Large scale tests to evaluate enclosure fire environments

This article describes a series of fire tests conducted by Factory Mutual Research Corporation under the direction of Sandia National Laboratories for the US Nuclear Regulatory Commission. The primary purpose of these tests was to provide data against which to validate computer fire environment simulation models to be used in the analysis of nuclear power plant enclosure fire situations. These tests were conducted in an enclosure measuring 60'x40'x20' (18mx12mx6m). All of the tests utilized forced ventilation conditions. The ventilation system was designed to simulate typical nuclear power plant installation practices and ventilation rates. A total of 22 tests using simple gas burner, heptane pool, methanol pool, and PMMA solid fires were conducted. Four of these tests were conducted with a full-scale control room mockup in place. An additional three tests involving the burning of cables in electrical control cabinets were also conducted. Parameters varied during testing were fire intensity, enclosure ventilation rate, and fire location. Data gathered includes air temperatures, air velocities, radiative and convective heat flux levels, optical smoke densities, inner and outer enclosure surface temperatures, enclosure surface heat flux levels, and gas concentrations within the enclosure in the exhaust stream