Radwaste reconditioning: a new approach through a gamma scanner/imaging system

Abstract The reconditioning of radioactive waste (radwaste) from energy and non-energy activities is a key challenge in nuclear decommissioning. Proper waste management is crucial, especially for Low-Level Waste (LLW) and Intermediate-Level Waste (ILW), which make up most of the radwaste. According to the IAEA, effective storage is essential for isolation, environmental protection, and potential future recovery. Sorting and segregation are vital steps in this process. The PI3SO project ( P roximity I maging S ystem for S ort and S egregate O perations) was developed as a gamma radiation spectroscopic scanner for radioactive waste. Its main goal is to speed up waste management while minimizing human intervention. The system uses proximity imaging and spectral analysis to identify “hot-spots” in materials, with precision down to 1 cm 2 . It consists of two linear arrays of 64 CsI(Tl) scintillators coupled to SiPMs, mounted on a motorized bridge to scan radwaste. Preliminary tests show a minimum detectable activity of a few hundred Bq, with an energy resolution of 5–6% FWHM at 662 keV 137 Cs peak. The system has successfully detected isotopes like 44 Ti, 44 Sc, and 22 Na during real-world tests. PI3SO promises to enhance safety, reduce human exposure, and improve the efficiency of waste management, particularly for ILW and LLW during decommissioning.