Pacific Gas & Electric is checking for leaks in 180 segments of its natural gas pipeline system, including part of a line where an explosion killed eight people in 2010.

PG&E said Tuesday it is conducting the emergency surveys after acknowledging it had ignored vulnerability to corrosion on the lines, in some cases for years, the San Francisco Chronicle reported Wednesday.

More than half of the 180 segments were found to have such vulnerabilities this year, with about a third in the San Francisco Bay area, according to a company letter to the California Public Utilities Commission.

PG&E policy calls for the company to develop a remedy plan within 60 days after discovering a transmission pipeline is susceptible to corrosion, but some major gas lines have been identified as potentially vulnerable since 2004, officials said.

One vulnerable pipe ruptured in San Bruno on Sept. 9, 2010, causing a massive blast and fire that destroyed 38 homes in the San Francisco suburb, PG&E said.

In a statement, the utilities commission said it was "analyzing the corrective actions PG&E has taken, including steps to prevent this from happening again, and will decide whether to issue a citation with a penalty for the violation."

The San Francisco-based utility discovered the problematic pipes in January as it reviewed its pipeline integrity management program following the San Bruno explosion, officials said.

PG&E plans emergency leak inspections of all 180 problem areas by the end of this month.