Coal Operations’ Design Change Notice Process

The Tennessee Valley Authority’s (TVA) drawing program is designed and maintained to document the configuration of TVA’s systems, structures, and components. Drawings are utilized for a variety of reasons, including plant operation, maintenance activities, troubleshooting, and to establish clearance boundaries for isolating equipment so that work can be performed safely. Modifications to configuration should be captured through TVA’s Design Change Notice (DCN) process to ensure configuration control is maintained and drawings are updated to reflect the changes. Due to the importance of accurate drawings to plant personnel safety, we initiated an evaluation of Coal Operations’ DCN process. Our objective was to determine if the DCN process was being followed for modifications made to coal plant drawings. We determined that when the DCN process was utilized, DCNs were generally in compliance with procedural requirements and drawings appeared to have been updated accordingly. However, we determined the DCN process was not always followed for modifications made to coal plant drawings. Specifically, we found (1) modified drawings onsite that had not been updated through DCNs; (2) hand-illustrated drawings utilized in lieu of approved, computer-generated drawings; (3) outdated drawings potentially referenced in the course of work; and (4) reluctance at the sites to initiate the DCN process. Additionally, we identified opportunities for improvement related to (1) training, (2) drawing descriptions, (3) communication of DCN status and drawing availability, and (4) outdated standard programs and processes and intergroup agreements.