilation.
It includes four tests:
- the first, or reference, test (VSP_1) will be performed only in the lower room, with a centred combustion chamber and set ventilation rate;
- VSP_2 will be performed with the same combustion chamber and ventilation rate as the reference test, but with a connection to the upper room open just above the combustion chamber and smoke exhaust taking place through the upper room;
- VSP_3 differs from the previous by the off-centring positioning of the combustion chamber and smoke exhaust and new gas intake taking place in each of the two rooms;
- VSP_4 is identical to the previous test except there will no longer be smoke exhaust in the lower room.
Test campaign 2: Propagation of a fire in cableways, or cable fire spreading (CFS)
This campaign studies propagation of a fire between several stacked cableways and an electrical cabinet open to cableways passing over it, and the propagation of smoke from the room with the fire to an adjacent room.
It includes two test series (see figure below):
- tests CFS_1-CFS_4 concern propagation of a fire between five stacked cableways with the goal of testing three types of cables and two ventilation levels;
- tests CFS_5-CFS_7 study propagation of the fire from an electrical cabinet open to three cableways located above it; for these tests, a third room will be used to study the effects of pressure on a fire door (connecting a third room to the room adjacent to the room with the fire).
These tests are representative of fire scenarios in nuclear facilities that are initiated by an electrical fault in a control panel or electrical cabinet, for example.
Test campaign 3: fire extinction system (FES)
The objective of this test campaign is to assess the performance of sprinkler-type fire extinction systems. In four to six tests (FES_1-FES_6), the effectiveness (ambient environment cooling and fire extinction) of two or three types of industrial sprinkler nozzles will be evaluated for two water flow rates under conditions that represent a fire in a confined and ventilated environment.
Test campaign 4 and additional tests
The last test campaign will involve three to five fire tests to be performed in conditions that will be defined in view of the results of the first three test campaigns. It may involve all five rooms at the DIVA facility.
Sixteen experiments are planned as part of these four campaigns in order to characterize the combustible materials (physicochemical properties and behaviour when exposed to fire) and provide more extensive analysis for the PRISME 2 tests. Initial results and analyses from these experiments are expected in late 2013.