High Temperature Hydrogen Attack (HTHA) - Risks and mitigation in light of the .S. Chemical Safety Board (CSB) investigation into the Tesoro Refinery industrial accident

摘要

1 The Tesoro Refinery industrial accident in Anacortes, WA, USA in 2010 resulted from damage due to high temperature hydrogen attack (HTHA). 2 The risk of related failures was assessed using API RP 941 Nelson curves. 3 The U.S. Chemical Safety Board (CSB) concluded that the carbon steel Nelson curve methodology is inaccurate, cannot be depended on to prevent equipment failures due to HTHA, and cannot be reliably used to predict the occurrence of damage due to HTHA. 4 The CSB has identified at least eight incidents of HTHA occurrence below the carbon Nelson curve; i.e. which did not indicate high risk of HTHA. The 2016 edition of API RP 941 reports 13 new failures below the carbon steel Nelson curve.