C. J. Lissenden Engineering Science and Mechanics, Penn State, University Park, PA 16801 S. Choi Engineering Science and Mechanics, Penn State, University Park, PA 16801 H. Cho Engineering Science and Mechanics, Penn State, University Park, PA 16801 A. Motta Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801 K. Hartig Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801 X. Xiao Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801 S. Le Berre Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801 S. Brennan Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801 K. Reichard Applied Research Laboratory, Penn State, University Park, PA 16801 R. Leary Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801 B. McNelly Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801 I. Jovanovic Mechanical and Nuclear Engineering, Penn State, University Park, PA 16801; Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 Toward Robotic Inspection of Dry Storage Casks for Spent Nuclear Fuel Extended dry storage of spent nuclear fuel makes it desirable to assess the structural integrity of the storage canisters. Stress corrosion cracking of the stainless steel canister is a potential degradation mode especially in marine environments. Sensing technologies are being developed with the aim of detecting the presence of chloride-bearing salts on the surface of the canister as well as whether cracks exist. Laser-induced breakdown spectroscopy (LIBS) methods for the detection of Chlorine are presented. In addition, ultrasonic-guided wave detection of crack-like notches oriented either parallel or perpen- dicular to the shear horizontal wave vector is demonstrated using the pulse-echo mode, which greatly simplifies the robotic delivery of the noncontact electromagnetic acoustic transducers (EMATs). Robotic delivery of both EMATs and the LIBS system is necessary due to the high temperature and radiation environment inside the cask where the meas- urements need to be made. Furthermore, the space to make the measurements is very con- strained and maneuverability is confined by the geometry of the storage cask. In fact, a large portion of the canister surface is inaccessible due to the presence of guide channels on the inside of the cask’s overpack, which is strong motivation for using guided waves for crack detection. Among the design requirements for the robotic system are to localize and track where sensor measurements are made to enable return to those locations, to avoid wedging or jamming of the robot, and to tolerate high temperatures and radiation levels. [DOI: 10.1115/1.4035788] Contributed by the Pressure Vessel and Piping Division of ASME for publication in the JOURNAL OF PRESSURE VESSEL TECHNOLOGY. Manuscript received August 12, 2016; final manuscript received January 11, 2017; published online February 8, 2017. Assoc. Editor: Haofeng Chen. Journal of Pressure Vessel Technology JUNE 2017, Vol. 139 / 031602-1 Copyright VC 2017 by ASME Downloaded from http://asmedigitalcollection.asme.org/pressurevesseltech/article-pdf/139/3/031602/6408488/pvt_139_03_031602.pdf by guest on 05 November 2021