PACIFIC GAS & ELECTRIC CO — Integrity Assurance Notification

ASSUMED TOUGHNESS  PG&E is planning to use conservative, statistically representative upper-shelf Charpy V Notch (CVN) toughness values and transition temperatures for determination of fracture toughness for PG&E’s gas transmission pipelines where traceable, verifiable and complete (TVC) records do not exist for CVN toughness at the present time. This notification addresses the determination of statistically representative CVN toughness values as “Other Appropriate Values” with technical justification under 49 CFR §192.712(e)(2)(i)(E) for pipelines which lack TVC test records for material toughness. This notification also details PG&E’s analysis process, data and procedures that form the basis for concluding that statistically representative CVN toughness values are appropriate and provide a conservative estimate of toughness for analysis of predicted failure pressure of pipelines. This notification is being submitted under provisions of 49 CFR §192.18(c).#