NTSB San Bruno Report Points to Welding Problem

The National Transportation Safety Board on Friday released the first in a series of reports into the deadly pipeline explosion in San Bruno on Sept. 9.  Investigators found multiple defects, including cracks, on welds in the pipe that exploded killing eight people and destroying dozens of homes.

The report only gave facts and gave no analysis.  The pipeline in question was installed in 1956 and was originally thought to be "seamless," according to  PG&E.

It detailed flaws in Line 132. Federal investigators said they found multiple defects and cracks in the welds that held segments of the pipe together.

The report is the result of an NTSB investigation. Experts spent more than a week discecting three sections of the 30-inch pipe at a facility in Ashburn, Virginia.

The Associated Press talked to engineering experts who said the report shows the welds on the segments of pipe that failed could have broken under increased pressure in the line.
The pipeline's owner, Pacific Gas & Electric Co. has admitted it spiked gas pressure prior to the blast.

PG&E President Chris Johns seemed to respond to that in his statement released following the report's release.  John said  PG&E will continue to operate its lines at pressures that have been reduced by 20 percent, noting that would build a "significant additional margin of safety" into their current operating conditions.

"While additional work still lies ahead to reach a final conclusion on what caused the September 9, 2010, tragedy in San Bruno, today’s metallurgical report by the NTSB is another important step in that process," Johns said in the statement. "In keeping with our focus on safety, we will continue working with all due diligence to incorporate data and recommendations by the NTSB into the various initiatives now under way within PG&E to ensure the safety and integrity of our system."

The report gave no recommendations. The NTSB said it has not yet finished its inquiry and did not
yet know the cause of the blast.
 Rep. Jackie Speier released a statement that said she was "profoundly disturbed" by the report, noting that PG&E believed the pipe was seamless.
"Over the past several months, experts have told me that welding flaws are detectable," she said in a statement.

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