TVA Mitigation of Risks from Bulk Industrial Gases

The Tennessee Valley Authority (TVA) uses bulk industrial gases, including oxygen, hydrogen, nitrogen, and carbon dioxide as part of its normal operations. Due to hazards associated with handling bulk industrial gases and the importance of worker and public safety at TVA, the OIG initiated an audit of TVA's mitigation of risks from bulk industrial gases. We limited our scope to the explosive and flammable risks of hydrogen and oxygen and the asphyxiation risks of nitrogen and carbon dioxide. Our objective was to determine whether TVA designed mitigating actions for fire, explosion, and asphyxiation risks related to hydrogen, oxygen, nitrogen, and carbon dioxide bulk industrial gases. We determined TVA designed mitigating actions for fire, explosion, and asphyxiation risks related to hydrogen, oxygen, nitrogen, and carbon dioxide bulk industrial gases. However, we identified several areas for improvement to further mitigate the risks from bulk industrial gases. Specifically, we found (1) contract terms did not require a supplier to provide TVA with inspection and maintenance reports for bulk gas tanks, (2) emergency plans do not list types and quantities of on-site gases, and (3) unsecured portable compressed gas cylinders at Gallatin Fossil Plant and Widows Creek Fossil Plant. We recommended the Senior Vice President, Power Operations, update site emergency plans to identify types and quantities of compressed gases and cryogenic fluids stored at generating plants and assess the root cause of unsecured compressed gas cylinders at Gallatin Fossil Plant and Widows Creek Fossil Plant and address as appropriate. In addition, we recommended the Vice President, Supply Chain, amend gas supplier contracts to require suppliers to provide TVA with inspection and maintenance reports that show contractor compliance with appropriate inspection/maintenance-related codes and regulations and enable TVA to confirm the supplier is meeting its obligations for tank safety. TVA management agreed with our findings and provided the actions they have taken or plan to take to address each of our recommendations.