Southern Nuclear Operating Uses GT STRUDL® on $10 Million Digital Turbine Controls Project

Owner operator in Alabama (USA) saves $3 million on project to upgrade analog technology to all new digital controls in nuclear project

Case Study, Southern Nuclear

The Challenge

Southern Nuclear Operating Company in Alabama (USA) is overseeing the licensing and construction of two new nuclear units at the Plant Vogtle site near Augusta, Georgia.

The US$2 billion Vogtle 3 and 4 units are among the first new nuclear plants built in America in more than 30 years. The existing cable tray infrastructure in the turbine building was a typical early 1980s design. At that time, the use of structural analysis was limited and computations were performed by hand.

The project required upgrading the plant’s turbine-generator analog controls with a new Mark 6e (VI) digital turbine control (DTC) system. The project involved significant new equipment, 65,000 feet of new cable, and 2,000 feet of new conduit. This type of modification could cost millions of dollars plus considerable plant resources and time.

The Solution

“As part of the DTC upgrade, our engineers decided to investigate the attachment of commodities to cable trays,” said Parimal Gandhi, lead engineer on the project. When reviewing the original hand calculation, the team discovered a simple unit conversion error. When corrected, engineers determined that the torsion levels exceeded the allowable stresses.

This called for a different type of structural analysis. Using Intergraph GT-STRUDL, engineers created models for portions of the cable tray infrastructure system and linked individual supports using cable tray attributes, which enabled engineers to create structural systems for multiple tray supports. The group evaluated stiffness of upstream and downstream supports with cable trays using NF17-Code commands for the torsion analysis, addressing the excessive torsion and preventing the expense of nuclear plant outages.

“With GT STRUDL, we saved $1 million in manpower expenses and an overall $3 million in time and resources, performing the evaluation in less than 23 days,” Gandhi added. Without GT STRUDL, the team could not have implemented the project as quickly, adding significantly to costs. The new controls system is a significant improvement for the plant, with modern equipment that is easier to operate and more reliable. The new equipment also provides more accurate controls which results in both long-term time and cost savings for the plant.

Southern Nuclear received the 2016 GT STRUDL Drivers of Success Award for its use of the software. The annual Drivers of Success competition recognizes innovative applications of Intergraph products, impressive project results, and significant benefits from collaboration among disciplines and the integration of the products.