This CASL visualization shows the thermal distribution of neutrons in Watts Bar Unit 1 Cycle 1 reactor core at initial criticality, as calculated by the VERA program. (Image courtesy of Oak Ridge National Laboratory)This week, the Consortium for Advanced Simulation of Light Water Reactors (CASL) announced that its scientists have successfully completed the first full-scale simulation of an operating nuclear reactor. The goal of the simulation is to help researchers better understand reactor performance. The new model offers higher reliability than previously available methods and can ultimately lead to increased power output, extended reactor life, and reduced waste.
Simulation results from the Virtual Environment for Reactor Applications (VERA) program, developed by CASL, were compared with actual data provided by the Tennessee Valley Authority’s (TVA) Watts Bar Nuclear Plant in Tennessee, which confirmed its accuracy.
“VERA’s capabilities range from simulating single fuel pins to modeling an entire operational reactor core,” said Jess Gehin of Oak Ridge National Laboratory’s Reactor and Nuclear Systems Division. “It addresses operational challenges and supports increased power generation by exploring greater efficiency and life extensions.”
During cycle startup of commercial nuclear power reactors, technicians perform a series of tests to confirm the reactor is operating as expected. For CASL, results of previous tests are useful for demonstrating the accuracy of the VERA software. As a CASL partner, TVA provided detailed historical information and measured operational data from the Watts Bar plant to allow comparisons of the VERA simulation.
The simulations of the reactor startup tests are just a first step in the demonstration of VERA. CASL is extending the program’s capability to simulate full power operation of the TVA reactor, which will require further VERA development to integrate the nuclear and thermal hydraulic physics. These additional capabilities will allow researchers to pursue breakthroughs in understanding key phenomena in the operating reactors.
CASL, headquartered at ORNL, is one of the Department of Energy’s Energy Innovation Hubs. First established in 2010, CASL brings together industry, academia, and national labs to provide advanced modeling and simulation solutions for commercial reactors. Its mission is to confidently predict the performance of nuclear reactors through comprehensive science-based modeling and nuclear reactor simulation technology that is deployed and applied broadly throughout the nuclear energy industry to enhance safety, reliability and economics.
