Muon Radiography to Visualise Individual Fuel Rods in Sealed Casks

TL;DR

This paper explores the use of cosmic-ray muon scattering data to non-invasively detect missing fuel rods in sealed nuclear casks, demonstrating the potential for reliable identification through simulations.

Contribution

It presents the first theoretical feasibility study of detecting individual missing fuel rods in sealed casks using muon radiography, including simulation-based analysis.

Findings

Missing rods can be reliably detected depending on their position and measurement parameters.

Muon scattering analysis can distinguish missing fuel rods within reasonable measurement times.

The method's effectiveness varies with cask configuration and detector setup.

Abstract

Cosmic-ray muons can be used for the non-destructive imaging of spent nuclear fuel in sealed dry storage casks. The scattering data of the muons after traversing provides information on the thereby penetrated materials. Based on these properties, we investigate and discuss the theoretical feasibility of detecting single missing fuel rods in a sealed cask for the first time. We perform simulations of a vertically standing generic cask model loaded with fuel assemblies from a pressurized water reactor and muon detectors placed above and below the cask. By analysing the scattering angles and applying a significance ratio based on the Kolmogorov-Smirnov test statistic we conclude that missing rods can be reliably identified in a reasonable measuring time period depending on their position in the assembly and cask, and on the angular acceptance criterion of the primary, incoming muons.