Nuclear scientists at Oak Ridge National Laboratory have established a Nuclear Quality Assurance-1 program for a software product designed to simulate today’s commercial nuclear reactors, removing a significant barrier for industry adoption of the technology.

The suite of tools called VERA, the Virtual Environment for Reactor Applications developed by the Consortium for Advanced Simulation of Light Water Reactors, or CASL, can be used to solve various challenges in nuclear reactor operations and consists of several physics codes related to neutron transport, thermal hydraulics, fuel performance and coolant chemistry.

VERA is an ORNL-led collaboration with the University of Michigan, the Massachusetts Institute of Technology (MIT), North Carolina State University (NCSU), Tennessee Valley Authority, Westinghouse, the Electric Power Research Institute, and Idaho, Sandia, and Los Alamos Laboratories, with contributions from many other partners in academia, industry, and the national laboratory system.

The tool sets leverage key components of the SCALE system, most notably the fundamental nuclear data processing and isotopic depletion capabilities, and they have rapidly enhanced the state of the practice for advanced multiphysics simulation of light-water reactors (LWRs).

Integrating high-resolution neutronics using (1) the MPACT code, jointly developed with the University of Michigan, with subchannel two-phase flow with CTF and (2) high-fidelity depletion with ORIGEN provides fully coupled estimates of the state of every pin and coolant channel in a pressurized water reactor’s core without traditional homogenizing of materials.

Coupling with CRUD chemistry (Los Alamos National Laboratory’s MAMBA chemistry code) and fuel performance (Idaho National Laboratory’s BISON fuel performance codes) enables advanced solutions to complex industry problems.

The goals of the continued work in improving the simulation software are to help industry by boosting the power output from existing reactors and to improve designs and confidence in current and future reactors.

ORNL’s Shane Stimpson co-leads MPACT, the component of VERA responsible for modeling power distribution throughout the reactor core.

When developing these codes, we’re listening to industry’s needs to provide reactor simulations with broader appeal and value.

—Shane Stimpson