Docket No. PHMSA-2016-0131
PHMSA has issued an advisory bulletin ADB-2017-01 to inform owners and operators of gas transmission pipelines that PHMSA has issued guidance on threat identification and the minimum criteria for deactivation of threats as well as guidance regarding documenting rationale of analyses, justifications, determinations, and decisions related to threat identification.
According to ASME B31.8S–2004, Section 2.2, an operator must consider nine individual threat categories as part of an IM program. As stated by ASME B31.8S–2004, Section 5.10, an IM program should provide criteria for eliminating a threat from consideration during a risk assessment; however, 49 CFR part 192—Subpart O does not include provisions for the permanent elimination of threats. An operator, therefore, must continually consider all threats in the evaluation of their IM program through periodic reviews and assessments, as required by section 192.937.
Some operators inappropriately label threats as inactive after they are eliminated from consideration during prior reviews and assessments, ignoring the continuous supply of new information provided during routine O&M activities. Others have opted to eliminate threats from consideration based on a lack of data, including missing, incomplete, or unsubstantiated data. Using insufficient data to eliminate a threat is not technically justified and is contrary to the guidance in ASME B31.8S–2004, Appendices A1–A9.
PHMSA acknowledges that the threats identified in ASME B31.8S–2004 may be considered active or inactive, but are never permanently eliminated. ASME B31.8S–2004, Appendix A, identifies the information an operator must collect and analyze for threats, which must demonstrate an individual threat is not acting on the pipe before an operator can properly declare the threat inactive for each assessment period. A threat must be considered active if any data required by Appendix A is missing, as lack of data indicating the existence of a threat is not an acceptable justification for considering the threat inactive.
Documents to support the determination of an inactive threat status must be maintained, as per the requirements of § 192.947(d). An operator does not need to assess a threat for the current assessment cycle if that threat is properly deemed inactive. When conditions warrant a review or new information becomes available during the required § 192.937 evaluation, operators are required to examine each applicable threat to determine it is active or inactive.
The advisory bulletin gives detailed guidance for each of the nine threat categories to help operators determine the active or inactive status. The advisory states that 4 of the 9 threats may be considered inactive if the facts warrant: internal corrosion; manufacturing; construction; and equipment threats. The remaining 5 threats (i.e., external corrosion; stress corrosion cracking; third party damage; incorrect operations; and weather related and outside forces), must always be considered active.
For a copy of ADB-2017-01 Deactivation of Threats, contact Jessica Foley.