US DoE develops algorithm to view nuclear energy

Ever wanted to see a nuclear reactor core in action? A new computer algorithm developed by researchers at the US Department of Energy's (DoE) Argonne National Laboratory allows scientists to view nuclear fission in much finer detail than ever before.

Development of the UNIC code is funded principally by DoE's Office of Nuclear Energy through the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program.

A team of nuclear engineers and computer scientists at Argonne National Laboratory are developing the neutron transport code UNIC, which enables researchers for the first time to obtain a highly detailed description of a nuclear reactor core.

The code could prove crucial in the development of nuclear reactors that are safe, affordable and environmentally friendly. To model the complex geometry of a reactor core requires billions of spatial elements, hundreds of angles and thousands of energy groups - all of which lead to problem sizes with quadrillions of possible solutions.

Such calculations exhaust computer memory of the largest machines, and therefore reactor modelling codes typically rely on various approximations. But approximations limit the predictive capability of computer simulations and leave considerable uncertainty in crucial reactor design and operational parameters.

''The UNIC code is intended to reduce the uncertainties and biases in reactor design calculations by progressively replacing existing multilevel averaging techniques with more direct solution methods based on explicit reactor geometries,'' said Andrew Siegel, a computational scientist at Argonne and leader of Argonne's reactor simulation group.