Investigation, Re-creation Indicates Likely Ignition Point of Thermalito Fire

摘要

The results of the fire forensic and relay engineer investigations lead DWR to think the Thermalito fire's point of ignition occurred at Elevation 136. However, lab testing on circuit No. 19 was not able to confirm the fire expert forensics. This inability to confirm circuit No. 19 as the root cause can be attributed to the extent and severity of fire damage (cables and breakers destroyed) that limited the fire forensic investigation and the relay engineer's inability to replicate absolutely the actual event in a laboratory setting. Additionally, although no forensic evidence was found to support a DC series arcing fault as starting this fire, literature and laboratory experiments suggest the DC series arcing fault as a possible root cause of plant fires.