Uncertainties in transport theory pressure vessel neutron fluence calculations

TLDR: In this article, the authors use particle transport theory methods and analysis to estimate the neutron and/or gamma fluence distributions of the pressure vessel in PWRs and vessel internals in boiling water reactors.

Abstract: The desire for increasing safety margins (increased power production and plant availability), the fact that many existing plants are approaching the final years of their design lifetime, and the consideration of life extension have resulted in the need for performing more accurate estimation of parameters that affect plant performance and safety. This means that more accurate calculational and experimental methodologies for estimating the neutron and/or gamma fluence distributions are needed to ensure the structural integrity of the pressure vessel in pressurized water reactors (PWRs) and vessel internals in boiling water reactors. Such an estimation requires the use of particle transport theory methods and analysis; because of the existing uncertainties in the input parameters and numerical methods, it is necessary to estimate the uncertainties in the calculated results.