Cable-Spreading Room Fire

A number of issues arise in using the available data to estimate (he rates of location-dependent fire occurrence. These include the possible reduction in the frequency of fires due to increased awareness. Apostolakis and Kazarians (1980) use the data of Table 5.2-1 and Bayesian analysis to obtain the results in Table 5.2-2 using conjugate priors (Section 2.6.2), Since the data of Table 5.2-1 are binomially distributed, a gamma prior is used, with a and P being the parameters of the gamma prior as presented inspection 2.6.3.2. For example, in the cable- spreading room fromTable 5.2-2, the values of a and p (0.182 and 0.96) yield a mean frequency of 0.21, while the posterior distribution a and p (2.182 and 302,26) yields a mean frequency of 0.0072. 

About 15 min after the fire started (at approx. 12 35 p.m.), a siren alarm sounded to warn personnel in the cable-spreading room to evacuate because the permanently installed CO2 Cardox fire-extinguishing system was to be actuated. This system flushes the room with enough CO2 to displace most of the oxygen required for the survival of the personnel. After the room was evacuated, an assistant shift engineer attempted to actuate the Cardox system... 

The fire that started on the cable-spreading room side of the penetration spread into the... 

Path From Cable-Spreading Room to Reactor-Building Fire Area... 

The cable spreading room below the control room is significant but not dominant in the fire analysis. The scenario of interest is a fire-induced transient coupled with fire-related failures of the control power for the high-pressure coolant injection system, the reactor core isolation cooling system, the automatic depressurization system, and the control rod drive hydraulic system. The analysis gave credit to the automatic CO2 fire-suppression system in this area. 

---