VERAShift – VERAShift is the hybrid deterministic-Monte Carlo ex-core radiation transport interface package serving as the application programming interface (API) for integrating in-core depletion and thermal-hydraulics calculations performed with MPACT and CTF with ex-core calculations performed with Shift [1]. Its initial development began in 2015 and it is mainly used to perform ex-core transport calculations for light water reactors in the VERA code suite. These calculations include vessel fluence, detector response including during reactor startup, and concrete fluence.

VERAShift is also used as a verification and/or validation tool by utilizing its Monte Carlo eigenvalue solution capability. 

For further questions or inquiries about VERAShift please contact Tara Pandya at

VERAShift References

1. Pandya, Tara M., Seth R. Johnson, Thomas M. Evans, Gregory G. Davidson, Steven P. Hamilton, and Andrew T. Godfrey. “Implementation, Capabilities, and Benchmarking of Shift, a Massively Parallel Monte Carlo Radiation Transport Code.” Journal of Computational Physics 308 (March 2016): 239–72.

2. VERAShift User Manual

3. VERAShift Theory Manual

VERAShift Images


Pin adjoint and vessel fluence at axial midplane plotted in VERAView

Pin powers and vessel fluence at axial midplane plotted in VERAView

Contour plot of fast neutron flux at nozzle and in concrete bioshield (above) and its relative error (below)