The first campaign of the PRISME 3 program, led under the auspices of the OECD, took place from October 2017 to March 2018 at the IRSN’s DIVA facility, where a renovated ventilation system installed in 2017 enables better measurement of combustion products and ventilation flow rate. This campaign, entitled S3 for “smoke stratification and spread,” complements the tests conducted during the previous OECD projects, PRISME and PRISME 2, which focused on the study of smoke stratification in a building and its propagation throughout the structure via openings (doors, vents, etc.)
PRISME 3-S3 is an experimental study of smoke propagation in various configurations representative of the fire scenarios encountered in nuclear facilities. During the campaign, 5 tests were conducted through which data was gathered on:
- the ways in which smoke propagates through doorways and horizontal section openings connecting containment structures placed on top of each other, when using the mechanical or natural ventilation system (2 tests were conducted to determine the influence of the type of ventilation);
- the interaction between two fire sources and its consequences on smoke stratification in a facility (2 tests);
- the combustion of an elevated fire source in a facility and the associated smoke propagation (1 test).
DIVA room before (left) and after (right) a test
These tests enabled to better characterize smoke propagation in nuclear facilities in various fire scenarios selected, and to improve and validate SYLVIA and ISIS, both IRSN simulation tools used for studies supporting safety analyses. These tests provided opportunities to expose electrical equipment to a real fire, which generated data on representative conditions in which this equipment would malfunction, namely in terms of soot concentration and critical exposure temperature.
The next test campaign will focus on the propagation of an electrical cabinet fire, and consist of four tests at the DIVA facility. A total of three test campaigns are set to take place by the end of the program expected in 2021.