Regular Article

Muon radiography to visualise individual fuel rods in sealed casks

¹ GRS gGmbH, Schwertnergasse 1, 50667 Cologne, Germany
² GRS gGmbH, Boltzmannstr. 14, 85748 Garching, Germany
³ GRS gGmbH, Kurfürstendamm 200, 10719 Berlin, Germany
⁴ BGZ mbH, Dammstraße, 84051 Essenbach, Germany

^* e-mail: thomas.braunroth@grs.de

Received: 26 February 2021
Received in final form: 4 May 2021
Accepted: 11 May 2021
Published online: 15 June 2021

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.