August 19,2008

DIABLO CANYON FIRE EXPLOSIVE

The transformer fire shortly after midnight on Sunday, August 17, at Diablo Canyon nuclear plant was an explosive event that would have endangered workers if it had happened during the daytime. The transformer in question was the size of a small room, and was cooled by highly flammable oil. Pacific Gas and Electric Company (PG&E), which operates the plant, confirms that the fire caused damage to a nearby building and another transformer.

San Luis Obispo Mothers for Peace (MFP) will be monitoring the investigation of this explosive fire. County Emergency planners and the public need to know the cause of this fire and how a repeat might be prevented, as well as what consequences to expect should another transformer blow up when workers are present. Diablo workers need reassurance that future transformer fires will be prevented.

MFP will be looking for the following information from investigation results:

1. While it is appropriate for the Nuclear Regulatory Commission (NRC) and PG&E to work together to determine the cause of this fire, the NRC should also do some investigating, such as interviewing workers responsible for maintaining and monitoring the transformers, independently of PG&E.
2. The possible role of human error needs to be assessed. Was there a lack of training or failure to inspect the transformer? Transformers sometimes give warning signals of impending failure, such as overheating. The NRC needs to determine if such warning had occurred and/or if they were looked for.
3. The role of mechanical failure must also be assessed. Were there components of the transformer that were aging?
4. What steps will be taken to prevent reoccurrence? A previous transformer fire at Diablo Canyon occurred in May of 2000, and 2 transformers burned in 1995, all at unit 1. Were the causes of those fires assessed? If so, were there factors in common with those that triggered the recent fire? What steps were taken to prevent a repetition of the 2000 and 1995 fires?
5. The investigation should determine what the consequences would have been if this kind of fire had happened during the daytime when workers were present. Videos of burning transformers of smaller sizes show violent fire punctuated by explosions and are available at Google Video

Read the Union of Concerned Scientists' report on the fire, "Diablo Canyon Transformer Fire (Again)."